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.