Association Between Midlife Obesity and Kidney Function Trajectories: The Atherosclerosis Risk in Communities (ARIC) Study

Rationale & Objective Obesity has been related to risk for chronic kidney disease. However, the associations of different measures of midlife obesity with long-term kidney function trajectories and whether they differ by sex and race are unknown. Study Design Observational study. Setting & Participants 13,496 participants from the Atherosclerosis Risk in Communities (ARIC) Study. Predictors Midlife obesity status as measured by body mass index (BMI), waist-to-hip ratio, and predicted percent fat at baseline. Outcomes Estimated glomerular filtration rate (eGFR) calculated using serum creatinine level measured at 5 study visits, and incident kidney failure with replacement therapy (KFRT). Analytical Approach Mixed models with random intercepts and random slopes for eGFR. Cox proportional hazards models for KFRT. Results Baseline mean age was 54 years, median eGFR was 103 mL/min/1.73 m2, and median BMI was 27 kg/m2. Over 30 years of follow-up, midlife obesity measures were associated with eGFR decline in White and Black women but not consistently in men. Adjusted for age, center, smoking, and coronary heart disease, the differences in eGFR slope per 1-SD higher BMI, waist-to-hip ratio, and predicted percent fat were 0.09 (95% CI, −0.18 to 0.36), −0.25 (95% CI, −0.50 to 0.01), and −0.14 (95% CI, −0.41 to 0.13) mL/min/1.73 m2 per decade for White men; −0.91 (95% CI, −1.15 to −0.67), −0.82 (95% CI, −1.06 to −0.58), and −1.02 (95% CI, −1.26 to −0.78) mL/min/1.73 m2 per decade for White women; −0.70 (95% CI, −1.54 to 0.14), −1.60 (95% CI, −2.42 to −0.78), and −1.24 (95% CI, −2.08 to −0.40) mL/min/1.73 m2 per decade for Black men; and −1.24 (95% CI, −2.08 to −0.40), −1.50 (95% CI, −2.05 to −0.95), and −1.43 (95% CI, −2.00 to −0.86) mL/min/1.73 m2 per decade for Black women. Obesity indicators were independently associated with risk for KFRT for all sex-race groups except White men. Limitations Loss to follow-up during 3 decades of follow-up with 5 eGFR assessments. Conclusions Obesity status is a risk factor for future decline in kidney function and development of KFRT in Black and White women, with less consistent associations among men. Obesity has been related to risk for chronic kidney disease. However, the associations of different measures of midlife obesity with long-term kidney function trajectories and whether they differ by sex and race are unknown. Observational study. 13,496 participants from the Atherosclerosis Risk in Communities (ARIC) Study. Midlife obesity status as measured by body mass index (BMI), waist-to-hip ratio, and predicted percent fat at baseline. Estimated glomerular filtration rate (eGFR) calculated using serum creatinine level measured at 5 study visits, and incident kidney failure with replacement therapy (KFRT). Mixed models with random intercepts and random slopes for eGFR. Cox proportional hazards models for KFRT. Baseline mean age was 54 years, median eGFR was 103 mL/min/1.73 m2, and median BMI was 27 kg/m2. Over 30 years of follow-up, midlife obesity measures were associated with eGFR decline in White and Black women but not consistently in men. Adjusted for age, center, smoking, and coronary heart disease, the differences in eGFR slope per 1-SD higher BMI, waist-to-hip ratio, and predicted percent fat were 0.09 (95% CI, −0.18 to 0.36), −0.25 (95% CI, −0.50 to 0.01), and −0.14 (95% CI, −0.41 to 0.13) mL/min/1.73 m2 per decade for White men; −0.91 (95% CI, −1.15 to −0.67), −0.82 (95% CI, −1.06 to −0.58), and −1.02 (95% CI, −1.26 to −0.78) mL/min/1.73 m2 per decade for White women; −0.70 (95% CI, −1.54 to 0.14), −1.60 (95% CI, −2.42 to −0.78), and −1.24 (95% CI, −2.08 to −0.40) mL/min/1.73 m2 per decade for Black men; and −1.24 (95% CI, −2.08 to −0.40), −1.50 (95% CI, −2.05 to −0.95), and −1.43 (95% CI, −2.00 to −0.86) mL/min/1.73 m2 per decade for Black women. Obesity indicators were independently associated with risk for KFRT for all sex-race groups except White men. Loss to follow-up during 3 decades of follow-up with 5 eGFR assessments. Obesity status is a risk factor for future decline in kidney function and development of KFRT in Black and White women, with less consistent associations among men.