Pubarche as Well as Thelarche May Be a Marker for the Onset of Puberty

Study ObjectiveTo define anthropometric and hormonal differences in a group of black and white girls who began puberty with breast development alone (“thelarche” pathway) compared to those who began with pubic hair development alone (“pubarche” pathway), and test the hypothesis that pubarche may represent true pubertal development.DesignLongitudinal cohort seen annually for ten years.SetttingRecruited through elementary schools in Cincinnati, OH, and Richmond, CA; through HMO in Washington, DC.Participants9 years old, either Black or White, in the National Heart, Lung, and Blood Institute Growth and Health Study.InterventionsNone; observational study.Main Outcome MeasuresInitial secondary sexual characteristic at onset of puberty; anthropometric measures; hormone measures.Results478 of 1155 girls matured through a defined pathway. Age at onset of secondary sexual characteristics was similar between pathways, although girls in the thelarche pathway had puberty at a somewhat younger age, and black participants entered at a significantly younger age. Height velocity was the same in both pathways, and in the pubertal range. DHEA-S levels at onset of puberty were significantly greater in girls in the pubarche pathway, but levels of estradiol and testosterone were not different. Age of menarche was different by race (younger in blacks) and pathway (younger in thelarche pathway).ConclusionsGiven similar age and height velocities at onset of secondary sexual characteristics, these results suggest that pubarche, the development of pubic hair without breast development, may represent true pubertal maturation.