Problem: Pregnancy-induced hypertension (PIH) affects up to 15% of all pregnancies. Disturbed placentation is one factor associated with PIH. Leptin and peroxisome proliferator activator receptors (PPAR) seem to play an important role in placentation, fetal development, and blood pressure regulation. Therefore, we investigated polymorphisms in the genes encoding leptin, the leptin receptor, and PPARgamma2 in patients with PIH.
Method of study: In this retrospective case-control study, 103 patients with PIH [gestational hypertension (GH) n = 39; preeclampsia n = 27; eclampsia n = 5; HELLP n = 32] and 100 controls were analyzed for the LEP tetranucleotide repeat (TTTC)(n) and the leptin receptor (LEPR) R223Q and PPARgamma2 P12A substitutions. Statistical analysis was performed using the chi-square, Mann-Whitney U-, and Kruskal-Wallis tests (P < 0.05 significant).
Results: The frequency of the three possible genotypes did not differ significantly between patients and controls [LEP (TTTC)(n): P = 0.43; LEPR R223Q: P = 0.94; PPARgamma2 P12A: P = 0.94]. However, postpartal diastolic blood pressure of PIH patients was significantly higher in homozygous carriers of the LEPR Q223-encoding allele as compared with patients carrying the wild-type allele (P < 0.01).
Conclusion: Hypertensive disorders in pregnancy were not associated with the LEP, LEPR, and PPARgamma2 polymorphisms studied. The role of other variations in the LEP and PPAR genes in the pathophysiology of PIH and in exacerbations are the objective of ongoing research.