BACKGROUND - Cardiovascular disease, including myocardial infarction (MI), is increasing in developing countries. Knowledge of risk factors and their impact on the population could offer insights into primary prevention.
METHODS AND RESULTS - We estimated the population-attributable risk (PAR) for major MI risk factors among Costa Ricans without a history of diabetes, hypertension, or regular use of medication (889 MI cases, 1167 population-based controls). Lifestyle and dietary variables were measured with validated questionnaires. In multivariate analyses, abdominal obesity (PAR, 29.3%), smoking (PAR, 25.6%), nonuse of alcohol (PAR, 14.8%), caffeine intake (PAR, 12.8%), physical inactivity (PAR, 9.6%), and poor diet (PAR, 6.0%) were the most important MI risk factors. Subjects in the favorable categories of the above 6 risk factors showed a lower risk of MI (odds ratio, 0.09; 95% CI, 0.03 to 0.33) than those in the unfavorable categories. Compared with women, men were more likely to smoke (31% versus 10%) but less likely to have waist circumferences greater than Adult Treatment Panel III cutoffs (9% versus 35%). Many subjects did not meet the American Heart Association or World Health Organization/Food and Agriculture Organization dietary guidelines. For instance, 95% obtained > or = 7% of energy from saturated fat, 25% had < or = 5% of energy from polyunsaturated fat, 63% had > or = 1% energy from trans fat, and 53% had low fiber intake (< 25 g/d).
CONCLUSIONS - These findings confirm the benefit of a healthy diet, physical activity, moderate alcohol, and cessation of smoking as approaches for the primary prevention of MI. Obesity and smoking were the 2 most important risk factors for nonfatal MI in Costa Rica.