Relationship between Body Mass Index and Chronic Kidney Disease among Appalachian Adults

Background: While some previous studies reported a positive association between body mass index (BMI) and chronic kidney disease (CKD), others reported that this association was entirely explained by factors such as diabetes and hypertension. Also several studies reported that an association was present among men, but not women.

Hypothesis: We examined the hypothesis that BMI is positively associated with CKD, separately in men and women.

Methods: We analyzed data from the C8 Health Study, a population-based cross-sectional study of Appalachian adults residing in six communities in Ohio and West Virginia, who were aged ÿ18 years and free of cardiovascular disease (n=48,567, 53% women). BMI categories were defined as normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) or obese (ÿ30 kg/m2). The main outcome of interest was CKD (n=2954), defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m2.

Results: In men, we found a positive association between BMI and CKD, independent of age, race-ethnicity, education, smoking, alcohol intake, diabetes, hypertension, and serum cholesterol. Compared to normal weight men (referent), the multivariable odds ratio (OR) (95% confidence interval (CI)) of CKD was 1.17 (0.96-1.43) for overweight men and 1.35 (1.09-1.66) for obese men; p-trend <0.0001. In contrast, in women, we found no association between BMI and CKD. Compared to normal weight women (referent), the OR (95% CI) was 1.06 (0.93-1.21) for overweight women and 0.93 (0.82-1.07) for obese women; p-trend <0.0001.

Conclusion: Higher BMI levels are associated with CKD in men, but not women, in a population-based study of Appalachian adults.