Apolipoprotein E phenotypes, lipoprotein composition, and xanthelasmas.

The different types of serum lipoproteins, including apolipoprotein E phenotypes, were measured in 50 patients with xanthelasma. Half of them were found to be hyperlipemic. The normolipemic and hyperlipemic groups with xanthelasma were compared with two control groups (one a group of normolipemic patients and another a group of hyperlipemic patients without xanthelasma) selected as homogeneously as possible with regard to age, sex, degree of obesity, and hyperlipemic phenotype. The only significant differences found among the groups, regardless of the presence of hyperlipemia, were the increased levels of total and high-density lipoprotein phospholipids, and lower levels of apolipoprotein B, found in the group with xanthelasmas. The distribution of apolipoprotein E phenotypes was the same in both groups, with slight differences between the normolipemic and hyperlipemic groups. Patients with xanthelasmas showed slight deviations in the metabolism of lipoproteins that require further clarification.