Chronic Infections Raise Heart Risk in Smokers

If you have a chronic infection—such as bronchitis, an ulcer, a urinary tract infection, or even gum disease—smoking raises your risk of developing cardiovascular disease.

A new study has found that smokers with chronic infections were three times as likely to develop early atherosclerosis—hardening of the arteries caused by plaque deposits—than smokers without such an infection. The researchers also found the risk remained high in former smokers. Even passive or secondhand smoke increased the risk for early atherosclerosis in people with chronic infections.

"Part of the effects of smoking are irreversible when chronic infections have emerged, and smoking risk starts with a few cigarettes per day," says Dr. Stefan Kiechl, a professor of neurology at Innsbruck University Hospital in Austria and lead author of the study. The research appeared in the September issue of Stroke, Journal of the American Heart Association.

The Health Impact of Smoking

Nearly 47 million Americans still smoke cigarettes, and more than 400,000 die every year from smoking-related diseases, according to the Centers for Disease Control and Prevention (CDC). Direct medical costs from smoking top $75 billion annually in this country, the CDC reports.

Kiechl and his colleagues examined ultrasound scans of 826 men and women from northern Italy who were between the ages of 40 and 79. Four hundred and fifty three had never smoked; 212 were former smokers and 161 were current smokers.

Two ultrasound scans were taken—one in 1990 and the other in 1995. The scans detailed the carotid arteries, the main arteries that send blood to the brain. During the five years, 332 people had new plaque deposits in their carotid arteries.

Smoking Raises Health Risks

The more a person smoked—number of years and number of cigarettes per day—the more likely they were to develop atherosclerosis, the study found. Interestingly, the increased risk was only for those who also had a chronic infection.

Smokers with a chronic infection had 2.9 times the risk for early atherosclerosis, while past smokers with a chronic infection had a 1.9 times increased risk. Even nonsmokers who had chronic infections had a 1.8 times higher risk.

Kiechl says a chronic infection is one that lasts for three or more months in at least two consecutive years. So, someone who has five bouts of acute bronchitis that last a week or two each during a year would not be considered to have chronic bronchitis.

Smokers who did not have a chronic infection did not appear to be at any greater risk of developing early atherosclerosis, according to the study.

Does that mean it is OK to continue smoking?

Absolutely not, says Kiechl. Smoking is detrimental to a person's health in many ways. Smokers are at an increased risk of cancer and many other diseases. "In addition, the risk of acquiring chronic infections continuously increased with increasing duration of smoking and age, reaching near 100 percent in subjects over age 60 with more than 35 years [of smoking a pack a day]. They should not miss the opportunity to stop smoking before chronic infections have emerged," Kiechl says.

Smokers are more susceptible to chronic infection because the habit impairs the body's ability to fight infection, explains Dr. Dan Fisher, a cardiologist at New York University Medical Center.

Fisher says smokers who already have chronic infections should not be discouraged by this study's findings. While it appears that the risk for early atherosclerosis stays high even after quitting, it does go down. And, he says, the sooner you quit, the sooner you start reducing your risk.

"Smoking increases your risk of coronary disease dramatically," Fisher says. "I can't say it enough: Don't smoke."

Always consult your physician for more information.

Online Resources      

American Heart Association

Centers for Disease Control and Prevention (CDC)

National Heart, Lung, and Blood Institute (NHLBI)

Stroke, Journal of the American Heart Association