Swedish moist snuff and myocardial infarction among men

Background: Previous studies have provided inconsistent results on possible increased risk of cardiovascular disease with the use of smokeless tobacco. The aim of this study was to assess whether long-term use of Swedish moist snuff (widely used among Swedish men) increases the risk of acute myocardial infarction. Methods: This case-control study was conducted in 2 Swedish counties. We identified 1760 men, age 45-70 years, who had a myocardial infarction in 1992-1994. We randomly selected male controls from the study base after stratification for age and hospital catchment area. Information about snuff consumption, smoking history, hypertension, and other factors was obtained by mailed questionnaire and medical examination. The participation rate was 77% among cases and 78% among controls, with tobacco use data available for 1432 cases and 1810 controls. Results: After adjustment for age, hospital catchment area, and smoking, the relative risk of first acute myocardial infarction was 1.1 (95% confidence interval = 0.8-1.5) for former snuff users and 1.0 (0.8-1.3) for current snuff users. Analyses limited to either nonfatal or fatal cases did not change the results. Among the controls, the consumption of smokeless tobacco was strongly associated with certain risk factors for myocardial infarction such as smoking, hypertension, and high body mass index. Conclusion: The hypothesis that smokeless tobacco increases the risk for myocardial infarction is not supported in the present study.