Impact of primary aldosteronism on renal function in patients with type 2 diabetes

Follow-up care and assessment of comorbidities and complications in patients with primary aldosteronism: The clinical practice guideline of the Taiwan Society of aldosteronism

Primary aldosteronism (PA) is the most common form of endocrine hypertension, characterized by excess aldosterone production that leads to an increased risk of cardiovascular events and target organ damage. Both adrenalectomy and medical treatment have shown efficacy in improving clinical outcomes and comorbidities associated with PA, including a specific subtype of PA with autonomous cortisol secretion (ACS). Understanding the comorbidities of PA and establishing appropriate follow-up protocols after treatment are crucial for physicians to enhance morbidity and mortality outcomes in patients with PA. Additionally, the screening for hypercortisolism prior to surgery is essential, as the prognosis of patients with coexisting PA and ACS differs from those with PA alone. In this review, we comprehensively summarize the comorbidities of PA, encompassing cardiovascular, renal, and metabolic complications. We also discuss various post-treatment outcomes and provide insights into the strategy for glucocorticoid replacement in patients with overt or subclinical hypercortisolism. This clinical practice guideline aims to equip medical professionals with up-to-date information on managing concurrent hypercortisolism, assessing treatment outcomes, and addressing comorbidities in patients with PA, thereby improving follow-up care.

The Effect of Aldosterone on Cardiorenal and Metabolic Systems

Aldosterone, a vital hormone of the human body, has various pathophysiological roles. The excess of aldosterone, also known as primary aldosteronism, is the most common secondary cause of hypertension. Primary aldosteronism is associated with an increased risk of cardiovascular disease and kidney dysfunction compared to essential hypertension. Excess aldosterone can lead to harmful metabolic and other pathophysiological alterations, as well as cause inflammatory, oxidative, and fibrotic effects in the heart, kidney, and blood vessels. These alterations can result in coronary artery disease, including ischemia and myocardial infarction, left ventricular hypertrophy, heart failure, arterial fibrillation, intracarotid intima thickening, cerebrovascular disease, and chronic kidney disease. Thus, aldosterone affects several tissues, especially in the cardiovascular system, and the metabolic and pathophysiological alterations are related to severe diseases. Therefore, understanding the effects of aldosterone on the body is important for health maintenance in hypertensive patients. In this review, we focus on currently available evidence regarding the role of aldosterone in alterations of the cardiovascular and renal systems. We also describe the risk of cardiovascular events and renal dysfunction in hyperaldosteronism.

Diagnostic value of the fractional excretion of urine potassium for primary aldosteronism

Background

Primary aldosteronism (PA) is a common form of secondary hypertension, which usually manifests low blood potassium levels. The fractional excretion of urine potassium (FEK) has been proposed as a useful tool to measure urinary potassium excretion. However, the role of the FEK in PA remains unclear. In the current study, we assessed the diagnostic value of FEK in PA.

Methods

A total of 155 hypertension patients were included in this cross-sectional study, of which 62 were confirmed by a positive screening test for PA. We collected the serum, 24-hr urine samples, and spot urine samples to evaluate the diagnostic value of the spot and 24-hr FEK in the diagnosis of PA and renal potassium loss compared to other indices. The sensitivity and specificity of the related diagnostic indexes were analyzed using receiver operating characteristic (ROC) curves, and the optimal cut-point value of the diagnostic index was determined according to the Youden index (YI) (sensitivity + specificity - 1). Correlation analysis was performed between the spot FEK and 24-hr FEK using Pearson's correlation coefficient.

Results

The spot FEK (7.3 vs. 5.9) and 24-hr FEK (9.3 vs. 8.0) levels were statistical differences between the PA and essential hypertension groups. PA patients had a significant tendency to lose potassium through the kidneys. We found that FEK from spot urine distinguished renal potassium loss with a sensitivity of 86.7% and a specificity of 87.1% at a cut-off of 9.8%. The sensitivity and specificity of the spot FEK in screening PA were 51.6% and 76.3%, respectively.

Conclusions

FEK is significantly related to renal potassium loss. Spot FEK and 24-hr FEK performed a certain diagnostic value for PA, which may be potential indicators for the differential diagnosis of PA.

The Entity of Connshing Syndrome: Primary Aldosteronism with Autonomous Cortisol Secretion

Connshing syndrome (CoSh) (adrenal-related synchronous aldosterone (A) and cortisol (C) excess) represents a distinct entity among PA (primary hyperaldosteronisms) named by W. Arlt et al. in 2017, but the condition has been studied for more than 4 decades. Within the last few years, this is one of the most dynamic topics in hormonally active adrenal lesions due to massive advances in steroids metabolomics, molecular genetics from CYP11B1/B2 immunostaining to genes constellations, as well as newly designated pathological categories according to the 2022 WHO classification. In gross, PA causes 4-10% of all high blood pressure (HBP) cases, and 20% of resistant HBP; subclinical Cushing syndrome (SCS) is identified in one-third of adrenal incidentalomas (AI), while CoSh accounts for 20-30% to 77% of PA subjects, depending on the tests used to confirm autonomous C secretion (ACS). The clinical picture overlaps with PA, hypercortisolemia being mild. ACS is suspected in PA if a more severe glucose and cardiovascular profile is identified, or there are larger tumours, ACS being an independent factor risk for kidney damage, and probably also for depression/anxiety and osteoporotic fractures. It seems that one-third of the PA-ACS group harbours mutations of C-related lines like PRKACA and GNAS. A novel approach means we should perform CYP11B2/CYP11B1 immunostaining; sometimes negative aldosteronoma for CYP11B1 is surrounded by micronodules or cell clusters with positive CYP11B1 to sustain the C excess. Pitfalls of hormonal assessments in CoSh include the index of suspicion (check for ACS in PA patients) and the interpretation of A/C ratio during adrenal venous sample. Laparoscopic adrenalectomy is the treatment of choice. Post-operative clinical remission rate is lower in CoSh than PA. The risk of clinically manifested adrenal insufficiency is low, but a synthetic ACTH stimulating testing might help to avoid unnecessary exposure to glucocorticoids therapy. Finally, postponing the choice of surgery may impair the outcome, having noted that long-term therapy with mineralocorticoids receptors antagonists might not act against excessive amounts of C. Awareness of CoSh improves management and overall prognosis.

Characteristics of aldosterone-producing adenomas in patients without plasma renin activity suppression

Primary aldosteronism (PA) usually accompanies suppressed plasma renin activity (PRA) through a negative feedback mechanism. While some cases of PA with unsuppressed PRA were reported, there have been no studies about the characteristics of PA with unsuppressed PRA; thus, these characteristics were examined herein. Nine patients with unsuppressed PRA and 86 patients with suppressed PRA were examined. All patients underwent segmental adrenal venous sampling (sAVS) and adrenalectomy, and were pathologically confirmed to have cytochrome P450 11B2 (CYP11B2)-positive aldosterone-producing adenoma according to international histopathology consensus criteria. Unsuppressed and suppressed PRA were defined as PRA levels of > 1.0 and ≤ 1.0 ng/mL/hr, respectively, in multiple blood samples obtained in the resting position. The unsuppressed PRA group had higher morning cortisol levels (12.6 [8.5, 13.5] vs. 8.5 [7.1, 11.0] μg/dL, P = 0.03) and higher cortisol levels after a 1 mg dexamethasone suppression test (DST) (2.2 [1.6, 2.5] vs. 1.3 [1.0, 1.9] μ g/dL, P = 0.004) than the suppressed PRA group. The unsuppressed PRA group also showed higher aldosterone levels on the non-surgical side during sAVS (P = 0.02 before adrenocorticotropic hormone (ACTH) stimulation, P = 0.002 after ACTH stimulation), a higher intensity of CYP17 expression in the resected adrenal gland (P = 0.02), and a lower clinical complete success rate 1 year after surgery (P = 0.04) compared with those in the suppressed PRA group. These findings suggest that PA should not be ruled out by unsuppressed PRA among patients with hypertension, particularly when their cortisol levels remain unsuppressed in the 1 mg DST. Meanwhile, it should be acknowledged that patients with unsuppressed PRA have higher aldosterone levels on the non-surgical side, and a lower likelihood of postoperative complete clinical success is to be expected.

Screening for Primary Aldosteronism in the Diabetic Population: a cohort study

CONTEXT

Primary aldosteronism (PA) is the most common endocrine cause of hypertension. It is associated with higher cardio-metabolic risk than essential hypertension. Hypertension is common in patients with type 2 diabetes who carry increased cardiovascular risk, however, it is unknown how frequently they are tested for PA.

OBJECTIVE

The study aims to assess the extent to which the Endocrine Society's 2016 PA screening guidelines have been applied in a tertiary diabetes care setting and evaluate the demographic, clinical and biochemical characteristics of patients who met screening criteria compared to those who did not.

RESEARCH DESIGN & METHODS

This is a retrospective cohort study. Data were collected from 272 patients who attended tertiary Diabetes Clinics and had two or more blood pressure measurements from January to December 2018.

RESULTS

Of 272 patients, 63 (23.2%) had indication(s) for PA screening but only 15 (23.8% of 63) were screened using the aldosterone-to-renin ratio (ARR). Four patients who did not meet screening criteria were screened. Only one of 19 patients screened had an abnormal ARR, however 16 were taking medications known to affect aldosterone and/or renin production.

CONCLUSIONS

In a tertiary diabetes outpatient setting, only a minority of patients who fulfilled the Endocrine Society criteria for PA screening were actually screened. Appropriate screening for PA in the diabetic hypertensive population is necessary for the diagnosis and targeted treatment of a highly modifiable cardiovascular risk factor. Further studies are needed to develop feasible strategies to identify patients with PA in this population. This article is protected by copyright. All rights reserved.