Low Birthweight Is Associated with Higher Risk of High Blood Pressure in Chinese Girls: Results from a National Cross-Sectional Study in China

Objective: To investigate the relationship between low birthweight (LBW) and blood pressure and to assess whether LBW leads to a higher risk of high blood pressure (HBP) by gender in Chinese students aged 6–18 years. Also, to investigate whether the association was affected by childhood obesity. Methods: Data was obtained from a baseline dataset of a national school-based program. Anthropometric parameters, including height, weight, and blood pressure, were measured, while birthweight and other characteristics were obtained from questionnaires. Stratified chi-squared tests were used to compare the prevalence of HBP between LBW and normal birthweight (NBW) groups in each age and sex category. Multivariable logistic regressions were conducted to estimate the HBP risks in each birthweight group. Results: Both systolic and diastolic blood pressure showed a U-shaped relationship with increased birthweight. Compared to NBW groups, LBW girls showed a higher HBP risk, with an odds ratio of 1.29 (95% confidence interval (CI): 1.02, 1.64, p = 0.033), regardless of their current body mass index status, while no significant association in boys was found. Conclusions: Low birthweight is associated with higher HBP risk in adolescent girls, regardless of their childhood BMI status.