Men who have low levels of testosterone are at an increased risk of heart disease and early death, particularly from cardiovascular diseases, a study revealed.

Testosterone is a male sex hormone essential for sexual development and functions in men. The normal testosterone levels range from 300 and 1,000 ng/dL. When testosterone levels are low, the condition is called low T or testosterone deficiency syndrome which affects around 2.1% of males. Men with low testosterone may develop symptoms such as reduced muscle mass, low sex drive, fatigue, irritability, and erectile dysfunction.

"Testosterone has a range of actions in the body — for example, affecting muscle and fat mass, and bone density, so it is possible that low testosterone concentrations might contribute to the development of poorer health outcomes. It is also possible that lower testosterone concentrations identify men already at risk of poorer health," said Bu B. Yeap, a study author from the University of Western Australia in Perth.

According to the findings published in the Annals of Internal Medicine, men who have testosterone levels below the normal range (less than 213 ng/dL) are at a 40 percent higher risk of death from all causes, and those with extremely low T (below 153 ng/dL) are at 60% higher risk of death from heart disease.

To evaluate the link between low testosterone and cardiovascular death risk, the research team reviewed 11 studies that involved more than 24,000 participants. Using individual patient data that contained the participant's baseline hormone concentrations, including total testosterone, sex hormone-binding globulin, luteinizing hormone, dihydrotestosterone, and estradiol, researchers evaluated the relative risk for developing cardiovascular diseases, deaths from CVD, and all-cause mortality.

"The data showed that only men with low total testosterone concentrations had higher risks for all-cause mortality. A key finding was that men with a testosterone concentration below 7.4 nmol/L (<213 ng/dL) had a higher risk for all-cause mortality, regardless of LH concentration. Men with a testosterone concentration below 5.3 nmol/L (<153 mg/dL) had increased risk of cardiovascular death," the news release stated.

The study also noted that having very low estradiol concentrations (a form of estrogen, female sex hormones) also increased all-cause mortality in men.

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