Childhood socioeconomic status, comorbidity of chronic kidney disease risk factors, and kidney function among adults in the midlife in the United States (MIDUS) study.
BACKGROUND
There is a lack of empirical effort that systematically investigates the clustering of comorbidity among known risk factors (obesity, hypertension, diabetes, hypercholesterolemia, and elevated inflammation) of chronic kidney disease (CKD) and how different types of comorbidity may link differently to kidney function among healthy adult samples. This study modeled the clustering of comorbidity among risk factors, examined the association between the clustering of risk factors and kidney function, and tested whether the clustering of risk factors was associated with childhood SES.


METHODS
The data were from 2118 participants (ages 25-84) in the Midlife in the United States (MIDUS) Study. Risk factors included obesity, elevated blood pressure (BP), high total cholesterol levels, poor glucose control, and increased inflammatory activity. Glomerular filtration rate (eGFR) was estimated from serum creatinine, calculated with the CKD-EPI formula. The clustering of comorbidity among risk factors and its association with kidney function and childhood SES were examined using latent class analysis (LCA).


RESULTS
A five-class model was optimal: (1) Low Risk (class size = 36.40%; low probability of all risk factors), (2) Obese (16.42%; high probability of large BMI and abdominally obese), (3) Obese and Elevated BP (13.37%; high probability of being obese and having elevated BP), (4) Non-Obese but Elevated BP (14.95%; high probability of having elevated BP, hypercholesterolemia, and elevated inflammation), and (5) High Risk (18.86%; high probability for all risk factors). Obesity was associated with kidney hyperfiltration, while comorbidity between obesity and hypertension was linked to compromised kidney filtration. As expected, the High Risk class showed the highest probability of having eGFR < 60 ml/min/1.73 m2 (P = .12; 95%CI = .09-.17). Finally, higher childhood SES was associated with reduced probability of being in the High Risk rather than Low Risk class (β = - 0.20, SE = 0.07, OR [95%CI] = 0.82 [0.71-0.95]).


CONCLUSION
These results highlight the importance of considering the impact of childhood SES on risk factors known to be associated with CKD.
['Surachman|Agus|A|0000-0001-7474-9450', 'Daw|Jonathan|J|', 'Bray|Bethany C|BC|', 'Alexander|Lacy M|LM|', 'Coe|Christopher L|CL|', 'Almeida|David M|DM|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D015897:Comorbidity D003404:Creatinine D003920:Diabetes Mellitus D000078022:Economic Status D004522:Educational Status D005260:Female D005919:Glomerular Filtration Rate D006801:Humans D006937:Hypercholesterolemia D006973:Hypertension D007249:Inflammation D000077272:Latent Class Analysis D008297:Male D008875:Middle Aged D009765:Obesity D011632:Public Assistance D051436:Renal Insufficiency, Chronic D012307:Risk Factors D012923:Social Class D014481:United States
Socioeconomic status Kidney disease Obesity Hypertension Diabetes Early adversity