Gender differences and the risk of myocardial infarction

Abstract

To investigate gender differences in prevalence and effect of the known risk factors of myocardial infarction (MI). Data from an interviewer-led questionnaire from 394cases with first MI (316 men up to 70years and 78 women up to 75years), and 465controls (327men and 138women) gender- and frequency-matched with cases, from the Maltese Acute Myocardial Infarction (MAMI) Study was analysed. Odds ratios (OR) were adjusted for age, smoking, alcohol consumption, hypertension, hypercholesterolaemia and BMI. The mean age of occurrence of MI in women was 63years compared to 57years in men. Various risk factors of MI were less prevalent in women compared to men: in controls hypertension (30.1% vs. 37.9%); diabetes mellitus (9.6% vs. 12.8%); smoking (18.1% vs. 24.5%). The risk of MI for women with hypertension [OR2.2 (95%CI1.0-4.8)], and diabetes [OR3.9 (95%CI1.6-10.0)] was higher than the risk for men [OR1.0 (95% CI0.7-1.5); OR2.0 (95%CI1.3-3.4), respectively]. Women smokers had a 1.8-fold (95%CI0.6-5.4) increased risk of MI, while men smokers had a 3.9-fold risk (95%CI2.3-6.4). Although the prevalence of hypercholes- terolemia was higher in women (40.6% vs. 35.3% of men), they had a lower OR [1.1 (95%CI0.5-2.3)] then hypercholesterolemic men [OR1.4 (95%CI0.9-2.0)]. Men tend to suffer from MI at a younger age. Hypertension and diabetes are more common amongst men then women. When present, the risk of MI in women is higher than in men. Prevalence and risk of MI due to smoking are higher in men. Despite the higher prevalence of hypercholesterolemia in women, the risk of MI tended to be lower than in hypercholesterolemic men.