Maternal Age of Menarche and Blood Pressure in Adolescence: Evidence from Hong Kong's "Children of 1997" Birth Cohort.

BACKGROUND: Age of puberty has declined substantially in developed settings and is now declining in the rest of the world with economic development. Early age of puberty is associated with non-communicable diseases in adulthood, and may be a long-term driver of population health with effects over generations. In a non-Western setting, we examined the association of maternal age of menarche with blood pressure in late childhood/adolescence. METHODS: We used generalised estimating equations to estimate the adjusted association of maternal age of menarche with age-, sex- and height-adjusted blood pressure z-score from 10 to 16 years in Hong Kong's population-representative birth cohort, "Children of 1997" (n = 8327). We also assessed whether associations were mediated by body mass index (BMI) or pubertal stage. RESULTS: Earlier maternal age of menarche was associated with higher systolic blood pressure in adolescence [-0.02 z-score per year older maternal age of menarche, 95% confidence interval (CI) -0.04 to -0.003]. The association of maternal age of menarche with systolic blood pressure was mediated by adiposity and/or pubertal stage at 11 years. Maternal age of menarche was not associated with diastolic blood pressure. CONCLUSION: Earlier maternal age of puberty was associated with higher systolic blood pressure, largely mediated by adiposity, highlighting the importance of tackling childhood obesity as a public health priority in view of the secular trend of declining age of puberty.

Brief Report: Maternal Age of Menarche and Adiposity: Evidence from Hong Kong's "Children of 1997" Birth Cohort.

BACKGROUND: Earlier age of menarche predicts chronic diseases. Earlier maternal age of menarche is also associated with higher body mass index (BMI) and height into childhood. METHODS: We used generalized estimating equations in Hong Kong's "Children of 1997" birth cohort to examine the adjusted association of maternal age of menarche with BMI and height z score, and whether associations varied by maternal birthplace. RESULTS: Earlier maternal age of menarche was not associated with infant BMI but was associated subsequently with higher BMI in childhood and at puberty. Maternal age of menarche was negatively associated with height in children of Hong Kong-born mothers, but positively associated with infant length for children with mothers born in China (P value for interaction 0.02). CONCLUSION: These different patterns suggest drivers of adiposity and linear growth differ, and are more influential in some circumstances. Understanding these drivers may indicate setting-specific interventions to prevent childhood obesity.