Smoking, apolipoprotein E genotype, and early onset of coronary heart disease

BACKGROUND: We examined the association between smoking, apolipoprotein E (ApoE) genotype, and early onset of coronary heart disease (CHD). DESIGN AND METHODS: Smoking behaviour and ApoE genotype of 904 patients with CHD aged 30-70 years were assessed with respect to age at onset of CHD. RESULTS: The adjusted odds ratio for early onset of CHD (< or =55 years) was 1.86 (95% confidence interval, 1.31-2.62) for smokers compared to non-smokers. The ApoE genotype had no significant influence and there was no significant interaction between ApoE genotype and smoking. CONCLUSION: We found smoking but not ApoE genotype to be an independent risk factor for early onset of CHD.