Plasma apolipoproteins in patients with multi-infarct dementia.

We examined 27 elderly patients with multi-infarct dementia developed on the basis of cerebral arteriosclerosis. The levels of plasma cholesterol and triglyceride in the patients were 177 +/- 48 and 91 +/- 27 mg/dl (mean +/- SD), respectively. Despite normal plasma lipid levels, the patients had significantly higher plasma apo B (102 +/- 30 vs. 82 +/- 21 mg/dl for controls, P less than 0.01) and lower plasma apo A-I levels (104 +/- 25 vs. 130 +/- 22 mg/dl for controls, P less than 0.01) than the controls. Isoelectric focusing of apo E showed a 2-fold higher relative frequency for the epsilon 4 allele in patients than in Japanese controls (20.8 vs. 8.6-11.7% of total, P less than 0.05). The patients with phenotypes of E4/4 (n = 1) and E4/3 (n = 8) had higher plasma cholesterol levels than those with E3/3 (n = 15) (196 +/- 45 vs. 169 +/- 43 mg/dl). The results indicate that the patients had abnormalities in plasma lipoprotein metabolism and this may contribute to the development of cerebral arteriosclerosis.