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Twenty consecutive infertile women (mean age ± SD, 36.9 ± 5.4 years) undergoing ovarian stimulation with recombinant follicle stimulating hormone (rFSH) were recruited. Serial measurements of plasma total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), lipoprotein(a) (Lp(a)), oestradiol and progesterone were performed on day 3 before starting ovarian stimulation, on the day of human chorionic gonadotrophin (HCG) administration and on day 15 after HCG administration, respectively. The relationship between lipid and apolipoprotein concentrations and serum oestradiol and progesterone concentrations was sought. All women completed the ovarian stimulation protocol successfully. Plasma concentrations of HDL-C and Apo-A1 were significantly raised on the day of HCG administration and then returned to baseline values within 2 weeks. LDL-C, TG, Apo-B and Lp(a) were significantly increased on day 15 after HCG administration. Lp(a) variation between the first sample and the third sample correlated positively with serum progesterone concentrations (r = 0.472, P < 0.04). No other significant correlations were found between lipid and apolipoprotein variations and either oestradiol or progesterone concentrations. It was concluded that an increase of plasma lipid and apolipoprotein concentrations deserves particular consideration and all women undergoing ovarian stimulation should be monitored for long-term atherogenic and thrombogenic risks. [ABSTRACT FROM AUTHOR]

Low-density lipoprotein (LDL) oxidation in vivo depends on lipid composition and on plasma antioxidant status. The aim of our study was to investigate the relationship between plasma lipid composition and LDL oxidation and, in particular, to explore whether LDL-cholesterol/triglycerides ratio (LDL-C/TG) and LDL-cholesterol/high-density lipoprotein (HDL)-cholesterol ratio (LDL-C/HDL-C) can be used as predictive parameters of LDL oxidation in vivo. In 87 volunteers over a wide range of age plasma lipids and LDL oxidation were studied. Blood was collected after 12 h overnight fast. LDL oxidation was estimated by the level of conjugated diene (BDC) in the lipid fraction isolated from plasma after gradient ultracentrifugation. The results were expressed as µmol/I (BDC/I) to evaluate the level of oxidized LDL, and as nmol of BDC for mg of LDL-cholesterol (BDC/LDL-C) for the evaluation of LDL oxidation degree. BDC/I correlated significantly with age, total and LDL-C, apolipoprotein B and TG, while BDC/LDL-C negatively correlated with total cholesterol, apolipoprotein B, LDL/TG and LDL/HDL ratios. Age of subjects significantly correlated with total and LDL-C and apolipoprotein B. TG have a significant inverse correlation with HDL-C. Our results support the hypothesis that among the several factors involved in LDL oxidation the most important determinants are LDL/TG. Plasma triglycerides appear to be very important even when circulating cholesterol levels are within normal limits. Moreover, we found that the LDL/HDL ratio is also very important with regard to the putative protective role of HDL against LDL oxidation in vivo. In conclusion, plasma lipid parameters must be evaluated not only for their absolute values but also for their mutual ratios as expression of plasma lipid homeostasis. Both LDL/TG and LDL/HDL ratios can be used as predictive parameters of in vivo LDL oxidation. [ABSTRACT FROM AUTHOR]

Objective: We sought to investigate the changes in circulating serum lipids and lipoproteins, including lipoprotein (a), and low-density lipoprotein size in women during normal pregnancy.Study Design: Twenty-two women (mean age, 31 +/- 5 years; 13 primiparous subjects) were studied during uncomplicated pregnancy with normal outcome. Twenty-four nulliparous women of similar age (31 +/- 4 years) were studied as control subjects.Results: Serum triglycerides and total and low-density lipoprotein cholesterol increased significantly during pregnancy in all women. Women with changes in low-density lipoprotein during the second and third trimesters showed a more marked increase in serum triglycerides, and this effect was slightly more evident in the multiparous subjects. No other differences were evident between primiparous and multiparous women apart from high-density lipoprotein cholesterol levels, which were slightly decreased in the latter subjects.Conclusions: Our results show that during normal pregnancy, the increase in plasma triglycerides may lead to the appearance of the atherogenic dense low-density lipoproteins in a subgroup of women. We suggest that the observed changes in low-density lipoprotein patterns during pregnancy might be used to identify those women who later in life will have these atherogenic small and dense low-density lipoproteins. [ABSTRACT FROM AUTHOR]