APOE E4 increases risk of heart disease in smokers

Apolipoprotein E (apoE) isoforms E2, E3, and E4, are important determinants of plasma lipid concentrations, with the ε4 allele particularly associated with heightened risk of coronary heart disease (CHD). However the inherited apoE genotype interactions with environmental risk factors such as smoking are not known. In 14 July Lancet, Steve Humphries and colleagues from University College London Medical School show that the E4 isoform of apoE is associated with a significantly increased risk of CHD from smoking.

Humphries et al. investigated prospectively 3052 men without coronary heart disease during a cardiovascular surveillance study in the UK. They correlated smoking habits (measured by a questionnaire) and the apoE genotypes (as determined by PCR) with the occurrence of CHD events.

The general risk of CHD among smokers was 1.94 higher than in never-smokers (p = 0.007). Those smokers who were carriers of the ε4 allele showed a high risk...