Role of bilirubin in pregnancy-induced hypertension

Role of bilirubin in pregnancy-induced hypertension

GYNECOLOGY & OBSTETRICS International Journal of Gynecology ScObstetrics 53 (1996) 267-268 Letter to the editor Role of bilirubin in pregnancy-induc...

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GYNECOLOGY & OBSTETRICS International Journal of Gynecology ScObstetrics 53 (1996) 267-268

Letter to the editor

Role of bilirubin in pregnancy-induced hypertension L. Chandra, P. Lali, A. Jain* Deportment of Biochemistry, Lady Hordinge Medical College and Smt. SK. Hospital, New Delhi, India Received 5 October 1995;revised 5 January 1996;accepted 11 January 1996

Keywords:Bilirubin; Pregnancy-induced hypertension;Antioxidant

Pregnancy-induced hypertension (PIH) is a common disorder of pregnancy associatedwith in&eased maternal and perinatal morbidity and mortality. Although the exact pathophysiology of the disease still remains a mystery, a number of hypotheses have been proposed. Lipids and lipoproteins are considered to be important risk factors for PIH. In recent years, it has been suggested that free radical-mediated lipid peroxidation may be involved in the endothelial cell damage seenin PIH [l]. This is supported by an increase in lipid peroxidation products like malonyldialdehyde and a decreasein natural antioxidant levels [2]. Bilirubin, a product of heme catabolism is a lipid soluble metabolite of the body. Studies have shown the beneficial role of bilirubin as a physiological chain-breaking antioxidant of lipid peroxidation [3]. The possibility of it having a similar role in PIH was investigated. The present prospective study was carried out on patients attending antenatal clinic or admitted to Smt. SK Hospital, Lady Hardinge Medical l

Corresponding author.

College, New Delhi. It includes 25 primigravidas in the age group 20-35 years with gestational age > 28 weeks.The diagnosis of PIH was established in accordancewith the definition of the American College of Obstetricians and Gynecologists. The blood pressure was more than 140/90 mmHg associated with/without proteinuria or edema. There was no other obstetric or medical complication. A similar number of healthy pregnant women matched for age, race, parity and period of gestation were chosen as controls. Fasting venous blood samples were taken for biochemical analysis after diagnosis but before the start of therapy. Various biochemical parameters were estimated on the Beckman Synchron CX-5 (Brea, CA, USA) system under strict quality control. The results are shown in Table 1. The data was analyzed statistically using Student’s f-test. Our results show a significant difference in the concentration of triglycerides and HDLC, which is in accordance with findings of other workers [4]. It could contribute to vascular endothelial dysfunction in PIH, which may be due to free radicalmediated lipid peroxidation.

0020-7292AW’$15.000 1996International Federation of Gynecology and Obstetrics PII SOOZO-7292(96)02656-2

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L. Chandra et al. /International

Journal of Gynecology & Obstetrics 53 (19%) 267-268

Table 1 Biochemical parameters Parameters

Total bilirubin (mg/dl) ALT (IU/I) ALP (IUiI) Cholesterol (m&h) Triglycerides (mg/dl) HDLC (mg/dl)

Subjects

statistical significance (IJ)

PIH

Control

0.48 zt 0.16 27.88 i 11.25 255.44 A 72.48 271.64 f 41.83 281.76 f 72.28 27.23 f 8.30

0.94 l 0.21 23.68 f 9.48 244.56 AE108.11 209.16 f 41.67 229.44 rt 70.53 6.80 41.45 f

O.OCHl N.S. N.S. 0.000 0.000 0.000

N.S., not statistically significant.

As seen from the results there is a significant decreasein the concentration of total bilirubin in PIH group versuscontrols, though it is within norma1 range (0.2-1.2 mg/dl) in both groups. This may be due to its increased utilization as a chainbreaking antioxidant similar to other natural antioxidant nutrients, namely ascorbic acid, ar-tocopherol and &carotene. A low concentration of bilirubin might also prevent solubilization of cholesterol and its clearance through the bile, thereby increasing serum cholesterol concentration. As is evident from our results, there is a highly significant increase of cholesterol in the PIH group. On the basis of these findings we suggest that bilirubin, a simple biochemical parameter, could be included in the routine testsundertaken in pregnant females for identification of high-risk PIH.

References

I11 Hubel CA, Roberts JM, Taylor RN, Musci TJ, Rodgers

GM, McLaughlin MK. Lipid peroxidation in pregnancy: New perspectiveson pre-eclampsia. Am J Obstet Gynecol 1989; 161: 1025-1034. 121 Mikhail MS. Anyaegbunam A, Gartinkel D, Palan PR, Basu J, Romney SL. Preeclampsia and anti-oxidant nutrients: Decreased plasma levels of reduced ascorbic acid, a-tocopherol and &carotene in women with preeclampsia. Am J Obstet Gynecol 1994, 171: 150-157. 131 Stocker R, Yamamoto Y, McDonagh AF, Glazer AN, Ames BN. Bilirubin is an anti-oxidant of possible physiological importance. Science 1987;235: 1043-1046. 141 Kaaja R, Tikkanen MJ, Viinikka L, Ylikorkala 0. Serum lipoproteins, insulin and urinary prostanoid metabolites in normal and hypertensive pregnant women. Obstet Gynecol 1995;85: 353-356.