Testosterone treatment increases bone density, strength in low-testosterone men
Testosterone treatment significantly increased volumetric bone mineral density (vBMD) and estimated bone strength in older men with low testosterone levels, according to a recent study.
In this placebo-controlled, double-blind trial, 211 men (mean age, 72.3 years) with low serum testosterone concentrations were randomized to receive a daily dose of testosterone gel (n=110) or placebo (n=101) for one year, 189 of whom completed the treatment (n=104 and 85 in the testosterone and placebo arms, respectively). [JAMA Intern Med 2017;doi:10.1001/jamainternmed.2016.9539]
Compared with placebo, testosterone treatment was associated with significantly greater increases in mean lumbar spine trabecular vBMD (7.5 percent, 95 percent confidence interval [CI], 4.8–10.3 percent vs 0.8 percent, 95 percent CI, -1.9 to 3.4 percent; p<0.001) and mean estimated strength of spine trabecular bone (10.8 percent, 95 percent CI, 7.4–14.3 percent vs 2.4 percent, 95 percent CI, −1.0 to 5.7 percent; p<0.001).
Testosterone treatment also increased mean areal BMD in the lumbar spine and total hip compared with placebo (3.3 percent, 95 percent CI, 2.01–4.56 percent vs 2.1 percent, 95 percent CI, 0.87–3.36 percent; p=0.01 for lumbar spine and 1.2 percent, 95 percent CI, 0.19–2.17 percent vs 0.5 percent, 95 percent CI, -0.45 to 1.46 percent; p=0.052 for total hip).
“[The] results are unequivocal compared with prior studies of the effect of testosterone treatment on bone in older men, in spite of treatment limited to [one] year, perhaps because the mean pretreatment testosterone level was lower,” said the researchers.
The incidence of fractures during the treatment period (n=6 in each treatment arm) and subsequent follow-up (n=3 and 4 in the testosterone and placebo arms, respectively) was also a notable finding. As men’s susceptibility to fracture increases with age, a more comprehensive trial is warranted to establish the role of testosterone treatment in reducing fracture risk in this population, they added.
Osteoporosis appeared to be a significant consideration, given previous study findings showing similar results of improved vBMD and estimated bone strength with anabolic or antiresorptive agents for osteoporosis. [J Clin Endocrinol Metab 2013;98:571-580; J Bone Miner Res 2014;29:158-165] However, the inclusion of nonosteoporotic men in the current study limited the findings as the results could not be presumed for a male population with osteoporosis but not low testosterone levels, noted the researchers.