Researchers reviewed the medical records of 55,593 men who were given testosterone for low testosterone levels and/or sexual dysfunction and compared them to men who received Viagra or Cialis but no testosterone. After three months, the risk for heart attacks was double in the testosterone group for all of the men older than 65, and for the men younger than 65 who had a history of heart disease (Public Library of Science, January 29, 2014). Men in both groups were similar in health problems and complained of similar symptoms. This study has prompted the U.S. Food and Drug Administration to start an investigation of the risk for heart attacks after taking testosterone.
Another study of 8709 men with low testosterone levels showed an increased risk of strokes, heart attacks, and deaths after starting testosterone (JAMA, November 6, 2013). A study to see if testosterone gel helped frail older men to build muscle and strength had to be stopped early because of a marked increase in heart attacks and one death (NEJM November 4, 2010).
Why Would Testosterone Increase Heart Attack Risk?
Testosterone lowers the good HDL cholesterol that helps to prevent heart attacks. It also causes the bone marrow to increase production of red blood cells, which, at high concentrations, can cause red cells to clump together to form clots that can block blood flow to the heart.
How Many Men Take Testosterone?
Testosterone is available by prescription as a topical skin gel or skin patch, by injections or as a paste applied in the mouth. More than five million North American men over 40 take testosterone and spend 1.6 billion dollars each year for their prescriptions. A very aggressive marketing program by drug companies is largely responsible for a fivefold increase in testosterone prescriptions from 2000 to 2011. This increase in testosterone use is greatest in younger men who are least likely to gain any benefits from taking it.
Some drug companies have falsely claimed that men with normal testosterone levels should take testosterone to increase energy, grow larger muscles, increase sexual drive, have increased interest in making love, and even prevent diabetes. None of the claims are supported by scientific evidence.
What Causes Low Testosterone?
Many of the drug companies that sell testosterone advertise that testosterone deficiency or “male menopause” is very common, but it is not. Only two percent of men age 40 to 80 suffer from symptoms of low testosterone (New England Journal of Medicine, published online June 16, 2010).
Testosterone declines naturally as a man ages, but many men who have low testosterone levels function perfectly normally sexually. The men who are most likely to take testosterone are weightlifters or other athletes who are trying to increase their strength by taking steroids. Steroids lower testosterone and also shorten lives.
High Rises in Blood Sugar Can Cause Low Testosterone
Among men not taking steroids, those who store fat primarily in their bellies are most likely to have low testosterone levels. Fat cells lower testosterone by converting testosterone (the male hormone) into estrogen (the female hormone). Having a fat belly is usually a sign that the person has high insulin levels and blood sugar levels. Many studies show that low testosterone is associated with insulin resistance with increased risk of diabetes and the metabolic syndrome (J Clin Endocrinol Metab, 2011 Aug;96(8):2341-53). High rises in blood sugar can damage the testicles to prevent them from making testosterone. This can be reversed by losing weight and making lifestyle changes to control high blood sugar levels (Journal of Endocrinology, published online December 18, 2013).
If You Suffer from Impotence
If you are a man who is impotent, check with your doctor. Male impotence is commonly caused by the same arterial plaques that cause heart attacks, and is rarely caused by low testosterone levels. Start a heart-attack preventing program of:
• losing excess weight,
• growing muscle,
• losing body fat,
• avoiding red meat, sugared drinks, sugar-added foods and fried foods,
• eating plenty of fruits and vegetables,
• exercising every day,
• getting blood levels of hydroxy vitamin D above 75 nmol/L, and
• avoiding alcohol and tobacco.