Assessing different anthropometric indices and their optimal cutoffs for prediction of type 2 diabetes and impaired fasting glucose in Asians: The Jinchang Cohort Study

Background To study the association between anthropometric measurements and the risk of diabetes and impaired fasting glucose (IFG) and compare body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) to determine the best indicator and its optimal cutoffs for predicting type 2 diabetes and IFG. Methods A Chinese prospective (2011-2019) cohort named the Jingchang cohort that included 48 001 participants was studied. Using Cox proportional hazard models, hazard ratios (HRs) for incident type 2 diabetes or IFG per 1 SD change in BMI, WC, and WHtR were calculated. Area under the curve (AUC) was compared to identify the best anthropometric variable and its optimal cutoff for predicting diabetes. Results The association of BMI, WC,0 and WHtR with type 2 diabetes or IFG risk was positive in the univariate and multivariable-adjusted Cox proportional hazard models. Of all three indexes, the AUC of BMI was largest and that of WC was smallest. The derived cutoff values for BMI, WC, and WHtR were 24.6 kg/m(2), 89.5 cm, and 0.52 in men and 23.4 kg/m(2), 76.5 cm, and 0.47 in women for predicting diabetes, respectively. The derived cutoff values for BMI, WC, and WHtR were 23.4 kg/m(2), 87.5 cm, and 0.50 in men and 22.5 kg/m(2), 76.5 cm, and 0.47 in women for predicting IFG, respectively. Conclusions Our derived cutoff points were lower than the values specified in the most current Asian diabetes guidelines. We recommend a cutoff point for BMI in Asians of 23 kg/m(2) and for WC a cutoff point of 89 cm in men and 77 cm in women to define high-risk groups for type 2 diabetes; screening should be considered for these populations. Highlights We observed significant and positive associations of the risk of type 2 diabetes with BMI, WC and WHtR, and we identified BMI as the best obesity predictor for diabetes. Our derived cutoff points were lower than the values specified in the most current Asian diabetes guidelines, and we recommend a cutoff point for BMI in Asians of 23 kg/m(2) and a cutoff point for WC of 89 cm in men and 77 cm in women to define high-risk groups for type 2 diabetes; screening should be considered for these populations.