Sex dimorphism in the relation between early adiposity and cardiometabolic risk in adolescents

CONTEXT: Birth weight and childhood adiposity are associated with subsequent cardiovascular risk.

OBJECTIVE: We investigated the associations between metabolic clusters in young adults with body fat distribution from early childhood, focusing on sex differences.

DESIGN, SETTING, AND PATIENTS: A total of 1053 17 yr olds from an Australian birth cohort had measures of anthropometry, blood pressure, and fasting insulin, glucose, and lipids.

MAIN OUTCOME MEASURES: Two-step cluster analysis identified 17 yr olds at high metabolic risk. The two risk groups were compared by sex with regard to birth weight and serial anthropometry, including skinfold thickness from nine time-points.

RESULTS: The "high-risk" metabolic cluster at age 17 yr included 16% of males and 19% of females. Compared to the "low-risk" group, the high-risk cluster participants had greater waist circumference, triglycerides, insulin, and systolic blood pressure and lower high-density lipoprotein-cholesterol (all P <0.0001). There was a significant birth weight by sex interaction upon the metabolic cluster outcome (P = 0.011). Compared to their low-risk counterparts, females in the high-risk cluster at 17 yr were heavier from birth (odds ratio, 1.8; 95% confidence interval, 1.0, 3.2) (P = 0.034), with consistently higher body mass index and skinfold thickness thereafter. In contrast, there was no statistical difference in birth weight between high- and low-risk males (odds ratio, 0.62; 95% confidence interval, 0.38, 1.02).

CONCLUSIONS: These data show sexual dimorphism in effects of early life body mass index and fat distribution upon cardiometabolic risk factors. Females in a contemporary population are particularly prone to increased risk when born heavier. This has implications for targeted prevention of obesity and metabolic diseases with increasing maternal obesity and gestational diabetes.