ApoE phenotype influences plasma ASP in hyperapoB subjects

Acylation stimulating protein (ASP) is increased in cardiovascular patients who often present with dyslipidemias. The aim of the present study was to examine the influence of apolipoprotein E (apoE) phenotype and lipids on ASP. Plasma ASP, lipids and apoE phenotype were measured in 407 subjects and separated according to the 75th percentile of apolipoprotein B (apoB) into a HyperapoB (HB) group (apoB=152±34 mg/dl, 117 men, 80 women) and a normal apoB (NB) group (apoB=88±19 mg/dl, 126 men, 84 women). Triglyceride (TG), cholesterol and LDL cholesterol were significantly increased in HB versus NB but there was no difference in age or body mass index (BMI). HB had increased ASP (42%>75th percentile, MEDIAN=48.4 nM, P<0.001) versus NB (36.5 nM). There was no difference in ASP in NB with any apoE3 variant (E3/3=41 nM, n=98; E3/4=46 nM, n=55; E3/2=50 nM, n=41), but ASP was increased in E2/2 (126 nM, n=9), and E4/4 (186 nM, n=5, P<0.001 ANOVA). In HB, ASP was increased in three apoE phenotypes: E2/4 (209 nM, n=6), E2/2 (135 nM, n=6) and E4/4 (189 nM, n=26), P<0.001 ANOVA relative to the other apoE phenotypes (E3/3=50 nM, n=102; E3/4=41 nM, n=40; E3/2=87 nM, n=17) with a wide range of values. By stepwise regression analysis, the best model that predicted ASP was: plasma non-esterified fatty acid (NEFA)+TG+cholesterol], where r=0.407, P=0.001. These data suggest that apoE phenotype may potentially influence ASP, although primarily in rare apoE phenotypes.