Augmentation of bone mineral density in hirsute women.

Abstract

Hirsutism is associated with both hyperandrogenism and oligomenorrhea or amenorrhea, which have opposing effects on bone mineral density (BMD). We tested the hypothesis that hyperandrogenism in hirsute women counteracts the osteopenic effects of menstrual dysfunction. Using dual energy x-ray absorptiometry, we measured BMD and total bone mineral content (BMC) in 32 young women referred for hirsutism. The control group consisted of 25 matched, nonhirsute women. Among the hirsute women, 21 reported regular menses, and 11 gave a history of oligomenorrhea; all members of the control group reported regular menses. Compared with controls, hirsute women had higher total BMD (1.202 +/- 0.02 vs. 1.116 +/- 0.02 g/cm2, P < 0.01), lumbar spine BMD (1.183 +/- 0.02 vs. 1.125 +/- 0.02 g/cm2, P < 0.01), and total BMC (2700 +/- 66 vs. 2400 +/- 70 g, P < 0.001). Serum total testosterone levels were similar, but androstenedione levels were higher (11.7 +/- 0.80 vs. 7.9 +/- 0.79 nmol/L, P < 0.005) and sex hormone binding globulin levels lower (22.0 +/- 3.0 vs. 57.6 +/- 8.5 nmol/L, P < 0.001) in hirsute women than controls. Oligomenorrheic hirsute women had higher BMD than nonhirsute women, although the augmentation was less pronounced than in eumenorrheic hirsute women. These results indicate that hirsutism is associated with higher bone density and mineral content, consistent with a net positive effect of hyperandrogenism on skeletal mass.