Division of Cardiology, Chung-Ang University Gwangmyeong Hospital, Gwangmyeong, Republic of Korea.
Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
JAMA Netw Open. 2024 Nov 4;7(11):e2442639. doi: 10.1001/jamanetworkopen.2024.42639.
The association between smoking cessation and cardiovascular disease (CVD) risk in relation to cumulative smoking exposure remains poorly understood.
To evaluate the associations among smoking cessation, lifetime smoking burden, and CVD risk according to the number of years elapsed after smoking cessation.
DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study of the Korean National Health Insurance Service database investigated smoking duration and intensity between January 2006 and December 2008. Participants were categorized by self-reported smoking habits as current, ex-, or never-smokers. Smoking records were updated every 2 years until December 2019, with participants whose smoking status changed or whose smoking status was unclear excluded. Data analysis was performed between June and December 2022.
Time-updated self-reported smoking status, years since quitting, and cumulative smoking amount (pack-years [PY]).
The primary outcome was incidence and hazard ratio of CVD (composite of cardiovascular death, myocardial infarction, stroke, and heart failure).
Overall, 5 391 231 participants (39.9% male; mean [SD] age, 45.8 [14.7] years; 853 756 [15.8%] current smokers, 104 604 [1.9%] ex-smokers, and 4 432 871 [82.2%] never smokers) were followed up for a mean (SD) of 4.2 (4.4) years. The median (IQR) baseline cumulative smoking amounts were 14.0 (7.5-20.0) PY in current smokers and 10.5 (5.3-20.0) PY in ex-smokers. The median (IQR) duration of smoking cessation was 4 (2-8) years for ex-smokers. Regardless of continued smoking, a dose-dependent association was evident between smoking and incident CVD. Compared with current smokers, ex-smokers with a lifetime smoking burden of less than 8 PY (light ex-smokers) experienced a significant reduction in CVD risk within 10 years of cessation, with a CVD risk similar to that of never-smokers. Conversely, ex-smokers with at least 8 PY (heavy ex-smokers) exhibited a slower decline in CVD risk than light ex-smokers, requiring more than 25 years for the residual CVD risk to disappear.
In this cohort study, smoking and CVD risk exhibited a dose-dependent association, with light ex-smokers having a CVD risk similar to that of never-smokers relatively soon after smoking cessation. For heavy ex-smokers, greater than 25 years might be required for the residual CVD risk to align with that of never-smokers.
关于与累计吸烟量相关的戒烟与心血管疾病（CVD）风险之间的关联，人们仍知之甚少。
根据戒烟后经过的年数，评估戒烟、终生吸烟负担与 CVD 风险之间的关联。
设计、地点和参与者：这项来自韩国国家健康保险服务数据库的回顾性队列研究调查了 2006 年 1 月至 2008 年 12 月期间的吸烟持续时间和强度。参与者根据自我报告的吸烟习惯分为当前吸烟者、前吸烟者或从不吸烟者。吸烟记录每 2 年更新一次，直到 2019 年 12 月，期间排除了吸烟状况发生变化或吸烟状况不明的参与者。数据分析于 2022 年 6 月至 12 月进行。
时间更新的自我报告吸烟状况、戒烟年限和累计吸烟量（包年数[PY]）。
主要结局是 CVD 的发病和危险比（心血管死亡、心肌梗死、卒中和心力衰竭的综合指标）。
共有 5391231 名参与者（39.9%为男性；平均[SD]年龄为 45.8[14.7]岁；853756[15.8%]为当前吸烟者，104604[1.9%]为前吸烟者，4432871[82.2%]为从不吸烟者）接受了平均（SD）4.2（4.4）年的随访。当前吸烟者的基线累计吸烟量中位数（IQR）为 14.0（7.5-20.0）PY，前吸烟者为 10.5（5.3-20.0）PY。前吸烟者戒烟年限的中位数（IQR）为 4（2-8）年。无论是否持续吸烟，吸烟与发病 CVD 之间均存在明显的剂量-反应关系。与当前吸烟者相比，终生吸烟量少于 8 PY（轻度前吸烟者）的前吸烟者在戒烟后 10 年内 CVD 风险显著降低，其 CVD 风险与从不吸烟者相似。相比之下，至少 8 PY（重度前吸烟者）的前吸烟者的 CVD 风险下降速度比轻度前吸烟者慢，需要 25 年以上的时间才能使残余 CVD 风险消失。
在这项队列研究中，吸烟与 CVD 风险呈剂量依赖性相关，轻度前吸烟者在戒烟后不久其 CVD 风险与从不吸烟者相似。对于重度前吸烟者，可能需要 25 年以上的时间，残余 CVD 风险才会与从不吸烟者的风险相匹配。
