Endocrine Abstracts

Primary aldosteronism (PA) is the most common cause of secondary hypertension. Although decline in renal function especially that experienced after adrenalectomy (ADX) has been demonstrated, details of the mechanism remain to be elucidated. Aim of the study was to investigate the factors predicting renal outcome after ADX in PA. Twenty patients with PA and four patients with non-functioning adrenal tumor (NFT) as control were studied. eGFR, serum potassium, plasma aldosterone concentration (PAC), and plasma renin activity (PRA) before and 1 month after ADX were analyzed. The study was approved by the institutional ethical committee. Baseline characteristics (M±SD, PA vs. NFT) were as follows: age; 51±9 vs. 65±9 yrs, blood pressure; 138±13 (estimated duration of hypertension 10.3±9.1 yrs) vs. 114±10 (mmHg), eGFR; 79.2±18.4 vs. 75.3±19.2 (ml/min/1.73 m²), serum potassium; 3.1±0.9 vs. 4.4±0.3 (mEq/L), PRA; 0.3±0.3 vs. 1.0±0.6 (ng/ml/h), PAC; 336±238 vs. 87±35 (pg/mL), and ARR; 2089±2728 vs. 131±102. Eighty % of PA patients (16/20) showed decline in eGFR after ADX (79.2±18.4 to 72.2±21.5, P=0.002). Post-ADX eGFR was correlated positively to baseline eGFR (r=0.82) and ΔPAC (r=0.46) and negatively to ΔK (r=0.44) and estimated duration of hypertension (r=0.63). Of the 13 patients with PA with hypokalemia before ADX, twelve patients showed normokalemia and 1 patient showed hyperkalemia (5.6 mEq/L) after ADX. Post-ADX serum potassium was correlated positively to baseline PAC (r=0.70) and ARR (r=0.75) and negatively to ΔPAC (r=0.63) and ΔARR (r=0.76). By contrast to the changes in PA, there were no changes in eGFR and serum potassium in NFT after ADX. These results suggest that duration of hypertension and PAC is the predicting factors for a significant decline in eGFR and hyperkalemia after ADX. Early diagnosis with correction of hypertension and hyperaldosteronism is essential for a better renal outcome in PA.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.