Objectives: To identify body mass index (BMI) trajectories in Chinese children and to compare the risk of incident high blood pressure (HBP) across trajectory groups.
Methods: A total of 9286 children were included. The mean age at baseline was 8.9 years; age at endpoint ranged between 16 and 18 years. At least 8 measurements were obtained from each involved child. We used group-based trajectory modeling to identify BMI trajectory groups in each sex. We used blood pressure from each measurement to define HBP.
Results: We identified 4 BMI trajectories for each sex. Compared with the low trajectory group, the hazard ratios of HBP in the higher trajectory groups ranged from 1.17 (95% confidence interval [CI] = 1.11, 1.23) to 2.00 (95% CI = 1.78, 2.27) during follow-up, and HBP risk at late adolescence ranged from 1.36 (95% CI = 1.22, 1.52) to 3.63 (95% CI = 3.12, 4.21). All trend P values across trajectories were less than .001. In terms of population level, overweight started 3 years earlier than HBP.
Conclusions: Children of higher BMI trajectories had a higher risk of HBP during adolescence. The transition period from overweight to HBP onset could be critical for HBP prevention.