Men receiving testosterone therapy (TT) who develop polycythemia are at greater risk for major adverse cardiovascular events (MACE) and venous thromboembolism (VTE) in the first year of therapy, according to a recent study.
In this study, the authors sought to determine whether secondary polycythemia among men receiving TT confers an increased risk of MACE and VTE.
Two cohorts of men with low testosterone (total testosterone <350 ng/dl) who received TT and subsequently either developed polycythemia (n=5,887) or did not (n=42,784) were identified using a multi-institutional database of 74 million patients. Polycythemia was defined as haematocrit ≥52 percent.
The authors also identified two cohorts of hypogonadal men without polycythemia who either did (n=26,880) or did not (n=27,430) receive TT. Kaplan-Meier survival analysis was performed to examine the differences in MACE and VTE survival time; associations were then measured following propensity score matching.
Overall, 5,842 men on TT who developed polycythemia were matched and compared to 5,842 men who did not develop polycythemia. Participants with polycythemia showed a higher risk of MACE or VTE (number of outcomes: 301, 5.15 percent) than did those who had normal haematocrit (n=226, 3.87 percent) while on TT (odds ratio, 1.35, 95 percent confidence interval, 1.13‒1.61; p<0.001).
The risk of MACE and VTE did not increase in hypogonadal men who received TT compared with those naïve to TT.
“Future research on the safety of TT should include haematocrit as an independent variable,” the authors said.