Distinct developmental trajectories of body mass index and diabetes risk: A 5‐year longitudinal study of Chinese adults

AIMS/INTRODUCTION: This longitudinal study aimed to explore whether distinct developmental trajectories of body mass index (BMI) would be predictive of diabetes risk in general Chinese adults. MATERIALS AND METHODS: A total of 4,519 participants aged >18 years who were free of diabetes in 2011 (baseline of the current analysis) were enrolled in this study. All participants completed a medical examination every year during 2011–2016, and BMI levels were measured two to six (average 5.6) times. Group‐based trajectory modeling was applied to identify BMI trajectories over time. New‐onset diabetes was confirmed in 2016. RESULTS: During 2011–2016, four distinct BMI trajectories were identified according to BMI range and changing pattern over time: “low” (19.6%), “moderate” (33.4%), “moderate‐high” (33.4%) and “high” (13.6%). A total of 168 (3.7%) new‐onset diabetes cases were confirmed in 2016. Compared with the “low” BMI trajectory, participants in the “high” BMI trajectory were at significantly higher risk for new‐onset diabetes (adjusted relative risk 3.24, 95% confidence interval 1.27–8.24). Notably, BMI trajectories based on the first four or three annual BMI tests yielded similar results. By contrast, no significant correlation was found between categories of baseline BMI and new‐onset diabetes in 2016 after multivariate adjustment. CONCLUSIONS: The present results show that distinct BMI trajectories, even identified using just four or three annual BMI tests, are significantly associated with new‐onset diabetes. Monitoring BMI trajectories over time might provide an important approach to identify subpopulations at higher risk for developing diabetes.