Age at menarche and blood pressure in late adolescence: the role of body adiposity in a Brazilian birth cohort.

OBJECTIVE: To investigate the association between age at menarche and blood pressure in adolescence, and to examine the role of body adiposity in this relationship. METHODS: This was a cross-sectional analysis nested within a population-based birth cohort conducted in São Luís, Maranhão, Brazil. The study included 885 female adolescents aged 18-19 years. Age at menarche was self-reported. Systolic and diastolic blood pressure were measured using a validated digital device, and body adiposity was assessed by air displacement plethysmography. Pearson correlation coefficients were estimated, and linear regression models were used to evaluate the association between age at menarche and blood pressure, with sequential adjustment for socioeconomic, behavioral, family, and perinatal factors, followed by additional adjustment for body adiposity. RESULTS: Age at menarche showed weak inverse correlations with systolic and diastolic blood pressure and a negative correlation with body adiposity. Body adiposity, in turn, was positively correlated with both systolic and diastolic blood pressure. In adjusted models, age at menarche remained significantly associated with blood pressure after controlling for socioeconomic, behavioral, family, and perinatal factors; however, these associations were attenuated and lost statistical significance after additional adjustment for body adiposity. CONCLUSION: The association between age at menarche and blood pressure in adolescence appears to be largely influenced by body adiposity, highlighting the importance of considering body composition when evaluating cardiovascular risk related to pubertal timing.