Sex-specific associations between body mass index trajectories and risk of hypertension

Although it is well established that obesity is a risk factor for hypertension, the effect of distinct long-term patterns of body mass index (BMI) on blood pressure (BP) in later life is poorly understood.

Based on the China Health and Nutrition Survey, we analyzed 2920 participants aged 3-17 years with initial normal BP at baseline (1991-2011), who were followed up for the development of hypertension (1993-2015). The group-based trajectory model was applied to identify BMI trajectories, and Cox regression was used to assess their associations with hypertension risk. Stratified analyses were conducted to explore differences across subgroups.

During an average follow-up time of 11.20 (7.69) years for males and 7.20 (5.21) years for females, 339 males and 212 females were identified with hypertension, respectively. Three BMI trajectories were identified: low-increasing (60.58% of males and 73.03% of females), moderate-increasing (33.08% of males and 24.22% of females), and high-increasing (6.34% of males and 2.76% of females). Our study found a significant positive association between a higher BMI trajectory and hypertension risk in males (all P for trend < 0.05). Specifically, males in the high-increasing BMI group had a higher risk of hypertension compared with those in the low-increasing group (HR = 1.76, 95% CI: 1.04-2.97). Stratified analyses revealed stronger associations among smokers, drinkers, and inactive individuals.

Our findings suggest that maintaining a normal BMI and healthy lifestyle from childhood may lower subsequent risk of hypertension.