Background and purpose: Apolipoprotein E polymorphism may influence the early development of coronary artery disease. We investigated the putative role of apolipoprotein E phenotypes in cerebral infarction.
Methods: The apolipoprotein E phenotypes of 69 patients (mean +/- SD age, 72 +/- 11 years) who had suffered completed stroke or a transient ischemic attack and 68 sex- and age-matched control subjects free of cerebrovascular disease were determined by isoelectric focusing. The relative frequency of the apolipoprotein E phenotypes in the general population was estimated in 498 healthy blood donors (mean age, 37 years).
Results: The prevalences of hypertension, diabetes mellitus, obesity, and intermittent claudication were significantly higher in patients than in control subjects. Serum lipid and apolipoprotein B concentrations and the composition of very low density lipoproteins were not significantly different between patients and control subjects. Apolipoprotein A-I and E levels were significantly lower in patients. Cholesterol levels were higher in male patients than in male control subjects (5.10 +/- 1.46 versus 4.41 +/- 0.80 mmol/L; p = 0.036), and the ratio of apolipoprotein A-I to B was lower (0.77 +/- 0.29 versus 1.03 +/- 0.37; p < 0.001). The E3/E3 phenotype was more frequent in control subjects (85%) than in patients (72.5%; p < 0.05) and healthy blood donors (64%; p < 0.02). The E3/E2 phenotype was more frequent in patients (10.1%) than in control subjects (1.4%; p < 0.05). A stepwise logistic regression showed that the presence of stroke was significantly related to high blood pressure (p < 0.0001), low apo E levels (p < 0.008), obesity (p < 0.041), the apo E phenotype (p < 0.05), and diabetes mellitus (p < 0.05).
Conclusions: The E3/E3 phenotype may protect against early vascular morbidity, and the epsilon 2 gene may be a risk factor for cerebrovascular morbidity, possibly related to diabetes, hypertension, and/or obesity.