Background: Childhood body mass index (BMI) predicts adult hypertension. However, information is lacking regarding the relationship between BMI growth trajectories during childhood and adult hypertension risk. We aimed to test the hypothesis that BMI growth rates at different childhood ages have differential influences on adult hypertension risk, independent of BMI levels.
Methods: The study included 1,772 Whites and 960 Blacks with repeated BMI and blood pressure measurements from childhood (4-19 years) to adulthood (20-51 years). A random-effects mixed model was used to construct BMI growth curves by race and sex. Model-estimated linear growth rates of BMI at different childhood ages were linked to adult hypertension (defined by measured blood pressure or antihypertensive medication) in multivariable logistic regression models.
Results: Hypertensive adults had higher BMI across childhood than normotensive adults. Overall, linear slope and cubic parameters of BMI were higher in hypertensive adults than in normotensive adults in all four race-sex groups (p ≤ 0.023). Odds ratio of adult hypertension for each kg/m2/year increase in BMI linear slope was 1.22 (95% CI =1.11-1.34) at age 4, was non-significant between ages 5-9, and gradually increased thereafter and plateaued beginning at age 15 (odds ratio = 1.41 and 95% CI = 1.28-1.56) (Figure).
Conclusions: Rapid increase in BMI during and after puberty is associated with elevated risk of hypertension in adult life, which has implications for early prevention.