Apolipoprotein E Polymorphism and Impotence

Park, Im Chan; Park, Jong Kwan

Abstract

PURPOSE: Apolipoprotein E (Apo E) is composed of 299 amino acids, and is classified into three subtypes (E2, E3, E4), which respectively have influences on serum lipid levels. Arteriogenic erectile dysfunction (AED) is related to hyperlipidemia, hypertension, DM and traumas of the pelvis and perineum. Therefore, we evaluated the frequency and relationship of an apolipoprotein E gene in patients with erectile dysfunction.
MATERIALS AND METHODS
202 patients, with no history of either trauma in the pelvis or perineum, and radiation therapy, were selected from patients with erectile dysfunction. History taking, physical examination, Apo E genotyping and penile Doppler ultrasonography were performed. Serum cholesterol, triglyceride, high and low density lipoprotein (HDL and LDL), and apolipoprotein A and B were also measured.
RESULTS
Apo E genotypes were E2/2, E2/3, E3/3, E2/4, E3/4 and E4/4, with distributions of 0.5, 11.7, 70.4, 0.5, 15.8 and 1.0%, respectively. As a result of penile Doppler ultrasonography, 112 patients turned out to have an AED. In the AED group, the serum triglyceride increased significantly (p<0.05), but there were no differences in the serum cholesterol, HDL, LDL or the apolipoprotein A and B. The distributions of apo E genotypes E2/3, E3/3 and E3/4 were 13.9, 68.6 and 17.6%, respectively, in the AED group. The serum triglyceride (TG) was significantly higher in the E3/4 than the E2/3 or E3/3 genotypes.
CONCLUSIONS
AED is related to age, smoking, hypertension, DM and high TG, and the Apo E genotype of E3/4, with a high level of TG. However, an Apo E gene is, generally, not considered a diagnostic tool of erectile dysfunction. In the future, it should be clarified if the Apo E gene can be used as diagnostic tool for AED.