Determination of ratio of aldosterone to renin in patients with primary aldosteronism at Dong'e County, Shandong Province by chemiluminescence immunoassay

Abstract

Objective To determine the aldosterone to renin ratio (ARR) in primary aldosteronism (PA) in Dong'e County, Shandong province. Methods 146 patients who took registration at the clinical center of our hospital between January and December, 2017 were selected, including 51 PA patients and 95 EH patients. CT scan was performed on the the patients’ right adrenal glands, and pathology biopsy was done. The blood parameters were detected in all the patients, including parathyroid hormone, plasma aldosterone concentration, and the concentration of plasma renin. The data were analyzed by the single factor analysis and binary logistic regression model. A ROC curve was drawn to predict the maximum sensitivity and specificity of ARR. Results The age of the PA patients was lower than that of the EH patients (P<0.05). The PTH level was (43.08±19.16) pg/ml in the PA patients, and was (55.71±18.66) pg/ml in the EH patients, with a statistical difference (P=0.033). The PA patients with high excretion of aldosterone had higher PAC and lower plasma renin concentration [578.7 ng/dl vs. 418.1 ng/dl and 6.5 ng/dl vs. 13.0 ng/dl]. Univariate analysis found that age, PTH, PRC, and PAC were correlated with ARR as continuous variables. According to the analysis of binary logistic regression model, the above factors are independent predictors, and the 95% CI of ARR and PAC were (-119.70, -51.75) and (-215.15, -73.00), respectively. The area under ARR curve was 0.984, and the boundary value between PA and EH was 43.6, showing a high sensitivity of 96.1% and a high specificity of 91.6%. Conclusion This study provides an accurate cut-off value for the diagnosis of PA and is of great significance for guiding the early screening of PA at Dong'e County, Shandong province. Key words: Primary aldosteronism; Aldosterone; Renin; Cut-off value