Clinical spectrum of premature pubarche: links to metabolic syndrome and ovarian hyperandrogenism.

Premature pubarche-defined as the appearance of pubic hair before age 8 years in girls and 9 years in boys-has been traditionally considered a benign entity. However, recent evidence supports the notion that premature pubarche in girls may be a forerunner of the metabolic syndrome, and may precede the development of clinical ovarian androgen excess in adolescence. This sequence seems to occur more frequently when premature pubarche was preceded by reduced fetal growth and followed by excessive postnatal catch-up in height and particularly in weight; hyperinsulinemia appears to be a key factor in the development of this sequence of events. In girls with premature pubarche and a history of a low birth weight, puberty tends to start earlier and to have a faster course, so that final height may be moderately reduced. In these girls, metformin therapy may reverse the progression to clinical ovarian hyperandrogenism, normalize body composition and excess visceral fat, and delay pubertal progression without attenuating linear growth and bone mineralization, suggesting that adult height may be improved. Long-term follow-up of these patients is needed to fully determine the ultimate effects of insulin sensitization as well as the maintenance of these benefits after discontinuation of therapy.