Smoking and other major coronary risk factors and acute myocardial infarction before 41 years of age - Two Danish case-control studies

Objective-The aim of two case-control studies of adults younger than 41 yea rs of age was to assess how the major coronary risk factors, family history of acute myocardial infarction (AMT), obesity, hypertension and hyperchole sterolemia add to the risk of AMI from self-reported current smoking (smoki ng). Design-An evaluation study included 35 patients and 70 individually matched controls. Results-The risk from smoking increased less than linearly and the risk fro m serum cholesterol concentration (cholesterol) increased linearly. In mult iple conditional logistic regression analyses, smoking as a discrete variab le and cholesterol as a continuous variable were significant coronary risk factors. In a final logistic regression model, the odds ratio was 6.4 (95% confidence interval (CI) 1.7-24.1) for smoking and 1.6 (CI 1.1-2.3) for eac h mmol/L cholesterol. A risk score summarizing the combined risk of the maj or coronary risk factors did not add to the final logistic regression model (p = 0.56), A validation study included 79 patients and 64 matching contro l patients. Conclusion-The major coronary risk factors were similar for the cases/patie nts and the two control groups in the two studies. Therefore, the final log istic regression model may reflect a general pattern in Denmark, Primary pr evention in individuals less than 41 years of age should focus on smoking a nd cholesterol instead of the summarizing risk score.