Inverse Correlation between Insulin like Growth Factor 1 and Leptin Levels in Preeclampsia
The basic pathology of preeclampsia is intense vasospasm affecting whole of the vascular system, especially renal, uterine, and cerebral vessels, which is probably due to an increase in vasopressor substances such as angiotensin II, thromboxane A2 , endothelin-1, and a decrease in vasodilator substances such as nitric oxide and prostacyclin due to endothelial cell dysfunction.
The mechanisms regulating fetal growth are poorly understood. Apart from genetic predisposition, factors such as chromosomal aberrations, nutritional and environmental factors or toxic exposition during pregnancy, insulin, and insulin-like growth factors (IGFs) have been implicated as a primary determinant of fetal weight.
SUBJECTS AND METHODS:
The present study was conducted during 2011–2012 in the Department of Biochemistry in collaboration with the Department of Obstetrics and Gynaecology, Pt. B. D. Sharma, PGIMS, Rohtak. This study was approved by the Ethics Review Committee of the institute. Fifty pregnant women attending the outpatient Department of Obstetrics and Gynaecology were randomly enrolled and divided into two groups: Group I (control, n = 25) normotensive women with singleton pregnancy at the time of delivery; and Group II (study, n = 25) age- and gestation-matched women with singleton pregnancy and systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg with or without proteinuria at the time of delivery.
Informed consent was taken from all the patients. Women with a history of chronic hypertension, any metabolic disorder before or during pregnancy, or presence of high-risk factors such as heart disease, diabetes, renal disease were excluded.
IGF-1 levels were lowered in maternal blood of preeclamptic as compared to normotensive mothers(P < 0.001) . Leptin levels were significantly increased in preeclamptic mothers as compared to normotensive mothers (P < 0.001). Cord blood IGF-1 levels were significantly decreased inpreeclampsia mothers as compared to the normotensive mothers (P < 0.001) [Table 1], while serum leptin levels were significantly increased in preeclampsia mothers as compared to the normotensive mothers (P < 0.001). Maternal leptin and IGF-1 levels were about two-fold higher than fetal levels in both groups.
Conflicting evidence regarding alterations of IGFs in preeclamptic pregnancies are available in literature. Vatten et al. observed an increase in IGF-1 from the first to second trimester associated with preeclampsia, which the authors concluded was the result of placental disease.Contradicting these findings, Ning et al. reported a decrease in free IGF-1 levels in early pregnancy associated with the risk of developing preeclampsia Ingec et al. observed lowered IGF-1 levels in late pregnancy in women who developed moderate and severe preeclampsia and eclampsia. Cooley et al. and Hübinette et al. reported that IGF-1 levels are not changed in women with preeclampsia.Wilson et al. reported the higher concentration of IGF-1 in the third trimester, probably reflecting placental contribution.
Findings of the present study suggest that IGF-1 and leptin play a central role in controlling fetal growth.
Journal of Basic and Clinical Reproductive Sciences