Men might be at greater risk of developing heart failure, heart attacks or blood clots than women at least in part because they have higher levels of testosterone, scientists say.
The team said the finding could help in the development of new treatments for heart disease.
Prof Mary Schooling, co-author of the study from the City University of New York, said: “We need to be thinking of new directions for reducing heart disease and this is one way of doing it,” pointing out that statins , which are used to reduce the risk of heart attack and stroke, have been found to lower testosterone levels. “To protect men we should be looking at treatments and lifestyles which are more on the side of keeping testosterone lower rather than higher,” she said, although she added that marketing such interventions could be challenging.
According to recent figures , one in seven men in the UK die from coronary heart disease compared with one in twelve women.
While the latest study is not the first to suggest a link between cardiovascular problems and higher testosterone levels, the team said it was important because it was based on genetic predisposition to higher testosterone levels.
The research also adds weight to suggestions that people who take testosterone supplements, which have become increasingly popular , might be putting themselves at risk: the US Food and Drug Administration has already warned of a link between testosterone and cardiovascular risk, recommending such treatments are only prescribed to those with low testosterone levels caused by a medical problem. “There have also been court cases where men who have had cardiovascular events have sued the testosterone sellers,” said Schooling.
Writing in the BMJ , researchers from the UK, US and China reported how they used genetic data from participants of the UK BioBank to explore whether there was a link between levels of testosterone and the chance of experiencing heart conditions.
The team looked at data collected between 2006 and 2010 from about 400,000 men and women aged 40-69, focusing on two regions of the genome linked to testosterone production, with each explaining just over 1% of the variation in testosterone levels. They then predicted individuals’ testosterone levels from the combination of genetic variants each individual had and looked at whether the participants went on to develop heart conditions by April 2018.
The results revealed that, while one of the two regions of the genome showed little link to any of the heart problems considered, the other did - albeit only in men. Indeed, both blood clots and heart failure were found to be more common the more testosterone a man was predicted to have based on his genetic variants. The team found no link to heart attacks, but they said that it could have been down to participants being generally healthy at the outset and there being few heart attacks to study. An association between predicted testosterone and heart attacks emerged when the team looked at data from another study involving a larger number of men in poorer health.
The study had some limitations, such as the fact that it focused largely on white people and included health data based, in part, on self reports. The approach also involved assumptions - for example that the genetic variants did not have a direct impact on cardiovascular disease risk and that the same gene regions affected testosterone production in women as men.
Dr Vicky MacRae from the University of Edinburgh, who was not involved in the study, said the research added to a growing body of evidence that testosterone might play a role in cardiovascular disease. But she added more research was needed to unpick the mechanisms behind such action and how testosterone interacts with oestrogen before treatments were developed.
–Guardian News & Media Ltd