PUBERTAL ONSET AND MATURITY AND ADOLESCENT BLOOD PRESSURE: EVIDENCE FROM HONG KONG'S “CHILDREN OF 1997” BIRTH COHORT
Methods: We examined whether age at pubertal onset (Tanner stage II for breast or genitalia or pubic hair or testicular volume of 4 milliliters), or pubertal maturity (age at menarche or latest testicular volume) were associated with BP z-score at ~13 years relative to sex-, age- and height-specific reference for contemporary US children in a population-representative Chinese birth cohort (n=5,554). Mediation by menarche was examined for the associations of pubertal onset in girls.
Results: Younger age at pubertal onset or maturity was associated with higher systolic BP z-score in girls (breast stage II -0.08 mmHg, 95% confidence interval (CI): -0.11, -0.05; pubic hair stage II -0.08 mmHg, 95% CI: -0.13, -0.03; menarche -0.14 mmHg, 95% CI: -0.18, -0.10), adjusted for infant characteristics and socioeconomic position. The association for breast development was attenuated (-0.04 mmHg, 95% CI: -0.08, -0.003) by adjusting for age at menarche and that for pubic hair became null. Similarly adjusted, younger age at onset of testicular, but not genitalia or pubic hair, development (-0.06 mmHg, 95% CI: -0.10, -0.02) and greater testicular volume (0.03 mmHg, 95% CI: 0.02, 0.05) was associated with higher systolic BP in boys. Similar associations of smaller magnitude were found for diastolic BP.
Conclusion: Younger age at pubertal onset in both sexes was associated with higher BP, largely due in girls to younger age at menarche. Age of maturity plays a role on blood pressure, perhaps via up-regulation of the gonadotropic axis. The declining age at puberty, or factors which drive earlier puberty, may have contributed to the increasingly prevalence of cardiovascular diseases in rapidly developed or developing settings.