The presentation of adrenarche is sexually dimorphic and modified by body adiposity.

CONTEXT: Adrenarche refers to the onset of increased production of adrenal androgens in childhood leading variably to clinical signs of androgen action. The prevalence and presentation of adrenarche in prepubertal girls and boys is not well known.

OBJECTIVE: Our objective was to examine the prevalence and clinical presentation of adrenarche in a population sample of prepubertal children aged less than 9 years.

DESIGN AND PARTICIPANTS: This cross-sectional study included prepubertal children (209 girls and 228 boys; median age 7.6 [range 6.8-8.9] years) taking part in The Physical Activity and Nutrition in Children (PANIC) Study.

MAIN OUTCOME MEASURE: The prevalence of adrenarche was assessed.

RESULTS: The prevalence of any clinical sign of androgen action was higher in girls than in boys (26.1% vs 10.0%; P < .001) and biochemical adrenarche without any clinical sign was less common in girls than in boys (8.1% vs 16.7%; P = .007). When premature adrenarche was defined by serum dehydroepiandrosterone sulfate concentration ≥1 μmol/L (≥37 μg/dL) and any clinical sign before the age of 8 years in girls and 9 years in boys, its total prevalence was 8.6% in girls and 1.8% in boys. The risk of having any clinical sign increased with higher body fat percentage in boys and with higher serum dehydroepiandrosterone sulfate concentration in girls.

CONCLUSIONS: Clinical signs of androgen action are more common, but biochemical adrenarche without any clinical sign is less common in prepubertal girls than boys. This sexual dimorphism of adrenarche might be explained by sex-dependent differences in peripheral androgen metabolism or action that are modified by body fat.