This study was to determine dose-dependent effects of testosterone administration on voice changes in women with low testosterone levels.
71 women who have undergone a hysterectomy with or without oophorectomy with total testosterone <31ng/dl and/or free testosterone <3.5 pg/ml received a standardized transdermal estradiol regimen during the 12-week run-in period, and were then randomized to receive weekly intramuscular injections of placebo, or 3, 6.25, 12.5 or 25 mg testosterone enanthate for 24 weeks. Total and free testosterone levels were measured by LC-MS/MS and equilibrium dialysis, respectively. Voice handicap was measured by self-report using a validated Voice Handicap Index (VHI) questionnaire at baseline and 24-weeks post-intervention. Functional voice testing was performed using Kay Elemetrics-Computer Speech Lab (CSL) to determine voice frequency, volume and harmonics.
46 women with evaluable voice data at baseline and post-intervention were included in the analysis. The five groups were similar at baseline. Mean on-treatment nadir total testosterone concentrations were 13, 83, 106, 122 and 250 ng/dl in the placebo, 3, 6.25, 12.5 and 25-mg groups, respectively. Analyses of acoustic voice parameters revealed significant lowering of average pitch in the 12.5-mg and 25-mg dose groups compared to placebo (p<0.05); these changes in pitch were significantly related to increases in testosterone concentrations. No significant dose or concentration-dependent changes in self-reported VHI scores were observed.