Smokeless tobacco may increase stroke risk

Results of a new study suggest that the use of oral moist snuff, a type of smokeless tobacco widely used in Sweden that is also known as "snus," may increase the risk of fatal stroke.

Dr. Maria-Pia Hergens, of the Karolinska Institute in Stockholm, and colleagues examined data on Swedish construction workers attending health check-ups between 1978 and 1993 who completed questionnaires that included information on tobacco use.

A total of 118,465 men who had never smoked and had no history of stroke were followed through 2003. The Inpatient Register and Causes of Death Register were used to identify subsequent illness and death from stroke.

During an average of 18 years of follow-up, 3,248 men suffered a stroke. Most of these (70 percent) were "ischemic" strokes due to restricted blood flow ischemic, whereas 17 percent were "hemorrhagic" or bleeding strokes. Thirteen percent of strokes were "unspecified."

Overall, 29 percent of the subjects had ever used snuff. The overall relative risk of stroke was not increased in these ever users of snuff.

However, for fatal stroke, the relative risk was 27 percent higher among ever-users of snuff compared with never users. This was mainly driven by an excess 38 percent risk of fatal stroke among current users of snuff.

When the team analyzed subtypes of stroke, they found a 71 percent increased risk of fatal ischemic stroke associated with current snuff use. No increased risk was observed for hemorrhagic stroke.

This study, the researchers conclude, suggest that "snuff use may elevate the risk of fatal stroke, and particularly of fatal ischemic stroke."

SOURCE: Epidemiology, November 2008.