Testosterone replacement therapy among elderly males: the Testim Registry in the US (TRiUS)

Abstract

Background: Testosterone levels naturally decline with age in men, often resulting in testosterone deficiency (hypogonadism). However, few studies have examined hypogonadal characteristics and treatment in older (≥65 years) men.

Objective: To compare data at baseline and after 12 months of testosterone replacement therapy (TRT) in hypogonadal men ≥65 vs <65 years old. Data for participants 65-74 vs ≥75 years old were also compared.

Methods: Data were from TRiUS (Testim Registry in the United States), which enrolled 849 hypogonadal men treated with Testim(®) 1% (50-100 mg testosterone gel/day) for the first time. Anthropometric, laboratory, and clinical measures were taken at baseline and 12 months, including primary outcomes of total testosterone (TT), free testosterone (FT), and prostate-specific antigen (PSA) levels. Comparisons of parameters were made using Fisher's exact test or analysis of variance. Nonparametric Spearman's ρ and first-order partial correlation coefficients adjusted for the effect of age were used to examine bivariate correlations among parameters.

Results: Of the registry participants at baseline with available age information, 16% (133/845) were ≥65 years old. They were similar to men <65 years old in the duration of hypogonad-ism prior to enrollment (~1 year), TT and FT levels at baseline, TT and FT levels at 12-month follow-up, and in reported compliance with treatment. Older patients were more likely to receive lower doses of TRT. PSA levels did not statistically differ between groups after 12 months of TRT (2.18 ± 2.18 ng/mL for ≥65 vs 1.14 ± 0.84 ng/mL for <65 years old, P = 0.1). Baseline values for the >75-year-old subcohort were not significantly different from subcohorts aged 65-74 years and <65 years.

Conclusion: Hypogonadal men ≥65 years old showed significant benefit from TRT over 12 months, similar to that found for hypogonadal men <65 years old. TRT was well tolerated in older patients, successfully increased testosterone level regardless of age, and did not significantly increase PSA levels in older men.

Keywords: TRiUS registry; Testim; elderly; male hypogonadism; testosterone gel; testosterone replacement therapy.