Association of angiotensinogen rs699 single nucleotide polymorphism and pre-eclampsia in Lagos, Nigeria: A case-control study

Abstract

Preeclampsia is a pregnancy disorder that endangers the lives of bpth mother and child. Gene polymorphisms of Angiotensinogen have  been shown to be associated with hypertension and since pre-eclampsia is basically hypertension in pregnancy, there might be a genetic  correlation. Angiotensinogen rs699 (AGT rs699) polymorphism affects spiral arteries in the uterus and controls blood pressure. Various  association studies of SNP for pre-eclampsia have yielded conflicting results. This study investigated the association of AGT rs699 and ascertain the socio-medical factors with pre-eclampsia amongst gestating women in Lagos, Nigeria. Ethical approval and informed  consent were obtained from Health Research and Ethical committees. Thirty-eight (38) preeclamptic (P) and 39 normotensive (N) pregnant women from a selected maternity hospital were recruited for this study. Demographic characteristics, medical history, and  present medical conditions were assessed using questionnaires. Blood samples were collected and AGT rs699 was genotyped. Descriptive  statistics, independent sample t-test, chi-square, and multiple regression analysis were used to analyze the data obtained (p <0.05). The mean age and weight of women with pre-eclampsia were higher in preeclamptic women with no significant difference (P =  32.43 ± 5.76, N = 30.97 ± 4.54, and P =79.04 ± 10.28, N = 76.82 ± 15.35 respectively). Diastolic blood pressure (DBP), Systolic blood pressure  (SBP), and Proteinuria were significantly higher in preeclamptic patients. Surprisingly, the incidence of AGT rs699 was significantly higher  in 2 normotensive (82%) women than in preeclamptic women (17%) (X =29.150, p = 0.00001). A significant correlation was observed  between AGT rs699 and SBP in normotensive patients (r2 = 0.201, p=0.003) and a negative correlation in preeclamptic patients. In  contrast, AGT rs699 was negatively related to DBP with no statistical difference in both the normotensive and preeclamptic groups. In  addition, no correlation nor significant differences were observed between AGT rs699 and the weights of the preeclampsic and    normatensive women. In conclusion, this study revealed a negative significant association between preeclampsia and AGT rs699 among  cases and the control population studied.