Background: We performed a meta-analysis of randomized clinical trials to determine the risks of adverse events associated with testosterone replacement in older men.
Methods: The MEDLINE database was searched from 1966 to April 2004, using testosterone as the indexing term; limits included human, male, > or =45 years old, and randomized controlled trial. Of the 417 studies thus identified, 19 met the inclusion criteria: testosterone replacement for at least 90 days, men > or =45 years old with low or low-normal testosterone level, randomized controlled trial, and medically stable men. Odds ratios (ORs) were pooled using a random effects model, assuming heterogeneous results across studies, and were weighted for sample size.
Results: In the 19 studies that met eligibility criteria, 651 men were treated with testosterone and 433 with placebo. The combined rate of all prostate events was significantly greater in testosterone-treated men than in placebo-treated men (OR = 1.78, 95% confidence interval [CI], 1.07-2.95). Rates of prostate cancer, prostate-specific antigen (PSA) >4 ng/ml, and prostate biopsies were numerically higher in the testosterone group than in the placebo group, although differences between the groups were not individually statistically significant. Testosterone-treated men were nearly four times as likely to have hematocrit >50% as placebo-treated men (OR = 3.69, 95% CI, 1.82-7.51). The frequency of cardiovascular events, sleep apnea or death was not significantly different between the two groups.
Conclusions: Testosterone replacement in older men was associated with a significantly higher risk of detection of prostate events and of hematocrit >50% than was placebo; hematocrit increase was the most frequent adverse event associated with testosterone replacement. These data reaffirm the need to monitor hematocrit, PSA, and digital examination of the prostate during testosterone replacement in older men.