The purpose of this study was to examine the relationship of grit as a construct representing perseverance to overcoming barriers and the total number of school absences to academic performance (AP) while controlling for sociodemographics, fitness , and Body Mass Index (BMI).N = 397, SD = 1.85; 80.9% females; 77.1% Hispanic) from an urban, minority-majority city in the Southern United States completed the FitnessGram® assessment of physical fitness ) and the valid and reliable short grit survey. The schools provided sociodemographics, attendance, and AP data for the adolescents. Adolescents  and less total absences  performed better on AP. Hierarchical multiple regression indicated that grit and absences were associated with AP . Adolescents with higher grit scores ( Grit and a total number of absences are significant contributors to academic success, particularly among Hispanic adolescents. Further, grit and school attendance may serve as a better measure of protective factors over proximal health measures of cardiovascular health and BMI. Following No Child Left Behind (NCLB), which legislated that public school monies would be tied to adequate yearly progress in academic performance (AP), it has been reported that approximately 44% of public school districts reduced resource allocation towards physical education, recess, and/or the arts in favor of increased traditional academic time and test remediation . In the Adolescents who regularly participate in physical activity, including visual-motor coordination  and coorPhysical activity interventions like Physical Activity Across the Curriculum (PAAC) and Fitness Improves Thinking (FITKids) that increase physical activity participation and subsequently improve cardiovascular fitness also increase overall academic achievement , executiIt is important to note that the cognitive benefits associated with physical activity and fitness are not unilateral but instead are specific to the type, timing, and intensity of physical activity. Tomporowski et al.  suggest Not all interventions have equal cognitive benefits. For example, two cluster randomized controlled trials, the Active Smarter Kids (ASK) study  and ActiAP is dependent on a multitude of modifiable and nonmodifiable factors. Specifically, socioeconomic status (SES) and ethnicity have been identified as significant nonmodifiable inhibitors of academic success . The NatThe comorbidity of low SES, ethnicity, and low academic performance is complicated further as lower SES students also have an increased likelihood of health-related fitness standards falling below healthy criteria . Coe andBeyond nonmodifiable factors, modifiable factors like an individual perception of various psychological constructs may provide additional insight into decomposing the relationship between physical fitness and academic performance. Although over 200 studies suggest that physical fitness and to a lesser degree physical activity are positively related to cognitive performance, few studies have controlled for confounding variables such as age, ethnicity, intelligence, and psychosocial effect related to academic achievement . FurtherGrit. The construct of grit is defined as a “perseverance and passion towards long-term goals” [m goals” , pg. 1. m goals” –26. The School Attendance. Attending school, particularly in secondary education, remains an issue in the United States, with over 5 million school-aged children missing at least 30 days of school per year [per year . Of evenper year . MissingGiven the existing achievement gap and health disparities between White and Hispanic adolescent students, as well as the potential to address these health and educational issues through PA interventions, this study examined the relationship of these variables to AP. Specifically, the purpose of this study was to investigate the relationship of grit, as a construct representing passion and perseverance to overcome barriers, and school attendance to academic achievement and proxy health measures while controlling for school demographics and attendance.Multiple Institutional Review Boards approved this study at the university, district, and individual school level, with each governing body requiring that each human subject and a guardian actively consent to participate in this study. Specifically, parental consent and adolescent assent were secured for each participant. An overview of the study was presented during physical education and health classes, and once consent and assent were secured, data were collected during physical education classes.N = 397) across one large southern school district which serves over 83,000 students in a minority-majority city were recruited for this study. The participants were recruited from 12 different public schools (six high schools and six middle schools). All the schools that agreed to participate in this study were identified by the state education association as Title 1 Schools, meaning that they had a student population receiving free or reduced lunch more than 51%; however, the school district would not grant permission for the researcher to secure individual student SES. All students in this study participated in daily physical education for 60 minutes.In this study, adolescents enrolled in secondary education  physical fitness data collected using the FitnessGram , (2) psychosocial survey data, and (3) AP and demographic data supplied by the school district. Educational measures included standardized grade-level testing and subject test scores. Demographic information included age, sex which was coded as female = 1 and male = 2, ethnicity which was coded as White = 1, Hispanic = 2, and Other = 3, number of advanced classes, and the total number of absences for semesters 1 and 2. Student fitness was measured by the valid and reliable FitnessGram  battery of physical fitness tests. These tests were administered by the physical educator of record and primary investigator at the beginning and end of the school year.AP was measured by averaging year-end score on state academic accountability subject test. These tests have been used as valid and reliable measures for over 5 million public school students in the southwestern United States over two decades and are designed for vertical agreement with curricular objectives across the tested age range (8–18). Raw scores were converted to a 100-point scale and divided into quintiles for analysis . Separate analyses were also conducted by subject matter  with the scores for each subject similarly coded as 0 to 59 = 1, 60 to 69 = 2, 70 to 79 = 3, 80 to 89 = 4, and 90 to 100 = 5. Given the differing developmental level of the participants in this study, different AP assessments were administered. Students in the 7th grade took Reading, Math, and Writing exams, while students in the 8th grade completed the Reading, Math, Science, and Social Studies tests. High school students have more flexibility about matriculation and subsequent test administration, but this cohort supplied data for subject tests for English 1 and 2, Biology, Algebra 1 and 2, and U.S. History, corresponding to which course the student was enrolled in during the semester. Semester 1 and two final subject grades  were provided by the district, as well as data about the rigor of the scheduled courses  as well as school attendance.Health-related fitness was assessed by the physical educator of record at the beginning of the academic year (August/September). Students completed the FitnessGram battery of physical fitness tests. These tests included 20 m shuttle run , Body Mass Index , muscular strength and endurance (push-up and curl-up tests), and flexibility by shoulder mobility stretch and prone trunk extension test. Only BMI and PACER were used in the analysis for this study. These tests have established healthy criterion and sex norms  and are α = 0.78). The survey had previously been validated to correlate positively with achievement across a wide range of constructs: marriage duration, military academy ranking, PA adherence and fitness [The 8-item Short Grit Scale is an 8-item inventory that assesses commitment and likelihood to complete long-term goals . The par fitness , and AP  fitness .After obtaining site permission, the scope and purpose of the study were presented to students during physical education classes. Students completed surveys during class and had the primary investigator and other researchers available to answer any questions about the survey items. The physical education teacher conducted fitness testing during the first and last months of the academic year, each teacher was familiar with conducting this assessment and had received district training about how to do so. Academic accountability testing was completed in January (mid-year), March, and April. The achievement test scores, grades, sociodemographics, and school attendance data were not released by the school district until the beginning of the next school year (August).Continuous variables were represented by mean and standard deviations , while categorical variables are presented as absolute and relative frequencies . Spearman's correlations were conducted as an exploratory analysis to examine bivariate associations between the variables. A hierarchical multiple regression was calculated to examine the relationships between grit as well as the total number absences to AP controlling for sociodemographics, cardiovascular fitness, and BMI. To further explore the relationships between grit as well as the total number of absences to academic performance by different subjects , additional hierarchical multiple regression analyses were performed individually for the four subjects. This analysis was included to provide greater specificity for possible interventions by subject matter in the future. The level of confidence was set at a 0.05 significance level. All statistical analyses were performed using SPSS version 24.0 .age = 14.23, SD = 1.85). Most participants were female . The sample comprised 306 (77.1%) Hispanic, 32 (8.1%) White, and 59 (14.8%) Black, and other race/ethnicity. These values are representative of the district at-large, as the city was considered a minority-majority community. One hundred and twenty-eight students (32.2%) were not enrolled in any advanced classes, 37 (9.3%) students took one advanced class, 73 (18.4) students took two advanced classes, 113 (28.5%) students took three advanced classes, and 46 (11.6%) students took four or more advanced classes. Results from Spearman's correlations showed that age , number of advanced classes , and BMI  as well as grit  and total number of absences  were correlated with AP. Furthermore, students who had higher grit and lower total absences performed better on English , Math , Science , and Social Studies  (see Descriptive statistics are shown in 001) see .R2 = 0.25, F = 14.28, P < 0.001. Number of advance classes and grit were associated with AP . After entering BMI and PACER in the second model, the total variance explained by the model was 26%, R2 = 0.26, F = 11.53, P < 0.001. In the second model, BMI and PACER were not associated with AP. However, grit was related to AP . Finally, after entering a total number of absences with grit in the third model, the total variance explained by the model increased to 37%, R2 = 0.37, F = 16.78, P < 0.001. In the third model, grit and total number of absences were associated with AP ; see Next, a hierarchical regression analysis was used to examine the relationship of grit and total number of absences to AP while controlling for sociodemographics and cardiovascular fitness  and BMI. To better understand the role of grit and its relation to AP among adolescents, grit was included in all three models. In the first model of hierarchical multiple regression, sociodemographics including age, sex, ethnicity , the number of advanced classes, and grit were explaining 25% of the variance in grades, R2 = 0.26, F = 16.84, P < 0.001. Second, BMI, PACER, and grit were explaining 27% of the variance in English, with R2 = 0.27, F = 13.27, P < 0.001. The results showed that BMI and PACER were not associated with English. However, grit was associated with English . Lastly, grit and a total number of absences were explaining 34% of the variance in English, R2 = 0.34, F = 16.11, P < 0.001. The results revealed that both grit and the total number of absences were significant predictors of English  when all covariates are controlled , Science , and Social Studies  after controlling for age, gender, ethnicity, the number of advanced classes, BMI, and PACER.Because grit and the total number of absences were significantly associated with AP, the researchers further conducted additional hierarchical multiple regressions to evaluate the relationships between grit and total number of absences to four different subjects . Again, grit was included in all three models. First, the combination of sociodemographics, the number of advanced classes, and grit were explaining 26% of the variance in English, lled see . For othBased on previous research findings, an underlying assumption of this research project was that the construct physical fitness, as a proxy measure of health, would positively impact academic achievement. This study also sought to understand the potential influence of grit and school attendance in the relationship between physical fitness and AP. The construct of grit, which has yet to be included as a psychosocial variable that might influence AP among adolescents, was selected because of its previously reported independent connections to positive fitness and academic outcomes. The generalizability of previous research was inhibited because the studies failed to account for how students persevered in their pursuit of long-term academic success as well as how often they attended school. All previous studies assumed that the student had attended school regularly and was equally engaged in the learning process, thus leading to achievement.High levels of grit significantly predicted AP, but when this model was decomposed by subject matter, grit and attendance only predicted performance in English. This finding brings into question the preponderance of correlational analyses between physical activity/physical fitness and academic achievement. Although all of the students in this present study spoke English as the primary language, the findings are reasonable since many students may need grit to master the English language, when Spanish might be the language that was spoken in the household. This study sheds light on the possible ethnic and cultural differences in the physical activity/fitness and academic achievement line of research. We recommend that for investigations centered on academic performance to be rigorous, the studies should include measures of student attendance and/or engagement in the curriculum as well as grit. Further study on diverse populations is also warranted.Unexpectedly grit did not predict whether someone would achieve the healthy fitness zone in fitness testing. While these findings could suggest that grit is unimportant to physical fitness in adolescents, it is possible that student agency for academic performance supersedes that of physical fitness in low SES schools that devote greater resources towards developing students who can pass accountability measures, graduate, and ensure that state monies are distributed as expected. As such, the disconnect between fidelity towards long-term goals (grit) and fitness may be a point of intervention that physical educators can target in their lesson design to facilitate this connection in the minds of students. However, a limitation of this study was that student agency for and the saliency of physical fitness as a goal was never assessed.Previous research suggested that because physical education class is a place where students set fitness and physical activity goals as well as a course that all children are required to take over multiple years, the construct of grit can be applied and increased. The mastery of motor and tactic skills, as learning outcomes of physical education, means that students try, try, and try again as part of the process of mastering specific skills to achieve their long-term goals. Providing a mastery-oriented, over the ego-oriented, environment in physical education may help the students to increase the amount and frequency of grit applied in physical activity contexts. In a survey of physical education students, researchers discovered that students believed the motivational climate within the class was related to and even was a cause of their success . FurtherLike all researches, there were several delimitations and limitations of this study. A strength is the inclusion of school attendance and grit as indirect measures of student engagement. No previous study had included grit in its examination of the AP and fitness jointly. The large sample size of Hispanic students is also a strength of this study. As scholars, we have to make inferences that research findings apply unilaterally across many different ethnicities. All students in this study participated in daily physical education for 60 minutes. The lack of direct measures of health and engagement limited this study. The researchers did not directly observe the degree of school engagement of each participant in this study. Also, although state academic accountability tests are designed to align with grade-level learning outcomes and validated by millions of students annually different grade-level students took different tests, and our measure of AP loses its predictive power for specific content areas in favor of a broader accountability to pass grade-level assessment.Common assertions about the relationship between physical activity and physical fitness and how it may be physical and cognitively benefit Hispanic adolescents may be different than what was previously concluded. For Hispanic adolescents who participate in daily physical education and receive free and reduced lunch, grit and attending school are more appropriate determinants of academic success than physical fitness, the number of advanced classes that they take, or past academic success.For adolescents to reach learning outcomes as evidence of developmental progress and school effectiveness, adolescents must attend school, given the significant relationship with academic achievement. Further study is warranted regarding how adolescents participation in physical activity may increase grit and therefore success in school.


Measures of health-related quality of life may predict the future status of individuals with illnesses, and could therefore be a good indicator in children with cerebral palsy (CP). This study examines the causal relationship between spasticity, weakness, gross motor function, and health-related quality of life (QOL) in school-aged children with spastic CP and tests models of functional outcome mediated by gross motor function.A total of 62 children  with spastic CP were recruited. Strength was assessed with the Manual Muscle Test, spasticity with the Modified Ashworth Scale, and the Gross Motor Function Measure was also employed. Health-related QOL was assessed using the Korean version of the Childhood Health Assessment Questionnaire. Physical therapists interviewed the parents and assessed the children.The proposed path model showed good fit indices. The direct effects were significant between spasticity and gross motor function, strength and gross motor function, gross motor function and health-related QOL, and strength and health-related quality of life. Spasticity had a significant positive indirect effect and strength a significant negative indirect effect on health-related QOL through gross motor function.This is an initial study of the causal relationship between strength, spasticity, gross motor function, and health-related QOL. Cerebral palsy (CP) is defined as a permanent non-progressive developmental disorder. National population-based studies have reported that CP prevalence is about 1.8-2.3 cases per 1000 children in Europe, Australia, and the U.S. . AlthougThe International Classification of Functioning, Disability, and Health (ICF) model is concerned with the effect of disability on an individual’s daily life and social participation, beyond the idea of injury, which implies physical structure and functional deficiency. Since the conceptual model of ICF disability was presented, the reduction of disability and promotion of participation in individuals with disabilities has become the ultimate goal of rehabilitation and a health policy direction .Recently, based on the ICF concepts, research on functional assessment measures (activity limitation and participation restriction) and QOL has been conducted to determine the direction and effect of interventions. The Gross Motor Function Measure (GMFM) is a tool for functional assessment, and its scores have a close relationship with motor impairments, including spasticity and decreased muscle strength. Kim and Park  reportedSeverity of CP is associated with low physical QOL , 13. QOLPrevious studies have reported that gross motor function is related to QOL in children with CP. Gross motor function, measured by GMFM, and Gross Motor Function Classification System level were found to be highly correlated with physical well-being in school-aged children with CP . EspeciaImpairment-based therapy focuses on the inhibition of spasticity and improvement of muscle strength, while activity-based therapy focuses on the improvement of gross motor function. Given the recent emphasis on activity-based therapy in clinical practice, it is necessary to research the causal relationship between a variety of factors and how they affect HRQOL in spastic CP. The Childhood Health Assessment Questionnaire (CHAQ), a tool specifically developed to assess functional capacity and independence in everyday life, is a commonly used measure of health status. Although the CHAQ was designed to assess childhood idiopathic arthritis in children and adolescents , it has This study aimed to examine the causal relationship between spasticity, weakness, gross motor function, and HRQOL in children with spastic CP who attend school. Especially, the mediation effect of gross motor function was investigated.This study aimed to investigate the relationship between spasticity, weakness, gross motor function, and HRQOL in children with spastic CP who attend school using path analysis. This study employed a cross-sectional and prospective design. Informed consent was obtained from the parents of all children, as parents of children below 15 years of age are their legal representatives. Ethical approval for this study was granted by the Ethics Committee of Jeonju University.Participants were 62 children with spastic CP, 44 (71.0%) boys and 18 (29.0%) girls. Inclusion criteria were as follows: 1) clinical diagnosis of spastic CP, 2) age from 6 to 15 years, and 3) consent of parents to participate. Exclusion criteria were as follows: 1) spina bifida, 2) associated skeletal muscular disorders such as muscular dystrophy and myopathy, and 3) elective dorsal rizotomy surgery. Botulinum toxin injection was not considered as inclusion/exclusion criterion. The mean age of children was 9.02 years (SD = 2.6). The minimum required sample size was 42 based on a significance level of 0.05 and medium effect size of 0.50 in a correlation analysis . AccordiA spasticity rating was obtained through bilateral measurement of spasticity using the Modified Ashworth Scale (MAS), and a strength rating was obtained with the Manual Muscle Test (MMT). The GMFM and Children Health Assessment Questionnaire (CHAQ) were used to assess gross motor function and HRQOL, respectively.Spasticity was measured in the flexors and extensors of shoulder, elbow, along with the wrists of both the upper extremities. In both the lower extremities, spasticity was measured in the hip flexors and extensors, knee extensors, and ankle plantar flexors and dorsiflexors. The test was performed at moderate speed (180°/s) using standardized procedures. Intraclass correlation coefficients between 0.61-0.87 have been reported in children with spastic CP .Strength was measured in the flexors and extensors of shoulder, elbow, and wrists of both the upper extremities, and in the hip flexors and extensors, knee extensors, and ankle plantar flexors and dorsiflexors of both the lower extremities. Reliability values of the MMT between 0.60-0.91 have been reported in children with hemiplegic CP .Spasticity and strength were quantified by summating all MAS and MMT scores, respectively. MAS scores for all lower and upper extremities measurements were summated to provide a spasticity score. Likewise, MMT scores for all measurements were summated to provide a strength score. Both scores indicate the extent or magnitude of impairment.GMFM, a standard criterion-referenced test designed to assess changes in gross motor function in children with CP, was used in this study . The totThe HRQOL of school-aged children with CP was measured using the CHAQ. Physical therapists used the Korean version of the CHAQ to interview the parents. The CHAQ consists of eight domains: dressing/grooming, arising, eating, walking, hygiene, reach, grip, and activities. Questions are answered on a 4-point Likert scale from 0 to 3, where 0 means able to do with no difficulty, 1 able to do with some difficulty, 2 able to do with much difficulty, and 3 unable to do. The mean score of the 8 domains determines the CHAQ score. Cronbach’s alpha values ranging from 0.76 to 0.97 have been reported for the eight domains , with vaFigure The variables included in the path model and the direction of the causal relationship were based on previous research and general logic. In this study, correlations of variables were analyzed before performing path analysis, which involved verifying the significant coefficients in the recursive model, and subsequently investigating the proposed path model fit indices. In path analysis, a goodness of fit test is performed in order to confirm that the model shows the best possible fit.After testing the appropriateness of the model, direct, indirect, and total effects were examined through the bootstrap method. The AMOS 22.0 statistical program was employed to analyze the path models, obtain maximum-likelihood estimates of model parameters, and provide goodness-of-fit indices. The level of significance was set at 0.05.p < 0.001) in the expected directions. There was no multi-collinearity because bivariate correlations did not exceed 0.80 [Pearson correlation coefficients for all variables are presented Table eed 0.80 .Table 1Cp > 0.05)  to HRQOL was not significant (5) Table . Figure 2) and the root mean square error of approximation (RMSEA) were used as absolute fit indices, and the normed fit index (NFI) and the comparative fit index (CFI) as incremental fit indices. χ2 was not recommended as a judgment of model fit because it is sensitive to the sample size used in the analysis of model fit; therefore, it was only reported but not used as a fit statistic in this study.Multiple criteria were used for the evaluation of model fit. Fit indices include the theoretical meaningfulness of the model, absolute and incremental fit indices, and model cross-validation. Absolute fit indices are used to determine how well a model fits the data without comparing it to a baseline model, whereas incremental fit indices are used to investigate how much better the model fits than a baseline model. In this study, chi-square . The indirect effect of spasticity on HRQOL (.250) and of strength on HRQOL (−.269) were also statistically significant (p < 0.05).HRQOL measured with CHAQ was the dependent variable. Exogenous independent variables were spasticity and strength. The endogenous independent variable as a mediator was gross motor function. As shown in Table Information about HRQOL might be useful to evaluate the effect of interventions on overall well-being . MeasureQOL is concerned with the most important aspects resulting from disability in terms of an individual’s level of independence in life roles. Almost all therapy is provided on the assumption that a reduction in motor impairment will result in an increase in everyday functioning and participation for children with CP. However, the causal relationship between motor impairment and functional outcome was seldom empirically demonstrated , 37, espSome studies have identified fragmentary relationship between variables. Motor impairments such as spasticity, weakness, restricted range of motion, and selective motor control ability have an effect on functional ability in terms of gross motor function and daily activities outcomes –39. A stThis study employed path analysis to test the causal relationship between spasticity, strength, gross motor function, and HRQOL in school-aged children with spastic CP. Path analysis is superior to regression analysis as it provides an explanation for both the causal relationship and the relative importance of alternative paths of influence . The prop < 0.05). If the spasticity score is increased by 1 SD, total gross motor function score is reduced by 0.4 SD. These results are supported by previous studies that found a significant correlation between spasticity and gross motor function [The present data confirm and extend previous findings indicating that spasticity and weakness are causal factors of gross motor function. Furthermore, gross motor function was shown to be a causal factor of HRQOL. The path coefficients of spasticity and strength to gross motor function were significant . Spasticity, strength, and gross motor function were explanatory variables of HRQOL and accounted for substantial proportions of the variance in CHAQ scores (63.0%). Although a percentage above 60 accounted for is large, it also suggests that other variables should be included in the model to explain over 30% of the variance in HRQOL. Direct effects of spasticity and strength on gross motor function, and strength and gross motor function on HRQOL were detected. A significant positive indirect effect of spasticity and a significant negative indirect effect of strength on HRQOL were also identified. Indirect effects include the subsequent effects of spasticity and strength as exogenous variables through another variable, i.e., gross motor function, on HRQOL, the endogenous variable. This is known as a mediating effect of gross motor function, as the proposed path model shows that spasticity and strength influence HRQOL through their effect on gross motor function.This study provides primary evidence for the mediating role of gross motor function in the relationship of spasticity and strength with HRQOL. Spasticity and strength accounted for 61.4% of the variance in gross motor function; and spasticity, strength, and gross motor function accounted for 63.0% of the variance in HRQOL. The proportion of the variance in HRQOL explained by these variables included direct and indirect effects, as well as the mediating effect of gross motor function in relation of spasticity and strength with HRQOL. Furthermore, spasticity was completely mediated by gross motor function. The results of this study provide a starting point to establish causal relationships between motor impairment, gross motor function, and HRQOL. Although the results from path analysis in this study provide important insights into the links between spasticity, strength, gross motor function, and HRQOL, further research is needed to understand the nature of these relationships in more detail considering the ICF model.There are limitations to this study. Firstly, the sample size is small; thus, further research needs to include more children with CP to increase the statistical power and clinical meaning of the present study findings. A second limitation is related to the age range of the study sample. Although this was limited to school age, it is possible that 9 years of motor development make an important contribution to HRQOL changes; therefore, a further study should be conducted controlling for age. Finally, parent interviews were conducted to assess children’s HRQOL in the present study. Although QOL must be measured by directly assessing the concerned individuals whenever possible, in cases of severe cognitive impairment, intellectual problems, or communication difficulties, parent-reported QOL is used to obtain reliable information about children’s QOL , 45. In This study investigated the relationship between motor impairment, including strength and spasticity, gross motor function, and HRQOL using path analysis. Data were collected from 62 school-aged children with spastic CP. Significant paths from spasticity and strength to gross motor function and from strength and gross motor function to HRQOL were identified, and the role of gross motor function as a mediator was confirmed through path analysis in school-aged children with CP. This study provides initial evidence for the causal relationships between motor impairment, gross motor function, and HRQOL in children with spastic CP. In addition, the results of this study are meaningful in that the QOL is the final goal of health; the concept of ICF is assumed to be improved, as the limit of activity and the restriction of participation decreased in children with CP.The author declares no conflict of interests. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.


Obesity is a major epidemic for developed countries in the 21st century. The main cause of obesity is energy imbalance, of which contributing factors include a sedentary lifestyle, epigenetic factors and excessive caloric intake through food and beverages. A high consumption of caloric beverages, such as alcoholic or sweetened drinks, may particularly contribute to weight gain, and lower satiety has been associated with the intake of liquid instead of solid calories. Our objective was to evaluate the association between the substitution of a serving per day of water for another beverage (or group of them) and the incidence of obesity and weight change in a Mediterranean cohort, using mathematical models. We followed 15,765 adults without obesity at baseline. The intake of 17 beverage items was assessed at baseline through a validated food-frequency questionnaire. The outcomes were average change in body weight in a four-year period and new-onset obesity and their association with the substitution of one serving per day of water for one of the other beverages. During the follow-up, 873 incident cases of obesity were identified. In substitution models, the consumption of water instead of beer or sugar-sweetened soda beverages was associated with a lower obesity incidence (the Odds Ratio (OR) 0.80  0.68 to 0.94) and OR 0.85 (95% CI 0.75 to 0.97); respectively) and, in the case of beer, it was also associated with a higher average weight loss ). Thus, this study found that replacing one sugar-sweetened soda beverage or beer with one serving of water per day at baseline was related to a lower incidence of obesity and to a higher weight loss over a four-year period time in the case of beer, based on mathematical models. Obesity is a major epidemic in the 21st century for developed countries. In fact, 20%–30% of the Western adult population is obese . These hBeverages are major components of the daily diet. As for food, there are guidelines for beverage consumption in order to contribute to healthy diet ,11. BeveOur objective was to evaluate the effect of substituting a serving per day of water for one of another beverage, or group of beverages according to the Spanish Society of Community Nutrition  recommendations, on obesity incidence and weight change in a Mediterranean cohort, using mathematical models.The Spanish project Seguimiento Universidad de Navarra (University of Navarra Follow-Up) (SUN) is a multipurpose, dynamic and prospective cohort, designed to establish relationships between diet and chronic conditions, such as obesity. All the participants are university graduates. Recruitment started in December 1999, and is permanently open. When participants are invited to enter the study, they receive, with the baseline questionnaire, a letter explaining the methodology, aims, data management and all information about the SUN cohort, including how to withdraw from the study. Informed consent was implied by the voluntary completion of the baseline questionnaire. Every two years, information from participants is collected by mailed or e-mailed questionnaires. When participants do not return a questionnaire, we send them a short exit questionnaire. The Research Ethics Committee of the University of Navarra approved the study. Further details of the study design and methods have been published elsewhere .n = 300). Therefore, the final number of participants for this analysis was 15,765.Up to March 2013, 21,686 participants were recruited. Among them, we excluded 2046 participants with total energy intake beyond predefined limits  was included in the baseline questionnaire. It was previously validated in Spain and recently re-evaluated ,23. The All beverages reported were grouped according to SENC recommendations  and othe2 at baseline and equal to or higher than 30 during the follow-up. Average change in body weight was assessed between baseline and the four-year follow-up questionnaire, subtracting the first from the second.Weight information was self-reported at baseline and in the follow-up questionnaires every two years. BMI was calculated as weight in kilograms divided by the square of height in meters. The validity of these measures has been assessed in a subsample of this cohort . The mear = 0.51; 95% CI 0.232 to 0.707) [The baseline questionnaire also inquired about socio-demographic factors, medical history, and health-related habits. To quantify physical activity during free time, we assessed time spent in 17 activities at baseline, in order to compute an activity metabolic equivalent index (MET). Each activity was assigned a multiple of resting metabolic rate (MET score)  and timeo 0.707) . Adhereno 0.707) . When th2), physical activity (MET-h/week), smoking habit , personal and family history of obesity, following a special diet, adherence to the Mediterranean dietary pattern, snacking between meals, weight change during the five years prior to baseline, and total energy intake from other sources than the exchanged beverages. When the analyses were carried out for group of beverages, we additionally adjusted for servings per day of other groups. Interactions were assessed using the Wald test for the two product terms between each beverage involved in the substitution and the characteristic evaluated.We evaluated the association between substituting one serving per day of water for each beverage or beverage group (increasing one serving of water and decreasing one serving of the beverage/group in question) and incident obesity using mathematical models . These rR2 change. Furthermore, we estimated their contribution related to total fluid intake as the mL consumed from each beverage divided by total fluid intake (%).In order to calculate the contribution of each beverage (or group of them) to the between-person variability in fluid intake, we conducted nested regression analyses after a stepwise selection algorithm. The contribution of each beverage is shown in the cumulative 2; excluding participants with a total energy intake under or over limits of daily calorie requirements, which is the basal metabolic rate (BMR) value multiplied by a factor depending on the activity level. We excluded people under BMR*1.2 and/or over BMR*1.9. BMR was estimated with the Mifflin–St Jeor equation [p-values presented are two-tailed; p < 0.05 was considered statistically significant. Analyses were performed using STATA/SE V.12.1 .To ensure that the method of dealing with missing values did not influence the results, we performed a sensitivity analysis using multiple imputation technique to impute missing values in weight during follow-up. We imputed weight change over four years according to sex, age, BMI, physical activity, smoking status, if a special diet was followed, adherence to Mediterranean diet and snacking between meals, generating 20 complete datasets. Furthermore, we refitted the models in different sensitivity analyses to assess the robustness of our results: excluding participants who answered less than 10% of beverage items; excluding participants with weight change in previous five years due to pregnancy; excluding participants with personal history of obesity; excluding participants with family history of obesity; excluding participants with baseline BMI ≥ 27.5 kg/mequation . Analyseequation . All p-v2 (SD: 3.5). Participants in the fifth quintile of water consumption compared to those in the first quintile were more likely to be women, younger and with a personal and/or family history of obesity; more participants in the top quintile of water intake had lost weight in the previous five years and their total energy intake was higher; on average, they consumed snacks between main meals more frequently, they were more likely to have followed a special diet and had better adherence to Mediterranean diet; they had higher fibre intake and their intake of almost every nutrient analyzed was higher, except for alcohol, which was slightly smaller; they were more active, spent less time having a sleeping siesta and were less prone to be a former smokers than those in the first quintile. According to other beverage consumption, they drank more servings of beverages included in LNCBs, spirits, and milk, juice and sugared coffee groups, and less SSSBs and wine, although the differences were small.Our analysis included a total of 16,065 participants (6455 men and 9610 women). The principal baseline characteristics of participants across quintiles of water consumption are presented in There were 873 incident cases of obesity during the follow-up. The incidence of obesity was estimated according to the substitution of one of the beverages gathered in the questionnaire by one glass of water per day, in crude and multivariable-adjusted models . The subWhen we estimated the odds ratio additionally adjusted for the consumption of other beverage groups, the statistical significance was maintained for the beer group (OR 0.84 (95% CI 0.71 to 0.98)) but it was no longer significant for the group of SSSBs and spirits (OR 0.92 (95% CI 0.82 to 1.03)) or wine (OR 0.94 (95% CI 0.87 to 1.02)). We did not observe any significant association with obesity for people in the fifth quintile of water consumption versus those in the first quintile (OR 1.03 (95% CI 0.82 to 1.30)).p = 0.05), but this was not observed for the substitution of LNCBs neither for SSSBs and spirits (OR 0.94 (95% CI 0.83 to 1.06)) nor for wine (OR 0.96 (95% CI 0.88 to 1.05)).SENC recommends the use of water or, if not, low/non-caloric beverages instead of caloric options. For that reason, we performed the same analysis but replacing by LNCBs. When low/non-caloric options were assumed to be used to replace a serving of beer, this change was associated with a lower incidence of obesity (OR 0.84 (95% CI 0.71 to 1.00) p = 0.05) , this substitution is also statistically significant, decreasing 187 g  b. When wR2 = 0.715) in our population  and also the main source of variability (pulation .p = 0.65). Furthermore, this replacement was associated with a lower incidence of obesity in those who were less active (OR: 0.83 (95% CI 0.73 to 0.95)) but not among participants who practiced more physical activity (OR: 1.02 (95% CI (0.82 to 1.26)). Again, the interaction was not statistically significant (p = 0.16). Stratifying by sex, there was a difference as well for the substitution for wine group (OR: 1.23 (95% CI 0.95 to 1.59) for women, and OR: 0.92 (95% CI 0.85 to 1.00) for men), but the interaction was not significant (p = 0.11). We performed several sensitivity analyses in order to discard potential biases due to our assumptions and to test the robustness of our results . When weThe results from the present study indicate that replacing a serving of water for beer or sugar-sweetened soda beverages at baseline  was associated with a lower incidence of obesity, and, in the case of beer, this potential intervention would reduce average weight in a four-year period. Furthermore, water was the main source of fluid consumption among all beverage items as well as the main source of variability in our population.It is assumed that excessive alcohol consumption increases the risk of obesity because it is a source of energy per se and because energy from alcohol is not substitutive for the calories coming from food; instead, they are extra added calories . Our res2 [The positive correlation between beer consumption and weight gain and the risk of being overweight or obesity has been already published by our group for people whose BMI at baseline was lower than 25 kg/m2 . However2 .Nothing is stated in the SENC recommendations about spirits. We decided to classify it in the occasional consumption group with SSSBs, allowing a maximum of one serving per week. We did not observe any correlation between the substitution for a serving of spirit with a serving of water neither in incidence of obesity nor in weight change. This finding may explain that the previously reported effect on weight gain and the risk of obesity by the group composed of beer and spirits could be attributable only to beer , and in p = 0.062). Furthermore, for the replacement of a serving from the group of both types of wine, we found an association for obesity incidence, but not for weight change in a four-year period. In the Danish study previously described, they found a U-shape relationship between wine consumption and waist circumference [The SENC suggests that beer and wine consumption should both be moderate. However, deriving from our previous investigations where we did not observe a correlation between wine intake and changes on body weight or the risk of obesity , we decimference , so maybp for trend = 0.05)). Our results suggested that this replacement could be associated with a lower incidence of obesity. Olsen and Heitmann [Many studies have examined the association between intake of SSSBs and later weight change, and most of them suggested that their consumption increases the risk of obesity . We haveHeitmann  informedHeitmann . Thus, tHeitmann . FurtherHeitmann . This efHeitmann ,45. The SENC suggests always drinking water, or, if not, low/non-caloric beverages to control body weight. When we analyzed the effect of substituting one serving of low/non-caloric beverages for one serving of beer, we could observe a correlation with a decrease in body weight and in obesity incidence. However, in replacement of one serving of LNCBs for one of the group in which SSSBs are gathered, we have not seen any association nor with reduction of weight neither in the risk of obesity. It was also not observed for obesity incidence when the replacement was made for a wine group. Available evidence is not very clear about the topic of diet soda beverages and weight loss ,47. StudWe did not find any correlation between the replacement of water for any type of juice analyzed with weight change in a four-year period, nor with the incident of obesity. In a previous study, we found a 16% (OR 1.16 (95% CI 0.99 to 1.36)) increase in body weight when we compared people in the fifth quintile of sugared fruit juice consumption (six or more servings per week) with those in the first quintile (less than one serving per week) . Three AOur analysis did not find any relationship between the substitution of water for any dairy product and weight gain or obesity. These findings are consistent with the results obtained from other cohorts ,54,55 anThe strengths of our study include its prospective design, which avoids the possibility of reverse causation bias potentially present in other types of studies, the previous validation of the questionnaires used, the use of a wide range score for beverage consumption, and a relatively large sample size. Additionally, we were able to control for multiple possible confounding variables and conducted various sensitivity analyses. The generalizability of the findings may be considered to be weak because the SUN cohort participants are all university graduates, and therefore the sample is not representative of the Spanish population. However, this enhanced the internal validity of our study because of the homogeneity of the population and the high education level and socioeconomic status, which reduces potential confounding.Some potential limitations should be noted, as we used self-reported information. Although there is a tendency for participants to overestimate their height and underestimate their weight, self-reported weight and height was found to be valid in our cohort . BeveragThis study found that replacing one sugar-sweetened soda beverage  or beer with one serving of water per day at baseline was related to a lower incidence of obesity and to a higher weight loss over a four-year period time in the case of beer, based on mathematical models. Nevertheless, longitudinal investigations based on real interventions are needed to confirm these potential effects. As obesity carries a high risk for the development of other diseases like diabetes or cardiovascular disease, the possible effects of the substitution for these beverages with water is an important target to consider in future public health research.


Reliable exposure factors are essential to determine health risks posed by chemicals in consumer products. We analyzed five risk-concerned product categories  for 13 products  considered to be of high risk in order to determine exposure factors via web surveys and estimation of amount of product. Among the 3000 participants (1482 (49%) men) aged ≥19 years, drain disinfectants were used most frequently (38.2%); the rate of usage of the other products ranged between 1.1–24.0%. The usage rates for the consumer products differed by sex, age, income, and education. Some consumer products such as car and lens anti-fogging products, chlorine-based disinfectants, fabric repellents, and drain disinfectants were regularly used more than once a month, while car dye products, air conditioner disinfectants, insect repellents for food, and wood preservatives were not regularly used owing to the specific product purposes and seasonal needs. Our results could be used for managing or controlling chemical substances in consumer products and conducting accurate exposure assessments. People commonly use a variety of consumer products for household cleaning and personal care, as they improve sanitary conditions in daily life. However, consumer products are composed of various chemical substances, which act as active ingredients, solvents, preservatives, and additives. There is a growing concern that people are inevitably exposed to multiple chemicals through the use of consumer products ,2. PreviIn Korea, the potential adverse effects of consumer products were highlighted when a consumer applied disinfectants to a humidifier to sterilize a water tank. In 2011, an unidentified case of fatal lung disease was reported, probably caused by the hazardous chemicals present in these disinfectant products . AccordiTo conduct exposure assessments of consumer products, information on exposure factors  are necessary . SeveralExposure factors may vary by country ,16,17. AThe purpose of this study was to develop a national representative database of exposure factors for the risk-concerned products newly identified in June 2015 in Korea. To obtain information on exposure factors, 13 products were investigated for frequency of use, amount used per application, and daily consumption of products. These exposure factor data determined in this study could be useful in establishing safety guidelines for products and conducting accurate exposure and risk assessments.A total of 3000 people were selected for inclusion in this study in order to obtain a substantial number of users for each product. To ensure that the study population was representative of the actual product users in Korea, the exposure factor survey was conducted in 15 metropolitan areas and provinces, including rural areas in Korea. The number of participants included in each province was based on the proportional population of the province relative to the total population, while considering sex and age balances. Within each province, survey locations were randomly selected, and for each survey location, the number of participants was fixed for each metropolitan area. When a participant did not want to participate in this study, new participants were recruited until the required number of participants in each survey location was reached.A web questionnaire survey was administered between June and July 2015. Before starting the web survey, an e-mail was sent to potential participants. The email addresses were obtained from a national survey company and an online shopping voucher was offered in support of participation in the study. If the participant agreed to take the survey, a web link was sent to them in order to start the survey. All subjects gave their informed consent for inclusion before they participated in the study. This web survey collected current information on the exposure factors for five product categories  and 13 products , a lens anti-fogging product (tablets), a fabric repellent (trigger spray), an insect repellent for food (tablets), and a wood preservative (aerosol spray)).The questionnaire collected demographic information , frequency of use, amount used per application, duration of use, and protective action . Participants had to select from four options , and then fill the frequency of use  by selected duration. Participants additionally had to indicate the amount used per application. Different questions were used for the specific type of application. For trigger sprays, the number of squeezes per application was determined. For aerosol sprays, the spraying time per application was queried. For liquid types, the number of products used was estimated with reference to a 50-mL glass, the most popular glass size used for liquid in Korea . For penFor validation of the questionnaire, if a participant chose extreme values or left several questions blank, an additional questionnaire was conducted. After that, the questionnaire was validated (per the difference between the first and second questionnaire). If there was a large difference, the participants were excluded and new participants were recruited.Experiments were conducted to estimate the accurate amount of product used per application. The 13 products included among the target products in this study were purchased online and from supermarkets based on the sales rankings at a large Korean shopping mall . The products purchased were assumed to be commonly used by Korean people. Mass generation (g/s) or amounts of products used (g/unit or g/new product) were estimated by application type. To estimate mass generation for spray products (trigger and aerosol spray), a report from the Dutch National Institute for Public Health and the Environment (RIVM) was used as a reference . In the For liquid products, the volume of the product used was measured using a 50-mL glass, the most popular glass size used for liquid in Korea. For pen products, the differences in the mass before and after use of the product were measured by using depictions of four coins of different sizes . To checFor the purpose of this study, participants were stratified into three age groups: young (19–29 years), middle-aged (30–49 years), and older (≥50 years). Additionally, monthly income was categorized into three groups: low (<$USD 2000), middle ($USD 2000–4000), and high (>$USD 4000). Finally, participant education levels were categorized as follows: low (middle school or less), medium (high school), and high (college or greater). The product use rate was defined as the proportion of participants who reported the use of consumer products at least once in the last 12 months.p < 0.05 was considered to indicate statistical significance.All statistical analyses were conducted using R version 3.3.2 . Frequency tables were constructed to assess the rate of product use. Chi-square tests were used to analyze the differences in the rates of usage based on sex, age, education, and income. The frequency and duration of use were calculated using data from the web survey. The amount used per application (g/use) was calculated by multiplying the use patterns  obtained from the web survey by mass generation or amount of product obtained from the estimation of procedure. The consumption per day (g/day) was calculated by multiplying the individual frequency of use (use/month) by the individual amount of use per application (g/use) and the conversion factor (month/30 days). n = 1518) were women. Overall, 25.2%, 63.4%, and 11.4% of the participants were young, middle-aged, and older respectively. Additionally, 12.5%, 35.0%, and 52.5% of the participants were classified as belonging to low-, middle-, and high-income levels, respectively , whereas the proportions of individuals in each educational and age group significantly differed by sex (p < 0.01). Among men, the middle-aged group was the largest (67.6%) and the younger and older groups comprised 17.9% and 14.5% of participants, respectively. Among women, the younger and older groups comprised 32.4% and 8.3% of participants, respectively, and the middle-aged group was the largest . Participants in the elderly group used anti-fogging products most frequently (p < 0.05). Moreover, the higher earning and more educated participants were more likely to use anti-fogging products than those categorized as belonging to low and middle/medium income or education levels . Like anti-fogging products, the older age group used car dye products most frequently. Although higher earning participants were more likely to use car dye products than the low and medium income groups, those in the low education group used these products most frequently (p < 0.05).Dye products were used by 14.9% of the participants. Men used car colorant products more often than women (p < 0.01). However, men were more likely to use air conditioner disinfectants (p < 0.01). The rate of air conditioner and chlorine-based disinfectant use was higher among the older group than the other age groups (p < 0.05). For all disinfectant products, participants who earned more were more likely to use disinfectant products (p < 0.01). Furthermore, for drain disinfectant product and air conditioner product, highly educated participant more likely to use the products (p < 0.05).The rate of disinfectant product use ranged 5.6–38.2%. With the exception of chlorine-based disinfectants, the use of disinfectants significantly differed by sex. Women were more likely to use drain disinfectants  were used most frequently among the participants of this study, whereas wood preservatives (aerosol) were rarely used . In geneParticipants were asked how long it took them to use the product from beginning to end. In general, the duration of use for aerosol and trigger sprays was longer than that for tissue and tablet products. Among all products, car anti-fogging products (film) had the longest duration of use, while fabric and tablet repellents (both tablets) had the shortest duration of use.Participants were asked if they wore gloves or masks, ventilated rooms, and/or read product instruction manuals as protective measures. Seventy five percent of the participants used gloves when they used wood preservative products (aerosol), whereas for repellent products, the proportions of participants who used gloves ranged 13.4–22.5%. In general, when the participants used trigger or aerosol sprays, they were more likely to use masks and ventilate the room. Over 50% of participants claimed to read product instruction manuals for the majority of the products .The aim of this study was to create a national exposure factor database for risk-concern products designated by the MOE in June 2015. This study focused on the frequency of use and amount of use at each application, which is necessary for accurate exposure assessments.In April 2015, the MOE in Korea enforced its Notice No. 2015-41, setting regulations for safety and labelling standards for eight product categories designated as risk-concerned products. These products included the following: cleaning products, detergents, bleach, fabric softeners, coating products, air fresheners, adhesives, and deodorants . At thatIn previous studies that investigated exposure factors for household and personal care products, the actual users of the consumer products were considered when recruiting participants ,15,22. ITo obtain sufficient numbers of participants who consumed each product, 3,000 participants were recruited for inclusion in this study. One study found that as sample sizes increased, the exposure factors became more similar to those of the parent population for the majority of the consumer products, and a sample size of >50–100 was recommended for each product . Based oThe frequencies of usage for the products investigated differed by country . Insect This study reported that trigger and tablet disinfectants in Korea were used more than twice a month . HoweverIn general, when consumers use spray or liquid products, they might use gloves, a mask, or ventilate the area due to dermal contact and odor. A study investigated protective action taken to reduce exposure during use of cleaning, automotive care, and surface protection products . In thatSeveral studies have examined personal hygiene and cosmetic product exposure factors ,15,28,29To protect people from hazardous chemicals in consumer products, exposure and risk assessment are crucial tools. In particular, exposure assessment is a vital step of risk assessment for people exposed to hazardous chemicals from using consumer products. To estimate chemical exposure, the deterministic method is widely used ,30,31. WThere were some limitations. In this study, potential seasonal variations in product use were not considered; therefore, the frequency of use or amount used might have been affected by the study period. However, disinfectant products, repellent products, and preservative products are used more frequently in summer than in winter. Conducting surveys in summer guarantees that the exposure factors of these products were not underestimated. Face-to-face surveys often generate data of superior quality compared to that with web surveys. However, owing to the magnitude of the participant numbers enrolled, as well as a limited budget, it was not feasible to conduct in-person surveys. We believe that since the participants were aged ≥19 years, the frequency of use and amount of the products use per application could be recorded.This study investigated recent exposure factors for five categories and 13 products commonly used in daily life in Korea. The exposure factors were determined via a web survey including over 3000 people in Korea. The result showed that exposure factors can be different for the same product based on application. Therefore, when exposure assessments are conducted, type of application must be considered. The exposure factors investigated in this study can be used for managing or controlling chemical substances in consumer products and conducting accurate exposure assessments. The number of consumer products used during one’s lifetime have increased; therefore, further research on exposure factors for consumer products should be conducted.


The Gambian Bone and Muscle Ageing Study is a prospective observational study investigating bone and muscle ageing in men and women from a poor, subsistence farming community of The Gambia, West Africa. Musculoskeletal diseases, including osteoporosis and sarcopenia, form a major part of the current global non-communicable disease burden. By 2050, the vast majority of the world’s ageing population will live in low- and middle-income countries with an estimated two-fold rise in osteoporotic fracture. The study design was to characterise change in bone and muscle outcomes and to identify possible preventative strategies for fracture and sarcopenia in the increasing ageing population. Men and women aged ≥40 years from the Kiang West region of The Gambia were recruited with stratified sampling by sex and age. Baseline measurements were completed in 488 participants in 2012 who were randomly assigned to follow-up between 1.5 and 2 years later. Follow-up measurements were performed on 465 participants approximately 1.7 years after baseline measurements. The data set comprises a wide range of measurements on bone, muscle strength, anthropometry, biochemistry, and dietary intake. Questionnaires were used to obtain information on health, lifestyle, musculoskeletal pain, and reproductive status. Baseline cross-sectional data show preliminary evidence for bone mineral density and muscle loss with age. Men had greater negative differences in total body lean mass with age than women following adjustments for body size. From peripheral quantitative computed tomography scans, greater negative associations between bone outcomes and age at the radius and tibia were shown in women than in men. Ultimately, the findings from The Gambian Bone and Muscle Ageing Study will contribute to the understanding of musculoskeletal health in a transitioning population and better characterise fracture and sarcopenia incidence in The Gambia with an aim to the development of preventative strategies against both. Health priorities in low and middle-income countries (LMICs) have until recently focused on infectious diseases. As these populations undergo social, economic, and environmental transition, non-communicable diseases (NCDs) of older age are becoming prevalent. As life expectancy is increasing, within 35 years the vast majority of the world’s older population will live in LMICs, with a consequent increase in associated NCDs , 2. The The first study to investigate bone health in The Gambia was over 30 years ago and used single-photon absorptiometry to measure the radius of women aged 18–85 years and showed that Gambians had a 5.6% lower bone mineral content (BMC) compared to Caucasian women . At thatDual energy X-ray absorptiometry is used to measure areal bone mineral density (aBMD) as a predictor of fracture risk in older people from populations at high risk of osteoporosis . HoweverUnderstanding musculoskeletal health and better characterising fracture incidence in The Gambia may help in the development of preventative strategies against the predicted rise in osteoporotic fracture and sarcopenia. Ultimately, this would improve quality of life and reduce consequent morbidity and mortality associated with the conditions in the ageing population in The Gambia. Therefore, the Gambian Bone and Muscle Ageing Study (GamBAS) cohort was established to prospectively study musculoskeletal ageing in rural Gambian men and women. The primary aim of the study was to determine change in bone mineral density in men and women, the secondary aims were to characterise change in muscle, determine fracture and sarcopenia incidence, and finally to determine the biochemical and hormonal predictors of the detected changes in bone and muscle. This manuscript presents a general cohort description and findings from the baseline data.2 district in the Lower River Region of Kiang West  established a permanent field station in Keneba (MRC Keneba), which is located in the middle of a 750 kmt Figure . The popt Figure , and resAll men and women aged 40 years and over and residing within the four core survey villages of Kiang West were identified using the KWDSS Figure  3). Pot. Pot3). All eligible participants aged 40 years and over were given a verbal explanation of all the elements of the study and completed a screening questionnaire. If eligible, participants were given an information sheet and asked to sign or thumbprint an informed consent form and were enrolled in the study. Recruitment commenced in March 2011 and baseline measurements in 488 individuals were completed over 18 months  after the baseline measurement and were completed by the end of 2015 , weight (kg), mid upper arm circumference, and four skinfold measurements were measured . Blood pressure was measured using the OMRON 705IT blood pressure monitor during sitting, supine, and standing, and systolic and diastolic readings were recorded. A musculoskeletal and general health questionnaire collected data on: activities of daily living , mental health, diagnosed illnesses , medication use, falls, fractures, musculoskeletal pain (located on specific body parts), lifestyle , social demographics , and medical history . In women, there were also questions on menstrual cycle, breast-feeding history, pregnancy, parity, and menopausal status. Self-reported information on the use of medications and chronic medical conditions were collected.A 20 mL sample of venous blood was drawn from each participant in the early morning after an overnight fast; both lithium heparin and ethylene diamine tetra acetic acid (EDTA) plasma samples and an EDTA cell pellet for DNA extraction were stored at −80°C. Blood volume and all laboratory processing details were recorded on a data collection form. A 2-h fasting urine sample was collected, processed, and acidified and non-acidified samples were stored at −20°C. The 24-h urine samples were stored at −20°C in acidified and non-acidified aliquots; a further spun aliquot was stored at −80°C for assessment of microalbuminuria. To date, markers of calcium, vitamin D, bone metabolism, and kidney function have been measured.A 2-day prospective weighed dietary assessment was conducted in the participant’s home at a time close to the measurement day by trained and experienced fieldworkers. This method has been used in previous studies of children, adults, and older people in Kiang West , 19. Bri2), BMC (g), and bone area . Body composition outcomes were as follows: total body fat mass (kg), total body lean mass (kg), and appendicular lean mass (kg). Fat and lean mass were also subdivided into the following regions: android, which is the lower abdominal area of the trunk between the ribs and the pelvis; gynoid, which is the region that encapsulates the hips, upper thighs, and buttocks. Lateral vertebral assessment (LVA) scans were obtained to determine whether there was any spinal degeneration, assessing osteoarthritic changes (osteophytes). Vertebral fractures were assessed semiautomatically in the GE Lunar software. All scans and fractures were assessed by a single reader, trained by an expert consultant musculoskeletal radiologist , total vBMD , cross-sectional area ; 14, 33, 38, and 66% site: CSA (mm2), cortical vBMD , cortical BMC , Ct.Area (mm2), Ct.Thickness (mm), medullary area (mm2), stress strain index , cross-sectional moment of inertia , periosteal circumference (mm), endosteal circumference (mm); and 66% site: cross-sectional muscle area  and muscle density (mg/cm3). The range of CVs of duplicate measurements of bone outcomes in 62 Gambian adults was 1–4% for the radius and 1–3% for tibia measurements. The pQCT scans were also used to identify the presence or absence of vascular calcification at the 4, 14, 38, and 66% sites of the tibia  software version 6.20c, as previously described . MeasureTo assess lower limb muscle function, a Leonardo Ground Reaction Force Platform  was used as previously described –26. PartGrip strength was measured using a dynamometer  . The indEthics was obtained from the MRC Unit The Gambia Scientific Co-ordinating Committee (SCC) and joint Gambian Government/MRC Unit The Gambia Ethics committee (SCC#1222). All participants provided written informed consent. All procedures were carried out in accordance with the Declaration of Helsinki . If any Power calculations for GamBAS were determined to detect within individual change in femoral neck aBMD as it has the worst precision of all the sites measured with DXA. A sample size of 66 would be needed to detect a 1% change per annum over a random follow-up interval between 1.5 and 2 years later with a precision of 30% in the expected rate of change . To detect a 2% change over the same time with 30% precision, we would need a sample size of 16, or 37 for a precision of 20% in the expected rate of change. Thus, a minimum of 30 participants per 5-year age band will be sufficient to identify rates of change within an individual of 1–2% per annum at the hip with confidence. In the other DXA and pQCT regions, which can be measured with more precision, smaller rates of change will be detectable with this number of participants. These rates are similar to or less than those observed in Caucasian populations during ageing and are biologically plausible and clinically relevant in terms of fracture risk . StratifKiang West residents are mainly Muslim ; GamBAS p < 0.0001) and total body lean mass . In women, anthropometry and body composition outcomes all had significant negative associations with age, with the greatest difference observed in weight . Men had greater negative differences in total body lean mass with age than women following adjustments for weight and height . Waist circumference and body fat outcomes were not different with age in both men and women.Baseline data describing anthropometry and body composition in men and women are shown in Tables R2 = 0.41, interaction p < 0.0001).Dual energy X-ray absorptiometry bone parameters in men and women are displayed in Tables Z-scores for aBMD than the reference for both the lumbar spine and hip. The mean (SD), range of those Z-scores are: lumbar spine L1–L4, women −2.0 (1.1), −4.7 to 1.5; men −1.5 (1.3), −4.4 to 3.9 and for femoral neck, women −1.1 (0.9), −3.3 to 2.0; men −1.0 (0.9), −3.2 to 1.7. Peripheral vascular calcification in the lower-limb was visible in 16% of the population. There were no sex differences in the presence of peripheral vascular calcification: 19% in men vs 15% in women, p = 0.195.From the LVA scans, 9% of GamBAS participants had moderate or severe vertebral fractures (as defined by GE Lunar software), and 14% had spinal degeneration (osteophytes present). Hip fractures were self-reported; 3% of women and 0.4% of men reported a hip fracture, or fracture-like injury. Comparing the GamBAS participants to the manufacturers US Black reference database showed the population to have lower age, and gender-matched GamBAS is the first and largest prospective longitudinal study in West Africa in which quantitative measurements of bone and muscle have been collected. The initial findings have highlighted that women have a greater degree of aBMD loss compared to men, yet have less loss of muscle. Analyses of longitudinal data will allow more accurate quantification of this loss and investigation of the mechanisms driving these effects. Data from DXA demonstrate that height-adjusted BA increased with age at the total hip and radius in both men and women; however, pQCT revealed that the increase in cross-sectional BA at the radius was only evident in women. The decrease in cortical thickness in women suggests this increase in cross-sectional BA may be a biomechanical adaptation to loss of bone. However, whether this is indicative of a cohort effect or age-related periosteal apposition will be confirmed in analysis of prospective data. In agreement with our previous work, the magnitude of age-differences is similar to that observed in other populations, where fracture incidence is higher.Z-scores we report show that Gambian men and women had osteoporosis at the lumbar spine compared to the manufacturer’s reference US Black population. However, this population may not be the most appropriate one to use as a reference and may have led to overestimating the prevalence of osteoporosis in the population  from age-related changes from the reported cross-sectional data. However, this will be possible with the longitudinal data. The majority of recruits were from the four core villages which may be healthier than the other villages as they are located closer to MRC Keneba where the residents are able to receive medical care. This, and that we only needed to recruit 30% of the Kiang West residents, to achieve our target sample size, may cause bias in our findings. In The Gambia, traditional bone-setters tend to be used for the treatment of musculoskeletal disorders, including fractures, and the information is not added to clinic medical records. Therefore, the hip fracture data obtained are based on self-report and may be inaccurate or incomplete because verification through radiograph reports is not possible. The vertebral fracture data are from GE Lunar Prodigy scans; in later follow-up using the higher-resolution iDXA, we will be able to more accurately assess vertebral fractures. There was difficulty in obtaining medical records from the participants who were not living in the four core villages of Kiang West. This is a homogenous population with little variance in lifestyle characteristics. When comparing to other regions, sub-Saharan Africa or the globe, it will be important to investigate further the effects of environment such as physical activity levels and occupation. Finally, Kiang West is one region of The Gambia and the data may not be generalizable to urban areas of the country, to other West African countries or to the remainder of the continent.In conclusion, the GamBAS cohort provides important information on the aetiology of ageing in a rural sub-Saharan setting. This is crucial as the ageing population increases and with it, NCD burden.The MRC has a long and successful history of conducting collaborative research and we welcome specific proposals for new collaborations. Data sharing is available through collaborative agreements and initial enquiries should be made to the Principal Investigator Kate Ward (kw@mrc.soton.ac.uk).Ethics was obtained from the MRC Unit The Gambia Scientific Co-ordinating Committee (SCC) and joint Gambian Government/MRC Unit The Gambia Ethics committee (SCC#1222). All participants provided written informed consent. All procedures were carried out in accordance with the Declaration of Helsinki . If any KW, AP, GG, IS, AF, LJ, and YS designed the study; KW, AF, IS, GG, LJ, and YS contributed to the data collection; AZ and KW analysed the data from the study; AZ, KW, AP, IS, and GG interpreted the data from the study; AZ, KW, AF, and AP drafted the manuscript; AZ, KW, AP, GG, IS, AF, LJ, and YS revised the manuscript; and KW gave the final approval of the version to be published.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The prevalence of congenital cystic adenomatoid malformation among fetuses still varies in different studies in China. The present meta-analysis was intended to evaluate the pooled prevalence of fetuses in China. Four English  and four Chinese  databases were searched from inception to July 2016. Meta-analyses were performed using Stata (version 12.0), with prevalence and corresponding 95% confidence intervals using the random effect model. Five studies with 393496 fetuses were chosen for this meta-analysis. The overall pooled prevalence was 4.01/10000 (2.03/10000 - 6.00/10000) fetuses. Sensitivity analysis revealed that the results were stable, and Begg’s test and Egg’s test showed no potential risk of publication bias. This is, to our knowledge, the first study to systematically evaluate the literature of the prevalence of congenital cystic adenomatoid malformation among fetuses in China. Results showed that the prevalence among fetuses should be considerable. A large-scale multicenter study on the epidemiology across different areas in China is required. Congenital cystic adenomatoid malformation (CCAM), also called congenital pulmonary adenomatoid malformation (CPAM), is the most common causative fetal lung lesions , firstlyTherefore, we firstly present a pooled prevalence of CCAM for fetuses by conducting a systematic review of the literature published in China. Secondly, we also explore the prevalence according to different characters such as geographic distribution and maternal age in the subgroup.Figure Studies were conducted in mainland China   and central (8.93/10000) areas, and low in south areas 2.81/10000). In the three number groups, the prevalence was lower (2.81/10000) for the studies with sample size over 100000, and higher in those with 10000–100000 (8.39/10000) and less than 10000 (7.93/10000) individuals. Higher quality score had a higher prevalence than the lower quality score (5.59/10000 vs. 2.23/10000). All of the subgroups were tested significant heterogeneity  and Egg’s test  showed no potential risk of publication bias.Funnel plots and the method of Begg’s and Egger’s test were performed to assess the publication bias of the study. Although the funnel plot was slightly asymmetrical Figure , both BeTo our knowledge, the analysis provided the first comprehensive, current estimated of the China prevalence of CCAM among fetuses as well its major epidemiological characteristics. In the current meta-analysis, a total of 393496 fetuses were included. It indicated that, among fetuses in China, the prevalence of CCAM ranged from 1.14/10000 to 16.09/10000, and the pooled prevalence was 4.01/10000.It was reported that the prevalence of CCAM in developed country, such as Canada, was 1/25000 to 1/35000 among fetuses , 11. HowIn this study, we also found that the prevalence of CCAM in north areas (7.93/10000) was higher than south areas (2.81/10000). It is very important to identify the geographical environmental risk factors of CCAM in the study area. The regional differences were attributed to a variety of reasons, such as economic status, health service status, diagnose level, ethnicity, and environmental pollution. As the largest developing country, China has achieved rapid economic development and urbanization process in east or coastal area; on the other hand, most of the western regions are still relatively poor.More economically developed areas have better access to health care facilities. In this system review, only five studies reported the prevalence of CCAM among fetuses. All of them are from the eastern developed areas. The lack of balance and representatively made it extremely difficult to tell if the regional differences in prevalence were true or just a results of sampling bias. Therefore, it should be cautious and had better consider the confidence interval rather than the pooled result in the geographical distribution results.Moreover, all of the five studies included in this meta-analysis were retrospective observational studies from out-patient data. None of them reported the potential factors which may influence the result except to the main information. Any influence of the above mentioned factors, including economic status, diagnose level, ethnicity, on regional variation of CCAM incidence is just speculative and not supported by the presented data. Then, a larger-scale multicenter, epidemiological study is needed for more persuasive analysis in the CCAM among fetuses in China.There was only one study with sample size more than 100000 in this meta-analysis. Therefore, one potential reason for those heterogeneous findings may be that small sample sizes are more likely to lead to instable results, especially in the prevalence. Systematic review and meta-analysis provide a scientifically logical way to synthesize epidemiological data. Meta-analysis is a systematic approach to identifying, appraising, and synthesizing the results of relevant studies to make conclusions about a body of research, which could enhance the statistical power and draw a more reliable conclusion in comparison to a single study . HoweverThe study was strictly followed the MOOSE guidelines for reporting systematic reviews and meta-analysis, strict application of inclusion and exclusion criteria, using a critical appraisal of study quality, and up-to-date estimates using a DerSimonian-Laird random-effects model. Nevertheless, there were limitations due to the heterogeneity, and it should be considered when interpreting the findings of this study.First, all of them were located in eastern China, while, data for western China was lacking, which meant that geographical distribution was unbalanced and the sample was not sufficiently representative. Therefore, it should be cautious and best to consider the confidence interval rather than the pooled result in the geographical distribution. Second, the diagnosis of CCAM may be dependent on the skill, experience and bias of the pathologist. Although all of the included studies were diagnosis using high resolution ultrasound during pregnancy and clinical-autopsy in fetus corpses, and each study may contain non-CCAM lung lesions that were diagnosed as CCAM. The results may be affected by the diagnosis bias. Third, heterogeneity was found in our meta-analysis of prevalence of CCAM, which may be attributed to the differences in sample size and areas. Last, because of the limited included studies, this study could not consider the interaction effect between different factors, such as maternal age, education, occupational exposure, ethnicity, lifestyle, economic level, and environmental pollution. Therefore, a large-scale multicenter study on the epidemiology of CCAM among fetuses across different areas in China is required.In conclusion, our study pooled data from 393496 fetuses across five studies to provide the first estimates that reflect the present China burden and epidemiological characteristics of CCAM among fetuses. According to the results of this meta-analysis, the prevalence of CCAM among fetuses should be considerable in China.http://www.crd.york.ac.uk/PROSPERO/), and the registration number is CRD42016045413. The present research performed a systematic review, in accordance to the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies [The systematic review protocol has been published in the PROSPERO International Prospective Register of systematic reviews  and four Chinese  databases for studies containing the data on the prevalence of CCAM among Chinese fetuses population, using a combined search strategy that included the following search terms: “congenital cystic adenomatoid malformation”, “CCAM”, “congenital pulmonary adenomatoid malformation”, “CPAM”, “prevalence”, “incidence”, “epidemiology”, “survey”, “China”, and “Chinese”. The databases were searched from their inception to July 2016 and the language restriction was not applied. The reference lists of retrieved articles were manually screened, and the results were also available to obtain the additional data by contacting original authors.Original peer-reviewed publications were selected by two authors if they included: 1) > 1000 Chinese fetuses; 2) reported CCAM fetuses or newborns; 3) CCAM was diagnosed using high resolution ultrasound during pregnancy and confirmed after delivery using clinical-autopsy or Computed Tomography (CT). Studies were excluded based on the following criteria: 1) small sample size (less than 1000 fetuses), letters, reviews and editorials; 2) the full data was not accessible even after request from the corresponding/primary author. If multiple publications covered the same study, the most comprehensive one reporting the largest sample size was considered. This is a meta-analysis and approval by ethics committee or written consent could not require the extraction of data on the including studies.Two of the reviewers independently extracted the following information from each included study: the first author’s name, publication year, year of data collection, maternal age, gestational weeks, province or municipality name, study region  , CCAM loTwo review authors independently evaluated the methodological quality of the selected studies using the Newcastle-Ottawa Score (NOS) which was used to formally assess the quality of non-randomised cohort studies . Each stP ≤ 0.05 indicated that it was statistically significant.The prevalence of CCAM in the selected studies was combined and reported as proportions with 95% CI using the STATA 12.0 . Before performing an inverse-variance weighted, the prevalence was transformed via the Freeman-Tukey double arcsine method . The inv