12-month observation of testosterone replacement effectiveness in a general population of men

Testosterone decline becomes more prevalent as men age and symptomatic testosterone deficiency is associated with potentially serious comorbidities. Despite limitations, registries can provide an opportunity to accumulate data regarding disease management in a typical patient population, including diagnosis, treatment, and outcomes.

The Testim Registry in the United States (TRiUS) was a prospective, 12-month, observational cohort registry of men prescribed Testim® (1% testosterone gel; Auxilium Pharmaceuticals, Inc.) for the first time; patients previously on other forms of testosterone replacement therapy (TRT) were eligible to participate in the study as well. The registry recorded total testosterone (TT) and free testosterone (FT) levels, prostate-specific antigen (PSA), sexual function, mood/depression, and cardiometabolic and anthropometric criteria before and after TRT. Changes over time were analyzed by analysis of variance, and linear regression and Pearson product-moment correlation coefficients were used to examine relationships between variables.

At baseline, 849 patients from 72 sites were enrolled, with 743 of 849 started on 5 g gel/day (50 mg testosterone/day) and 106 of 849 started on 10 g gel/day (100 mg testosterone/day). Mean TT and FT levels increased significantly after 3 months of TRT (TT level, 16.8 ± 9.87 nmol/L [485 ± 284 ng/dL], P < 0.001; FT level, 286.3 ± 224.9 pmol/L [82.5 ± 64.8 pg/mL], P < 0.001) and were maintained at eugonadal levels. Mean PSA levels increased significantly (P = 0.004) from 1.12 ± 1.11 μg/L (1.12 ± 1.11 ng/mL) at baseline to 1.26 ± 1.22 μg/L (1.26 ± 1.22 ng/mL) after 12 months of TRT, although changes were well within guidelines (< 1.4 μg/L/year increase). Significant improvements were seen in sexual function and mood/depression at 3 months and in metabolic parameters at 12 months.

Testosterone deficiency symptoms improved with TRT use in men; sexual function and mood/depression improvements were seen before metabolic improvements. Prostate-specific antigen levels increased, although increases were within guideline-determined safety limits.