Longstanding primary aldosteronism (PA) has deleterious effects on renal function, often masked until treatment (adrenalectomy or spironolactone) is initiated. It has been suggested that PA causes relative glomerular hyperfiltration, explaining the decline in estimated glomerular filtration rate (eGFR) after treatment. In this retrospective study, the authors retrieved the clinical characteristics and eGFR of 134 PA patients before and 6 months after treatment. Using multiple regression analysis, the predictors for eGFR decline and the predictors of ultimately attained renal function in 113 patients was assessed. eGFR declined by 15.3±14.2 (range 19–63) mL/min, independent predictors were pretreatment plasma aldosterone, eGFR, plasma renin, and plasma potassium. Independent predictors of ultimately attained eGFR after treatment were pretreatment plasma aldosterone, age, eGFR, and plasma potassium. Our findings lend support to the hypothesis that higher aldosterone levels cause relative glomerular hyperfiltration. The severity of pretreatment aldosterone excess is the most important risk factor for renal function decline.
