The long-term effect of specific type II 5alpha-reductase inhibition with finasteride on bone mineral density in men: results of a 4-year placebo controlled trial.

Author(s): Matsumoto AM, Tenover L, McClung M, Mobley D, Geller J, Sullivan M, Grayhack J, Wessells H, Kadmon D, Flanagan M, Zhang GK, Schmidt J, Taylor AM, Lee M, Waldstreicher J, Pless Study Group

Affiliation(s): VA Puget Sound Health Care System and University of Washington, Seattle, USA.

Publication date & source: 2002-05, J Urol., 167(5):2105-8.

Publication type: Clinical Trial; Randomized Controlled Trial

PURPOSE: We determine the effect of long-term suppression of dihydrotestosterone with finasteride, a specific type II 5alpha-reductase inhibitor, on bone mineral density. MATERIALS AND METHODS: As part of a large (3,040 cases) 4-year, double-blind, placebo controlled trial designed to assess the long-term effects of finasteride in men with benign prostatic hyperplasia, 157 men 46 to 76 years old who were randomized to receive either 5 mg. finasteride or placebo underwent dual energy x-ray absorptiometry of the lumbar spine at baseline and at years 2, 3 and 4. RESULTS: Of 117 patients who had a baseline measurement and at least 1 additional measurement during the study baseline mean plus or minus standard deviation bone mineral density values were 1.12 +/- 0.17 gm./cm.2 in the finasteride group (63) and 1.10 +/- 0.17 gm./cm.2 in the placebo group (54). After 4 years bone mineral density was not different between treatment groups (finasteride 1.14 +/- 0.17 gm./cm.2 and placebo 1.13 +/- 0.18 gm./cm.2). Similar results were obtained for the 33 finasteride and 25 placebo treated patients who completed the study with year 4 bone mineral density measurements. CONCLUSIONS: These data demonstrate that long-term inhibition of type II 5alpha-reductase with finasteride does not adversely affect bone mineral density.