In older men with low testosterone concentrations, testosterone therapy improves self-reported walking ability and outcomes on the 6-minute walking test but has no effect on fall frequency, according to study data published in The Lancet Diabetes & Endocrinology.
As part of a broader series of 7 testosterone trials, researchers conducted the Physical Function Trial to determine whether testosterone replacement positively affects measures of mobility in older men with testosterone concentrations below 275 ng/dL, mobility limitation, and a walking speed <1.2 m/s. In the trial, 390 community-dwelling men age ≥65 were randomly assigned to receive a daily dose of 1% testosterone gel or placebo for 12 months. Baseline characteristics were similar in both groups.
The researchers did not find a significant difference between Physical Function Trial groups with regard to absolute distance change from baseline on the 6-minute walking test. However, compared with all men included in the broader trials, men in the testosterone intervention groups were significantly more likely to improve their 6-minute walking test distance by at least 50 m than men in the placebo group (treatment effect, 1.77; P =.003).
Men treated with testosterone with baseline walking speeds of ≥1.2 m/s demonstrated significantly greater improvements on the 6-minute walking test (treatment effect, 14.2 m; P =.0004). Furthermore, men in the intervention groups were more likely to self-report improvement in their walking ability in both the Physical Function Trial population (effect size, 2.21; P =.002) and men not enrolled in the Physical Function Trial (effect size, 3.01; P =.0006).
The researchers reported a significant association between changes in 6-minute walking test distance and changes in total testosterone, free testosterone, dihydrotestosterone, and hemoglobin concentrations. However, they found fall frequency (27% had at least 1 fall) to be identical.
Certain limitations were noted for this study, including uncertainty regarding long-term functional improvements.
Based on their findings, the researchers said, “testosterone therapy should probably not be started specifically to improve physical function, although men who are treated with testosterone for other reasons could have some improvement in physical function.”
Bhasin S, Ellenberg SS, Storer TW, et al. Effect of testosterone replacement on measures of mobility in older men with mobility limitation and low testosterone concentrations: Secondary analyses of the testosterone trials. Lancet Diabetes Endocrinol. 2018;6:879-890.