Risk factors associated with a low glomerular filtration rate in primary aldosteronism

Abstract

Context: Primary aldosteronism (PA) is associated with vascular end organ damage. Objective: We evaluated the newly established German Conn's Registry for evidence of renal impairment and compared the data with those from hypertensive subjects of a population-based survey. Design: We conducted a case-control study. Patients and Controls: A total of 408 patients with PA from the Conn's registry treated in five German centers were matched for age, sex, and body mass index in a 1:1 ratio with 408 hypertensive control subjects from the population-based F3 survey of the Kooperative Gesundheitsforschung in the region of Augsburg (KORA). Main Outcome Measures: We measured serum creatinine and calculated glomerular filtration rate (GFR). Results: The percentage of patients with a serum creatinine concentration above the normal range of 1.25 mg/dl was higher in patients with PA than in hypertensive controls (29 vs. 10%; P 〉 0.001). Regression analysis showed that age, male sex, low potassium, and high aldosterone concentrations were independent predictors of a lower GFR. Adrenalectomy reduced systolic blood pressure from a mean of 160 to 144 mm Hg. In parallel, we observed an increase in serum creatinine and a decrease of GFR from 71 to 64 ml/min (P 〈 0.001). A similar trend was seen after spironolactone treatment. Conclusions: In a large cohort of patients with PA, markers of disease activity such as plasma aldosterone and serum potassium are independent predictors of a lower GFR. Specific interventions, such as adrenalectomy or spironolactone treatment, are associated with a further decline in GFR.