Association of Changes in Smoking Intensity With Risk of Dementia in Korea
Open accessAbstract
Importance: Several observational studies have reported that smoking cessation is associated with a lower risk of dementia. However, no studies have examined the association between change in smoking intensity and risk of dementia. Objective: To investigate the association between a change in smoking intensity, including smoking reduction and smoking cessation, and risk of all dementia. Design, Setting, and Participants: This cohort study used data from the National Health Insurance Service database of Korea. The cohort included participants 40 years or older who underwent biennial health examinations (2009 and 2011) and had current smoking status at the first health examination. The cohort was followed up until December 31, 2018, and statistical analysis was performed between July and December 2021. Exposures: Change in smoking intensity from baseline was defined operationally as follows: quitters (stopped smoking), reducers I (decreased number of cigarettes smoked per day by ≥50%), reducers II (decreased number of cigarettes smoked per day by 20%-50%), sustainers (maintained [decreased or increased] number of cigarettes smoked per day by less than 20%), or increasers (increased number of cigarettes smoked per day by ≥20%). Main Outcomes and Measures: The primary outcome was newly diagnosed dementia, which was identified by prescribed antidementia medications with concomitant International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes for dementia. Adjusted hazard ratios and 95% CIs were used to determine the association between change in smoking intensity and incidence of dementia, including Alzheimer disease (AD) and vascular dementia (VaD). Results: A total of 789 532 participants (756 469 males [95.8%]; mean [SD] age, 52.2 [8.5] years) were included. During a median (IQR) follow-up period of 6.3 (6.1-6.6) years, 11 912 dementia events, including 8800 AD and 1889 VaD events, were identified. Overall, participants in the quitter group had a significantly lower risk of all dementia (adjusted hazard ratio [aHR], 0.92; 95% CI, 0.87-0.97) compared with those in the sustainer group. Those in the reducer I (aHR, 1.25; 95% CI, 1.18-1.33) and increaser (aHR, 1.12; 95% CI, 1.06-1.18) groups had a significantly higher risk of all dementia compared with those in the sustainer group.The patterns for AD and VaD remained consistent with patterns for all dementia. Conclusions and Relevance: The results of this study showed that smoking cessation was associated with a lower risk of dementia compared with sustained smoking intensity, while smoking reduction was associated with a higher risk. Smoking cessation should be emphasized in efforts to reduce the disease burden of dementia.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Smoking cessation is associated with lower dementia risk compared with continued smoking (HR 0.92, 0.87-0.97).
“exsmokers had a lower risk of all cause dementia HR 0.92 (0.87-0.97) compared with continuing smokers”
From Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission (2024) · cites this paper as [146]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
The citation lists haven’t been fetched yet
References 43 · Cited by 48
Research works printed but not linked: 28
- [4]Lu Y, Sugawara Y, Zhang S, Tomata Y, Tsuji I. Smoking cessation and incident dementia in elderly Japanese: the Ohsaki Cohort 2006 Study. Eur J Epidemiol. 2020; 35(9): 851- 860. doi: 10.1007/s10654-020-00612-9 32060675 PMC7525275 · DOI
- [6]Johnson AL, Nystrom NC, Piper ME,. Cigarette smoking status, cigarette exposure, and duration of abstinence predicting incident dementia and death: a multistate model approach. J Alzheimers Dis. 2021; 80(3): 1013- 1023. doi: 10.3233/JAD-201332 33646160 PMC8044009 · DOI
- [8]Swan GE, Lessov-Schlaggar CN. The effects of tobacco smoke and nicotine on cognition and the brain. Neuropsychol Rev. 2007; 17(3): 259- 273. 17690985
- [9]Centers for Disease Control and Prevention; National Center for Chronic Disease Prevention and Health Promotion; Office on Smoking and Health. Figure 6.3, dose-response relationship between number of cigarettes smoked per day and relative risk of ischemic heart disease. In: How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. Centers for Disease Control and Prevention; 2010. Accessed June 30, 2022. https://www.ncbi.nlm.nih.gov/books/NBK53012/figure/ch6.f3/
- [10]Bjartveit K, Tverdal A. Health consequences of smoking 1-4 cigarettes per day. Tob Control. 2005; 14(5): 315- 320. doi: 10.1136/tc.2005.011932 16183982 PMC1748107 · DOI
- [11]Hackshaw A, Morris JK, Boniface S, Tang JL, Milenković D. Low cigarette consumption and risk of coronary heart disease and stroke: meta-analysis of 141 cohort studies in 55 study reports. BMJ. 2018; 360: j5855. doi: 10.1136/bmj.j5855 29367388 PMC5781309 · DOI
- [12]Schane RE, Ling PM, Glantz SA. Health effects of light and intermittent smoking: a review. Circulation. 2010; 121(13): 1518- 1522. doi: 10.1161/CIRCULATIONAHA.109.904235 20368531 PMC2865193 · DOI
- [14]Jeong SM, Jeon KH, Shin DW,. Smoking cessation, but not reduction, reduces cardiovascular disease incidence. Eur Heart J. 2021; 42(40): 4141- 4153. doi: 10.1093/eurheartj/ehab578 34431997 · DOI
- [15]Shin DW, Cho J, Park JH, Cho B. National General Health Screening Program in Korea: history, current status, and future direction. Precis Future Med. 2022; 6(1): 9- 31. doi: 10.23838/pfm.2021.00135 · DOI
- [17]Song YM, Cho HJ. Risk of stroke and myocardial infarction after reduction or cessation of cigarette smoking: a cohort study in Korean men. Stroke. 2008; 39(9): 2432- 2438. doi: 10.1161/STROKEAHA.107.512632 18617660 · DOI · Paper page
- [19]Yoo JE, Han K, Shin DW,. Effect of smoking reduction, cessation, and resumption on cancer risk: a nationwide cohort study. Cancer. 2022; 128(11): 2126- 2137. doi: 10.1002/cncr.34172 35298026 · DOI
- [20]Jeong SM, Shin DW, Lee JE, Hyeon JH, Lee J, Kim S. Anemia is associated with incidence of dementia: a national health screening study in Korea involving 37,900 persons. Alzheimers Res Ther. 2017; 9(1): 94. doi: 10.1186/s13195-017-0322-2 29212527 PMC5719530 · DOI
- [21]Yoo JE, Shin DW, Han K,. Blood pressure variability and the risk of dementia: a nationwide cohort study. Hypertension. 2020; 75(4): 982- 990. doi: 10.1161/HYPERTENSIONAHA.119.14033 32148122 · DOI
- [22]Kang J, Shin DW, Han K,. Risk of dementia in prostate cancer survivors: a nationwide cohort study in Korea. Curr Probl Cancer. 2020; 44(6): 100578. doi: 10.1016/j.currproblcancer.2020.100578 32360240 · DOI
- [23]Yoo JE, Shin DW, Han K,. Female reproductive factors and the risk of dementia: a nationwide cohort study. Eur J Neurol. 2020; 27(8): 1448- 1458. doi: 10.1111/ene.14315 32396982 · DOI
- [24]Lee JE, Shin DW, Han K,. Changes in metabolic syndrome status and risk of dementia. J Clin Med. 2020; 9(1): 122. doi: 10.3390/jcm9010122 31906539 PMC7019689 · DOI
- [25]Kim J, Lee J, Jeong JH, Kang M, Bang JS. Study of the drugs prescribed on Alzheimer’s disease: from the insurance claims data of Korea National Health Insurance Service. Korean J Clin Pharm. 2014; 24(4): 255- 264.
- [26]Austin PC, Fine JP. Practical recommendations for reporting Fine-Gray model analyses for competing risk data. Stat Med. 2017; 36(27): 4391- 4400. doi: 10.1002/sim.7501 28913837 PMC5698744 · DOI
- [27]Sterne JA, White IR, Carlin JB,. Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls. BMJ. 2009; 338: b2393. doi: 10.1136/bmj.b2393 19564179 PMC2714692 · DOI · Paper page
- [28]Durazzo TC, Mattsson N, Weiner MW; Alzheimer’s Disease Neuroimaging Initiative. Smoking and increased Alzheimer’s disease risk: a review of potential mechanisms. Alzheimers Dement. 2014; 10(3 suppl): S122- S145. doi: 10.1016/j.jalz.2014.04.009 24924665 PMC4098701 · DOI
- [29]Liu Y, Li H, Wang J,. Association of cigarette smoking with cerebrospinal fluid biomarkers of neurodegeneration, neuroinflammation, and oxidation. JAMA Netw Open. 2020; 3(10): e2018777. doi: 10.1001/jamanetworkopen.2020.18777 33006621 PMC7532384 · DOI
- [31]Toda N, Okamura T. Cigarette smoking impairs nitric oxide-mediated cerebral blood flow increase: implications for Alzheimer’s disease. J Pharmacol Sci. 2016; 131(4): 223- 232. doi: 10.1016/j.jphs.2016.07.001 27530818 · DOI
- [32]Hughes JR, Carpenter MJ. The feasibility of smoking reduction: an update. Addiction. 2005; 100(8): 1074- 1089. doi: 10.1111/j.1360-0443.2005.01174.x 16042638 PMC1419056 · DOI · Paper page
- [33]Valentine G, Sofuoglu M. Cognitive effects of nicotine: recent progress. Curr Neuropharmacol. 2018; 16(4): 403- 414. doi: 10.2174/1570159X15666171103152136 29110618 PMC6018192 · DOI
- [34]Quick MW, Lester RA. Desensitization of neuronal nicotinic receptors. J Neurobiol. 2002; 53(4): 457- 478. doi: 10.1002/neu.10109 12436413 · DOI · Paper page
- [35]Nardone N, Shahid M, Strasser AA, Dempsey DA, Benowitz NL. The influence of nicotine metabolic rate on working memory over 6 hours of abstinence from nicotine. Pharmacol Biochem Behav. 2020; 188: 172836. doi: 10.1016/j.pbb.2019.172836 31812759 PMC7009742 · DOI
- [36]García AM, Ramón-Bou N, Porta M. Isolated and joint effects of tobacco and alcohol consumption on risk of Alzheimer’s disease. J Alzheimers Dis. 2010; 20(2): 577- 586. doi: 10.3233/JAD-2010-1399 20164550 · DOI
- [37]Zhou S, Zhou R, Zhong T, Li R, Tan J, Zhou H. Association of smoking and alcohol drinking with dementia risk among elderly men in China. Curr Alzheimer Res. 2014; 11(9): 899- 907. doi: 10.2174/1567205011666141001123356 25274108 PMC4428477 · DOI
- Authors
- Jeong, S.-M., Park, J., Han, K., Yoo, J., Yoo, J. E., Lee, C. M., Jung, W., Lee, J., Kim, S., & Shin, D. W.
- Affiliations
- Seoul National University (KR)
- Samsung Medical Center (KR)
- Soongsil University (KR)
- University of Southern California (US)
- Corresponding author
- Shin, Dong Wook
- ORCID
- Venue
- JAMA Network Open
- Publisher
- American Medical Association (AMA)
- Published
- 2023-01-19
- Volume
- 6
- Issue
- 1
- Pages
- e2251506
- ISSN
- 2574-3805 (ISSN-L)
- PMC
- PMC9857334
- OpenAlex
- W4317436887
- Cited by
- 48
- References
- 43
- Citations by year
- 2026: 10 · 2025: 17 · 2024: 12 · 2023: 9
- FWCI
- 8.52
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- cc-by
- Locations
- JAMA Network Open (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Physiology › Smoking Behavior and Cessation
- Health Sciences › Medicine › Psychiatry and Mental health › Dementia and Cognitive Impairment Research
- Health Sciences › Medicine › Epidemiology › Acute Ischemic Stroke Management
- Keywords
- smoking intensity, smoking cessation, smoking reduction, dementia risk, Alzheimer's disease, vascular dementia, tobacco use, dementia incidence, Korea, health examination data, tobacco control
- MeSH terms
- Alzheimer Disease, Humans, Male, Middle Aged, Smoking, Cohort Studies, Smoking Cessation, Republic of Korea
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review