Overweight Patients Less Improved Kidney Function After Laparoscopic Surgery for Adrenocortical Adenoma With Excess Cortisol Secretion

Abstract

Purpose: Glucocorticoid (GC) is known to be involved in the deterioration of kidney function both directly by affecting the glomeruli and renal tubules and indirectly by affecting cardiovascular function. Autonomous GC secretion is the main feature of primary adrenal hypercortisolism (PAHC). However, the ideal treatment option (operation vs. medical treatment and observation) for patients with PAHC has not been established yet. In this study, we assessed a time series of kidney function in patients with PAHC treated via laparoscopic adrenalectomy and investigated the predictive factors for kidney function 1 year after surgery. Methods: From September 1997 to July 2017, 175 laparoscopic adrenalectomies were performed for adrenal tumors at Akita University. Thirty patients, who were diagnosed as having PAHC via preoperative endocrinological evaluations and followed up for at least 1 year after surgery, were included in this study. Patients with severe complications or simultaneous aldosteronism were excluded. The mean age of the 30 patients was 57.5 years (range, 33-79 years; males, 4; females, 26), and the right and left sides were affected in 9 and 21 patients, respectively. Results: In all, 18 patients were diagnosed as having Cushing's syndrome and 12 as having subclinical Cushing's syndrome. The steroid cover was required in all cases after surgery. The estimated glomerular filtration rate significantly improved (78.4 mL/min [64.8-95.8] vs. 84.1 mL/min [66.8-104.0], p = 0.012) 1 year after surgery. Patients showing 5% or more improvement in kidney function and those showing less than 5% improvement were compared. On performing univariate analyses, factors such as a longer operative time, heavy body mass index (BMI), and preoperative unsuppressed ACTH were associated with worse improvement in kidney function. No significant associations were observed regarding metabolic disorders, clinical symptoms, and gross proteinuria. On multivariate analysis, patients with a higher BMI (≥ 24 kg/m²) showed worse improvement in kidney function at 1 year after surgery (odds ratio 14.0, 95% confidence interval 1.3-142.9, p = 0.012). Conclusions: In PAHC patients, after 1 year of follow-up, kidney function improved in terms of estimated glomerular filtration rate. Therefore, this improvement seems to be delayed in overweight patients, suggesting its direct role in renal function.

Keywords: adrenal tumor; hypercortisolism; kidney function; laparoscopic adrenalectomy; overweight.

Figure 1

The patients who underwent laparoscopic adorenalectomy were enrolled. Of those, 53 patients were diagnosed as primary adrenal hypercortisolism. Twenty-three patients were excluded from the analysis due to a short follow-up period, severe pre-existing complications, and the simultaneous presence of aldosteronism.

Figure 2

Time series of kidney function before and after adrenalectomy. The eGFR at 1 year after surgery significantly improved compared with the preoperative value (78.4 [64.8–95.8] mL/min vs. 84.1 [66.8–104.0] mL/min, p = 0.012).

Figure 3

Improvement in the rate of kidney function after adrenalectomy. With a cut-off value at a BMI of 24 kg/m², the improvement rate of kidney function was worse in patients with BMI ≥ 24 kg/m² at 1 month and 1 year after surgery (1 month, 8.6 [−6.2–30.4]% vs. −0.9 [−18.9–22.1]%, p = 0.038; 1 year, 12.6 [−14.0–42.4]% vs. 1.1 [−22.2–21.3]%, p = 0.024).