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 m² or greater with baseline eGFR of 60 mL/min/1.73 m² or greater and final eGFR less than 60 mL/min/1.73 m². 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/m² 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 WHR rather than BMI as an anthropomorphic measure of obesity.

Index Words: Obesity, kidney disease, body mass index, waist-to-hip ratio, mortality