Associations of body mass index trajectory, waist circumference trajectory, or both with type 2 diabetes mellitus risk in Chinese adults: The China-PAR project

Aims: To identify the trajectories of body mass index (BMI) and waist circumference (WC), and assess the associations of BMI trajectory, WC trajectory, or the two combined, with type 2 diabetes mellitus (T2DM) risk in Chinese adults. Materials and Methods: This study was based on a prospective project-the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). A total of 54 434 participants (39.21% men) who were measured on at least two occasions were included. Three slowly increasing trajectory patterns were identified for BMI, and four for WC, by latent mixed modelling. A nine-category variable was derived by combining the WC trajectory (low, moderate, moderate-high/high) and the BMI trajectory (low, moderate, high). Logistic regression models were applied to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Results: The risk of developing T2DM increased with elevated BMI or WC trajectory levels (all p(trend) <0.001). The risks were 2.85 (2.59-3.14) for high BMI trajectory and 4.34 (3.78-4.99) for high WC trajectory versus low trajectory groups, respectively. The association was more pronounced among younger individuals (p(interaction) <0.001). In the joint analysis, compared to participants with low WC and BMI trajectory, those with moderate-high/high WC combined with high BMI trajectory had the highest risk of T2DM (OR 3.96, 95% CI 3.48-4.50); even those who maintained moderate-high/high WC but low BMI trajectory showed a higher T2DM risk (OR 3.00, 95% CI 2.31-3.91). Conclusions: This study suggests that simultaneous dynamic and continuous monitoring of BMI and WC may contribute more than single measurements to predicting T2DM risk and determining preventive strategies.