Maternal blood lipoprotein-cholesterol prior to and at the time of diagnosis of preeclampsia: a systematic review.

Abstract

Objective: Wide-spread endothelial dysfunction is thought to underlie the maternal symptoms of preeclampsia. Endothelial dysfunction is strongly associated with abnormal circulating lipoprotein-cholesterol levels. This systematic review aimed to assess whether maternal circulating high-density lipoprotein-cholesterol [HDL], low-density lipoprotein-cholesterol [LDL] and very-low-density lipoprotein-cholesterol [VLDL] are altered prior to or at the time of preeclampsia diagnosis. This may inform understanding of the pathogenesis of preeclampsia and the predictive and diagnostic utility of these lipoprotein-cholesterols in distinguishing preeclamptic pregnancies from normotensive pregnancies.

Data sources: Literature searches were conducted in OVID Medline, EMBASE, CINAHL and Google Scholar from inception to April 2024 for studies reporting HDL, LDL, and VLDL levels in normotensive and preeclamptic pregnancies.

Study eligibility criteria: Selected studies included the following: a population of pregnant women, exposure to preeclampsia, blood samples collected during a specific trimester of pregnancy and at least 1 primary outcome (HDL, LDL or VLDL). Two reviewers were involved in study selection. Studies excluded had pregnancies complicated by other risk factors for preeclampsia (eg. pre-existing hypertension, diabetes, obesity) and other pregnancy-related hypertensive disorders (pregnancy induced hypertension, eclampsia, HELLP syndrome).

Methods: The quality of the included studies was evaluated using the Newcastle-Ottawa scale for case-control, cohort and cross-sectional studies.

Results: A total of 41 studies were included. The quality of the studies was generally of good quality, however 59% did not control for the gestational age that the blood samples were collected. No consistent changes in HDL or LDL were found prior to preeclampsia diagnosis in the 1^st, 2^nd or 3^rd trimesters. VLDL was significantly elevated in 2/2 studies that reported levels prior to preeclampsia diagnosis in the late 2^nd (>23 weeks gestation) or 3^rd trimesters. After preeclampsia diagnosis in the 3^rd trimester, VLDL levels were significantly elevated in 9/11 studies and HDL was significantly decreased in 15/19 studies.

Conclusions: VLDL are highly atherogenic and their elevation prior to and at the time of preeclampsia diagnosis suggests a role in the pathogenesis of the endothelial dysfunction associated with preeclampsia. Both VLDL and HDL show promise as prospective (VLDL only) and diagnostic biomarkers of preeclampsia.