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

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.