Factors associated with renal function change after unilateral adrenalectomy in patients with primary aldosteronism

Decreased glomerular filtration rate has been reported in patients with primary aldosteronism after unilateral adrenalectomy. Glomerular hyperfiltration has been assumed to mask the preoperative subtle renal impairment. In this study, we investigated predictors for decreased estimated glomerular filtration rate after adrenalectomy in patients with primary aldosteronism.

From January 2006 through September 2018, 328 patients with confirmatory diagnoses of primary aldosteronism received unilateral laparoscopic adrenalectomy and subsequent follow-up for 12 months. We prospectively collected related parameters of the clinical outcomes and renal function to identify predictors of renal function impairment at 12 months after surgery.

Patients were stratified into three groups by preoperative estimated glomerular filtration rate level: 144 (43.9%) with estimated glomerular filtration rate ≥90, 130 (39.6%) with estimated glomerular filtration rate within 60-89.9, and 54 (16.5%) with estimated glomerular filtration rate <60 mL/min/1.73 m² . The estimated glomerular filtration rate decreased significantly at the 6th month and remained stable at the 12th month, postoperatively. Patients with estimated glomerular filtration rate ≥90 had better clinical outcome with 59.6% success rate (P = 0.006) among three groups. Multivariate logistic regression analysis indicated that preoperative estimated glomerular filtration rate (odds ratio 1.012, P = 0.02) and hypokalemia (odds ratio 2.018, P = 0.024) were associated with renal impairment at 12th month after adrenalectomy. Multivariate linear regression analysis revealed high preoperative estimated glomerular filtration rate (β = 0.261, P < 0.001), high preoperative systolic blood pressure (β = 0.168, P = 0.003), high level of microalbuminuria (β = 0.024, P = 0.001), and low level of serum potassium (β = -4.883, P = 0.007) were associated with estimated glomerular filtration rate percentage decline at 12th month after adrenalectomy.

Estimated glomerular filtration rate declined significantly after adrenalectomy in patients with estimated glomerular filtration rate ≥90. The study provided important information to identify primary aldosteronism patients with higher risk of estimated glomerular filtration rate decline after adrenalectomy and might help to adopt early interventions to improve the outcomes.