A study of almost 45,000 men confirms that smoking is a key risk factor for poor circulation in the legs, a condition known as peripheral artery disease (PAD). Diabetes, high blood pressure and high cholesterol levels are other risk factors, the study found.

PAD increases the risk of heart attack and stroke, HealthDay reports. An estimated 8 million to 10 million Americans have PAD, the article notes.

In the new study, published in the Journal of the American Medical Association, researchers followed participants for more than two decades. They found that among the 537 men who developed PAD, smoking, diabetes, high blood pressure and high cholesterol levels were significantly and independently associated with the disease.

Men who did not have any of the four risk factors were 77 percent less likely to develop PAD, compared with the other men in the study.

Interventional cardiologist Dr. Maja Zaric of Lenox Hill Hospital in New York City, who was not associated with the study, pointed out that the study found smoking can affect the risk of PAD even 20 years after a person quits. “That should not discourage smokers from abstinence since the PAD risk amongst current smokers appears to be threefold higher than in former smokers,” she told HealthDay.