Association between puberty timing and metabolic health at young adulthood

CONTEXT: Metabolic syndrome (MetS) is a cluster of abnormalities that increase the risk of type 2 diabetes and cardiovascular disease. Cross-sectional studies in adults suggest that early pubertal timing is associated with a higher risk of MetS. OBJECTIVE: We aimed to determine whether early puberty onset in boys and girls increases the risk of developing MetS at 18 years. METHODS: We conducted a longitudinal study within the Growth and Obesity Chilean Cohort Study. Pubertal timing was assessed by Tanner stage (breast stage 2 [B2] in girls; gonadarche stage 2 [G2; testicular volume >3 cc] in boys) and age at menarche (AAM). MetS and insulin resistance markers were evaluated at age 18 (n = 729). Logistic regression models were used to examine associations between early pubertal markers and MetS and related metabolic parameters, adjusting by body mass index at puberty and maternal education. RESULTS: At age 18, boys had higher prevalence of MetS (9.8% vs 4.1%), elevated blood pressure (9.8% vs 0.3%), and elevated triglycerides (18.1% vs 8.5%). In boys, only crude models showed inverse associations between age at G2 and MetS, waist circumference, and waist to height ratio. In girls, fully adjusted models confirmed an inverse association of AAM and the risk of MetS (odds ratio [OR] 0.54, 95% CI: 0.33-0.90), high triglycerides (OR 0.57, 95% CI: 0.39-0.83), and high triglycerides/glycemia ratio (OR 0.63, 95% CI: 0.43-0.92). No associations were observed for B2. CONCLUSION: Earlier puberty is associated with adverse metabolic outcomes, but this persists after adjustment only in girls. Secular trends toward earlier pubertal timing may therefore have significant public health implications.