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

Impact of primary aldosteronism on kidney function: results from the SPAIN-ALDO registry

AIM

To evaluate the impact of aldosterone excess on renal function in individuals with primary aldosteronism and to compare its evolution after surgery or mineralocorticoid receptor antagonist (MRA) treatment.

METHODS

A multicentre, retrospective cohort study of primary aldosteronism patients in follow-up in 36 Spanish tertiary hospitals, who underwent specific treatment for primary aldosteronism (MRA or adrenalectomy).

RESULTS

A total of 789 patients with primary aldosteronism were included, with a median age of 57.5 years and 41.8% being women. At primary aldosteronism diagnosis, the prevalence of chronic kidney disease (CKD) was 10.7% ( n  = 84), with 75% of cases classified as state 3a ( n  = 63). Primary aldosteronism patients with CKD had a longer duration of hypertension, a higher prevalence of type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. Unilateral adrenalectomy was performed in 41.8% of cases ( n  = 330), and 459 patients were treated with MRA. After a median follow-up of 30.7 months (range 13.3-68.4), there was a significant decline in the estimated glomerular filtration rate (eGFR) in operated patients and those receiving MRA. During follow-up, 24.4% of patients with CKD at the time of primary aldosteronism diagnosis had normalized renal function, and 39% of those with albuminuria had albuminuria remission. There were no differences in renal function or albuminuria regression between the two therapy groups. However, development of albuminuria was less common in operated than in medically treated patients (0 vs. 6.0%, P  = 0.009).

CONCLUSION

CKD affects around 10% of the patients with primary aldosteronism, with a higher risk in individuals with long-term hypertension, type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. At short-term, both MRA and surgical treatment lead to a reduction of renal function, but adrenalectomy led to higher renal protection.

The impact of superselective adrenal artery embolization on renal function in patients with primary aldosteronism: a prospective cohort study

Superselective adrenal artery embolization (SAAE) is an effective treatment for patients with primary aldosteronism (PA). However, the impact of SAAE on renal function in the PA population remains uncertain. We investigated the estimated glomerular filtration rate (eGFR) and age, sex, body mass index, and diabetes-specific percentiles of eGFR residuals in 182 PA patients treated with SAAE in a prospective cohort from Nanchang SAAE in treating PA registry study. Data suggest that SAAE caused a significant decrease in eGFR from 91.9 ± 26.1 to 88.7 ± 24.1 ml/min/1.73 m2 (p < 0.05) after a median follow-up of 8 months in PA patients. Patients experienced a significant decrease in eGFR from 110.6 ± 18.9 to 103.8 ± 18.2 ml/min/1.73 m2 (p < 0.001) and a very slight increase from 71.1 ± 14.8 to 71.8 ± 17.8 ml/min/1.73 m2 (p = 0.770) with baseline eGFR ≥90 and <90 ml/min/1.73 m2, respectively. Patients with high eGFR residuals (glomerular hyperfiltration) experienced a significant decrease in their eGFR levels from 123.1 ± 22.6 to 105.0 ± 18.6 ml/min/1.73 m2 (p < 0.001). In contrast, there was no significant impact of SAAE on the eGFR of patients with normal or low eGFR residuals. The very early eGFR changes (24 h after SAAE) best predicted the effect of SAAE on eGFR changes after median of eight months in PA patients. On the whole, SAAE seems to have a beneficial impact on renal function in patients with PA, the results of which vary depending on the patient's baseline eGFR and glomerular hyperfiltration status.

Comparative study of stretched-exponential and kurtosis models of diffusion-weighted imaging in renal assessment to distinguish patients with primary aldosteronism from healthy controls

PURPOSE

To compare the ability of diffusion parameters obtained by stretched-exponential and kurtosis models of diffusion-weighted imaging (DWI) to distinguish between patients with primary aldosteronism (PA) and healthy controls (HCs) in renal assessment.

MATERIALS AND METHODS

A total of 44 participants (22 patients and 22 HCs) underwent renal MRI with an 11 b-value DWI sequence and a 3 b-value diffusion kurtosis imaging (DKI) sequence from June 2021 to April 2022. Binary logistic regression was used to construct regression models combining different diffusion parameters. Receiver-operating characteristic (ROC) curve analysis and comparisons were used to evaluate the ability of single diffusion parameters and combined diffusion models to distinguish between the two groups.

RESULTS

A total of six diffusion parameters (including the cortical anomalous exponent term [α_Cortex], medullary fractional anisotropy [FA_Medulla], cortical FA [FA_Cortex], cortical axial diffusivity [Da_Cortex], medullary mean diffusivity [MD_Medulla] and medullary radial diffusivity [Dr_Medulla]) were included, and 10 regression models were studied. The area under the curve (AUC) of Dr_Medulla was 0.855, comparable to that of FA_Cortex and FA_Medulla and significantly higher than that of α_Cortex, Da_Cortex and MD_Medulla. The AUC of the Model_all parameters was 0.967, comparable to that of Model_FA (0.946) and Model_DKI (0.966) and significantly higher than that of the other models. The sensitivity and specificity of Model_all parameters were 87.2% and 95%, respectively.

CONCLUSION

The Model_all parameters, Model_FA and Model_DKI were valid for differentiating between PA patients and HCs with similar differentiation efficacy and were superior to single diffusion parameters and other models.

Kidney function predicts new-onset cardiorenal events and mortality in primary aldosteronism: approach of the 2021 race-free eGFR equation

Individuals with primary aldosteronism (PA) exhibit glomerular hyperfiltration, which may conceal underlying kidney damage. This observational cohort study enrolled 760 coronary artery disease-naive patients diagnosed with PA between January 1, 2007 and December 31, 2018 (male, 45%; mean age, 52.3 ± 11.9 years). The baseline estimated glomerular filtration rate (eGFR) was calculated using the 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, which includes serum creatinine and cystatin C but omits the race variable. During a mean follow-up of 5.8 ± 3.2 years, new-onset composite cardiovascular events (total death, non-fatal myocardial infarction, and coronary revascularization procedure) occurred at a crude incidence rate of 10.9 per 1,000 person-years. Multivariable Cox proportional hazards analysis showed that baseline eGFR was independently associated with composite cardiovascular events (hazard ratio [HR], 0.98 [95% CI, 0.97-0.99]). Penalized splines smoothing in multivariable regression analysis demonstrated that the risk of composite cardiovascular events increased negatively and linearly when patients had a baseline eGFR less than 85 mL/min/1.73 m2. Patients with baseline eGFR <85 mL/min/1.73 m2 were independently associated with higher risks of composite cardiovascular events (HR, 2.39 [95% CI, 1.16-4.93]), all-cause mortality (HR, 4.63 [95% CI, 1.59-13.46]), and adverse kidney events (sub-distribution HR, 5.96 [95% CI, 3.69-9.62], with mortality as a competing risk). Our data support baseline eGFR as a predictor for new-onset adverse cardiorenal events and emphasizes the importance of the early detection of kidney function impairment in hypertensive patients with PA. We also firstly validate the 2021 race-free CKD-EPI eGFR equation in Asian patents with PA. Even with the glomerular hyperfiltration phenomenon, baseline eGFR in patients with primary aldosteronism is associated with subsequent cardiorenal outcomes. The results also firstly point to the validity of the 2021 race-free CKD-EPI eGFR equation in healthcare and clinical decision-making.

Laparoscopic adrenalectomy for adrenal tumors with endocrine activity: Perioperative management pathways for reduced complications and improved outcomes

The major adrenal tumors with endocrine activity are primary aldosteronism, Cushing's syndrome/mild autonomous cortisol secretion, and pheochromocytoma/paraganglioma. Excessive aldosterone secretion in primary aldosteronism causes cardiovascular, renal, and other organ damage in addition to hypertension and hypokalemia. Cortisol hypersecretion in Cushing's syndrome/mild autonomous cortisol secretion causes obesity, hypertension, impaired glucose tolerance, and cardiometabolic syndrome. Massive secretion of catecholamines in pheochromocytoma/paraganglioma causes hypertension and cerebrocardiovascular disease due to rapid blood pressure fluctuation. Moreover, pheochromocytoma multi-system crisis is a feared and possibly fatal presentation of pheochromocytoma/paraganglioma. Thus, adrenal tumors with endocrine activity are considered an indication for adrenalectomy, and perioperative management is very important. They have a risk of perioperative complications, either due to direct hemodynamic effects of the hormone hypersecretion or due to hormone-related comorbidities. In the last decades, deliberate preoperative evaluation and advanced perioperative management have significantly reduced complications and improved outcomes. Furthermore, improvements in anesthesia and surgical techniques with the feasibility of laparoscopic adrenalectomy have contributed to reduced morbidity and mortality. However, there are still several challenges to be considered in the perioperative care of these patients. There are very few data available prospectively to guide clinical management, due to the rarity of adrenal tumors with endocrine activity. Therefore, most guidelines are based on retrospective data analyses or small case series. In this review, the latest knowledge is summarized, and practical pathways to reduce perioperative complications and improve outcomes in adrenal tumors with endocrine activity are presented.

Monoexponential, biexponential, stretched-exponential and kurtosis models of diffusion-weighted imaging in kidney assessment: comparison between patients with primary aldosteronism and healthy controls

PURPOSE

This study used various diffusion-weighted imaging (DWI) models (including monoexponential, biexponential, stretched-exponential and kurtosis models) in renal magnetic resonance imaging (MRI) to compare whether there were differences in each diffusion parameter between patients with primary aldosteronism (PA) and healthy volunteers.

MATERIALS AND METHODS

Twenty-two (female:male, 14:8; age, 48 ± 10 years) patients with PA and 22 age- and sex-matched healthy controls (HCs) underwent MRI examinations of the kidneys. The independent-sample t test or the Mann‒Whitney U test was used to detect differences in the diffusion metrics of the kidneys between the two groups. Univariable and multivariable linear regression were applied to analyze the correlations between diffusion parameters and the clinical indicators.

RESULTS

The mean diffusivity (MD, p < 0.001) and radial diffusivity (Dr, p < 0.001) values in the medulla were lower in the PA group than in the HC group. The medullary fractional anisotropy (FA, p < 0.001) was higher than that of HCs. The FA (p < 0.001) and axial diffusivity (Da, p < 0.001) values in the cortex were lower in the PA group. The cortical α (anomalous exponent term, p = 0.016) was higher in the PA patients than in the HCs. Linear regression analysis showed that log(plasma aldosterone concentration) and the estimated glomerular filtration rate (eGFR) were correlated with medullary FA.

CONCLUSION

The stretched-exponential model (cortical α) and the kurtosis model (FA, MD and Dr in the medulla and FA and Da in the cortex) showed significant differences between PA patients and healthy volunteers and may have potential for noninvasive renal assessment in PA patients.

Novel insights in classic versus relative glomerular hyperfiltration and implications on pharmacotherapy

PURPOSE OF REVIEW

Glomerular filtration rate (GFR) assessment and its estimation (eGFR) is a long-lasting challenge in medicine and public health. Current eGFR formulae are indexed for standardized body surface area (BSA) of 1.73 m2, ignoring persons and populations wherein the ratio of BSA or metabolic rate to nephron number might be different, due to increased BSA, increased metabolic rate or reduced nephron number. These equations are based on creatinine, cystatin C or a combination of the two, which adds another confounder to eGFR assessment. Unusually high GFR values, also known as renal hyperfiltration, have not been well defined under these equations.

RECENT FINDINGS

Special conditions such as solitary kidney in kidney donors, high dietary protein intake, obesity and diabetes are often associated with renal hyperfiltration and amenable to errors in GFR estimation. In all hyperfiltration types, there is an increased intraglomerular pressure that can be physiologic, but its persistence over time is detrimental to glomerulus leading to progressive glomerular damage and renal fibrosis. Hyperfiltration might be underdiagnosed due to BSA standardization embedded in the formula. Hence, timely intervention is delayed. Reducing intraglomerular pressure in diabetes can be achieved by SGLT2 inhibitors or low protein diet to reverse the glomerulopathy process.

SUMMARY

Accurate identification of glomerular hyperfiltration as a pre-CKD condition needs accurate estimation of GFR in the above normal range should establish a threshold for timely intervention.