Smoking cessation for 30 years confers reduced PAD risk similar to never smokers
Smoking has been shown to have significant associations with peripheral artery disease, CHD and stroke, with the strongest link seen for PAD, according to a study published in the Journal of the American College of Cardiology.
The study also found that the increased risk for PAD persisted for up to 30 years after smoking cessation and the risk for CHD continued for 20 years.
“It is important to recognize that the risk of the atherosclerotic diseases started to decline after smoking cessation in a short time frame of < 5 years, which would be encouraging to persons attempting or considering quitting smoking,” Ning Ding, MBBS, ScM, data analyst at Johns Hopkins Bloomberg School of Public Health, and colleagues wrote. “In addition, a clear dose-response relationship between the length of smoking cessation and lower risk of atherosclerotic diseases may encourage individuals with short-term smoking cessation to maintain cessation.”
ARIC study data
Researchers analyzed data from 13,355 participants (mean age, 54 years; 56% women) from the ARIC study aged 45 to 64 years without CHD, PAD and stroke at baseline. Information on smoking status, age smoking started and stopped, and smoking intensity was collected during a baseline interview.
Outcomes of interest included hospitalizations and deaths. Follow-up was conducted until death, a CV outcome, date of last contact or September 2015, whichever occurred first.
Of the participants in the study, 25% were current smokers, 31% were former smokers and 44% were never smokers. During a median follow-up of 26 years, there were 1,798 cases of CHD, 492 cases of PAD and 1,106 cases of stroke.
Participants who smoked for at least 40 pack-years had an estimated fourfold increased risk for PAD compared with those who never smoked. The HR for CHD was 2.1 and 1.8 for stroke. The link to pack-years was stronger for PAD compared with stroke and CHD (P for difference < .001). A stronger association with PAD vs. CHD and stroke was seen when smoking intensity and duration were assessed separately.
Compared with current smokers, participants who quit smoking for 5 to less than 10 years had an HR of 0.71 for CHD (95% CI, 0.57-0.88), 0.43 for PAD (95% CI, 0.28-0.64) and 0.61 for stroke (95% CI, 0.45-0.82). Smoking cessation for at least 30 years resulted in an HR of 0.47 for CHD (95% CI, 0.39-0.56), 0.22 for PAD (95% CI, 0.16-0.31) and 0.49 for stroke (95% CI, 0.39-0.62).
Participants who quit smoking for at least 30 years had a similar risk for PAD compared with those who never smoked. When participants quit smoking for 20 to less than 30 years, there was still an elevated HR for PAD (HR = 1.71; 95% CI, 1.2-2.44).
“Our study provides evidence for an anti-smoking campaign to continue to advocate smoking prevention and cessation,” Ding and colleagues wrote. “Although public statements about smoking and CVD have been focusing on CHD and stroke, our results indicate the need to take account of PAD as well for comprehensively acknowledging the effect of smoking on overall cardiovascular health.”
Understanding tobacco use
“Clinicians’ experience may be that smokers are not ready to quit, that treatments are ineffective or that long-term success is rare,” Nancy Rigotti, MD, professor of medicine at Harvard Medical School and director of the Tobacco Research and Treatment Center at Massachusetts General Hospital, and Mary M. McDermott, MD, Jeremiah Stamler Professor and professor of medicine (general internal medicine and geriatrics) and preventive medicine at Northwestern University Feinberg School of Medicine, wrote in a related editorial. “This stems from a misunderstanding of the nature of tobacco use. It is best understood as a chronic relapsing disorder driven by nicotine dependence whose treatment is characterized by repeated cycles of abstinence and relapse. Nonetheless, long-term tobacco abstinence is achievable using a chronic disease management approach resembling the strategies used to manage other risk factors.” – by Darlene Dobkowski
Disclosures: Ding reports no relevant financial disclosures. Rigotti reports she received royalties from UpToDate, consulted for Achieve Life Sciences and received travel expenses from Pfizer. McDermott reports she received research funding from Regeneron and received other research support from Chromadex, Hershey Company, ReserveAge and ViroMed. Please see the study for all other authors’ relevant financial disclosures.