The associations of body mass index and waist circumference with the risk of diabetic complications in people with type 2 diabetes mellitus

Aims: To determine the associations of body mass index (BMI) and waist circumference (WC) with severe diabetic complications in patients with type 2 diabetes. Materials and Methods: In total, 114 254 participants with type 2 diabetes (82% male; mean age, 52.52 +/- 8.27 years; median follow-up, 4.64 years) were enrolled from a nationwide Japanese medical claims database. Cox proportional models with multivariate adjustment were used to assess the associations of BMI and WC with treatment-requiring diabetic eye disease (TRDED), initiation of dialysis, coronary artery disease (CAD), cerebrovascular disease (CVD), heart failure (HF) and amputation. Results: BMI was inversely associated with TRDED, especially in women. Men with WC >= 95 cm had a significantly lower risk of TRDED (hazard ratio [HR] = 0.79, 95% CI = 0.69-0.91). Dialysis initiation displayed L-shaped associations with BMI and WC. The risk of CAD was significantly reduced among men with BMI < 20.0 kg/m(2) (HR = 0.68, 95% CI = 0.49-0.94). HF had U-shaped associations with BMI and WC. Abdominal obesity increased CVD risk (HR = 1.36, 95% CI = 1.08-1.70). BMI >= 25 kg/m(2)/WC >= 90 cm significantly reduced the risk of dialysis (HR = 0.42, 95% CI = 0.29-0.62) and increased the risk of HF (HR = 1.33, 95% CI = 1.03-1.72). Conclusions: BMI/WC had both positive and negative associations with diabetic complications. Therefore, each patient's BMI/WC target should be carefully determined for each diabetic complication, considering the risk of developing other diseases.