Background: Finasteride is a 5alpha-reductase inhibitor that has proved to be an effective treatment for men with androgenetic alopecia.
Objectives: To investigate the hormonal influence of finasteride 1 mg daily on hormonal levels and hair growth in men of different ages and with different degrees of alopecia according to the Hamilton-Norwood scale.
Methods: Two hundred and seventy men aged 14-58 years with male androgenetic alopecia III-VI Hamilton-Norwood score (II-III Ebling score) were treated with finasteride 1 mg daily. Steroid hormone (free testosterone, 5alpha-dihydrotestosterone, dehydroepiandrosterone-sulphate, delta4-androstenedione, 17-hydroxyprogesterone), prostate-specific antigen (PSA) and sebum levels, and trichogram changes were determined at baseline, and at 6 and 12 months of treatment.
Results: According to significant hormonal statistical analysis, the patients were divided by age (up to or over 26 years). In the group of patients<or=26 years, higher levels of 5alpha-dihydrotestosterone were found at the beginning of the treatment, but there was a 50% decrease between the onset of treatment and month 12, particularly noticeable at 6 months (P<0.05) of treatment, running parallel to an improvement of the alopecia and an increase of anagen hairs in the trichogram. At 1 year, PSA levels decreased 20%, particularly in patients>26 years. No variations in sebum levels were observed.
Conclusions: High levels of 5alpha-dihydrotestosterone in patients<or=26 years at the beginning of treatment are a predictive factor of good response to treatment with finasteride 1 mg daily.