Peripheral artery disease and the impact of smoking

A recent study found that cigarette smoking not only boosts the risk of peripheral artery disease (PAD), but this elevated risk can persist up to 30 years after smoking cessation. The study also evidenced that the link between smoking and peripheral artery disease was even stronger than the established link between coronary heart disease and stroke.

The 2019 study was led by researchers at the Johns Hopkins Bloomberg School of Public Health and published in the Journal of the American College of Cardiology. It is the first comprehensive comparison of the elevated risks of smoking and peripheral artery disease, as well as coronary heart disease, and stroke. Study results were based upon 13,355 participants, including over 3,300 current smokers and approximately 4,200 former smokers, who were tracked for a period of 26 years.

The study found that compared with people who never smoked, those who did smoke for more than 40 pack-years had roughly four times more risk for peripheral artery disease, versus twice the risk for coronary heart disease and stroke. A pack-year is a parameter of smoking: 10 pack-years can mean one pack per day for 10 years or two packs per day for five years.

Likewise, participants who reported currently smoking more than a pack per day had a relative increased risk—5.4 times more for peripheral artery disease versus 2.4 for coronary heart disease and 1.9 for stroke—compared to those who had never smoked.

As one of the most common vascular diseases, peripheral artery disease features the atherosclerotic buildup of cholesterol-laden deposits in arteries that serve the legs. The reduction of blood flow leads to limb pain, poor wound healing, and various other signs and symptoms. The U.S. Centers for Disease Control and Prevention (CDC) estimates that about 8.5 million people in the U.S. have peripheral artery disease, including more than 10 percent of people older than 69, though most cases go undiagnosed because of little public awareness of the disorder.

The Johns Hopkins study ultimately proved that the effect of smoking on peripheral artery disease risk is longer lasting than risk factors for coronary heart disease, heart attacks, and stroke. Only after 30 years of smoking cessation did the peripheral artery disease risk for former smokers return to the baseline level seen in non-smokers. By comparison, coronary heart disease risk took about 20 years to return to baseline after smoking cessation.

The positive takeaway from the analysis is that quitting smoking appeared to bring a meaningful drop in peripheral artery disease risk fairly quickly. Smoking cessation for five to nine years was linked to a 57 percent drop in peripheral artery disease risk, compared to 30 to 40 percent for coronary heart disease and stroke.

Overall, the study results suggest that public health campaigns against smoking should begin to include a reference to the elevated peripheral artery disease risk and should emphasize how long it takes to eliminate that risk as a deterrent to starting smoking.