Title | Lung function decline in former smokers and low-intensity current smokers: a secondary data analysis of the NHLBI Pooled Cohorts Study. |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Oelsner, EC, Balte, PP, Bhatt, SP, Cassano, PA, Couper, D, Folsom, AR, Freedman, ND, Jacobs, DR, Kalhan, R, Mathew, AR, Kronmal, RA, Loehr, LR, London, SJ, Newman, AB, O'Connor, GT, Schwartz, JE, Smith, LJ, White, WB, Yende, S |
Journal | Lancet Respir Med |
Volume | 8 |
Issue | 1 |
Pagination | 34-44 |
Date Published | 2020 01 |
ISSN | 2213-2619 |
Keywords | Adult, Aged, Case-Control Studies, Ex-Smokers, Female, Follow-Up Studies, Humans, Lung, Male, Middle Aged, National Heart, Lung, and Blood Institute (U.S.), Non-Smokers, Respiratory Physiological Phenomena, Smokers, Smoking, Spirometry, United States, Young Adult |
Abstract | <p><b>BACKGROUND: </b>Former smokers now outnumber current smokers in many developed countries, and current smokers are smoking fewer cigarettes per day. Some data suggest that lung function decline normalises with smoking cessation; however, mechanistic studies suggest that lung function decline could continue. We hypothesised that former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers, including among those without prevalent lung disease.</p><p><b>METHODS: </b>We used data on six US population-based cohorts included in the NHLBI Pooled Cohort Study. We restricted the sample to participants with valid spirometry at two or more exams. Two cohorts recruited younger adults (≥17 years), two recruited middle-aged and older adults (≥45 years), and two recruited only elderly adults (≥65 years) with examinations done between 1983 and 2014. FEV decline in sustained former smokers and current smokers was compared to that of never-smokers by use of mixed models adjusted for sociodemographic and anthropometric factors. Differential FEV decline was also evaluated according to duration of smoking cessation and cumulative (number of pack-years) and current (number of cigarettes per day) cigarette consumption.</p><p><b>FINDINGS: </b>25 352 participants (ages 17-93 years) completed 70 228 valid spirometry exams. Over a median follow-up of 7 years (IQR 3-20), FEV decline at the median age (57 years) was 31·01 mL per year (95% CI 30·66-31·37) in sustained never-smokers, 34·97 mL per year (34·36-35·57) in former smokers, and 39·92 mL per year (38·92-40·92) in current smokers. With adjustment, former smokers showed an accelerated FEV decline of 1·82 mL per year (95% CI 1·24-2·40) compared to never-smokers, which was approximately 20% of the effect estimate for current smokers (9·21 mL per year; 95% CI 8·35-10·08). Compared to never-smokers, accelerated FEV decline was observed in former smokers for decades after smoking cessation and in current smokers with low cumulative cigarette consumption (<10 pack-years). With respect to current cigarette consumption, the effect estimate for FEV decline in current smokers consuming less than five cigarettes per day (7·65 mL per year; 95% CI 6·21-9·09) was 68% of that in current smokers consuming 30 or more cigarettes per day (11·24 mL per year; 9·86-12·62), and around five times greater than in former smokers (1·57 mL per year; 1·00-2·14). Among participants without prevalent lung disease, associations were attenuated but were consistent with the main results.</p><p><b>INTERPRETATION: </b>Former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers. These results suggest that all levels of smoking exposure are likely to be associated with lasting and progressive lung damage.</p><p><b>FUNDING: </b>National Institutes of Health, National Heart Lung and Blood Institute, and US Environmental Protection Agency.</p> |
DOI | 10.1016/S2213-2600(19)30276-0 |
Alternate Journal | Lancet Respir Med |
PubMed ID | 31606435 |
PubMed Central ID | PMC7261004 |
Grant List | HHSN268201300026C / HL / NHLBI NIH HHS / United States N01HC95160 / HL / NHLBI NIH HHS / United States HHSN268201500001C / HL / NHLBI NIH HHS / United States U01 HL130114 / HL / NHLBI NIH HHS / United States R01 HL077612 / HL / NHLBI NIH HHS / United States R21 HL121457 / HL / NHLBI NIH HHS / United States R01 AG028050 / AG / NIA NIH HHS / United States N01HC85080 / HL / NHLBI NIH HHS / United States N01HC85081 / HL / NHLBI NIH HHS / United States N01HC95163 / HL / NHLBI NIH HHS / United States U01 HL080295 / HL / NHLBI NIH HHS / United States HHSN268200800007C / HL / NHLBI NIH HHS / United States N01HC95169 / HL / NHLBI NIH HHS / United States HHSN268201300048C / HL / NHLBI NIH HHS / United States RC1 HL100543 / HL / NHLBI NIH HHS / United States N01HC95164 / HL / NHLBI NIH HHS / United States HHSN268201300025C / HL / NHLBI NIH HHS / United States N01HC55222 / HL / NHLBI NIH HHS / United States N01HC95162 / HL / NHLBI NIH HHS / United States R01 NR012459 / NR / NINR NIH HHS / United States N01HC85086 / HL / NHLBI NIH HHS / United States R01 HL093081 / HL / NHLBI NIH HHS / United States N01HC95168 / HL / NHLBI NIH HHS / United States HHSN268201300027C / HL / NHLBI NIH HHS / United States HHSN268201300049C / HL / NHLBI NIH HHS / United States HHSN268201200036C / HL / NHLBI NIH HHS / United States HHSN268201700001I / HL / NHLBI NIH HHS / United States HHSN268200900041C / HL / NHLBI NIH HHS / United States HHSN268201300028C / HL / NHLBI NIH HHS / United States HHSN268201700004I / HL / NHLBI NIH HHS / United States N01HC95165 / HL / NHLBI NIH HHS / United States N01HC95159 / HL / NHLBI NIH HHS / United States K23 HL138165 / HL / NHLBI NIH HHS / United States HHSN268201500001I / HL / NHLBI NIH HHS / United States R21 HL129924 / HL / NHLBI NIH HHS / United States N01HC95161 / HL / NHLBI NIH HHS / United States HHSN268201300047C / HL / NHLBI NIH HHS / United States HHSN268201300050C / HL / NHLBI NIH HHS / United States HHSN268201700005C / HL / NHLBI NIH HHS / United States HHSN268201700001C / HL / NHLBI NIH HHS / United States N01HC85082 / HL / NHLBI NIH HHS / United States N01HC95167 / HL / NHLBI NIH HHS / United States HHSN268201700003C / HL / NHLBI NIH HHS / United States N01HC85083 / HL / NHLBI NIH HHS / United States R01 HL130506 / HL / NHLBI NIH HHS / United States N01HC25195 / HL / NHLBI NIH HHS / United States HHSN268201700004C / HL / NHLBI NIH HHS / United States HHSN268201300046C / HL / NHLBI NIH HHS / United States HHSN268201700002I / HL / NHLBI NIH HHS / United States HHSN268201700005I / HL / NHLBI NIH HHS / United States N01HC85079 / HL / NHLBI NIH HHS / United States N01HC95166 / HL / NHLBI NIH HHS / United States HHSN268201300029C / HL / NHLBI NIH HHS / United States K23 HL130627 / HL / NHLBI NIH HHS / United States R01 AG023629 / AG / NIA NIH HHS / United States R01 HL122477 / HL / NHLBI NIH HHS / United States HHSN268201700003I / HL / NHLBI NIH HHS / United States |