Vicky MacRae and colleagues find that testosterone may be linked to the hardening of blood vessels associated with heart disease Image Testosterone might be involved in explaining why men have a greater risk of heart attacks than women of similar age. The study, funded by the British Heart Foundation (BHF) and the Biotechnology and Biological Sciences Research Council (BBSRC), could lead to new therapies to help reduce heart attack risk. Each year in the UK 188,000 people visit hospital whilst suffering from a heart attack, which is around one person every three minutes. The team led by Vicky MacRae at The Roslin Institute 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, by removing the testosterone receptor, so they could no longer respond to testosterone, they produced far fewer calcium deposits. The researchers also looked at blood vessel and valve tissue from humans 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 humans. Calcification causes blood vessels to harden and thicken, which means the heart has to work harder to pump blood around the body. It is strongly linked to increased risk of heart attack and stroke. Calcification can also affect the heart's valves, meaning that the valves cannot open and shut properly and may need to be replaced. Little is known about what triggers calcification. The research team now hope to drill down into the exact mechanism behind this process. 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. Dr Vicky MacRaeGroup Leader at The Roslin Institute 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 replacement therapy. Professor Jeremy PearsonAssociate Medical Director at the British Heart Foundation Further details can be found in the article published in Scientific Reports
