Evaluation of Aldosterone-to-renin Ratio Among Hypertensive Patients at the National Hospital Galle

Abstract

Background: Hypertension among young adults (18-42 years) is an emerging global public health concern. The Aldosterone-to-renin ratio (ARR) is a biochemical test used to identify inappropriate aldosterone activity and screen for primary aldosteronism (PA). It is recommended for patients with hypertension, adrenal nodules, or those unresponsive to standard hypertensive medications. Objectives: To estimate the prevalence and causes of raised ARR, to determine the prevalence of young hypertension (18-42 years) among ARR tested patients, to estimate the prevalence of primary aldosteronism in patients with elevated ARR who undergo further investigations and to determine the association of serum Na+, K+ levels with raised ARR (>3.7) and normal groups Methods: A cross-sectional retrospective study was conducted among 300 ARR-tested hypertensive patients (aged>18 years) who attended medical clinics, endocrine clinic, and chemical pathology laboratory at National Hospital Galle. Data were collected using convenient sampling method. Records of patients with psychiatric illnesses, pregnant women and patients aged> 60 years were excluded. ARR cut-off ≥3.7 was considered as elevated. Clinic records of ARR tested patients were screened for clinic details, blood pressure, endocrine disorders, other medical history, and demographic information. Results were analysed using SPSS version 21.0. Results: In this study group 18.3% (55/300) ARR-tested hypertensive patients had raised ARR (>3.7). Furthermore, 49.3% (148/300) of the study sample were young hypertensive patients (18- 42 years). It was observed that young hypertension is common in males, 64.19% (95/148) than in females, 35.81% (53/148). Among raised ARR patients, 34.54% (19/55) were diagnosed with PA. Furthermore, essential hypertension [25.45%, (14/55)], renal impairments (mostly CKD) [20%, (11/55)], renal artery occlusion [9%, (5/55)] were identified as other causes for raised ARR. The mean±SD values of serum Na+ and K+ levels among normal subjects (245/300) were 140.52±17.77 and 4.00±0.28 mmol/L, respectively. The mean±SD values for serum Na+ and K+ levels among raised ARR subjects (55/300) were 139.24±2.41 and 3.74±0.31 mmol/L, respectively. There was no significant difference between mean Na+ (p=0.258) and K+ (p=0.512) levels among ARR normal and raised groups. Conclusions: There is a 18.3% prevalence of raised ARR in ARR tested population and study identifies PA as the most common cause for raised ARR. Furthermore, this study shows a 49.3% prevalence of hypertension in young adult, majority being males which seems alarming. However, it is better to expand the study with a wider sample