Production rates of testosterone and of dihydrotestosterone in female pattern hair loss.

Vierhapper H, Maier H, Nowotny P, Waldhausl W.

Division of Endocrinology and Metabolism, Department of Internal Medicine III, University of Vienna, Austria.

Production rates of testosterone (T) and of dihydrotestosterone (DHT) were determined in young women (n=8, age, 23 to 40 years) with female-pattern hair loss using the stable isotope dilution technique and mass spectrometry.

1 alpha,2 alpha-d-testosterone and 2,3,4-13C-dihydro-testosterone were infused for 10 hours at a dose of 2 microg/h each and blood samples were obtained at 20-minute intervals during the last 4 hours of the observation period.

In the presence of normal metabolic clearance rates (MCRs), production rates of T were increased (9.4+/-5.0 microg/h; normal, 4.3+/-1.9 microg/h, P<.05). MCRs of DHT (8.0+/-3.4 L/h; normal, 25.9+/-12.3 L/h, P<.002) were subnormal in all women and the production rates of DHT were within or below the normal range (mean, 1.6+/-0.6 microg/h; normal, 2.9+/-1.1 microg/h, P<.02).

Unlike men with male-pattern baldness, women with female-pattern baldness are characterized by increased production rates of T, but not of DHT.

These results are compatible with the idea that 5 alpha-reductase inhibition is of no therapeutical value in female-pattern baldness.

PMID: 12870172 [PubMed - indexed for MEDLINE]