The risk of myocardial infarction and sudden cardiac death amongst snuff users with or without a previous history of smoking.

OBJECTIVES: To investigate the risk of a first myocardial infarction (MI) and sudden cardiac death (SCD) amongst male snuff users.
DESIGN: We used a prospective incident case-referent study design nested in the population-based Västerbotten Intervention Program and the Northern Sweden MONICA study.
SUBJECTS: Tobacco habits and cardiovascular risk factors were assessed at baseline screening and compared in 525 male MI cases (including 93 SCD cases) and 1798 matched referents.
RESULTS: Myocardial infarction occurred on average 4 years and 2 months after the baseline screening. No increased risk for MI was found amongst snuff users without a previous history of smoking compared with nontobacco users after adjustments for body mass index, leisure time physical activity, educational level and cholesterol level (OR 0.82; 95% CI, 0.46-1.43). For snuff users with a previous history of smoking, the adjusted OR was 1.25 (95% CI, 0.80-1.96). Significantly increased risk for MI was found in current smokers with or without current snuff use. For SCD cases with survival time<24 h, the adjusted OR for snuff users without previous history of smoking was 1.18 (95% CI, 0.38-3.70) and for cases with survival time<1 h the OR was 0.38 (95% CI, 0.08-1.89).
CONCLUSIONS: We found no increased risk for MI amongst snuff users without a previous history of smoking. Amongst snuff users with a previous history of smoking, the tendency towards an increased risk for MI may reflect the residual risk from former smoking. This study does not support the hypothesis that the risk for SCD is increased amongst snuff users.