Association between obesity and the prevalence of type 2 diabetes mellitus among Chinese adults aged 18-65 years in 15 provinces in 2018

Abstract

Objective: To analyze the association between different types of obesity, BMI, and waist circumference (WC) and the risk of type 2 diabetes mellitus (T2DM) in Chinese adults. Methods: Based on the China Health and Nutrition Survey data in 2018, different types of obesity were defined across different BMI and WC combinations based on Criteria of weight for adults (WS/T 428-2013), including non-obesity, simple general obesity, simple central obesity, and complex obesity. The associations of different types of obesity, BMI, and WC with T2DM risk were explored using two-level mixed-effects logistic regression and restricted cubic spline models. Results: A total of 7 030 subjects aged 18-65 were included in this study. The prevalence of general obesity and central obesity were 16.29% (502/3 082), 42.28% (1 303/3 082) in males, and 14.41% (569/3 948), 37.87% (1 495/3 948) in females. The prevalence of complex obesity was 14.70% and 12.97% in males and females, respectively. The prevalence of T2DM was 11.28% in participants, and the prevalence in complex obesity (18.98%, 22.07%) was higher than in simple central obesity (16.24%, 15.26%) and non-obesity (9.65%, 5.18%) in males and females, respectively. Multilevel regressions showed that males with simple central obesity and complex obesity had 1.61 (95%CI: 1.24-2.08) and 2.11 (95%CI: 1.56-2.86) times the odds of T2DM, respectively, as compared with the non-obesity; and the odds of T2DM in females were 2.70 (95%CI: 1.16-6.28) times for simple general obesity, 2.62 (95%CI: 2.01-3.40) times for simple central obesity, and 4.47 (95%CI: 3.35-5.98) times for complex obesity. A nearly linear positive association was observed between BMI and T2DM risk. WC was also positively associated with T2DM risk and a non-linearly increased risk in females (P for non-linear=0.024). The risk of T2DM increased when BMI ≥22.5 kg/m2 and 23.0 kg/m2, WC ≥85.0 cm and 80.0 cm in males and females, respectively. Conclusions: Complex obesity adults are more likely to suffer from T2DM. The risk of T2DM increases significantly when BMI is at the normal high values and waist circumference at the stage of pre-central obesity.