Testosterone Injections Bring Their Own Risks

Compared to gels and patches, testosterone injections resulted in an elevated chance of experiencing cardiovascular and cerebrovascular events.

Published online in JAMA Internal Medicine, J. Bradley Layton, PhD and his colleagues identified cardiovascular and cerebrovascular events including myocardial infarction (MI), unstable angina, stroke, and composite acute event (MI, unstable angina, or stroke), venous thromboembolism (VTE) mortalities, and all-cause hospitalizations through assessing inpatient or outpatient medical records, diagnoses, or claims.

They limited their to analysis to patients in the United States and United Kingdom who started using testosterone patches, gels or injections after 180 days of testosterone withdrawal.

Using 3 secondary data sources, the team found 544,115 patients who began using testosterone, of which 37.4% injected, 6.9% used a patch, and 55.8% administered a gel. While a majority of men used a gel, US Medicare recipients used injections (51.2%) and UK patients equally used injections and gels (approximately 41%). Since Medicare recipients were the oldest on average, they noted the 1-year incidence of composite MI, angina, and stroke outcome was 23.1 events per 1000 person-years in gels, 36.6 in injections, and 34.9 in patches.

Overall, injection initiators had higher cardiovascular events (i.e., MI, unstable angina, and stroke) (1.26; 1.18-1.35), hospitalization (1.16; 1.13-1.19), and mortality (1.34; 1.15-1.56) occurrences than gel users. However, they found injectors had no elevated VTE risk (0.92; 0.76-1.11).

Moreover, a gel versus patches comparison produced no increased probability for cardiovascular events (1.10; 0.94-1.29), hospitalization (1.04; 1.00-1.08), death (1.02; 0.77-1.33), or VTE (1.08; 0.79-1.47).

Concluding their research, the authors disclosed that their study did not explore whether the patients were correctly or incorrectly prescribed testosterone or if former users were better off using testosterone than individuals that never used the drug.

Nevertheless, they touted their study for being widely representative of the general population, as it included patients of varying age groups, populations, medical histories, and health care systems.