Testosterone link to heart attacks in men, say Edinburgh researchers
Testosterone may be one of the reasons why men are more prone to heart attacks than women, according to new research.
Edinburgh University scientists examined the effects of testosterone on blood vessel tissue and found it triggered the production of hard deposits or calcification.
The deposits "powerfully" predict the chance of death or major problems due to heart disease, they said.
During the study mice had testosterone receptors removed.
The mice then produced fewer hard deposits as they could no longer respond to the hormone.
Calcification causes blood vessels to harden and thicken, making the heart work harder to pump blood around the body.
It can also affect the valves of the heart, preventing them opening and shutting properly.
The authors said their findings suggested testosterone played a role in calcification and the discovery may lead to new treatments to prevent heart disease.
Researchers also examined blood vessel and valve tissue from people with heart disease.
They found tissue cells containing the hard bone-like deposits also carried the testosterone receptor.
This further suggested that testosterone may trigger calcification, they said.
At least 119,000 men are admitted to hospital every year suffering a heart attack, compared to 69,000 women.
Dr Vicky MacRae, from the University of Edinburgh's Roslin Institute, said: "Calcification is particularly difficult to treat, as the biological processes behind the disease are similar to those used by our body to make and repair bone.
"By finding this link between testosterone and calcification we may have discovered a new way of treating this disease and also reducing heart disease.
"This is a new pathway that hasn't really been examined before in the formation of calcification in the cardiac tissue.
"We hope that by understanding in more detail the pathways that are contributing to this, we may be able to work out therapies in future that may be able to target it and prevent calcification from happening, because at the moment there is no real therapy available to stop these calcium deposits from forming in blood vessels and heart valves."
Prof Jeremy Pearson, associate medical director at the British Heart Foundation, said: "The role of male sex hormones in the control of vascular calcification is poorly understood.
"This study, in cells taken from mice and human tissue, provides new evidence that testosterone can increase calcification.
"But significantly more research is needed to understand whether the results have implications for patients with heart disease or those taking androgen (testosterone) replacement therapy."
Funded by the British Heart Foundation (BHF) and the Biotechnology and Biological Sciences Research Council (BBSRC), the study was published in the journal Scientific Reports.