FRIDAY, Nov. 1, 2024 (HealthDay News) -- There is a dose-dependent association for smoking and cardiovascular disease (CVD) risk, according to a study published online Nov. 1 in JAMA Network Open.
Jun Hwan Cho, M.D., from Chung-Ang University Gwangmyeong Hospital in South Korea, and colleagues conducted a retrospective cohort study to examine the associations between smoking cessation, lifetime smoking burden, and CVD risk based on the numbers of years elapsed after smoking cessation.
The analyses included 5,391,231 participants: 15.8, 1.9, and 82.2 percent current smokers, ex-smokers, and never smokers, respectively, who were followed for a mean of 4.2 years. The researchers found that the median baseline cumulative smoking amounts were 14.0 and 10.5 pack-years for current smokers and ex-smokers, respectively. For ex-smokers, the median duration of smoking cessation was four years. There was a dose-dependent relationship observed between smoking and incident CVD, regardless of continued smoking. Ex-smokers with a lifetime smoking burden of less than eight pack-years (light ex-smokers) had a significant reduction in CVD risk within 10 years of cessation compared with current smokers, with the risk becoming similar to that of never-smokers. Ex-smokers with eight or more pack-years (heavy ex-smokers) had a slower decline in CVD risk, with the residual CVD risk not disappearing until after more than 25 years.
"Heavy ex-smokers should be considered to have a CVD risk equivalent to that of patients who continue to smoke, and management should be planned accordingly," the authors write.
One author disclosed ties to the pharmaceutical industry.