Endocrine Abstracts

Introduction: Primary aldosteronism (PA) is a common cause of secondary hypertension that can lead to renal sequelae. Treatment of hyperaldosteronism leads to reductions in albuminuria and glomerular hyperfiltration. We aimed to evaluate the effect of treatment on albuminuria and temporal changes in renal function after treatment with both surgery and medications.

Methods: We prospectively recruited patients with PA over three years. Spot urine samples for albumin were collected at baseline and one-year post-treatment. Degree of albuminuria was categorized based on the KDIGO classification. Serum creatinine values were collected at baseline and annually up to three years post-treatment, while estimated glomerular filtration rates (eGFR) were calculated using the MDRD equation. All patients keen for surgical cure were offered adrenal vein sampling (AVS). Patients with unilateral PA were treated with surgery, while those with bilateral disease were given medical therapy.

Results: Fifty-seven patients were recruited in the study, with no drop-outs. Forty-eight patients underwent AVS, and all had successful bilateral cannulation. Eventually, 25 patients underwent adrenalectomy whilst 32 patients received medications. Patients treated with surgery were younger, had more severe hypokalemia, and were less likely to have ischemic heart disease and hyperlipidemia. Overall, in 18 patients, there was improvement in albuminuria category, it remained the same in 19 patients, and worsened in 5 patients. In the surgical group, albuminuria improved significantly, from median 46.0mg/g to 6.0mg/g, P=0.001. In the medical group, albuminuria changed from median 41.5mg/g to 18.5mg/g, P=0.356. Significant declines in eGFR after treatment was observed in both groups. In the surgical group, eGFR continued to decline year-on-year until the second year when it stabilized, whereas in the medical group, there was greater eGFR decline in the first year and then it stabilized. Overall, over three years, there was no difference in the magnitude of decline between the surgical and medical groups (8.1ml/min/1.73m² vs 7.4ml/min/1.73m², P=0.992).

Discussion: Treatment of PA leads to reversal of glomerular hyperfiltration and resultant decline in eGFR. However, renal function is subsequently stable after the initial decline. The improvement of renal function is best observed in the improvement of albuminuria amongst patients with PA, with surgical treatment associated with a greater degree of improvement.