Obesity, weight change, and chronic kidney disease in patients with type 2 diabetes mellitus: A longitudinal study in Taiwan

Background The aim of the present study was to investigate relationships between the risk of chronic kidney disease (CKD) and obesity and weight changes in Asian patients with type 2 diabetes. Methods At baseline (2003–05), 1187 diabetic patients aged 30–70 years were recruited to the study, with follow‐up surveys completed in 2008, 2009, and 2010. Chronic kidney disease was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m 2 ; body mass index (BMI) was categorised as normal (18.5–22.9 kg/m 2 ), overweight (23–27.4 kg/m 2 ), or obese (≥27.5 kg/m 2 ); waist circumference (WC) ≥80 cm for women and ≥90 cm for men was taken to indicate abdominal obesity. Changes in weight and WC were calculated from baseline to each follow‐up survey. Relative risk (RR) and 95% confidence intervals (CIs) of CKD were estimated. To estimate the risk for incident CKD, associations were examined in patients without CKD at baseline ( n = 881). Results Over 7 years of follow‐up, obesity (RR 1.48; 95% CI 1.08–2.04; P = 0.015) and high WC (RR 1.23; 95% CI 1.00–1.52; P = 0.049) were associated with CKD after adjusting for covariates. Among participants without CKD at baseline, those who gained >10% weight (RR 1.43; 95% CI 1.07–1.90; P = 0.015) and in whom WC increased >15% (RR 1.37; 95% CI 1.01–1.85; P = 0.045) had a higher risk of incident CKD than those who remained stable (±5% changes in weight or WC). Conclusions Diabetic patients who are obese and those with excessive central fat were more likely to have CKD. Large weight gain (>10%) and increases in WC (>15%) independently predicted incident CKD.