HOUSTON — Administering testosterone to surgically menopausal women resulted in dose- and concentration-dependent increases in lean body mass, according to Grace Huang, MD, a fellow at Boston University Medical Center, who presented results of a randomized trial.
To establish the relationship between testosterone and changes in body composition and muscle strength in women, and more specifically the dose-dependent effect of graded doses of testosterone on these outcomes in surgically menopausal women, Huang and colleagues conducted a randomized trial of 71 women.
All women were surgically menopausal and underwent a standardized estrogen regimen during a 12-week run-in period, after which they were randomly assigned to one of five intramuscular injection groups for 24 weeks:
- 3 mg testosterone enathate (Delatestryl, Endo)
- 6.25 mg testosterone enathate
- 12.5 mg testosterone enthate
- 25 mg testosterone enthate
Liquid chromatography–mass spectrometry and equilibrium dialysis were used to measure total and free testosterone levels; DXA scan was used to measure lean body mass and fat mass; and one-repetition maximum method was used to assess muscle strength at baseline and 24 weeks.
Baseline characteristics were: mean age, 53 years; BMI, 30; total testosterone, 13.7 ng/dL; and free testosterone, 2.2 pg/mL.
In the five treatment groups, on-treatment nadir testosterone levels were 14 ng/dL for placebo, 78 ng/dL for the 3-mg dose, 105 ng/dL for 6.25-mg dose, 130 ng/dL for 12.5-mg dose and 211 ng/dL for 25-mg dose.
According to Huang, changes in testosterone concentrations were greatly associated with changes in lean body mass. Additionally, patients in the 25-mg dose group experienced a significant increase in lean body mass of 1.8 kg, on average (P=.01).
There were no significant changes in fat mass or leg press strength, according to Huang. However, the researchers saw significant gains in chest press power and loaded stair climb power at the 25-mg dose only.
“Although we saw few androgenic side effects in our trial, even in the highest dose group, the overall safety profile of testosterone administration at these doses remain unclear, these include metabolic outcomes such as fasting insulin and glucose, lipid profile, as well as body fat distribution and mood, which our group is still in the process of analyzing for this trial,” Huang said during her presentation.
“If the safety profile of these outcomes are established, then we could consider short-term clinical trials of testosterone therapy in special subpopulations of women with physical limitations, for example women recovering from hip fracture and other types of physical rehab, as well as the use of Selective Androgen Receptor Modulators,” she said. – by Stacey L. Fisher
For more information:
Huang G. Abstract #S18-5. Presented at: the Endocrine Society’s 94th Annual Meeting and Expo; June 23-26, 2012; Houston.
Disclosure: The researchers report no relevant financial disclosures.