Body mass index trajectory across childhood and subsequent risk of elevated blood pressure.

We investigated the relationship between the body mass index (BMI) trajectory across childhood and the subsequent occurrence of elevated blood pressure (BP) in the Chinese pediatric population. The study cohort from the China Health and Nutrition Survey comprised 1484 children, each of whom underwent three BP and BMI assessments during childhood and had a non-elevated BP during the first childhood assessment. A group-based trajectory model was used to identify four distinct BMI trajectories across childhood: lean-stable increase, medium-marked increase, heavy marked decrease, and heavy marked increase. Elevated BP in childhood was as defined in the China's national BP reference for children. Covariate-adjusted logistic regression models were used to assess the associations of BMI trajectories with elevated BP. Overall, 27.6% of all participants between 3 and 13 years of age during the first childhood assessment developed elevated BP during a mean 6.5-year follow-up. Compared with participants in the lean-stable increase group, those in the medium-marked increase and heavy marked increase groups were more likely to have elevated BP (odds ratio [95% confidence interval], OR [95% CI]: 1.46 [1.08, 1.96] and 5.29 [2.44, 11.48], respectively; P < .05). The OR for the heavy marked decrease group was not statistically significant (OR [95% CI]: 1.58 [0.80, 3.13]; P = .192). In summary, distinct BMI trajectories conferred significantly different odds of elevated BP upon children, thus underscoring the importance of weight management in early life.