Smokeless tobacco and the risk of stroke.
BACKGROUND
: In Sweden, use of smokeless tobacco (oral moist snuff) is common among adult men. Research on cerebrovascular effects associated with long-term use of snuff is limited and inconclusive. We aimed to study whether long-term use of snuff affects the risk of stroke.


METHODS
: Information on tobacco use was collected by questionnaire among Swedish construction workers attending health check-ups between 1978 and 1993. In total, 118,465 never-smoking men without a history of stroke were followed through 2003. We used the Inpatient Register and Causes of Death Register to identify subsequent morbidity and mortality from stroke and its subtypes (ischemic, hemorrhagic, and unspecified stroke). Relative risk estimates were derived from Cox proportional hazards regression model.


RESULTS
: Almost 30% of the nonsmoking men had ever used snuff. Overall, 3248 cases of stroke were identified during follow-up. Compared with nonusers of tobacco, the multivariable-adjusted relative risks for ever-users of snuff were 1.02 (95% confidence interval; 0.92-1.13) for all cases and 1.27 (0.92-1.76) for fatal cases. Further analyses on subtypes of stroke revealed an increased risk of fatal ischemic stroke associated with current snuff use (1.72; 1.06-2.78), whereas no increased risk was noted for hemorrhagic stroke.


CONCLUSIONS
: Snuff use may elevate the risk of fatal stroke, and particularly of fatal ischemic stroke.
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. maria-pia.hergens@ki.se
Maria-Pia
MP
Hergens
Mats
M
Lambe
Göran
G
Pershagen
Andreas
A
Terent
Weimin
W
Ye
D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003644:Death Certificates; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012306:Risk; D020521:Stroke / Q000209:etiology* / Q000401:mortality; D013548:Sweden / Q000453:epidemiology; D014030:Tobacco, Smokeless / Q000009:adverse effects*