Purpose: In two countries with contrasting risk for coronary artery disease (CAD)-Northern Ireland and France-a case-control study was performed on baseline data within a cohort study to compare the strength of the associations between CAD prevalence and classical risk factors.
Method and results: A sample of 9561 men, aged 50-60 years, was studied: 382 had had myocardial infarction or angina, and 9179 were controls. In both countries, variables associated with CAD were age, body mass index, hypertension, diabetes, family history of myocardial infarction (MI), tobacco consumption, triglycerides, HDL-cholesterol, apolipoprotein A-I and B levels. Logistic regression analyses were conducted using standardized odds ratios. The strength of the associations with CAD was rather similar in the two countries (Northern Ireland versus France) for age [1.26 (1.10-1. 45) vs. 1.41 (1.17-1.69)], family history of MI [1.50 (1.04-2.15) vs. 1.83 (0.99-3.37)], hypertension [1.49 (1.13-1.97) vs. 1.67 (1.14-2. 44)], diabetes [5.42 (2.53-11.60) vs. 2.24 (1.06-4.73)], tobacco consumption [1.43 (1.27-1.60) vs. 1.39 (1.22-1.58)], HDL-cholesterol [0.80 (0.68-0.94) vs. 0.86 (0.70-1.06)] and triglyceride levels [1. 17 (1.01-1.36) vs. 1.10 (0.91-1.32)]. Discrepancies concerned lipoprotein(a) [1.22 (1.06-1.40) vs. 0.96 (0.81-1.15), P<0.01], with stronger associations in Northern Ireland than in France.
Conclusion: It is concluded that the higher prevalence of CAD in Northern Ireland cannot be explained by major differences in the susceptibility to classical risk factors; the difference in risk of CAD appears mainly related in Northern Ireland to other risk factors including a worse lipid profile and genetic/environmental interactions.