Lipids and Lipoproteins in Normal and Complicated Pregnancies

Sattar, Naveed Amjid (1998) Lipids and Lipoproteins in Normal and Complicated Pregnancies. PhD thesis, University of Glasgow.

Abstract

It is clear that there are substantial changes in lipids and lipoproteins in normal pregnancy with up to four-fold rise in triglycerides and up to a 50% increase in cholesterol. It is generally held that such changes exist to meet the demands of the feto-placental unit in terms of cellular proliferation and development and also to support lactation. In some situations the mechanisms regulating this physiologic hyperlipidaemia may malfunction. In women with pre-eclampsia, plasma free fatty acids and triglyceride concentrations climb substantially above those observed in normal pregnancy and do so well in advance of the appearance of clinical manifestations of the disorder. Lipoprotein classes are not homogeneous entities but include subclasses of differing function and metabolic potential. For example, particles such as low density lipoprotein itself can be broken down into distinct subpopulations with small, dense LDL (LDL-III) exhibiting strong atherogenic potential, in particular, promoting the development of foam cells and stimulating endothelial dysfunction. In the non-pregnant situation, plasma triglyceride is the major factor promoting the synthesis of LDL-III. However, this relationship is not linear, rather recent cross-sectional studies imply a threshold effect: synthesis of LDL-III proceeding only once triglyceride concentrations go beyond a 'threshold' value. To the best of our knowledge no longitudinal studies have been designed to examine this phenomenon in individual subjects. The physiological changes in plasma triglyceride which accompany pregnancy provide such an opportunity. In addition, at the time this thesis was initiated there was no information on the concentrations of very low density (VLDL) and LDL subfractions in pre-eclampsia. The primary objectives of the thesis were: to establish the lipoprotein subfraction changes occurring during the physiological hyperlipidaemia of normal pregnancies and the pathological hyperlipidaemia of pre-eclampsia. In addition, the consequences of the altered lipoprotein metabolism in pre-eclampsia for the promotion of the characteristic endothelial dysfunction present in this disorder was examined, as well as the relationship between lipid changes and haemostatic factors during normal gestation. Finally, lipid and lipoprotein concentrations in pregnancies complicated by IUGR, a condition in which the placental appearance is similar to that seen in pre-eclampsia but where the maternal systemic problems of hypertension and proteinuria are absent, were documented.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Shepard
• Keywords: Biochemistry, Obstetrics
• Date of Award: 1998
• Depositing User: Enlighten Team
• Unique ID: glathesis:1998-74485
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 13 Nov 2019 15:58
• Last Modified: 13 Nov 2019 15:58
• URI: https://theses.gla.ac.uk/id/eprint/74485