Association between body mass index and CKD in apparently healthy men.

Overweight and obesity are well-established risk factors for cardiovascular disease and decline in kidney function in individuals with existing chronic kidney disease (CKD). Conversely, their association with the development of CKD is less clear. We evaluated the association between body mass index (BMI) and risk for CKD in a cohort of 11,104 initially healthy men who participated in the Physicians' Health Study and provided a blood sample after 14 years. BMI was calculated from self-reported weight and height. We estimated glomerular filtration rate (GFR) by using the abbreviated equation from the Modification of Diet in Renal Disease Study and defined CKD as GFR less than 60 mL/min/1.73 m2 (<1 mL/s/1.73 m2). After an average 14-year follow-up, 1,377 participants (12.4%) had a GFR less than 60 mL/min/1.73 m2 (<1 mL/s/1.73 m2). Higher baseline BMI was associated consistently with increased risk for CKD. Compared with participants in the lowest BMI quintile (<22.7 kg/m2), those in the highest quintile (>26.6 kg/m2) had an odds ratio (OR) of 1.45 (95% confidence interval [CI], 1.19 to 1.76; P trend <0.001) after adjusting for potential confounders. We found similar associations by using different categories of BMI. Compared with men who remained within a +/-5% range of their baseline BMI, those who reported a BMI increase greater than 10% had a significant increase in risk for CKD (OR, 1.27; 95% CI, 1.06 to 1.53). In this large cohort of initially healthy men, BMI was associated significantly with increased risk for CKD after 14 years. Strategies to decrease CKD risk might include prevention of overweight and obesity.