0736 GMT August 22, 2019
The study, conducted in 400 healthy men ages 20 to 50, found that higher levels of testosterone led to lower levels of HDL cholesterol, or "good" cholesterol, but estrogen appeared to have no effect on HDL cholesterol. In contrast, the investigators reported that low levels of estrogen led to higher fasting blood glucose (sugar) levels, worsening insulin resistance and more fat in muscle, markers for developing diabetes, which is itself a risk factor for heart disease, MedIndia said.
At the start of the study, all men received the drug goserelin (Zoladex, AstraZeneca) to suppress their own production of testosterone and estrogen. Then the 198 men in the first group received daily treatment for four months with either a placebo (dummy) gel or one of four doses of testosterone gel (AndroGel, AbbVie), ranging from low to high (1.25 to 10 grams).
The other group, made up of 202 men, received the same treatment as in group 1 but also received anastrozole (Arimidex, AstraZeneca) to block conversion of testosterone to estrogen. Men naturally convert some testosterone to estrogen.
Study participants had their weight measured and had fasting blood tests for markers of heart disease and diabetes. At the start and end of the study, they had a thigh scan with quantitative computed tomography (CT) to measure muscle fat.
The researchers found that neither testosterone nor estrogen regulated changes in LDL, or "bad" cholesterol, blood pressure and body weight.