Alendronate for osteoporosis in men with androgen-repleted hypogonadism

Male hypogonadism is associated with low bone mineral density (BMD) and an increased risk of fractures. Testosterone replacement therapy improves BMD in young hypogonadal men. This effect is milder in older patients, who are at greater risk for fractures. We studied the effects of alendronate or placebo on BMD in 22 osteoporotic men, 29-69 years of age (mean, 50.2+/-11.2 years) with long-standing hypogonadism, receiving standard testosterone replacement treatment. Alendronate 10 mg daily (n=11) increased lumbar-spine BMD by 6.0 and 8.4% at 6 and 12 months, respectively, compared with -0.5% at 6 months and +3.3% at 12 months in the placebo group (n=11; P<0.005). Alendronate also increased mean femoral-neck BMD by 1.9% after 1 year, compared to a 1.4% decrease with placebo (P<0.005), and increased the total body bone mineral content by 4.4%, compared to a 0.6% decrease with placebo (P=0.07). After 6 months alendronate suppressed urinary deoxypyridinoline by 50% (P<0.005), compared to a 24% decrease in the placebo group. Both the alendronate and placebo groups continued with alendronate 70 mg once weekly for the following 2 years. Lumbar-spine BMD during this open-label study phase did not change significantly in the group originally treated with alendronate, but continued to increase in the placebo-alendronate group by 5.4, 6.5, and 6.2% after 18 (6 months of alendronate), 24 and 36 months, respectively (P<0.05). Femoral-neck BMD continued to increase in both groups receiving active therapy; in the alendronate-alendronate group by 3.7, 2.7, and 5.2% after 18, 24, and 36 months, respectively (P=0.01), and in the placebo-alendronate group by 0.7 and 1.9% at 24 (first 12 months of alendronate) and 36 months, respectively (P<0.05). Our results support the long-term administration of alendronate along with testosterone replacement to men with hypogonadism-induced osteoporosis.