Cigarette smoking and coronary heart disease in Puerto Rico

Abstract

Cigarette smoking habits were assessed in over 9000 men, aged 45–64 years, who participated in a prospective study of coronary heart disease (CHD) in Puerto Rico beginning in 1965. Fewer Puerto Rican men smoked cigarettes, and they smoked fewer cigarettes per day than in comparable studies in the mainland United States. Even in this lower-smoking, low-CHD population, cigarette smoking showed a significant independent association with the incidence of myocardial infarction (MI) over an 8-year period both in the rural and urban areas; however, this association was not statistically significant for other manifestations of CHD. Pipe and cigar smokers had a risk of MI similar to nonsmokers. Those men who used filter cigarettes or who stated that they did not inhale showed the same risk of MI as other cigarette smokers. Ex-smokers had a risk of MI intermediate to that of nonsmokers and current smokers. The risk of MI did not increase with an increase in the number of cigarettes smoked, but the risk of MI in smokers as a group relative to those who had never smoked was 3.4 in the rural area and 2.0 in the urban area. These results emphasize that there is an excess risk of MI in those cigarette smokers who report that they used filter cigarettes, did not inhale, or smoked a small number of cigarettes a day.