Waist-to-hip ratio, body mass index, and subsequent kidney disease and death

Background: Chronic kidney disease (CKD) and obesity are important public health concerns. We examined the association between anthropomorphic measures and incident CKD and mortality. Study Design: Cohort study. Setting & Participants: Individual patient data pooled from the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study. Predictors: Waist-to-hip ratio (WHR), body mass index (BMI). Outcomes & Measurements: Incident CKD defined as serum creatinine level increase greater than 0.4 mg/dL with baseline creatinine level of 1.4 mg/dL or less in men and 1.2 mg/dL or less in women and final creatinine level greater than these levels, and, in separate analyses, estimated glomerular filtration rate (eGFR) decrease of 15 mL/min/1.73 m(2) or greater with baseline eGFR of 60 mL/min/1.73 m(2) or greater and final eGFR less than 60 mL/min/1.73 m(2). Multivariable logistic regression to determine the association between WHR, BMI, and outcomes. Cox models to evaluate a secondary composite outcome of all-cause mortality and incident CKD. Results: Of 13,324 individuals, mean WHR was 0.96 in men and 0.89 in women and mean BMI was 27.2 kg/m(2) in both men and women. During 9.3 years, 300 patients (2.3%) in creatinine-based models and 710 patients (5.5%) in eGFR-based models developed CKD. In creatinine-based models, each SD increase in WHR was associated with increased risk of incident CKD (odds ratio, 1.22; 95% confidence interval [CI], 1.05 to 1.43) and the composite outcome (hazard ratio, 1.12; 95% CI, 1.06 to 1.18), whereas each SD increase in BMI was not associated with CKD (odds ratio, 1.05; 95% CI, 0.93 to 1.20) and appeared protective for the composite outcome (hazard ratio, 0.94; 95% CI, 0.90 to 0.99). Results of eGFR-based models were similar. Limitations: Single measures of creatinine, no albuminuria data. Conclusions: WHR, but not BMI, is associated with incident CKD and mortality. Assessment of CKD risk should use WHIR rather than BMI as an anthropomorphic measure of obesity.