The APOE gene and differences in life expectancy in Europe.

Common alleles of the apolipoprotein-E gene (APOE) are associated with different risks of ischemic heart disease, Alzheimer's disease, and other chronic conditions in European populations. Also, the APOE allele frequencies vary widely among European countries. We estimated the proportion of differences in mortality and differences in life span that are attributable to differences in APOE allele frequencies in Europe. Mortality rates by age, sex, and APOE genotype for six countries (Denmark, Finland, France, Italy, the Netherlands, and Sweden) were used to standardize mortality rates to the allele frequencies in Italy. Differences in APOE allele frequencies explain 12%-17% of the variation among these countries in mortality in people older than 65 years and 1%-2% of the variation in life span in those older than 65 years. Differences by genotype in mortality in people older than 15 years account for about 3.5% of the genetic contribution to the variation in life span in Denmark.