The purpose of this study was to assess the risk of ischaemic heart disease (IHD) and stroke (non-fatal and fatal) among adult ever-users of smokeless tobacco (ST).
Design
The study design involved a systematic review and meta-analysis of observational studies.
Methods
Data sources for the review included key electronic databases and reference lists. Studies were included based on design (cohort or case-control), exposure (exclusive use of ST or adjusted for smoking), and outcome (non-fatal and fatal IHD and stroke). Data extraction included reported measures of association (risk ratios (RRs) or odds ratios (ORs)) between ever-use of ST (current or past) and cardiovascular disease (CVD) outcomes among non-smokers, and other study characteristics. The Newcastle-Ottawa scale was used to assess study quality. Summary measures were estimated using random effects models.
Results
Twenty studies were included in the meta-analyses. Overall, significantly increased risk of IHD deaths (1.15, 95% confidence interval (CI: 1.01–1.30) and stroke deaths (1.39, 95% CI: 1.29–1.49) was found among ever-users of ST. We did not find an overall significant increased risk for IHD (1.14, 95% CI: 0.92–1.42) or stroke (1.01, 95% CI: 0.90–1.13). But geographical variations were marked for IHD, with significant positive association in Asian studies (1.40, 95% CI: 1.01–1.95), and the INTERHEART study, where ST data was mainly reported from Asia (2.23, 95% CI: 1.41–3.53). European studies did not show an increased risk for non-fatal CVD.
Conclusion
An association was found between ever use of ST and risk of fatal IHD and stroke, consistent with previous reviews. ST consumption also appears to significantly increase risk of non-fatal IHD among users in Asia, but not in Europe.
National Cancer Institute and Centers for Disease Control and Prevention. Smokeless tobacco and public health: A global perspective. Bethesda, MD: US Department of Health and Human Services, Centers for Disease Control and Prevention and National Institutes of Health, National Cancer Institute, 2014.
2.
SinhaDNPalipudiKMRolleI. Tobacco use among youth and adults in member countries of South-East Asia region: Review of findings from surveys under the Global Tobacco Surveillance System. Indian J Public Health2011; 55: 169–176.
3.
International Agency for Research on Cancer (IARC). Smokeless tobacco and some tobacco-specific N-nitrosamines. IARC monographs on the evaluation of carcinogenic risks to humans. Lyon: IARC, 2008.
4.
KallischniggGWeitkunatRLeePN. Systematic review of the relation between smokeless tobacco and non-neoplastic oral diseases in Europe and the United States. BMC Oral Health2008; 8: 13–13.
5.
BoffettaPHechtSGrayN. Smokeless tobacco and cancer. Lancet Oncol2008; 9: 667–675.
6.
CritchleyJAUnalB. Health effects associated with smokeless tobacco: A systematic review. Thorax2003; 58: 435–443.
7.
Broadstock M. Systematic review of the health effects of modified smokeless tobacco products (NZTA Report), Vol. 10 (1). Christchurch: New Zealand Health Technology Assessment, 2007.
8.
Mendis S, Puska P and Norrving B (Eds). Global Atlas on Cardiovascular Disease Prevention and Control. Geneva: World Health Organization, 2011.
9.
BoffettaPStraifK. Use of smokeless tobacco and risk of myocardial infarction and stroke: Systematic review with meta-analysis. Br Med J2009336.
10.
ZhangL-NYangY-MXuZ-R. Chewing substances with or without tobacco and risk of cardiovascular disease in Asia: A meta-analysis. J Zhejiang Univ Sci B2010; 11: 681–689.
11.
RahmanMAMahmoodMASpurrierN. A systematic review of epidemiological studies on the association between smokeless tobacco use and coronary heart disease. J Public Health Epidemiol2011; 3: 593–603.
12.
Wells G, Shea B, O’Connell D, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. Ottawa (ON): Ottawa Health Research Institute, 2000.
13.
Review Manager (RevMan). 5.3 ed. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.
14.
MoherDLiberatiATetzlaffJ. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. Ann Intern Med2009; 151: 264–269.
15.
HanssonJPedersenNLGalantiMR. Use of snus and risk for cardiovascular disease: Results from the Swedish Twin Registry. J Intern Med2009; 265: 717–724.
16.
HergensM-PAhlbomAAnderssonT. Swedish moist snuff and myocardial infarction among men. Epidemiology2005; 16: 12–16.
17.
HergensMPAlfredssonLBolinderG. Long-term use of Swedish moist snuff and the risk of myocardial infarction amongst men. J Intern Med2007; 262: 351–359. Erratum appears in J Intern Med 2007; 262: 590.
18.
HuhtasaariFAsplundKLundbergV. Tobacco and myocardial infarction: Is snuff less dangerous than cigarettes?Br Med J1992; 305: 1252–1256.
19.
HuhtasaariFLundbergVEliassonM. Smokeless tobacco as a possible risk factor for myocardial infarction: A population-based study in middle-aged men. J Am Coll Cardiol1999; 34: 1784–1790.
20.
JohanssonS-ESundquistKQvistJ. Smokeless tobacco and coronary heart disease: A 12-year follow-up study. Eur J Cardiovasc Prev Rehabil2005; 12: 387–392. (Erratum appears in Eur J Cardiovasc Prev Rehabil 2007; 14: 722.).
21.
WennbergPEliassonMHallmansG. The risk of myocardial infarction and sudden cardiac death amongst snuff users with or without a previous history of smoking. J Intern Med2007; 262: 360–367.
22.
BolinderGAlfredssonLEnglundA. Smokeless tobacco use and increased cardiovascular mortality among Swedish construction workers. Am J Public Health.1994; 84: 399–404.
23.
AsplundKNasicSJanlertU. Smokeless tobacco as a possible risk factor for stroke in men – A nested case-control study. Stroke2003; 34: 1754–1759.
24.
HergensM-PLambeMPershagenG. Smokeless tobacco and the risk of stroke. Epidemiology2008; 19: 794–799. (Erratum appears in Epidemiology 2009; 20: 471).
25.
AccorttNAWaterborJWBeallC. Chronic disease mortality in a cohort of smokeless tobacco users. Am J Epidemiol2002; 156: 730–737.
26.
HenleySJThunMJConnellC. Two large prospective studies of mortality among men who use snuff or chewing tobacco (United States). Cancer Causes Control2005; 16: 347–358.
27.
RahmanMASpurrierNMahmoodMA. Is there any association between use of smokeless tobacco products and coronary heart disease in Bangladesh?PLoS One2012; 7: e30584–e30584.
28.
RahmanMAZamanMM. Smoking and smokeless tobacco consumption: Possible risk factors for coronary heart disease among young patients attending a tertiary care cardiac hospital in Bangladesh. Public Health2008; 122: 1331–1338.
29.
MateenFCaroneMAlamN. A population-based case-control study of 1250 stroke deaths in rural Bangladesh. Eur J Neurol2012; 19: 999–1006.
30.
GuptaPCPednekarMSParkinD. Tobacco associated mortality in Mumbai (Bombay) India. Results of the Bombay cohort study. Int J Epidemiol2005; 34: 1395–1402.
31.
VendhanGVendhanK. Tobacco chewing and adult mortality: A case-control analysis of 22,000 cases and 429,000 controls, never smoking tobacco and never drinking alcohol, in South India. Asian Pac J Cancer Prev2015; 16: 1201–1206.
32.
Alexander M. Tobacco use and the risk of cardiovascular diseases in developed and developing countries. PhD Thesis, University of Cambridge, 2013.
33.
TeoKKOunpuuSHawkenS. Tobacco use and risk of myocardial infarction in 52 countries in the INTERHEART study: A case-control study. Lancet2006; 368: 647–658.
34.
World Health Organization (WHO). The international statistical classification of diseases and health related problems ICD-10. Geneva: WHO, 2004.
35.
SinhaDNSuliankatchiRAGuptaPC. Smokeless tobacco (SLT) associated cancers: A systematic review and meta-analysis of Indian studies. Int J Cancer2015; 138(6): 1368–1379.
36.
StepanovIHechtSSRamakrishnanS. Tobacco-specific nitrosamines in smokeless tobacco products marketed in India. Int J Cancer2005; 116: 16–19.
37.
ÖsterdahlB-GJanssonCPaccouA. Decreased levels of tobacco-specific N-nitrosamines in moist snuff on the Swedish market. J Agric Food Chem2004; 52: 5085–5088.
38.
PianoMRBenowitzNLFitzGeraldGA. Impact of smokeless tobacco products on cardiovascular disease: Implications for policy, prevention, and treatment a policy statement from the American Heart Association. Circulation2010; 122: 1520–1544.
39.
GuhJ-YChenH-CTsaiJ-F. Betel-quid use is associated with heart disease in women. Am J Clin Nutr2007; 85: 1229–1235.
40.
LinW-YChiuT-YLeeL-T. Betel nut chewing is associated with increased risk of cardiovascular disease and all-cause mortality in Taiwanese men. Am J Clin Nutr2008; 87: 1204–1211.
41.
ArainSSKaziTGArainJB. Preconcentration of toxic elements in artificial saliva extract of different smokeless tobacco products by dual-cloud point extraction. Microchem J2014; 112: 42–49.
42.
McNeillABediRIslamS. Levels of toxins in oral tobacco products in the UK. Tob Control2006; 15: 64–67.
43.
MahmarianJJMoyéLANasserGA. Nicotine patch therapy in smoking cessation reduces the extent of exercise-induced myocardial ischemia. J Am Coll Cardiol1997; 30: 125–130.
44.
ArefalkGHergensMPIngelssonE. Smokeless tobacco (snus) and risk of heart failure: Results from two Swedish cohorts. Eur J Prev Cardiol2012; 19: 1120–1127.
45.
HaglundBEliassonMStenbeckM. Is moist snuff use associated with excess risk of IHD or stroke? A longitudinal follow-up of snuff users in Sweden. Scand J Public Health2007; 35: 618–622.
46.
HergensMPLambeMPershagenG. Risk of hypertension amongst Swedish male snuff users: A prospective study. J Intern Med2008; 264: 187–194.
47.
RonksleyPEBrienSETurnerBJ. Association of alcohol consumption with selected cardiovascular disease outcomes: A systematic review and meta-analysis. Br Med J2011; 342: d671–d671.
48.
CroucherRDahiyaMGowdaKK. Contents and price of vendor assembled paan quid with tobacco in five London localities: A cross-sectional study. Tob Control2013; 22: 141–143.
