Healthy men under the age of 65 who are prescribed testosterone by their doctors are not more at risk of having a heart attack. But in men over 65 and younger men with cardiovascular problems, testosterone therapy can increase the chance of a heart attack by a factor two to three. Researchers at the private Consolidated Research in Los Angeles have reached this conclusion.
Cardiologists still don’t know exactly how dangerous testosterone therapy is. There are studies in which testosterone, in older men in particular, raises the chances of cardiovascular disease, but there are others that indicate the risks are negligible. Meta-studies therefore tend to conclude that the cardiological risks of testosterone therapy have not been proven – but sometimes add a warning note that most of the research has been funded by manufacturers of testosterone products.
The researchers wanted to throw more light on the safety of testosterone supplementation in an unusually big study. They gathered data on 55,593 men who had been prescribed injectable testosterone cypionate or testosterone gels by doctors, and monitored them for a period.
The maximum length of time that the researchers monitored the men was 25 months. The researchers noted whether the men had a heart attack.
They also looked at whether the men had had a heart attack in the period before they started using testosterone. This way they could determine whether testosterone boosted the chance of a heart attack, and if so, by how much.
The researchers also gathered data on 167,279 men who had been prescribed the erection medicines sildenafil or tadalafil by their doctors. This enabled the researchers to compare the risks of both types of medication.
Erection medicines did not increase the likelihood of a heart attack, the researchers discovered. The miniscule increase shown in the figure below was not statistically significant.
Testosterone, on the other hand, did increase the likelihood of a heart attack, as the graph below shows.
In healthy men under 65 the testosterone therapy did not increase the risk of a heart attack, but in men with cardiovascular problems in this age group, testosterone administration tripled the chance of a heart attack. Testosterone doubled the chance of a heart attack in men over the age of 65.
“Given the rapidly increasing use of testosterone therapy, the current results, along with other recent findings emphasize the urgency of the previous call for clinical trials adequately powered to assess the range of benefits and risks suggested for such therapy”, the researchers conclude. “Until that time clinicians might be well advised to include serious cardiovascular events in their discussions with patients of potential risks, particularly for men with existing cardiovascular disease.”
Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men.
An association between testosterone therapy (TT) and cardiovascular disease has been reported and TT use is increasing rapidly.
We conducted a cohort study of the risk of acute non-fatal myocardial infarction (MI) following an initial TT prescription (N = 55,593) in a large health-care database. We compared the incidence rate of MI in the 90 days following the initial prescription (post-prescription interval) with the rate in the one year prior to the initial prescription (pre-prescription interval) (post/pre). We also compared post/pre rates in a cohort of men prescribed phosphodiesterase type 5 inhibitors (PDE5I; sildenafil or tadalafil, N = 167,279), and compared TT prescription post/pre rates with the PDE5I post/pre rates, adjusting for potential confounders using doubly robust estimation.
In all subjects, the post/pre-prescription rate ratio (RR) for TT prescription was 1.36 (1.03, 1.81). In men aged 65 years and older, the RR was 2.19 (1.27, 3.77) for TT prescription and 1.15 (0.83, 1.59) for PDE5I, and the ratio of the rate ratios (RRR) for TT prescription relative to PDE5I was 1.90 (1.04, 3.49). The RR for TT prescription increased with age from 0.95 (0.54, 1.67) for men under age 55 years to 3.43 (1.54, 7.56) for those aged ? 75 years (p trend = 0.03), while no trend was seen for PDE5I (p trend = 0.18). In men under age 65 years, excess risk was confined to those with a prior history of heart disease, with RRs of 2.90 (1.49, 5.62) for TT prescription and 1.40 (0.91, 2.14) for PDE5I, and a RRR of 2.07 (1.05, 4.11).
In older men, and in younger men with pre-existing diagnosed heart disease, the risk of MI following initiation of TT prescription is substantially increased.
PMID: 24489673 [PubMed – in process] PMCID: PMC3905977