Heart disease and insulin resistance in men linked to testosterone and oestrogen levels

The sex hormones testosterone and oestrogen can affect a man’s likelihood of developing heart disease and type 2 diabetes, according to new research.
The study, presented at the Endocrine Society’s 97th annual meeting in San Diego, suggests that high levels of testosterone make men more likely to develop heart disease.
Low levels of oestrogen increase the likelihood of insulin resistance, high fasting blood glucose levels, and fat in the muscles, thereby increasing the risk of type 2 diabetes.
Heart disease is one of the most common diabetic complications, the cause of death for 80 per cent of people with diabetes. High blood glucose levels can damage the makeup of blood vessels, making them thicker. This, in turn, can impair blood flow.
The study
Researchers gathered 400 healthy men between the ages of 20 and 50. They found that higher levels of testosterone caused lower levels of high-density lipoprotein (HDL). HDL is known as “good” cholesterol because it clears “bad” cholesterol out of the arteries.
Moreover, the men with lower levels of oestrogen had higher fasting blood glucose levels, higher risk of insulin resistance, and more fat in their muscles, factors which suggested a higher risk of type 2 diabetes. Because diabetes increases the risk of heart disease, low levels of oestrogen indirectly increase the risk of heart disease.
Elaine Yu, MD, MSc, and lead investigator, said: “These observations may help explain why men have a higher risk of cardiovascular disease.”
Neither testosterone or oestrogen were associated with higher levels of low-density lipoprotein, or “bad” cholesterol. “It appears that these common risk factors for cardiovascular disease are not regulated by sex hormones,” said Yu.