Nicotine and carbon monoxide content of cigarette smoke and the risk of myocardial infarction in young men.

To evaluate whether the nicotine and carbon monoxide content of cigarette smoke is related to the risk of nonfatal first myocardial infarction in young men, we compared 502 cases with 835 hospital controls, all between the ages of 30 and 54 years. As expected, the estimated risk of myocardial infarction increased with the number of cigarettes smoked; overall, the relative-risk estimate for current smokers was 2.8 (95 per cent confidence interval, 2.0 to 4.0). The risk did not appear to vary according to the amount of nicotine or carbon monoxide in the cigarette, and the mean amounts of both substances per cigarette were similar for the cases and controls. The results suggest that men who smoke the newer cigarettes with reduced amounts of nicotine and carbon monoxide do not have a lower risk of myocardial infarction than those who smoke cigarettes containing larger amounts of these substances.