Apolipoprotein E polymorphism influence on lipids, apolipoproteins and Lp(a) in a Spanish population underexpressing apo E4

The apolipoprotein E (apo E) polymorphism in a Spanish working population of Tenerife (Canary Islands, Spain) was analyzed. The distribution of apo E alleles ( 3, 0.850; 2, 0.075; 4, 0.075) and phenotypes (E3/3, 72.6%; E3/4, 13%; E3/2, 11.5%; E4/4, 0.8%; E2/2, 1.5%; E4/2, 0.5%) was significantly different from those of a combined Caucasian population owing to a lower frequency of apo E4. We have also investigated the effect of apo E polymorphism on serum levels of cholesterol, LDL-cholesterol, HDL-cholesterol, Lp(a) and apolipoproteins A-I, B and E. The average effect of E4 (in whole sample and men only, respectively) was to raise serum levels of total cholesterol (by 4.1 mg/dl and 8.3 mg/dl), LDL-cholesterol (by 6.5 mg/dl and 9 mg/dl), and apo B (5.3 mg/dl and 4.5 mg/dl). The average effect of E2 was to lower serum levels of total cholesterol (by 14.8 mg/dl and 8.3 mg/dl), LDL-cholesterol (by 20.2 mg/dl and 15.5 mg/dl) and apo B (11.5 mg/dl and 6.5 mg/dl), and to raise apo E (1.14 mg/dl and 3.4 mg/dl). We found significantly higher serum triglyceride levels in individuals carrying E4, but no differences were found in serum HDL-cholesterol, apo A-I or Lp(a) by alleles. Data confirm previous reports about an underexpression of apo E4 in societies living in Southern Europe, and its repercussion in a more beneficial lipid profile and relatively low cardiovascular mortality rate in the Mediterranean region.