Testosterone may be one of the reasons why men have a greater risk of heart attacks than women of similar age, research suggests.
Scientists have found that the hormone can help to trigger the hardening of blood vessels that is associated with heart disease.
The study could lead to new therapies to help reduce heart attack risk, the researchers say.
Researchers at the University of Edinburgh examined the effects of testosterone on blood vessel tissue from mice.
They found that the hormone triggers cells from the blood vessels to produce bone-like deposits – a process called calcification.
When the mouse cells were modified so that they no longer carried the receptor for testosterone, they could no longer respond to the hormone and produced far less of the calcium deposits, the research showed.
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.
The team also looked at blood vessel and valve tissue from patients with heart disease who had undergone surgery for their condition.
They found that cells from these tissues contained bone-like deposits and also carried the testosterone receptor on their surface.
This suggests that testosterone may trigger calcification in people.
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.
Calcification causes blood vessels to harden and thicken, which means the heart has to work harder to pump blood around the body.
It can also affect the heart’s valves so that they cannot open and shut properly and may need to be replaced.
Little is known about what triggers calcification and there are currently no treatments.
The study, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the British Heart Foundation, is published in the journal Scientific Reports.