Sex differences in the relationship between body mass index in Chinese adolescents and future risk of hypertension: a decade-long cohort study

OBJECTIVE: This study aimed to investigate the relationship between body mass index (BMI) during adolescence and the future risk of developing hypertension, with a particular focus on potential sex differences. METHODS: This study was a secondary analysis based on a cohort study involving 2,020 adolescents aged 10-15 years who underwent health check-ups at the MJ Health Screening Center between 1999 and 2008. Cox proportional hazards regression models were used to evaluate the association between BMI and hypertension risk, with stratification by gender. Cox proportional hazards regression with cubic spline functions was employed to explore potential nonlinear relationships, and sensitivity analyses were conducted to ensure robustness. RESULTS: The multivariate Cox proportional hazards regression model showed a significant positive association between BMI and hypertension risk in the overall adolescent population and particularly in males, with hazard ratios (HRs) of 1.204 (95% CI: 1.038-1.396) and 1.181 (95% CI: 1.013-1.377), respectively. In females, a nonlinear relationship with a threshold effect was identified, with an inflection point at a BMI of 24.11 kg/m². Beyond this threshold, each 1 kg/m² increase in BMI was associated with a 3.491-fold higher risk of hypertension (HR = 4.491, 95% CI: 1.185-17.020). CONCLUSION: Among Chinese adolescent males, there was a positive dose-response relationship between BMI and future hypertension risk. In adolescent females, a specific nonlinear association with a threshold effect (inflection point: 24.11 kg/m²) was observed. Maintaining a BMI below 24.11 kg/m² in adolescent females may reduce their future risk of developing hypertension.