5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase activity in prepubertal Hispanic girls with premature adrenarche

Girls with idiopathic premature adrenarche, characterized by the early appearance of pubic hair and adrenal hyperandrogenism, may be at an increased risk for polycystic ovarian syndrome and its associated complications. Alterations of peripheral metabolism of adrenal steroids, specifically increased 5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase activities, have been documented in patients with polycystic ovarian syndrome and proposed as an underlying mechanism for the adrenal hyperandrogenism in this syndrome. We sought to investigate whether alterations in 5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase activities are present in girls with premature adrenarche, suggesting a possible role in the pathogenesis of the hyperandrogenism of this condition. We studied C19 and C21 urinary steroid metabolites, 5 alpha/5 beta and 11 oxo/11 hydroxy metabolite pairs as well as the ratios of the total 5 alpha/total 5 beta and total 11 oxo/total 11 hydroxy metabolites in 24-h urine samples from 17 prepubertal Hispanic girls with premature adrenarche and seven controls. We found no differences in the 5 alpha-reductase or 11 beta-hydroxysteroid dehydrogenase activities in the prepubertal girls with premature adrenarche, compared with the controls. When age and body mass index Z-score were controlled for in the statistical analysis, the results did not change. Total cortisol metabolites were not different in the girls with premature adrenarche, compared with the controls. In conclusion, we did not demonstrate a difference in the peripheral steroid metabolism, specifically 5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase activities, in prepubertal Hispanic girls with premature adrenarche, compared with controls. Therefore, in this group of young girls, alterations in 5 alpha-reductase or 11 beta-hydroxysteroid dehydrogenase activities do not appear to contribute to their early pubic hair development.