255-POS

Abstract

Objectives 27-hydroxycholesterol (27-OHC) is the hydroxylation product of cholesterol by the enzyme sterol 27-hydroxylase (CYP27A1). 27-OHC is a potent inhibitor of cholesterol synthesis and increases cholesterol efflux from extrahepatic cells in vitro. Its transport from peripheral cells to the liver contributes to the high-density lipoprotein HDL-dependent reverse-cholesterol-transport and represents a potentially anti-atherogenic mechanism. Our hypothesis was (1) that the rise in cholesterol concentration during pregnancy is attributed to a lower catabolism and excretion by a relative decrease in 27-OHC concentration during the course of pregnancy and (2) that 27-OHC plays a role in pregnancy related pathologies linked to a disturbed lipid metabolism. Methods 223 serum samples were analyzed. Group A: 33 patients with uncomplicated pregnancies were analyzed at three different time points (first to third trimester). Group B consists of 45 patients (24–42 weeks of gestation) with pregnancy pathologies (IUGR n = 14, preeclampsia n = 14, HELLP n = 10, intrahepatic cholestasis n = 7) and 45 gestational age matched controls. 27-OHC was measured by GC–MS and related to cholesterol concentrations. Statistics: Spearman’s rank coefficient and Kruskal–Wallis test with Dunn’s multiple comparisons. Results Group A: 27-OHC was positively correlated to total cholesterol concentration ( ρ = 0.518). The 27-OHC/cholesterol ratio dropped with the course of pregnancy with higher values in first and second trimester as compared to the non-pregnant state postpartum (mean (SD), 1st trimester: 1.367 (0.38) p p Conclusions Our analysis revealed an increased 27-OHC/cholesterol ratio in the first and second trimester, indicating a lower cholesterol catabolism accounting for increased cholesterol concentrations throughout gestation. However, it does not support a role of 27-OHC in the patho-mechanism of pregnancy pathologies. Disclosures B. Winkler: None. N. Kleine-Eggebrecht: None. N. Maass: None. M. Mohaupt: None. G. Escher: None. U. Pecks: None.