Based on the existing medical literature on anabolic steroid-induced side effects, steroids provide the highest risk to the cardiovascular system. This is particularly true with the oral steroid drugs. The drugs do this through several mechanisms, such as a lowering of protective high density lipoprotein cholesterol (HDL), a possible rise in blood pressure, and adverse effects on blood clotting factors. But whether these adverse effects will prove significant depends on other factors. For example, most athletes who use steroids are healthy, with few other cardiovascular risk factors. They usually also have low body fat levels, and good heart function as a result of aerobic and weight-training exercise.Indeed, animal studies show that having an abundance of possible protective factors related to cardiovascular conditioning is enough to offset the possible risks imposed by steroid usage.On the other hand, little is known about the cumulative effects on cardiovascular function with long-term extensive steroid use by athletes. A while ago, I wrote an article in Ironman magazine about a study that examined coronary artery calcium deposits in a group of 14 elite professional bodybuilders. The study found that while these bodybuilders showed few CVD risk factors, most did show calcium deposits in their coronary arteries. Just today, a new report has been published in the Journal of the American Medical Association confirming that measuring coronary artery calcium deposits is a good predictor of future heart attacks.
Another study was also published online today related to athletic use of anabolic steroids. This study featured 12 weightlifters (they could have been bodybuilders, since medical journals often don't differentiate between actual weightlifters and bodybuilders) average age 40, who had used an average of 675 milligrams of anabolic steroids for nine years. They were compared to a control group, same age range, also weightlifters, but who had never used steroids. As expected, the steroid users showed greater muscle mass compared to the non-users. Both groups underwent a test called Doppler echocardiography that uses high frequency sound waves, or ultrasound, to measure the structure and function of the left ventricle, the pumping chamber of the heart that sends out blood to the body. The pumping power of the left ventricle is expressed as ejection fraction, with a normal level at 55 to 70 percent of the blood that fills the heart. But 83% of the steroid users in the study showed an ejection fraction of less than 55%. Only one of the non-steroid users showed a low ejection fraction. While the ejection fraction measurement relates to the pumping ability of the left ventricle, the steroid users also showed a significant impairment in the diastolic activity of the heart, or when the left ventricle relaxes and the heart refills with blood. Left ventricular relaxation was reduced by almost half in the steroid users. Interestingly, there was no significant differences between the steroid and and the non-steroid groups in relation to left ventricle structure.
Does this mean that those who are long-term anabolic steroids can expect to eventually get heart failure due to a weakness of left ventricular pumping ability? An initial study of only 12 subjects does not yet constitute scientific evidence of a cause and effect relationship between long-term steroid usage and heart failure.The study didn't disclose the precise exercise habits of the study subjects. I have previously discussed the fact that any exercise that places pressure on the heart leads to a compensatory increase in the thickness of the left ventricle, which some refer to as "athlete's heart." Athlete's heart is considered a benign condition, just a muscular adaptation of the heart to exercise. But some emerging studies also suggest that having an enlarged heart can predispose to later heart failure, even among athletes, if regular exercise isn't continued. Since aerobic exercise balances the structural heart changes that occur with athlete's heart, I would think that it's prudent for those who use high dose steroid regimes to also ensure including some aerobic exercise along with their weight-training regimes. I admit that this suggestion is strictly hypothetical on my part, but it does make sense when you consider the scenario discussed above.
Long term anabolic-androgenic steroid use is associated with left ventricular dysfunction. Circulation:Heart failure 2010: in press.
