A  STUDY OF LIPID METABOLISM IN PREGNANCY INDUCED HYPERTENSION

ABSTRACT

Background:  Pregnancy Induced Hypertension (PIH) is a multi system disorder of Pregnancy and is a major cause of maternal morbidity and mortality worldwide.

Objectives: To evaluate changes in serum lipoproteins in women with pregnancy induced hypertension and compare it with normotensive pregnant women and see its association with various risk factors like different fractions of serum lipids,sub types of PIH,maternal age, body mass index, parity and family history of PIH in different sub groups.

Methods: This cross sectional study was conducted on pregnant women attending the Gynecology and Obstetrics Department of tertiary care hospitals of Peshawar, North West Frontier Province (NWFP) Pakistan. Pregnant women with a gestational age of 26-28 weeks were registered in the study after taking their informed consent. The study subjects were divided into four groups of pregnant women; with three patient groups of 50 each [A (gestational hypertension), B (pre-eclampsia), C (eclampsia)] of pregnancy induced hypertension and one control group (D).

History of each participant was recorded on a pre designed questionnaire. Height, weight and blood pressure were measured and 5 ml of venous blood was drawn from patients and control groups. Biochemical analysis of lipoprotein included Total Cholesterol (TC), High Density Lipoprotein Cholesterol (HDL-C), Low Density Lipoprotein Cholesterol (LDL-C), Very Low Density Lipoprotein Cholesterol (VDRL-C), Triglycerides (TG), Apolipoprotein-A1 (APO-A1), Apolipoprotein- B100 (APO-B100), Lipoprotein-a (LPA), Hemoglobin (Hb) and Platelet count. These investigations were performed in PMRC Research Centre, Khyber Medical College, Peshawar and in the Pathology labs of Post Graduate Medical Institute (PGMI) Lady Reading Hospital, Peshawar. The data was processed on computer software package SPSS version 10. A ‘P’ value at 95% confidence interval (CI) was considered as significant (P < 0.05).

Results: Significant (P < 0.001) differences were noted in the maternal serum lipids and lipoprotein concentrations in the three patient groups when compared with the control pregnant group. Total cholesterol was same in cases with gestational hypertension, and pre-eclampsia, while a significant increase was noted in eclampsia group when compared with the control group. Apolipoprotein A1 was not significant in cases with gestational hypertension, while it was significantly low in eclampsia and pre eclampsia when compared with controls. Mean concentrations of APO-B100 were non significant in pre eclampsia group, while it was low (P < 0.05) in gestational hypertension and eclampsia when compared with controls. Mean values of LPA were not significant in gestational hypertension and pre eclampsia, while it was increased (P < 0.001) in eclampsia as compared to controls. Amongst the different lipoprotein ratio TC: HDL-C, LDL-C: HDL-C and TG: HDL-C ratio were higher (P < 0.001) in patient groups with gestational hypertension, pre eclampsia and eclampsia as compared to controls. TC: HDL ratios, LDL-C: HDL-C ratio and TG: HDL-C ratios were higher among women with pregnancy induced hypertension (P<0.001) as compared to controls. In the pregnancy induced hypertension group LDL-C: APO-B100 was markedly raised (P < 0.01), while the difference between test and control was not significant for LDL-C: APO-B100 ratio (P > 0.05). HDL-C: VLDL-C ratio were decreased in the patients as compared to controls (P <0.001). Age in all subjects ranged from 15 to 45 years with similar low socio-economic characteristics. In eclamptia patients, 32% were aged less than 20 years. About 60%  women in eclampsia were primiparous and were twice as likely to be eclamptic (OR 2.08, CI (1.08 - 4.03), χ² 5.55, P < 0.01) as compared to women having parity 2-4, while women with parity greater than 7 were 1.6 times (CI 0.71-3.76) more at risk to develop pregnancy induced hypertension. Overweight and obese women with body mass index (BMI) > 23.0 kg/m² had a two fold higher risk of pregnancy induced hypertension than women with normal BMI < 23.0 kg/m² (OR 1.95, CI 1.02-3.71, P < 0.02). A woman with a family history of pregnancy induced hypertension was five times more at risk to develop pregnancy induced hypertension (OR 4.73, CI 1.07-29.24, P < 0.02) as compared to those having no such family history. 

Conclusion: It was concluded that evaluation of lipoprotein concentrations during antenatal care could be helpful in the early detection and prevention of pregnancy induced hypertension.