Objectives: To examine the longitudinal changes in adiposity and related risk variables of Syndrome X from childhood to young adulthood with respect to early onset of menarche.
Design: Community-based longitudinal cohort of female subject (65% white, 35% blacks subjects) who participated in two or more surveys from childhood to young adulthood and had reported their menarcheal age (<12 y, n=437 vs > or =12 y, n=1042).
Results: In childhood (5-11 y), adolescence (12-18 y), and young adulthood (19-37 y), females with early menarche displayed significantly higher body mass index (BMI) and triceps skinfold thickness; higher stature in childhood and adolescence; higher fasting insulin and homeostasis model assessment index of insulin resistance (HOMA-IR) in childhood and adulthood; and higher fasting glucose in adulthood. Blood pressure and lipoprotein variables showed no early menarche-related differences. Longitudinal rates of change in BMI (P=0.002), triceps skinfold thickness (P=0.05), insulin (P=0.09), and HOMA-IR (P=0.05) were positive and faster among female subjects with early menarche; fasting glucose decreased slowly in this group (P=0.006). In a multivariate analysis, body fatness and insulin related independently to early menarche (P<0.001). This association was stronger in white subjects (P=0.0008). In adulthood, the prevalence of clustering of three to four risk factors of syndrome X (highest quartile of: (1) BMI, (2) fasting insulin, (3) systolic or mean arterial pressure, and (4) total cholesterol to HDL cholesterol or triglycerides to HDL cholesterol ratio specific for age, race, and study year) was higher among those with early menarche (10.7 vs 6.2%, P=0.002). The odds for developing such clustering in adulthood among those with early menarche was 1.54 (95% CI=1.14-2.07), regardless of race.
Conclusion: Early menarche is characterized by excess body fatness and insulin beginning in early childhood and higher prevalence of clustering of adverse levels of risk variables of metabolic Syndrome X in young adulthood.