FRI143 Serum Aldosterone Levels Predict Decline In Renal Function After Unilateral Adrenalectomy For Primary Aldosteronism

Disclosure: M.A. Stumpf: None. N.L. Queiroz: None. V.C. Souza: None. A.W. Maciel: None. G.F. Fagundes: None. V. Srougi: None. F.Y. Tanno: None. J.L. Chambo: None. M.A. Pereira: None. A. Pio-Abreu: None. L.A. Bortolotto: None. A. Latronico: None. M.B. Fragoso: None. L.F. Drager: None. B.B. Mendonca: None. M.Q. Almeida: None. Background: Primary aldosteronism (PA) is a very prevalent disease, characterized by an autonomous aldosterone secretion. Unilateral PA accounts for approximately 40% of the cases and is preferentially treated with surgery. Several studies reported decrease in renal function following unilateral adrenalectomy, but the risk factors associated with this decline remain to be better elucidated. Aim: Our aim was to investigate predictive factors of the decrease in renal function after unilateral adrenalectomy for PA. Methods: We retrospectively evaluated 89 PA patients submitted to unilateral adrenalectomy. Serum aldosterone, direct renin concentration, estimated glomerular filtration rate (eGFR), and electrolytes were determined at the pre-operative period and at 1 week, 1, 3 and 6 months (m) after unilateral adrenalectomy. The primary endpoint was the DELTAeGFR (eGFR after surgery at different times – eGFR before surgery). Results: Thirty-seven patients (41.6%) were men and 52 (58.4%) were women, with a median age of diagnosis of 49 years (range, 20 to 74 years). At diagnosis, the median aldosterone and renin levels were 29.8 ng/dl (7.3 - 217) and 4 μIU/mL (4 – 8.2), respectively. Hypokalemia at diagnosis was evidenced in 75 out of 89 (84.3%) of the patients. Unilateral PA was confirmed in 78 out of 89 cases (87.6%) by biochemical cure after adrenalectomy. The mean pre-operative creatinine and eGFR were 1.14 ± 0.48 mg/dL and 53.5 ± 17.1 mL/min, respectively. After adrenalectomy, the DELTAeGFR was −6.7 ± 12.1 mL/min at 1 week (p= 0.001), 0.17 ± 10 mL/min at 1m (p= 0.91), −2 ± 8.7 mL/min at 3m (p= 0.13) and −1.8 ± 10.9 mL/min at 6m (p= 0.24). Interestingly, aldosterone levels at diagnosis were significantly associated with the DELTAeGFR at 1 week (p= 0.024). PA patients with aldosterone levels >50 ng/dL (n= 13) at diagnosis presented a higher deterioration in renal function at 1 week when compared to those with aldosterone <50 ng/dL (n= 76) (αeGFR −12 ± 8.6 mL/min vs. −5.9 ± 12.5 mL/min, respectively; p= 0.032). Moreover, the patients with hypoaldosteronism (aldosterone <5 ng/dl) at 1 week had a lower decrease in renal function (DELTAeGFR −4.4 ± 12mL/min (n= 41) vs. −9.9 ± 11.6 mL/min (n= 42), respectively; p= 0.014) and lower levels of aldosterone at diagnosis (31.5 ± 21.1 ng/dL vs. 50.4 ± 44.4 ng/dL, respectively; p= 0.008). The post-operative decline in renal function did not correlate with age, hypokalemia, number of anti-hypertensive medications at diagnosis, immediate pre-operative and post-operative renin, and hypertension remission after surgery. Conclusion: The renal function decreased precociously after adrenalectomy but returned to basal levels after 1m. Aldosterone levels at diagnosis and at 1 week after surgery were significantly associated with decline in renal function. Support: This work was supported by the Sao Paulo Research Foundation (FAPESP) grant 2019/15873-6. Presentation: Friday, June 16, 2023