Genes predict if medication can help you quit smoking

The same gene variations that make it difficult to stop smoking also increase the likelihood that heavy smokers will respond to nicotine-replacement therapy and drugs that thwart cravings, a new study shows.

The research, led by investigators at Washington University School of Medicine in St. Louis, will appear online May 30 in the American Journal of Psychiatry.

The study suggests it may one day be possible to predict which patients are most likely to benefit from drug treatments for nicotine addiction.

“Smokers whose genetic makeup puts them at the greatest risk for heavy smoking, nicotine addiction and problems kicking the habit also appear to be the same people who respond most robustly to pharmacologic therapy for smoking cessation,” says senior investigator Laura Jean Bierut, MD, professor of psychiatry. “Our research suggests that a person’s genetic makeup can help us better predict who is most likely to respond to drug therapy so we can make sure those individuals are treated with medication in addition to counseling or other interventions.”

For the new study, the researchers analyzed data from more than 5,000 smokers who participated in community-based studies and more than 1,000 smokers in a clinical treatment study. The scientists focused on the relationship between their ability to quit smoking successfully and genetic variations that have been associated with risk for heavy smoking and nicotine dependence.

“People with the high-risk genetic markers smoked an average of two years longer than those without these high-risk genes, and they were less likely to quit smoking without medication,” says first author Li-Shiun Chen, MD, assistant professor of psychiatry at Washington University. “The same gene variants can predict a person’s response to smoking-cessation medication, and those with the high-risk genes are more likely to respond to the medication.”

What are the benefits over time?

20 minutes after quitting

Your heart rate and blood pressure drop.

(Effect of smoking on arterial stiffness and pulse pressure amplification, Mahmud A, Feely J. Hypertension. 2003:41:183)

12 hours after quitting

The carbon monoxide level in your blood drops to normal.

(US Surgeon General's Report, 1988, p. 202)

2 weeks to 3 months after quitting

Your circulation improves and your lung function increases.

(US Surgeon General's Report, 1990, pp.193, 194,196, 285, 323)

1 to 9 months after quitting

Coughing and shortness of breath decrease; cilia (tiny hair-like structures that move mucus out of the lungs) start to regain normal function in the lungs, increasing the ability to handle mucus, clean the lungs, and reduce the risk of infection.