Congenital Adrenal Hyperplasia in Children: The Relationship between Plasma Renin Activity and Hypertension

Children with Congenital Adrenal Hyperplasia (CAH) have a higher chance of hypertension. The likelihood of hypertension is higher in CAH children who get fludrocortisone medication and have an over-suppression. Plasma renin activity (PRA) is a sensitive indicator when the fludrocortisone dose is insufficient. The objective of this study is to assess the relationship between plasma renin activity with hypertension in 21-hydroxylase-deficient (21-OHD) CAH children.  This cross-sectional observational analytical study was conducted in 2019 at the Pediatric Endocrinology Outpatient Clinic in Dr. Cipto Mangunkusumo Hospital (RSCM), Jakarta, Indonesia. The subjects were 21-OHD CAH children, aged >6 months to 18 years who had already taken hydrocortisone with or without fludrocortisone for at least 6 months, and were divided into hypertension and non-hypertension groups. The subjects were selected by a consecutive sampling method. Data was analyzed using SPSS software (version 23.0) with unpaired t test analysis and multiple logistic regression test. Statistical significance was achieved if P<0.05. Forty 21-OHD CAH patients were included, and 20 subjects (50%) had hypertension. A higher incidence of hypertension was found in salt-wasting CAH than in simple virilizing types (59.3% vs 30.8%). There was a significant mean difference in PRA levels between hypertension and non-hypertension groups in salt-wasting patients (P=0.016). A significant difference between the last dose of hydrocortisone with the number of hypertension patients in salt-wasting patients (P=0.032) was found, and low PRA levels showed a 1.09 times higher risk of hypertension.  Children with salt-wasting CAH with low PRA levels had a higher risk of getting hypertension.