Obesity is a risk factor for dyspnea. However, investigations of daily living obesity-related dyspnea are limited and its mechanisms remain unclear. We conducted a cross-sectional study to analyze the relationships between dyspnea in daily living, lung function, and body composition in patients with obesity.2 were included. Dyspnea was assessed by the modified Medical Research Council (mMRC) scale. Comorbidities, laboratory parameters, pulmonary function tests, arterial blood gases, six-minute walk test (6MWT), handgrip strength, and DXA body composition were analyzed.One-hundred and thirty patients (103 women/27 men), candidate for bariatric surgery, with a mean ± SD Body Mass Index (BMI) of 44.8 ± 6.8 kg/mvs 457 ± 73 m, p < 0.001), lower lung volumes including Expiratory Reserve Volume , Vital Capacity  and Forced expiratory volume in one second , a higher BMI  and a higher percentage of fat mass in the trunk (46 ± 5 vs 44 ± 5 p = 0.012) and android region . There was no difference regarding comorbidities (except hypertension), laboratory parameters, and sarcopenia markers between patients with (mMRC ≥ 2) and without (mMRC < 2) disabling dyspnea.Thirty-one percent of patients exhibited disabling dyspnea in daily living (mMRC ≥ 2). Compared with patients without disabling dyspnea (mMRC < 2), significant dyspnea (mMRC ≥ 2) was associated with a lower 6MWT distance (395 ± 103 m Dyspnea in patients with obesity is associated with a reduction in lung volumes and a higher percentage of fat mass in central body regions. How dyspnea and body composition may change with interventions like physical activity or bariatric surgery remains to be investigated.The online version contains supplementary material available at 10.1186/s12890-022-01884-5. Although obesity is a significant risk factor for dyspnea –3, dailyAssociations between obesity and impaired skeletal muscle quality, poor physical performance, and a higher risk of sarcopenia have been well-established . DyspneaBody mass index (BMI) is the most commonly used measure to characterize obesity but is limited by its assessment of body weight relative to height, with no information on the body composition per se. Dual-energy X-ray absorptiometry (DXA) is a quick, weakly radiating, and reliable tool allowing to accurately measure body composition and to determine specific sites of fat deposition . RegardiThe main objective of this study was to assess the relationships between dyspnea in daily living according to mMRC, lung function and body composition assessed by DXA in patients with obesity. We hypothesized that patients with disabling dyspnea would have a higher BMI and a higher proportion of fat mass, especially in the central regions of the body. The secondary objectives were to analyze the relationships between dyspnea in daily living and sarcopenia assessed by appendicular lean mass and handgrip strength measurements. We also investigated relationships between dyspnea, comorbidities, and laboratory parameters.Between January 2017 to February 2020, consecutive adult patients with obesity referred to the Department of Nutrition at the University Hospital of Reims (France) for a project of bariatric surgery were systematically evaluated for dyspnea, lung function tests, handgrip strength, and body composition. All patients were included in the study before bariatric surgery, except those with a known respiratory, cardiac, or neuromuscular disease. Patients were also excluded if they did not perform the different investigations in a maximal period of two months.Written information was provided, and each patient gave his written consent to participate. The study was approved by the Reims University Hospital Institutional Review Board (IRB-17–10-2012).Demographic data , anthropometric characteristics , medical comorbidities , defined as an Apnea–Hypopnea Index > 30/h), medical treatments  and smoking status were systematically recorded.The depression symptoms were assessed using the QD2A depression scale , 18. ThiDyspnea in daily living was evaluated using the mMRC scale , 19, 20.Measurement of handgrip strength was conducted in a standardized manner by the use of a handgrip dynamometer type JAMAR  in neutral rotation and adducted position of the shoulder, with the elbow flexed to 90 degrees, and forearm and wrist in a neutral position. Three trials from the dominant hand were measured in kilograms. The mean value was considered for the analyses. Grip strength less than 16 kg for women and less than 27 kg for men were considered low handgrip strength , 23.The six-minute walk test (6MWT) was performed in a 30-m long, flat, covered corridor, marked meter-by-meter, according to the American Thoracic Society guidelines . Oxygen Arterial Blood Gases were measured in the morning in a sitting position on room air.1), FEV1/FVC ratio, expiratory reserve volume (ERV) were measured during spirometry [1, VC, FVC, FEV1/FVC, and ERV) were performed in patients weighing more than 150 kg. Results are expressed in milliliters and percentage of predicted values. A restrictive defect was defined as a TLC < 80% of predicted value. The carbon monoxide diffusing capacity of the lung (DLCO) was measured and expressed in percentage of predicted values [PFTs were performed according to the American Thoracic Society/European Respiratory Society guidelines   and Maximal Expiratory Pressure (MEP). The maximum value of three available tests that varied by less than 20% was recorded. Results were expressed in cmH2O and percentage of predicted values .Hemoglobin (Hb), C reactive protein (CRP), and N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) were determined from a blood sample.2) (or as the sum of the lean mass of an upper limb in whole included in the scan multiplied by 2 and lower limbs adjusted for height (m2)) [Baumgartner et al. [2 in men and 5.45 kg/m2 in women.Body composition was determined by DXA scan . DXA was quantified by the body tissue absorption of photons that were emitted at two energy levels to resolve body weight into bone mineral density (BMD), lean (LM), and fat (FM) soft tissue masses . FM (kg)ht (m2)) . Sarcoper et al.  as ALMI It’s a pilot study with a prospective inclusion of patients over 3 years . Quantitative variables were described as mean ± standard deviation (SD) and qualitative variables as number and percentage. Patients were separated into two groups according to their mMRC dyspnea scale: mMRC < 2 (no disabling dyspnea in daily living) and mMRC ≥ 2 (disabling dyspnea in daily living). Variables associated with mMRC scale were studied using Student or Wilcoxon or Khi2 or Fisher exact tests according application’s conditions. A multivariate analysis using an ascending stepwise logistic regression models for dyspnea (mMRC ≥ 2 versus mMRC < 2) was peformed. Variables proposed were BMI, Borg > 3/10, predicted VC, predicted FVC, predicted FEV1, predicted ERV, predicted FRC and predicted TLC. Association between the trunk fat mass or the android fat mass percentage and pulmonary function testing were studied using the Pearson’s correlation coefficient. There was no imputation of missing data. A p-value < 0.05 was considered statistically significant. All analyses were performed using SAS version 9.4 .One-hundred and seventy-three consecutive patients were included in the study. Thirty-two of them were excluded because of an inability to perform PFTs and/or DXA and eleven because of an interval longer than two months between respiratory assessment and DXA. The data of the remaining 130 patients (103 women and 27 men) were analyzed. Of note, 111 patients (85%) performed respiratory assessment and DXA on the same day  and MEP was 73 ± 36 cmH2O (66 ± 30%).Overall, pulmonary function tests remained in the normal range for most of the patients except for ERV . Regarding inspiratory and expiratory muscle strength, MIP was 61 ± 27 cmHAs shown in Table vs 14%, p = 0.312 for oral antidiabetics; 13% vs 7%, p = 0.312 for insulin; 5% vs 7%, p = 1 for cholesterol-lowering agents; 38% vs 26%, p = 0.148 for antihypertensive drugs) and comorbidities  except for hypertension . No significant difference was found regarding the depression state according to the QD2A depression scale (9% in patients with mMRC < 2 (n = 6) vs 11% in patients with mMRC ≥ 2 group (n = 3), p = 0.720). The percentage of active smokers  and the number of pack-years  were similar in the two groups of patients.There were no statistically significant differences between patients with (mMRC ≥ 2) and without (mMRC < 2) disabling dyspnea regarding treatments  had a lower 6MWT distance and a significant reduction in lung volumes Table . Two patComparisons of body composition between patients without (mMRC < 2) and with disabling dyspnea (mMRC ≥ 2) are presented in Table p = 0.031) as well as the percentage of patients with mMRC < 2 and mMRC ≥ 2 (p = 0.006) , who had also higher BMI and fat mass than patients with mMRC < 2, covered a lower distance during the 6MWT than patients with mMRC < 2 .1 and FVC are slightly reduced in people with obesity [1/FVC ratio is usually unaffected. We found similar results concerning lung function in this cohort of obese patients, showing that patients with disabling dyspnea in daily living (mMRC ≥ 2), who had also higher BMI, had a significant reduction in measures of lung function affected by obesity .It is well known that obesity causes substantial changes to the mechanics of the lungs and chest wall that affect lung function. The most frequent abnormality associated with obesity is a decrease in ERV, which is exponentially correlated with increased BMI . While o obesity , but FEVCollet et al. [Effects of obesity on inspiratory and expiratory muscle strength are variable and inconsistent , 12, 37.t et al. , we did Despite the absence of consensus on the definition of sarcopenic obesity, it is commonly accepted as the combination of obesity and muscle impairment, either defined by low muscle mass and/or poor muscle strength/function. In a large cohort from the National Health and Nutrition Surveys, the prevalence of sarcopenic obesity is 17% in obese patients aged 60 to 70 years . In our Sutherland et al. also showed that both thoracic and abdominal body fat had an impact on lung volumes [Disabling dyspnea according to mMRC was associated with an increase in weight, BMI, and fat mass in absolute value for all body segments. Interestingly, patients with disabling dyspnea also presented an increase in the percentage of fat mass for the central regions of the body: trunk and android region.  volumes . In our Our results have several clinical implications. First, it provides clinicians with a glimpse of the dyspnea endured by obese patients especially in patients with high and very high BMI Fig. . Second,One of the strengths of our study is the assessment of the relationships between dyspnea according to the mMRC scale, a very complete respiratory assessment , laboratory parameters, depression scale, and body composition assessed by DXA. As anxiety does not modify the mMRC impact score of dyspnea, it was not assessed in the study . Our resThis prospective study showed that dyspnea in daily living in obese patients is associated with a reduction in lung volumes and higher BMI, possibly related to a higher percentage of fat mass in central body regions. It remains to be investigated how dyspnea and body composition may change with interventions like physical activity or bariatric surgery.Additional file 1. Flowchart of study participants.


Mothers of preterm infants face many challenges in breastfeeding, especially regarding lactation. This study aimed to investigate the lactation status and challenges in breastfeeding faced by preterm infants’ mothers.We approached 124 mothers who gave birth to preterm infants between 26 May and 31 October 2018 in a tertiary hospital in China. Lactation status and challenges in breastfeeding on day 7 postpartum, at discharge of infants, 2 weeks post-discharge, and 3 months of corrected age were collected using questionnaires. The area under the receiver operating characteristic (ROC) curve for expressed milk volume on day 7 postpartum for predicting expressed milk volume ≥ 300 mL/d at discharge was calculated. Logistic regression analyses were performed to identify factors associated with delayed lactogenesis II onset and continuation of breastfeeding at 3 months of corrected age.U = 328.50, p = 0.001; at discharge: 425.0 mL vs. 612.5 mL, U = 372.00, p = 0.005), with a lower proportion of exclusive breastfeeding in their infants . The ROC showed that expressed milk volume > 190 mL/d on day 7 postpartum significantly predicted expressed milk volume ≥ 300 mL/d at discharge. Insufficient human milk was the main reason for breastfeeding discontinuation at 3 months of corrected age. Twins were less likely to continue breastfeeding at 3 months of corrected age . In singleton infants, mother’s own milk ≥50% of total milk uptake at 2 weeks post-discharge  was an independent predictor of continuous breastfeeding at 3 months of corrected age. Feeding complications in infants, poor breastfeeding technique, and low milk output are the main challenges in breastfeeding.Seventy mothers were enrolled, and 51.4% had delayed lactogenesis II. Multivariate logistic regression analysis revealed that older maternal age  and first live birth  were significant independent predictors of delayed lactogenesis II. Mothers with delayed lactogenesis II had significantly lower expressed milk volume (day 7 postpartum: 160.0 mL vs. 300.0 mL, Interventions to improve early postpartum lactation and breastfeeding techniques may increase breastfeeding adoption in mothers of preterm infants.The online version contains supplementary material available at 10.1186/s13006-021-00447-4. Preterm infants  benefit from breastfeeding in many ways, including shorter hospital stay –3, lowerHowever, the prevalence of breastfeeding among preterm infants varies greatly worldwide. In the United States, 75% of preterm infants in NICUs were breastfed in 2015 . In EuroParents usually participate in breastfeeding education and training during pregnancy, however, the stress associated with preterm delivery often disrupts their original breastfeeding plan . AlthougThe onset of lactogenesis II, which is defined as the time when mothers experience a sudden increase in the amount of breast milk, is an important indicator of early lactation . In prevWhile there is still room for improving the breastfeeding of preterm infants, studies on lactation status and the challenges of different breastfeeding stages facing the mothers of preterm infants in China are limited. Therefore, we aimed to investigate lactation status and understand the challenges in breastfeeding faced by mothers giving birth to preterm infants, to develop effective interventions to improve breastfeeding in preterm infants in the NICU in the future.This was a prospective cohort study. The study protocol was approved by the institutional review board of the hospital . Written informed consent was obtained from all participating mothers.Mothers of preterm infants were recruited between May 26th and October 31st, 2018 on day 1 to day 4 of infants’ NICU entry, and were followed up until infants’ 3 months of corrected age. The inclusion criteria were: (i) mothers giving birth to infants before 37 weeks of gestation and their infants being admitted to the NICU and (ii) mothers intended to breastfeed their infants. The exclusion criteria were as follows: (i) mothers did not sign the informed consent form, (ii) infant death, (iii) infants transferred to another department, and (iv) mothers took their infants home against medical advice.Enteral feeding was started as soon as the infant’s condition became stable and there were no contraindications . In infants with neonatal asphyxia, enteral feeding was started 12–24 h postpartum . The expParticipating mothers were required to complete questionnaires on lactation and breastfeeding practice on day 7 postpartum, the day of infant discharge, 2 weeks after infant discharge, and 3 months corrected age of infants either by filling the questionnaires by themselves or in telephone conversations . Categorical variables are presented as the number of cases and percentages. Chi-squared and Mann–Whitney U tests were performed to compare variables between different groups and analyze independent covariates. Mantel-Haenszel tests (Linear by Linear Test) were performed to compare the breastfeeding status at discharge, at 2 weeks post-discharge, and at 3 months of corrected age. The receiver operating characteristic (ROC) curve was used to examine the predictive validity of expressed milk volume on day 7 postpartum. The area under the graph was assessed for the sensitivity and specificity of expressed milk volume on day 7 postpartum in predicting expressed milk volume ≥ 300 mL/d at discharge .p values of 0.05 and 0.10, respectively. Twin was entered into the model through enter method due to potential clinical relevance. Cesarean section, older maternal age, first live birth, and twin entered the final model.Logistic regression analyses were performed to identify factors associated with delayed lactogenesis II onset and the continuation of breastfeeding at 3 months of corrected age. In the logistic regression analysis of factors associated with delayed lactogenesis II onset, cesarean section, maternal age, first live birth, twin, pregnancy complications, and GA were included as covariates and delayed lactogenesis II onset as the dependent variable. Maternal age was included as a continuous variable in statistical analysis. A backward LR variable selection method was used to identify significant variables among cesarean section, maternal age, first live birth, pregnancy complications, and GA. The inclusion and removal of variables in models were based on p values of 0.05 and 0.10, respectively. Hosmer-Lemeshow test was used to assess the goodness-of-fit of the final models (p > 0.05).In the logistic regression analysis of continuation of breastfeeding at 3 months of corrected age, breastfeeding at 3 months of corrected age was included as a dependent variable. In the model for all infants, a backward LR variable selection method was used to identify significant variables among cesarean section, maternal age, twin, GA, exclusive breastfeeding at discharge, own mother’s milk ≥50% at 2 weeks post-discharge, and direct feeding at 2 weeks post-discharge. Twin and own mother’s milk ≥50% at 2 weeks post-discharge entered the model. In models for twins and singleton infants respectively, a backward LR variable selection method was used to identify significant variables among cesarean section, maternal age, GA, exclusive breastfeeding at discharge, own mother’s milk ≥50% at 2 weeks post-discharge, and direct feeding at 2 weeks post-discharge. The inclusion and removal of variables in models were based on p < 0.05. IBM SPSS Statistics  was used for all statistical analyses.The statistical significance level was set at n = 12), did not sign the informed consent form (n = 1), neonatal death (n = 2), infants transferred to another department (n = 3), or neonatal non-medical discharge (n = 12). A total of 94 eligible mothers  participated in this study. During the study, 24 mothers failed to complete the questionnaire during their hospital stay. Data from 70 mothers (per protocol set) were analyzed. All 70 mothers and their 94 infants participated in the follow-up examination at 2 weeks post-discharge, while 62 mothers and their 81 infants participated at 3 months of corrected age.The participant flowchart is shown in Fig. Table A survey of the types of breast pumps used by mothers showed that 65.7% (46/70), 32.9% (23/70), and 1.4% (1/70) of the mothers used unilateral electric pumps, bilateral electric pumps, and manual breast pumps, respectively. The median of expressing frequency per 24 h was 7.5  times and 6.0  times on day 7 postpartum and at infants’ discharge, respectively . On day 7 postpartum, 65.7% of the mothers expressed more milk than their infants’ uptake, and this proportion increased to 68.6% at the time of discharge. The proportions of mothers with increased expressed milk volume at discharge, 2 weeks post-discharge, and 3 months of corrected age compared with the previous time point were 81.4, 50.0, and 33.9%, respectively  mL on day 7 postpartum, which increased significantly to 525.0  mL at discharge  and a higher percentage were mothers giving first live birth . Maternal age, complications during pregnancy, twin pregnancy, and gestational age were similar between the normal and delayed lactogenesis II onset groups  and 20.0% (14/70) failed to achieve lactogenesis II within 4 and 7 days postpartum, respectively. Compared to mothers with normal lactogenesis II onset, mothers with delayed lactogenesis II onset, a higher proportion underwent cesarean section , and first live birth  were significant independent predictors of delayed lactogenesis II onset  and discharge day  than those mothers with normal onset , breastfeeding rate  and exclusive breastfeeding rate  at 3 months of corrected age were also significantly lower in infants of mothers with delayed lactogenesis II onset , abdominal distension , diarrhea (n = 2), and necrotizing enterocolitis (n = 1), and 6 of the 13 infants resumed breastfeeding within 2 weeks after discharge. Four infants were diagnosed with necrotizing enterocolitis (Bell stage ≥IIA) during hospitalization, while three resumed breastfeeding after recovery, and the other was fed with an amino acid-based formula till 3 months of corrected age. At 2 weeks post-discharge, 17.0% (16/94) of infants discontinued breastfeeding, and the most common was also infant clinical condition . At 3 months of corrected age, 29.6% (24/81) of infants discontinued breastfeeding, and the most common reason was insufficient human milk  (Table The proportions of infants receiving breastfeeding (70.4%) and exclusive breastfeeding (33.3%) at 3 months of corrected age were lower than those at discharge  and 2 weeks post-discharge , infants receiving own mother’s milk ≥50% of total milk uptake at 2 weeks post-discharge , and direct feeding at 2 weeks post-discharge  were significantly associated with continued breastfeeding at 3 months of corrected age  were breastfed and 24 29.6%) were not at 3 months of corrected age  at 3 months of corrected age were 62.4 and 4.3%, respectively , which iTwins had no significant association with delayed lactogenesis II onset but were less likely to continue breastfeeding at 3 months of corrected age. The early cessation of breastfeeding in twins was conflicting in previous studies , 38. TheAt 3 months of corrected age, 53.2% of the mothers reported decreased milk production, a lower exclusive breastfeeding rate (33.3%) in infants, and a higher proportion of infants discontinuing breastfeeding because of insufficient human milk (58.3%), which is similar to the results of previous studies , 52.χ2 = 10.96, df = 1, p = 0.001) and was maintained, which is consistent with the findings of Callen et al. [In addition to mothers’ efforts, the overall health status and feeding tolerance of preterm infants also influence breastfeeding . In thisn et al. .Our study found that at 2 weeks post-discharge, the top challenge in breastfeeding associated with mothers was poor breastfeeding techniques. To improve breastfeeding skills, we recommend providing training on how to practice direct breastfeeding, use human milk fortifiers, adjust feeding volume, and clean breastfeeding devices. It is also important to train mothers on how to coordinate feeding rhythms with infants’ needs as described by Ikonen and Palmer , 54. In This was a single-center study. Although the number of participants was relatively small, the management and education of the mothers were highly consistent in this study. The GA range of the participating preterm infants was wide. Twins were also included in the analysis. The proportion of twins in this study is higher than that in some studies  but is cRegardless of these limitations, our study provides information for the early prediction of breastfeeding status which may help provide better-targeted instructions to the families of preterm infants. In addition, we chose the time points of 7 days postpartum, at infants’ discharge, 2 weeks post-discharge, and 3 months of corrected age to ask the mothers about their breastfeeding status and difficulties. These time points could best present the breastfeeding status during mother-infant separation, during the adaptation after discharge, and relatively long-term after discharge. Our time points may be better suited for preterm infants with different gestational ages, and better demonstrate the difficulties parents encounter after infants’ discharge.Older maternal age, and first live birth were independent predictors of delayed lactogenesis II. Milk output volume on day 7 postpartum > 190 mL/d predicted ≥300 mL/d milk output at discharge. Difficulties in breastfeeding infants, poor breastfeeding techniques, and insufficient milk output were the predominant challenges faced by mothers. Thus, interventions targeting the improvement of early postpartum lactation and training targeting to improve breastfeeding techniques and reduce the difficulties in breastfeeding may increase breastfeeding adoption in mothers giving birth to preterm infants.Additional file 1: Questionnaires on day 7 postpartum, at discharge, at 2 weeks post-discharge, and 3 months of corrected age (translated in English).


Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Besides, based on the results of the cell viability assays, the optimum concentration of ZnONPs and AgNPs in the nanofibrous mats is 0.2% w/v and 0.08% w/v respectively and had no cytotoxicity on fibroblast cells. The scaffold also showed good blood compatibility according to the effects of coagulation time. As well as significant fibroblast migration and proliferation on the wound margin, according to wound‐healing assay. All in all, the developed biocompatible, antioxidant, and antibacterial Ag‐ZnO NPs incorporated CS/PEO nanofibrous mats showed their potential as an effective wound dressing.Bacterial wound infection is one of the most common nosocomial infections. The unnecessary employment of antibiotics led to raising the growth of antibiotic‐resistant bacteria. Accordingly, alternative armaments capable of accelerating wound healing along with bactericidal effects are urgently needed. Considering this, we fabricated chitosan (CS)/polyethylene oxide (PEO) nanofibers armed with antibacterial silver and zinc oxide nanoparticles. The nanocomposites exhibited a high antioxidant effect and antibacterial activity against  Any kind of wound on the skin is susceptible to the accumulation of infectious bacteria.Advanced wound dressing is the barrier to care for sores and should mainly target bacterial infection by sufficient sealing of the injury microenvironment from peripheral contaminants. Simultaneously, they can eradicate excessive exudate, enhance autolysis debridement, and maintain adequate water for healing. In addition to barrier property, they would also have specific flexibility, applicability, constancy, biodegradability and be able to remove, pace the healing process, and decrease the risk of infection.Chitosan is a cationic biopolymer with a linear structure derived from hydrolysis of the natural polymer chitin.Recently, there has been a growing interest in research on nanofibrous scaffolds developed by electrospinning of natural and synthetic polymers solely or as blend with bioactive plant extracts and metallic nanoparticles for tissue regeneration.co‐3‐hydroxyvalerate)Silver nanoparticles are the most prevalent nanostructures for antimicrobial therapy due to their potent microbicide properties.Streptococcus mutans is significantly higher than that of Ag NPs at both 1% w/w.Antimicrobial properties of low concentration of ZnO NPs and their role in fibroblast proliferation, angiogenesis, and increased re‐epithelialization properties make them an active ingredient in wound dressings.Altogether, the purpose of this study was to design antibacterial and hemocompatible chitosan/PEO‐based wound dressings using the electrospinning technique. In this regard, silver and zinc oxide nanoparticles were employed to enhance the antibacterial capability of the nanofibers. We then evaluated the wound healing capability, cytotoxicity, and hemocompatibility of the nanofibrous mats. As the medical applications of metal‐based nanomaterials are associated with their cytotoxicity, many efforts have been committed for diminishing the cytotoxicity of nanometals. Different strategies can be deployed to decrease the cytotoxicity of metallic nanoparticles, such as immobilization of nanoparticles in polymeric matrices/nanocarriers or surface coatings. For instance, chitosan, dextran, chitosan/alginate beads, polyethylene glycol, silica, or titania prepare unique materials with new characteristics to both components, e.g., tensile strength, flexibility, and biodegradability.Combining biopolymers with nanofillers is an alternative for achieving materials with improved antibacterial properties.22.1Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa , and scaffold contain zinc oxide nanoparticles demonstrated the lowest scavenging activities (p < 0.001). When the skin is damaged, large amounts of ROS are produced in the inflammatory phase of wound healing, resulting in biological damage, including degradation of lipids, proteins, nucleic acids, and ultimately cell death, which disrupts the wound healing process. The use of antioxidants can effectively help with enzymatic repair and improve metabolism.2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) methods evaluated the antioxidant properties of prepared nanofibrous mats are shown in Figure 50 value in scavenging the DPPH (0.47 mg/ml).The DPPH free radical‐scavenging activity of the scaffolds at different concentrations was evaluated and compared to ascorbic acid and BHT used as a standard. Results indicated that AgNPs/CS/PEO exhibited antioxidant ability against DPPH in a dose‐dependent manner Figure . The hig2.5To assess the cell viability of the fibroblast cells against the nanofibrous mats, two different analysis including MTT and CCK‐8 assay were employed.For the dual nanoparticles (mix of Ag and ZnONPs), the cell viability of mix 1 was similar to the control group for all time point. Higher concentration of mix NPs (8.38% w/v) the viability reduced upon time. Besides, the cell viability of mix 1 was higher than mix2, indicating concentration dependence of cytotoxicity. The results of the MTT assay and CCK‐8 showed that the optimum ZnONPs concentration in the nanofibrous mats is 0.2% w/v.According to the American Society for Testing and Materials , each material can be classified into three different categories: hemolytic (hemolysis over 5%), slightly hemolytic (between 2% and 5%), and non‐hemolytic (below 2%). In our study, the hemolytic property of scaffolds was further determined for each nanofibrous mat. The maximal hemolysis percent were detected for CS/PEO mat (3.768%) after contacting erythrocytes over 60 min with prepared nanofibrous mats Figure . Hemolys2.6To assess cell migration, cell polarity, matrix regeneration, the wound‐healing assay was employed.According to Figure 3P. aeruginosa, S. aureus, and E. coli can undesirably influence the initial phases of the wound healing process via inadequate improvement of tissue granulation. Advanced wound healing antibacterial materials can kill the bacteria multiplied at the wound site and assist in reducing wound‐related complications and accelerated wound healing and may decrease the time of healing.Wound maintenance is crucial, particularly in diabetic patients and burn injuries. After creation, the wound is part of the skin, and microorganisms proliferate at the wound site. The wound healing process initiates depending on its location, the type of the wound, and wound management. The healing process may be interrupted by both external and internal agents. The internal prerequisite process in wound healing after releasing cytokines in the migration and proliferation of cells. Bacterial infections and reactive oxygen species are important disturbing issues in the wound healing process and can extend each phase.Likewise, after creating the wound, oxidative stress damages DNA and proteins in the inflammatory phase because of large amounts of generated ROS. Oral or topical administration of antioxidant materials can avoid oxidative stress by modulating the ROS.The results showed the prepared nanofibrous mats adorned with silver and zinc nanoparticles possess the considerable antioxidant ability and synergic antimicrobial activity. Consequently, these characteristics can synergistically prompt wound healing processes in acute and chronic forms. Figure E. coli, P. aeruginosa, and S. aureus were 21, 17, and 31 mm, respectively. The MICs of these nanoparticles were also announced as 16, 26, and 10 μg/ml, respectively.S. aureus is susceptible to other Gram‐negative bacteria; This difference results from the inhibitory concentration of zinc nanoparticles between Gram‐positive and Gram‐negative bacteria, which can be attributed to the presence of an outer membrane in the cell wall of Gram‐negative bacteria and its absence in Gram‐positive bacteria, which affects the permeability of these bacteria to nanoparticles.As reported, zinc oxide and silver nanoparticles cause bacterial death by acting on the bacterial cell wall and membrane, inhibiting protein and DNA synthesis, and disturbing the antioxidant system.S. aureus to composite mats containing the nanoparticles was observed compared to P. aeruginosa and E. coli. Based on the results of the MTT, and CCK‐8 assay, no toxicity was observed for fibroblast cells for composite mats containing AgNPs in all time points, while ZnONPs‐loaded mats showed concentration dependence toxicity. The cell viability as well as cell proliferation of dual‐loaded nanoparticles in composite mats exhibited high biocompatibility. Accordingly, the nanocomposites are promising scaffolds for cell growth and proliferation. This study simultaneously utilized two nanometals in combination of chitosan nanofibrous which showed accelerated the migration and proliferation of fibroblast cells. Scratches after 24 h of treatment showed significant repair. These results indicated that the chitosan/PEO nanofibers scaffolds containing 8.3% AgNPs‐ZnONPs could be a suitable choice for a wound dressing that facilitates the wound healing process; also, composite dressings, in addition to being more effective in treating wounds, can reduce the cost of treatment.In antibacterial studies, high sensitivity of 4E. coli (ATCC25922), S. aureus (ATCC25923), and P. aeruginosa (ATCC 27853), fibroblast cell (L929) was purchased from Pasteur Institute of Iran.Chitosan  was purchased from Solarbio Life Science . PEO , deionized water, 3‐‐2,5‐diphenyltetrazolium bromide (MTT), DPPH, CCK‐8 kit , Dulbecco's modified Eagle's medium (DMEM) , Fetal bovine serum (FBS) , Phosphate buffered saline (PBS), trypsin, penicillin & streptomycin (Sigma‐Aldrich), silver nanoparticle and zinc oxide nanoparticle (Sigma‐Aldrich); Acetic acid , Mueller Hinton agar  and Tryptic Soy Broth ; 4.1Based on similar studies, 100 μg/ml of silver nanoparticle was selected to prepare the suspension of Ag NP.S. aureus, the concentration of initial stock was 1.98 mg/ml: for E. coli, 64.8 mg/ml and for P. aeruginosa, 20 mg/ml.The solution comprising zinc oxide nanoparticle prepared as following; a specific concentration was considered by default for each studied bacteria based on previous studies. For 4.2There was no particular antibacterial guideline for nanoparticles. According to standard procedures recommended by the CLSI , the antibacterial effects of silver nanoparticles were measured by broth microdilution method. Broth microdilution approach with some modifications was employed to determine the minimum inhibitory concentration (MIC) of silver and zinc oxide nanoparticles of the tested microorganisms.This method was used to determine the MICs different concentrations, including 3.2–100 μg/ml AgNPs and 30.93–990 μg/ml, 1.01–32.4 μg/ml, 0.312–10 μg/ml ZnONPs. For culture on a microplate, 100 μL of Mueller Hinton broth was first added to all wells, 100 μL of the initial concentration of nanoparticle solution was poured into the first well and mixed with culture medium dilution was performed from well A to well F. Then, 100 μL of bacterial suspension with the inoculum concentration equivalent of 0.5 McFarland was added to each well and mixed well with the aid of a sampler. One well was considered as a positive control containing Mueller Hinton broth and bacterial suspension. One well, which contained only the Mueller Hinton broth, was considered as a negative control (NC). This procedure was performed for all three bacterial strains and specific concentrations of nanoparticles with three replications. After a slight rotation of the microplate to smooth the suspension into the wells, it was incubated for 24 h in an incubator at 37°C. After 24 h at 37°C, the turbidity of each sample was determined.4.3To prepare chitosan/PEO solution, chitosan and PEO solutions separately in 80% V/V and 0.5molar acetic acid, prepared respectively. Then, the prepared solutions are mixed to a certain proportion.S. aureus, a solution containing 0.08% silver nanoparticle for E. coli, and a solution containing 0.16% silver nanoparticle for P. aeruginosa. The prepared solution was then filled into the syringe and put into an electrospinning device with the following parameters: voltage 20 KV, a distance of needle from collector 14 cm, rotation of collector 700 rpm. To achieve nanofibrous mats adorned with silver nanoparticles with appropriate thickness, electrospinning was performed using the obtained parameters for 6 h.To prepare a 3 wt% chitosan solution, first, 0.3 g of chitosan powder was poured into a beaker, then 80% acetic acid was added. The solution was stirred for 16 h at room temperature on a magnetic stirrer at 700 rpm. A 3 wt% PEO solution was prepared similar to chitosan. After adding 0.5 molar acetic acid to 0.3 g of a PEO powder to give a uniform solution, it was stirred for 8 h at ambient temperature at 400 rpm; after separate preparation of these solutions, the chitosan solution and the PEO were mixed at a weight ratio of 9:1 and stirred at room temperature at 400 rpm for 12 h. Then, proper concentrations of silver nanoparticles according to MIC were added to the chitosan solution for each bacterium. Thus, a solution containing 0.16% silver nanoparticle was prepared for 4.4S. aureus. A scaffold containing 27% zinc nanoparticles was fabricated for E. coli. A scaffold containing 8.3% zinc nanoparticles was fabricated for P. aeruginosa. The same settings obtained from the electrospinning of silver scaffold were used for electrospinning, the polymeric solution containing zinc oxide nanoparticles.For fabrication of the nanofibers containing zinc nanoparticles, concentrations obtained from MIC zinc nanoparticles for each bacterium were added to the chitosan solution. Thus, a scaffold containing 0.2% zinc nanoparticles was produced for 4.5To preparing the nanofibrous mats containing the silver and zinc nanoparticles, concentrations obtained from MIC nanoparticles for each bacterium were added to the chitosan solution. Thus, Mix1 scaffold contains 0.28% zinc and silver nanoparticles (0.08% silver nanoparticles and 0.2% zinc nanoparticles), and Mix2 scaffold containing 8.4% zinc and silver nanoparticles (0.08% silver nanoparticles and 8.3% zinc nanoparticles) were obtained.A 1% TPP solution was used as a cross‐linker to improve the strength of the nanofibrous mats. Specimens were prepared from scaffolds measuring 3 × 2 cm and immersed in TPP solution for 5–15 min, washed with PBS after each step, and dried at room temperature.4.6−1 region using Bruker Tensor 27 IR to investigate the characteristic bonds in the nanofibrous mats. A tensile strength test was used with SANTAM universal testing machine (STM‐1 model) to evaluate the tensile strength of scaffolds. For this purpose, 30 × 10 mm specimens were cut from scaffolds with a diameter of 200 ± 20 μm and used for this test. A tensile strength test was performed using three samples of each scaffold, and the results were presented as mean.The morphology and diameter of the nanofibers were examined by scanning electron microscopy  after coating with gold by gold sputtering apparatus. ImageJ software was used to measure the average diameter of nanofibers. X‐ray energy dispersive spectroscopy coupled to FESEM apparatus was used for elemental analysis of prepared nanofibrous mats to confirm nanoparticles' presence in the nanofibrous mats. The FTIR was performed in the 4000 to 400 cm4.7l‐ascorbic acid (0.5–128 μg/ml) were used as standard antioxidant agents. The SC50 (scavenging capacity‐50) is the nanoparticle concentration causing 50% neutralization effects. The SC50 was determined from the equation of the best‐fitting linear or non‐linear regression curve plotted from the scavenging percent versus oil concentrations. All experiments were recorded three independent times, and the mean values ± SE were reported.The antioxidant activities of the prepared scaffolds were evaluated using DPPH radical‐scavenging activity. The DPPH radical‐scavenging activities of CS/PEO, AgNPs/CS/PEO, ZnONPs/CS/PEO, and AgNPs/ZnONPs/CS/PEO were determined as described as reported in4.8E. coli, P. aeruginosa) and one species of Gram‐positive bacterium (S. aureus). The microbial culture medium was prepared according to the manufacturer's protocol and poured into 10 cm plates, followed by separate preparation of a suspension of 0.5 McFarland bacteria. Sterilized cotton swabs from the suspension prepared on plate surface containing Mueller Hinton agar were cultured uniformly. The scaffolds were prepared by incubating the specimens in a 37°C incubator for 24 h, and then the inhibitory areas around the scaffolds were measured.The antimicrobial activity of nanocomposite scaffolds was evaluated by the disk diffusion method against the two species of Gram‐negative bacteria  as reported previously.The MTT assay was done to determine the fibroblast viability on the prepared nanofibrous mats. The cells were cultured in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin antibiotic under standard conditions of 37°C and 5% CO3 cells/well. Cell proliferation was investigated after 1, 3, and 7 days using CCK‐8 assay. To create a calibration curve, after preparing the wells with known numbers of viable cells, 10 μL of the CCK‐8 solution was added to each well of the plate. The plates were incubated for 1 to 4 h in the incubator, and the absorbance were measured at 450 nm using a microplate reader. The calibration curve prepared using the data obtained from the wells that contain known numbers of viable cells  was used to compare the cytotoxicity data.Cells were seeded on nanofibrous mats and well as controll in 96‐well plates at 5 × 10s Figure .43 The4.10CS/PEO, AgNPs/CS/PEO, ZnONPs/CS/PEO, and AgNPs/ZnONPs/CS/PEO nanofibrous mats were tested for their efficiency on human erythrocytes. The blood was obtained from the adult volunteers under consent and placed in heparinized tubes. The PBS  and Triton Xtm‐100 were used as negative (0% hemolysis) and positive (100% hemolysis) control, respectively. Centrifugation was done at 1500 rpm to segregate the RBCs (red blood cells) pellet from the blood (for 15 min at 4°C) followed by three times supernatant evacuation by PBS, and RBC was diluted with PBS. The specimens (1 cm × 1 cm) were incubated in 800 μL PBS at 37°C for 60 min. Then 200 μL diluted RBC was added to each sample and incubated at 37°C for 30 min. Then, the resulted solutions were centrifuged at 1500 rpm for 15 min, and the absorbance (545 nm) measurement of the supernatant was determined by the spectrophotometer (Shimadzu UV‐1800). Hemolysis cells percentage was calculated as follow:s, ODn, and ODp were the absorbances of sample, negative, and positive controls. All the hemolysis experiments were performed in triplicate.OD4.114 cells/ml on six‐wells to obtain a monolayer of cells. Then, a scratch was made across the middle of each well using a sterile 1000 μL pipet tip, and the plates were washed twice with PBS to remove the detached cells. A new medium was added, and approximately 1 × 1 cm sized of prepared scaffolds were placed over the scratched area. A control without any samples was also included. Scratches were observed and imaged under the microscope (Nikon Inverted Fluorescent Microscope) immediately after the wounding procedure and after 24 h of incubation. The wound area was calculated using the Image J public domain software. The percentage of wound area reduction or wound closure, expression of the cell migration rate, can be expressed as:The wound healing potential of the realized formulations was assessed by in vitro wound‐healing assay.0 is the area of the wound measured immediately after scratching, and At is the area of the wound measured 24 h after the scratch is performed. The closure percentage increases as cells migrate into the scratch over time.A5S. aureus to composite mats containing the nanoparticles was observed compared to P. aeruginosa and E. coli. Further investigation of cytotoxicity assessment revealed no toxicity for fibroblast cells, while the viability of fibroblast on composite mats was significantly increased, indicating that not only the composite mats had no toxic effect, but also is a promising scaffold for cell growth. This study showed the simultaneous use of these two nanoparticles in the combination of chitosan nanofibers, accelerating the migration and proliferation of fibroblast cells. Scratches after 24 h of treatment showed significant repair. These results indicated that the chitosan/PEO nanofibers scaffolds containing 8.3% AgNPs‐ZnONPs could be a suitable choice for a wound dressing that facilitates the wound healing process; also, composite dressings, in addition to being more effective in treating wounds, can reduce the cost of treatment.In the presented work, the results showed the chitosan nanofibrous mats adorned with silver and zinc nanoparticles possess considerable antioxidant ability and synergic antimicrobial activity. Moreover, the enhanced activity of the Zn/Ag combination with chitosan is also attractive as it improves the overall performance, bringing out the potential of single‐device antibiotic combinations with synergic antibacterial and antioxidant properties. In antibacterial studies, high sensitivity of The authors declare that they have no conflict of interest.Mitra Bagheri: Investigation ; methodology ; writing – original draft . Majid Validi: Methodology ; validation ; writing – review and editing . Abolfazl Gholipour: Funding acquisition ; project administration ; supervision . Pooyan Makvandi: Formal analysis ; investigation ; methodology ; writing – original draft ; writing – review and editing . Esmaeel Sharifi: Investigation ; methodology ; project administration ; supervision ; writing – review and editing .AppendixS1. Supporting information.Click here for additional data file.


N = 498 from five countries and more than 30 US states) to rate how attractive and emotionally arousing masks and other objects associated with COVID-19 were in comparison to neutral objects, as well as reporting on their mask-wearing habits. To confirm reliability of findings, the experiment was repeated in a subset of participants 8–10 weeks later. The findings show that regular use of protective masks was linked to their positive appraisal, with a higher frequency and a longer history of wearing a mask predicting increased mask attractiveness. These results extended to other COVID-related objects relative to controls. They also provide critical ecological validity for the idea that emotional appraisal of everyday objects is associated with our experience of using them. Practically, they imply that societal measures to encourage mask wearing may have contributed to positive emotional appraisals in those who put them on, whether due to personal choice or societal pressure.Protective facial masks reduce the spread of COVID-19 infection and save lives. Yet a substantial number of people have been resistant to wearing them. Considerable effort has been invested in convincing people to put on a mask, if not for their own sake than for those more vulnerable. Social and cognitive psychologists know that use and liking go both ways: people use what they like, and they like what they use. Here we asked whether positive attitudes towards facial masks were higher in those who had been wearing them longer. We asked participants in a diverse sample ( Protective facial masks reduced the spread of COVID-19 infection and saved lives . Yet a sA potentially useful tool in the effort to increase behaviours such as mask wearing during a pandemic comes from research in the cognitive sciences, particularly on the bidirectional relations between our actions towards and our emotional appraisals of objects in our environments. There is a large literature documenting that visual attention is involuntarily drawn to images of objects that we find emotionally rewarding . At the usage-positive appraisal hypothesis proposes that the emotional appraisal of objects faithfully mirrors the degree to which those objects are attended to and acted upon. Yet, very few studies have investigated this hypothesis in real-life circumstances. In fact, research on emotional appraisal of natural stimuli has traditionally focused on objects and scenes that possess strong affective valence, such as snakes and spiders on the negative side, and celebrations and flowers, or erotic imagery, on the positive side. Stimuli that lie between those extremes on average, or may vary in valence between individuals have been traditionally considered “neutral.” However, there is now evidence that mundane objects give raise to subtle, yet detectable and consistent valences, or microvalences  than for other objects that were previously familiar . As another control, we compared protective masks with other objects that were now more salient, but which, we assumed, were quite familiar to most people prior to the pandemic: latex gloves and hand sanitizers. Following the same reasoning, we expected that the effect would be strongest for masks than for gloves and hygiene products.The study was conducted online in the July–August 2020 (first wave) and October 2020 (replication) using participants’ personal devices  in a setting of their own choice, and over which we had no control. The experimental software we designed presented participants with product images to evaluate with subjective ratings, using the cover story that the study was intended to measure the aesthetics of various common consumer products. The products included the objects shown as examples in n = 493), 80.3% reported wearing protective masks “very often,” 13.2% reported wearing them “sometimes,” and the remaining 6.5% reported wearing masks rarely or never. 8.7% participants reported having worn protective masks previous to the pandemic.Because we wanted to maximise the range of mask use and experience, we recruited a majority of the sample from 19 US states where, at the time of testing (July–August 2020), wearing a mask was still optional. In our sample (www.prolific.co), without any other demographic or geographic restrictions. Out of 101 participants who completed the study, only 10 (9.9%) were not wearing masks or were wearing them rarely. We used these data to estimate that to get a minimum of 23 participants per group, we would need to recruit at least 400 more participants. We also limited this second round of recruitment to people from those US states where mask wearing was not mandatory at the time of the study (early August 2020).Our goal was to detect a statistical interaction in ratings made by participants in the following mixed-factor analysis of variance design: two levels of image  in a within-participant factor × 3 levels of mask use  in a between-participant factor. We estimated that a sample of 72 would be sufficient to reveal a small effect , and 379 completed both. The sample was well balanced in gender  and ranged in age from 18 to 78 years ; 45 participants (9.2%) had been diagnosed with COVID-19 or suspected they had it. Exclusion of those participants did not change any of the results that are reported.To test reliability of our measures and findings, we contacted all people who participated in the first wave of the study inviting them to take part in the second wave; 341 participants responded, 330 of them answered all the questions and completed the rating task.Images of masks, gloves, and personal hygiene products were used as stimuli, with 20 stimuli in each category. Half of the stimuli were COVID-related  and the other half were neutral . The items were downloaded from consumer websites. Aiming to represent the diversity of products that people encounter, we selected both relatively ugly and attractive items for each category. All items were then pre-rated by the study authors and research assistants to determine their general levels of attractiveness see . We selePavlovia.org.The study was programmed in PsychoPy3  and QualParticipants were asked to rate stimuli on two 7-point scales: attractiveness and emotional intensity. For the attractiveness scale, the poles were labelled “ugly” and “attractive.” Emotional intensity rating was phrased as the strength of feeling towards an object, ranging from “weak” to “strong.” Participants were told to rate the strength of the feelings, either positive or negative, that they experienced when viewing each item. The order of questions was randomised across stimuli.Supplementary Material. Out of 498 participants, the first 101 were presented with only a subset of these questions, 397 participants were presented with the full survey, and 384 of them answered all its questions.After the rating task, participants were asked a number of demographic information questions, as well as questions about practices and experiences with COVID and COVID-related equipment . The key questions were (1) how often did you use protective face masks before 2020? (2) how often do you use masks now? and (3) when did you start using masks? In addition, a range of sociocultural, situational, and demographic measures were collected. The full list of questions is provided in the The entire testing session took no longer than 20 min, and participants were paid 2 GBP. The study was approved by the Behavioural Research and Ethics Board at the University of British Columbia .Our main hypothesis was that subjective ratings of the attractiveness of protective masks would be predicted by their more frequent use. We tested this hypothesis in two ways. First, we compared attractiveness ratings for protective masks in participants who were wearing masks very often, sometimes, and rarely or never, while using recreational (diving and skiing) masks as control stimuli. Second, we tested whether the length of time an individual had regularly worn a mask predicted ratings of mask attractiveness.t(395) = 1.7, p > .08, and much more attractive than in the eyes of those who wore the masks only sometimes or not at all, ts > 3.5, ps < .002. The latter, in contrast to frequent mask-wearers, rated protective masks as much less attractive than recreational ones, ts > 4, ps < .001. These planned comparisons were supported by a mixed model ANOVA on attractiveness ratings, with frequency of wearing masks (between participants) and mask type  as independent variables. There were main effects of both mask wearing frequency F = 3.65, p = .027, F = 31.2, p < .001, F = 20.6, p < .001, M = 2.7, SD = 1), followed by ratings by participants who started wearing the masks during the pandemic . The highest ratings were given by people who had worn the masks before the pandemic . Furthermore, ratings increased linearly with time, as supported by a significant linear trend over the seven levels of time, β = .17, t(491) = 7.04, p < .001, while controlling for ratings for recreational masks, β = .51, t(491) = 13, p < .001. The overall model fit was R2 = .33.The test of whether the duration of regular mask-wearing predicted participants’ ratings of mask attractiveness was conducted using linear regression, with the main predictor being the number of months an individual had regularly worn a mask and the attractiveness ratings for recreational masks serving as a covariate. After viewing each product image, participants not only rated its attractiveness, but they also rated how emotionally intense it was. Participants were told to rate the strength of the feelings, either positive or negative, that they experienced when viewing each item (see Methods section). We submitted intensity ratings to the same analyses as described for mask attractiveness.F = 71.97, p < .001, F = 2.7, p = .066, F = 8, p < .001, ts > 2.2, ps < .032, those who wore the masks very often rated the protective masks as more emotionally intense then infrequent wearers, ts > 2.5, ps < .015. For recreational masks, there were no differences between participants, ts < .3, ps > .7.M = 4.1, SD = 1.4) than people who have been using masks for some time , F = 3.4, p = .035, t(491) = 2.19, p = .029, R2 = .196.p = .028, attractiveness and emotional intensity ratings did not differ between the genders, ps > .06, and neither was the interaction between frequency of use and item type (COVID-related vs. not) modulated by it, ps > .09. As for duration of mask-wearing, again, gender had no significant effect on either attractiveness or emotional intensity ratings, ps > .07. For attractiveness, there was an interaction between duration, in months, and gender, β = .012, t(491) = 2.39, p = .017. Although both male and female participants demonstrated an increase in attractiveness ratings the longer they were using the masks, for females the slope was steeper than for male participants. For emotional intensity, adding gender rendered the effect of duration to be insignificant, β = .084, t(491) = 1.83, p = .068, with no main effect or interaction with gender, ps > .07.We also tested for gender differences in this pattern of results. Although females reported wearing protective masks more frequently than males, The data so far suggest that attractiveness and intensity ratings of protective masks are positively associated with the frequency and duration of their use. At the same time, parallel results for skiing and diving masks, which are not associated with COVID, showed no association between emotional appraisal and the frequency and duration of wearing protective masks. But what is it that makes protective masks special?Our reasoning, following from the literature on object use and liking, was that the positive effects of usage on attractiveness would be most pronounced for objects that were newly introduced at the onset of the pandemic, namely, protective masks. We reasoned that previously-used objects, such as work gloves and hand sanitizers, might show a weaker or even no association with the pandemic-induced experience. This is why, in addition to asking participants about their mask-wearing practices, we asked analogous questions about the use of latex gloves and hand sanitizers to examine the effects of use on attractiveness and emotional intensity for each category specifically.F = 33.2, p < .001, F = 17.6, p < .001, F = 8.86, p < .001, F = 3.35, p = .036, F = 3.1, p = .045, F = 3.35, p = .036, We tested the association between frequency of use and emotional ratings with four ANOVAs; one for each combination of image-type  and rating-type . Each ANOVA examined the factors of frequency of use  and COVID relevance . F = 74, p < .001, F = 17.6, p < .001, F = 15.7, p < .001, F = 7.7, p = .001, F = 7.2, p = .001, p > .13. It is important to bear in mind that according to the participants’ reported frequency of use of objects before the pandemic, hand sanitizers had been used regularly by about one half of the participants. This stands in contrast to protective masks and gloves, which had been used much less frequently. We reasoned that for the participants for whom hand sanitizers were familiar, the continued use during the pandemic would likely not have added to the already-established valence of these products. Thus, the correlation we hypothesised between product type  and frequency of use should be stronger for novel than for familiar products, as described in the introduction. Therefore, we factored in previous use of hand sanitizer by adding another level to the between-participants factor of frequency of use. This analysis revealed an interaction for attractiveness as well, F = 3.02, p = .029, A similar pattern emerged for personal hygiene products. There was a main effect of product type, with COVID-related sanitizers rated lower on attractiveness and higher on emotional intensity than COVID-unrelated shampoo, One of the two non-mask categories  had been used extensively by participants before the onset of the pandemic whereas the other one (latex gloves) had not. Latex gloves and protective masks were both products that were generally familiar to participants prior to the pandemic. However, the frequency of use data we collected showed that they had not been part of most participants’ everyday lives. Because of this infrequent use, we expected their attractiveness and intensity ratings to be similar to the pattern for protective gloves: the more frequently one reported using gloves, the higher their ratings. And this is indeed what the data showed. This finding for latex gloves therefore further bolsters our hypothesis regarding use and liking for novel objects. Both masks and gloves, which had not been used very often before the pandemic, showed positive associations between frequency of use and emotional appraisal. Other products, such as hand sanitizers, were reported to be used more often before the pandemic by some participants and not by others. Here, the results showed that participants who had not used hand sanitizers previously rated their emotional appraisal in a similar way to their ratings for protective masks. Thus, we have three instances so far in which the novel use of items under natural circumstances is associated with an increase in their positive emotional appraisal.Although attractiveness and intensity ratings both showed a strong association with object use, with more frequent and longer use predicting more positive and stronger feelings, these data alone do not indicate what is driving this relationship. It is possible that the more frequent use of an object contributes to its appeal, but it is also possible that the aesthetic appeal of the object contributes to its more frequent use. It is also possible that a third set of factors, such as a participant’s political leaning to the right or left, or the requirements of mask wearing in workplace conditions, contribute to this relationship. Since this is an observational study, and not a controlled experiment, it is impossible to attribute direct causality to any of these factors. Nonetheless, a full examination of the individual differences gleaned from our demographic and attitude data helped to uncover some of the potential factors at play in the relationship between an object’s use and its emotional appraisal.Supplementary Material. The questions included participants’ age, gender, income, profession, cultural background, religion, and preferred news sources . The complete list of 54 questions is given in the  sources . In addi sources . As a fip < .001, KMO measure of sampling adequacy .704. To account for the possibility of large correlations between components to be extracted, we also tested Principal Axis Factoring with Direct Oblimin and Promax rotations (in turn). However, the correlations between the factors did were small (rs < .12), suggesting that the orthogonal solution is the most parsimonious.Our choice of the analysis—PCA—was dictated by the aim of summarising the demographic and situational data in the most parsimonious way. The dataset offered good opportunity for that, Bartlett’s test of sphericity,  with the following exceptions. Several questions were omitted from all participants because they were (a) measured on nominal scales , (b) their answers were conditional on other questions , or (c) the questions were directly related to the use of masks and other protective equipment. This left 26 items for the analysis. To account for differences in measurement units between these items, correlation-based PCA was used.A total of 384 participants completed the survey. Assuming an agnostic approach, we began by entering all the variables we possibly could to the PCA,Supplementary Figure 1). The inflection in the curve pointed to three primary components, which combined accounted for 34.6% of the total variance in the data. We first examined the Scree plot showing the relationship between goodness of fit and 10 potential candidate dimensions . These levels were dummy-coded to allow a comparison between occasional mask wearers (rarely vs. sometimes) and frequent mask wearers (rarely vs. often). The other three variables were participants’ factor loadings on the three PCA components . A sixth covariate was added to the model  to control for a participant’s baseline tendency to provide generally low or high ratings. To anticipate the results, including or removing this predictor had no influence on the pattern or the significance of the results.R2 = .402. p > .5. Higher attractiveness ratings were associated with a stronger belief in the danger of COVID, β = .24, t(372) = 4.98, p < .001, with greater environmental exposure to COVID, β = .17, t(372) = 3.9, p < .001, and with more frequent use of protective masks, βnever_vs_sometimes = .33, βsometimes_vs_often = .74, F = 10, p < .001. The overall model fit was R2 = .069. Neutral mask attractiveness ratings were negatively associated with belief in the danger of COVID, β = −.29, t(373) = −5.2, p < .001, and negatively associated with interest in politics, β = −.13, t(373) = −2.34, p = .0198, all other ps > .17. This means that participants with a stronger belief in the danger of COVID tended to rate recreational masks as less attractive, and so did participants who had greater interest in politics. Neither exposure to COVID, nor frequency of protective mask wearing correlated significantly with the attractiveness of recreational masks. This analysis confirms that the associations observed between mask attractiveness, frequency of mask wearing, and exposure to COVID were specific to protective masks. Most importantly, the association observed between the attractiveness of masks and belief in the danger of COVID ran in the opposite direction for protective and recreational masks: Belief in the danger of COVID was positively associated with the attractiveness of protective masks but negatively associated with the attractiveness of recreational masks. It suggests that participants who were suspicious of the dangers of COVID found protective masks less attractive and, when they were among the stimuli, may have compensated by rating recreational masks as more attractive.A test of the specificity of this interpretation was obtained by conducting the same simultaneous multiple regression analysis on attractiveness ratings for the COVID-unrelated masks (ski and diving masks). The overall model fit was very poor, R2 = .42. Attractiveness ratings for protective masks was associated significantly with belief in the danger of COVID, β = .25, t(373) = 5.49, p < .001, exposure to COVID, β = .18, t(373) = 4.16, p < .001, and duration of mask wearing, β = .15, t(373) = 5.35, p < .001, predicted higher ratings, while interest in politics did not, p > .7. As shown in We conducted the same set of simultaneous multiple regressions to predict protective mask attractiveness after replacing the frequency of mask use with the duration of mask wearing . R2 = .085. Belief in the danger of COVID and interest in politics were both negatively associated with attractiveness ratings, β = −.3, t(374) = −5.6, p < .001 and β = −.14, t(374) = −2.68, p = .008, respectively. In addition, duration of mask wearing was positively associated with attractiveness ratings for diving and ski masks, β = .097, t(374) = 2.8, p = .005. Thus, the longer people were wearing protective masks, the higher their ratings were for both protective and recreational masks. Yet the association between ratings of protective masks and duration of their use survived controlling for the ratings of recreational masks, as well as the other factors related to individual differences.A parallel test of specificity on attractiveness ratings of COVID-unrelated masks indicated a weak overall model fit, never_vs_sometimes = .12, βsometimes_vs_often = .54, F = 3.37, p = .035. None of the PCA components were significant, ps > .3. The overall model fit was R2 = .1996.We used the same analytic approach for the emotional intensity ratings as already reported for attractiveness ratings: A simultaneous multiple regression predicting intensity of emotions evoked by protective masks from frequency of mask wearing (dummy coded), the three PCA components, and intensity of emotions for recreational masks see . There wR2 = .038. Ratings for recreational masks were negatively associated with belief in the danger of covid, β = −.28, t(373) = −4.09, p < .001. No other variables had a significant effect, ps > .09. This pattern of results repeats the pattern observed for attractiveness ratings; frequency of mask wearing was associated with greater intensity of emotions evoked by protective, but not recreational masks. And this association held up even after other attitudinal and situational factors are controlled for.On the parallel test of specificity for recreational masks, the overall model fit was poorer, R2 = .188, and the only notable effect was a trend for association with belief in the danger of COVID, β = .12, t(373) = 1.9, p = .058. No other effects were significant, ps > .15. For recreational masks, the model fit was poorer, R2 = .0397, with the only significant association emerging with beliefs in the danger of COVID, β = −.26, t(374) = −3.99, p < .001.The analysis testing the duration of mask wearing (rather than frequency) showed only a few significant associations for either protective or recreational masks. For protective masks, the model fit was In summary, the rated intensity of emotions evoked by the protective masks was not reliably predicted by either of the three PCA components. However, once these three factors were controlled, there was a moderate association between intensity and frequency of use, but not between intensity and duration of mask wearing.In October 2020, we contacted participants who had participated in our study in July-August, asking them to do exactly the same tasks and answer the same survey. Our initial aim had been to investigate whether new users—that is, people who picked up mask-wearing practices between the two waves of data collection—would show the hypothesised effects of practice on emotional appraisal. However, given the high rates of mask use already in July–August 2020, we did not expect to see much change in mask-wearing practices (this was indeed the case). Yet we still could investigate whether two additional months of mask-wearing resulted in higher emotional ratings. To this end, we conducted a repeated measures ANOVA with time of testing (July–August vs. October) as a within-participant variable. In addition, we tested reliability of the results obtained in the first wave of testing.Participants were contacted through Prolific; 330 of the original participants consented to the re-testing and completed the follow-up study, and 326 of them completed all the tasks and answered all the questions. This sub-sample was balanced in gender  and ranged in age from 18 to 78 . 38 participants (11.3%) had been diagnosed with COVID-19 or suspected they had it.p < .001, see also In fall (October 2020), more participants were wearing masks on a regular basis (very often), We compared participants’ ratings for protective and recreational masks between the first  and the second  wave of data collection. Our primary question was whether the effects we had seen for frequency of mask wearing would replicate in a second occasion of testing. Hoping to replicate the initial finding, we used exactly the same stimuli in the second wave of testing. But doing this introduced the possibility that participants would be habituated to the specific images they had rated earlier. A secondary question was therefore whether testing the same images only a few months later would have an additional effect. To answer these two questions, we included frequency of mask-wearing (as of October 2020) as a between participant factor, resulting in a 2  × 2  × 3  mixed model ANOVA.frequentM = 3.73, sometimesM = 3.28, infrequentM = 2.91, F = 9.20, p < .001, F = 3.47, p = .0321, F = 18.87, p < .001, F < 1, p > .9, indicating that this pattern was stable across time of testing.F = 14.6, p < .001, F = 4.42, p = .013, F < 1, p > .8.The secondary finding in these data was an overall decrease in attractiveness for both protective and recreational images from time 1 to time 2, F = 6.44, p = .011, p > .3. Again, for recreational masks ratings were lower with greater frequency of use, as evidenced by an interaction between mask type and frequency of mask use, F = 2.92, p = .056, F = 16.8, p < .001, p > .12. The decrease over time was greater for infrequent mask-wearers than for participants who wore them often, F = 3.325, p = .037, The secondary effect of time of testing was also similar to that observed for the attractiveness ratings. Emotional intensity ratings decreased from the first to the second time of testing, In summary, the association between frequency of mask wearing and rated attractiveness we observed at time 1 was even stronger when we tested it at time 2. The association between emotional intensity and frequency of mask wearing was also stable over time. We interpret these two findings to imply that protective masks were more attractive and more emotionally engaging for wearers who used them more frequently. A secondary finding was that ratings for product images were generally lower at time 2 than at time 1. This finding was not specific to protective masks, but applied equally to both protective and recreational masks. We interpret this finding as stemming from repeated viewing of the same test images, rather than being related to the wearing of protective masks. This is consistent with numerous previous reports of a decrease in emotional appeal when the same stimulus is tested repeatedly over time . The decn = 19) in the never/rarely group. Ratings overall in this group decreased more than in any other group from time 1 to time 2. When we examined other data from this group more closely, we noted that they tended to be older than our sample as a whole (mean age = 42.7 vs. 35.8 years), disproportionately male (63% vs. 37%), and from regions that were relatively rural and with lower rates of mask wearing . It is difficult to know whether to attribute this group’s reduced ratings over time to measurement error  or to increased polarisation of opinions over time among infrequent mask wearers, but their data do contribute to even stronger associations between mask wearing and the emotional appeal of protective mask at time 2 than at time 1.The significant interaction of frequency of mask wearing × time, seen for both attractiveness ratings and emotional intensity ratings, were largely due to the small number of participants  and the three PCA components. To anticipate the results, the main pattern of findings reported earlier was replicated in all important respects.lavaan package for R  = 10.8, p = .002, and belief in the danger of COVID, β = .32, t(319) = 5.17, p < .001. There was also a trend for a negative association with interest in politics, β = −.103, t(319) = −1.86, p = .064, all other ps > .27. The test of specificity involving recreational masks yielded only a main effect of beliefs in the danger of COVID emerged, β = −.24, t(320) = −3.65, p < .001, for frequency of mask wearing ps > .19, all other ps > .07. The overall fit was R2 = .041The multiple regression predicting attractiveness of protective masks from frequency of mask wearing (dummy coded), the three PCA components, and attractiveness of recreational masks had an overall model fit of The overall pattern therefore closely resembled the data collected originally. The attractiveness of protective masks was associated with frequency of mask wearing above and beyond its association with beliefs in the danger of COVID. The specificity of this finding was again evident in that the attractiveness of recreational masks was not associated with frequency of mask-wearing, and its association with beliefs in the danger of COVID was negative.One subtle difference we observed between the two occasions was that situational exposure to COVID no longer accounted for any significant variance in the attractiveness of protective masks. While these observational data do not warrant strong causal interpretations, this finding is consistent with personal experience shaping one’s emotional appraisal of an object. Note that in the summer (July–August 2020—first wave of data collection), situational exposure forced some people to adopt mask-wearing sooner than others, thus amplifying the difference between people who had to use the masks regularly and those who could choose whether to do so or not. By October 2020 (the replication), even infrequent mask-wearers had become accustomed to seeing masks on others and being required to wear masks in some situations.R2 = .258. Significant predictors included duration of mask wearing, β = .069, t(320) = 2.29, p = .023, and belief in the danger of COVID, β = .33, t(320) = 5.17, p < .001. There was once again a trend for an association with interest in politics, β = −.109, t(320) = −1.95, p = .052, all other ps > .2.The multiple regression predicting attractiveness of protective masks based on duration of mask-wearing  rather than frequency had a model fit of R2 = .077. Yet, here was a significant association with duration of mask wearing, β = .11, t(321) = 3.6, p < .001, along with a negative effect of belief in the danger of COVID, β = −.308, t(321) = −4.78, p < .001, all other ps > .09. We found it surprising that the attractiveness of recreational masks should increase with a longer duration of wearing protective masks, but as seen in the previous analyses, attractiveness of protective masks was predicted by duration of mask wearing even when the attractiveness of recreational masks was statistically controlled. In general, the pattern closely resembled that obtained in the first wave of the study.The multiple regression predicting attractiveness of recreational masks had a very poor overall fit, t(319) = 2.86, p = .004, but not by frequency of mask wearing, F = 1.5, p = .2, overall fit R2 = .176. In a parallel model, duration of mask wearing did not have any effect either, p = .08, model fit R2 = .178. We interpret these finding to imply that the effect of wearing protective masks on the intensity of emotions was eliminated by October 2020.The emotional intensity of protective masks was predicted only by interest in politics, β = .21, To summarise, a within-participant replication of the study revealed that by October 2020, a larger number of people were wearing masks more frequently than in July–August 2020. Consistent with this observation of a significant change in baseline behaviour, the effects of mask-wearing frequency and duration had disappeared from ratings of the intensity of emotion elicited by the images, although they were still clearly evident in the ratings of attractiveness.The purpose of this study was to find ecological support for the well-established laboratory finding that merely acting on or using a novel object can increase its emotional appeal . This prAs we noted in the “Introduction” section, an observational study design like this one lacks many of the controls that are possible in a laboratory study. But in our view, the bi-directional causality seen in laboratory studies is no longer in question. Instead, an important unanswered question is whether these factors are operational in the everyday world as people quite naturally come into contact with novel objects and change their patterns of use with respect to them. Studying the emotional appraisal of protective face masks, which suddenly grew in popularity world-wide during 2020, therefore offered a ready-made opportunity to answer this question.For comparison stimuli we chose a variety of products that were similar to protective masks in several respects but differed from them in others. COVID-unrelated face masks that are used in recreation offered one such comparison . COVID-related products that were not as novel as masks offered another . Our understanding of the laboratory evidence led us to expect that the association between use and emotional appraisal would be more pronounced for the objects made novel by the pandemic  than for other objects that were previously familiar and/or used more frequently.One unanticipated benefit of the pandemic for our research was the rapid pivot among cognitive researchers to testing people online rather than in the laboratory. The rapid development of software and research approaches to facilitate remote testing, along with public acceptance of remote research as the “new-normal,” meant that we were able to access a much more diverse set of participants than is typical in laboratory studies.usage-positive appraisal hypothesis. The results clearly indicated that both the frequency of wearing a mask, and the duration of wearing it, were linked to the positive emotional appraisals of these objects. This interpretation is supported by the theory of microvalences  the data showed it was more similar to the data for protective masks than it was for personal hygiene products (familiar and frequently used by many previously). This interpretation was strengthened even further when we distinguished between participants who made regular use of these products pre-pandemic and those who did not. Those for whom these products were relatively more novel provided data that was more similar to that for protective masks.But perhaps the strongest evidence supporting a causal arrow linking the usage of protective masks with their positive emotional appraisal came when we compared the relative contributions of personal ideology (doubt/belief in the dangers of covid), environmental circumstances (workplace requirements to wear masks), and frequency of mask usage to ratings of mask attractiveness. Even though the expected links between doubt/belief in the dangers of covid and mask attractiveness were evident in the data , and even though the expected links between workplace requirements and mask attractiveness were in evidence , there was still a significant unique contribution to mask attractiveness that could be attributed to the frequency and duration of wearing a mask.The literature on perception and emotion teaches us that mere exposure to an object  can leadAn alternative account of these findings is that people who adopted protective masks early were those who initially held a more positive appraisal of them. Indeed, multiple studies show that a positive appraisal increases the tendency to approach an object . While tAn encouraging practical application of the present data, in conjunction with the theory of microvalence, is that taking societal measures to encourage mask wearing when there is a pandemic may help to move their emotional appraisal from negative to positive. It should give us hope that, among frequent and long-time wearers of protective masks, the emotional appraisal given to COVID-19 masks rivals those given to recreational and personal hygiene products.Click here for additional data file.Supplemental material, sj-docx-1-qjp-10.1177_17470218211037128 for In the hands of the beholder: Wearing a COVID-19 mask is associated with its attractiveness by Veronica Dudarev, Maria GM Manaligod, James T Enns and Rebecca M Todd in Quarterly Journal of Experimental PsychologyClick here for additional data file.Supplemental material, sj-docx-2-qjp-10.1177_17470218211037128 for In the hands of the beholder: Wearing a COVID-19 mask is associated with its attractiveness by Veronica Dudarev, Maria GM Manaligod, James T Enns and Rebecca M Todd in Quarterly Journal of Experimental PsychologyClick here for additional data file.Supplemental material, sj-docx-3-qjp-10.1177_17470218211037128 for In the hands of the beholder: Wearing a COVID-19 mask is associated with its attractiveness by Veronica Dudarev, Maria GM Manaligod, James T Enns and Rebecca M Todd in Quarterly Journal of Experimental PsychologyClick here for additional data file.Supplemental material, sj-jpeg-4-qjp-10.1177_17470218211037128 for In the hands of the beholder: Wearing a COVID-19 mask is associated with its attractiveness by Veronica Dudarev, Maria GM Manaligod, James T Enns and Rebecca M Todd in Quarterly Journal of Experimental Psychology


We aimed to examine the associations between the risk of decreased renal function, obesity, and weight changes in Korean type 2 diabetic patients with normal renal function.n = 1060) who visited the diabetic clinic at Soonchunhyang University Bucheon Hospital between 2001 and 2007 with follow up surveys completed in 2016 to 2017 were recruited into the study. Decreased renal function was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2. Weight change was calculated between baseline and each follow-up survey. Multivariate analysis was used to evaluate the longitudinal association of baseline obesity and weight changes with the risk of decreased renal function.Type 2 diabetic patients (p = 0.025). Follow-up (mean = 12 years) revealed that weight gain > 10% was associated with the risk of decreased renal function after adjusting for clinical variables in type 2 diabetic patients with normal renal function at baseline . Weight loss was not associated with the risk of decreased renal function in type 2 diabetic patients with normal renal function at baseline.This study revealed that baseline obesity was associated with the risk of decreased renal function after adjusting for clinical variables in type 2 diabetic patients (odds ratio [OR] 1.40; 95% confidence intervals [CI] 1.08–2.04; Baseline obesity was associated with the increased risk of decreased renal function in Korean type 2 diabetic patients with normal renal function. Weight gain > 10% independently predicted the risk of decreased renal function. Large prospective studies are needed to clarify causal associations between obesity, weight change, and decreased renal function in patients with type 2 diabetes. Obesity is a major risk factor for type 2 diabetes, hypertension, and other comorbidities . In KoreSince the prevalence of obesity in diabetic patients is increasing , and dian = 1060) who visited the diabetes clinic at Soonchunhynag University Bucheon Hospital between 2001 and 2007 with follow-up surveys completed in 2015 to 2017 were recruited into the study. Individuals diagnosed with type 1 diabetes, renal insufficiency (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m2), chronic liver disease, chronic infection, or malignancy were excluded. Decreased renal function was defined as an eGFR < 60 mL/min/1.73 m2. Based upon the Modification of Diet in Renal Disease formula, eGFR was calculated as follows: eGFR (mL/min/1.73 m2) = 186 × serum creatinine (mg/dL) - 1.154 × (age) - 0.203 × .Korean patients with type 2 diabetes (2), overweight (23–24.9 kg/m2), or obese (≥25 kg/m2) in accordance with WHO guidelines for the Asia-Pacific region [n = 861). The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Institutional Review Board (IRB) of Soonchunhyang University Bucheon Hospital (IRB no. 2020–03-015).BMI was categorized as normal , fasting total serum cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, aspartate aminotransaminase, alanine aminotransferase (ALT), and creatinine were measured. Serum creatinine was assayed by calorimetry using Beckman Coulter AU analyzer  following the Jaffe method and it was IDMS standardized . HbA1c wP-values less than 0.05 were considered to be statistically significant. A chi-square test was performed to compare categorical variables. One-way analysis of variance was performed to evaluate the differences in means among BMI categories. Multivariate logistic regression was performed to identify the longitudinal associations of baseline obesity and weight changes with the risk of decreased renal function.Statistical analyses were performed using SPSS Statistics version 26.0 . Values are represented as mean ± standard deviation for variables that were normally distributed, median (interquartile range) for variables that were not normally distributed, or the number of participants (percentages). n = 1060) were analyzed and divided into three groups according to BMI categories as described in Materials and Methods. The prevalence of obesity (BMI ≥25 kg/m2) was 45.8% in subjects with type 2 diabetes. Obese patients had higher HbA1c, higher ALT, and a less favorable lipid profile, whereas no differences were found between the three BMI groups in eGFR or the prevalence of albuminuria (Table The baseline characteristics of study participants are presented in Table p = 0.025) (Table p = 0.102) (Table Baseline obesity was associated with higher odds ratios (OR) for decreased renal function after adjusting for clinical factors such as age, sex, duration of type 2 diabetes, HbA1c, total cholesterol, triglycerides, and hypertension at baseline . However, weight gain of 5–10% and weight loss of 5–10% were not associated with the risk of decreased renal function in type 2 diabetic patients with normal renal function at baseline. Moreover, weight loss of any magnitude was not associated with the risk of decreased renal function in type 2 diabetic patients with normal renal function   after adjusting for clinical variables at baseline  did not have a higher risk of decreased renal function. Weight loss and weight gain < 10% were not associated with the risk of decreased renal function in type 2 diabetic patients with normal renal function at baseline.2) [In several population-based studies, higher BMI was associated with the presence of CKD , 16, dec2) , 24.. Ac2) . Sarcope2) . BMI may2) . ExtensiPatients with type 2 diabetes have several comorbidities . It is iIn this study, baseline body weight was associated with a higher risk of incidental CKD. Several recent studies demonstrated the association between obesity and increased risk of CKD. However, few studies have investigated whether weight gain increases the risk for CKD. In a Japanese study, the relative risk for incident CKD was higher in the normal weight participants with a weight gain of > 10 kg than those without weight gain .In another study in Europeans, waist circumference (WC) changes were not associated with the incident CKD in women, whereas a severe increase in WC was associated with increased risk of CKD . The effFactors involved in the progression of CKD and mechanisms by which obesity may affect CKD are not fully clarified yet. However, several mechanisms have been proposed. Various metabolic diseases associated with obesity may lead to kidney damage. The association between metabolic syndrome and kidney disease is well known , 30. ObeIn the present study, weight loss was not associated with decreased renal function. Similar to our findings, a decrease in WC was not related to a lower risk of CKD in another recent study . In anotThis study has several limitations. First, we focused on GFR in this study. Obesity is an important cause of proteinuria, such as obesity related nephropathy. Further study is needed to observe the association between obesity and proteinuria during the long-term follow-up. Second, the single-center design may introduce selection bias. However, the laboratory results of this study population are highly consistent with the broader Asian population. Despite these limitations, our study has the advantage of a long mean follow up of 12 years.In conclusion, obesity was associated with the increased risk of decreased renal function in Korean type 2 diabetic patients with normal renal function. Weight gain > 10% independently predicted decreased renal function. Large prospective studies are needed to clarify causal associations between obesity, weight change, and decreased renal function in patients with type 2 diabetes.