Impact of obesity on the association of active renin and plasma aldosterone concentrations, and aldosterone-to-renin ratio with preeclampsia

Abstract

Objective: To evaluate the association of active renin concentration (ARC), plasma aldosterone concentration (PAC) and aldosterone-to-renin ratio (ARR) with the risk of preeclampsia (PE), in particular according to the status of obesity.

Design: This retrospective case-control study involved 90 women with PE (mean gestation 35.6 ± 3.6 weeks) and 90 age-matched control women with uncomplicated pregnancies (mean gestation 38.5 ± 2.5 weeks). ARC and PAC were measured by radioimmunoassay; ARR calculated as PAC to ARC ratio. PE cases were stratified into 5 percentiles groups, and analyzed in multivariate logistic regression.

Results: Women with PE had significantly lower median ARC and PAC than control women, which were confirmed by percentiles analysis. Spearman correlation demonstrated negative correlation of ARC with body mass index, systolic/diastolic blood pressure. PAC correlated negatively with systolic/diastolic blood pressure, but positively with baby weight, ARC and ARR. On the other hand, ARR positively correlated with BMI and PAC, but negatively with ARC. Lower PAC was associated with PE, irrespective of body weight, while ARC levels were significantly lower in non-obese PE cases vs. control women. ARR was not significantly different between PE cases and control women, when stratified according to obesity.

Conclusion: Low ARC and PAC in third trimester are more strongly associated with preeclampsia respectively in non-obese and obese women.

Keywords: Aldosterone; Aldosterone-to-renin ratio; Obesity; Preeclampsia; Renin.