Feasibility of single-port laparoscopic partial adrenalectomy with selective adrenal venous sampling and high-resolution ultrasound for unilateral aldosterone-producing adenomas.

BACKGROUND: The surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy for patients with aldosterone-producing adenomas are unknown. Precise diagnosis of intra-adrenal aldosterone activity and a precise surgical procedure may improve outcomes. In this study, we aimed to determine the surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy with preoperative segmental selective adrenal venous sampling and intraoperative high-resolution laparoscopic ultrasound in patients with unilateral aldosterone-producing adenomas. We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. METHODS: A single-center, retrospective cohort study. All patients with unilateral aldosterone-producing adenomas diagnosed by selective adrenal venous sampling and treated surgically between January 2012 and February 2015 were included. Follow-up with biochemical and clinical assessments was set at 1 year after surgery for short-term outcomes and was performed every 3 months after surgery. RESULTS: We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. Single-port surgery was associated with shorter operative and laparoscopic times (odds ratio, 0.14; 95% confidence interval, 0.039-0.49; P = .002 and odds ratio, 0.13; 95% confidence interval, 0.032-0.57; P = .006, respectively). All single-port and multi-port partial adrenalectomy cases showed complete short-term (median 1 year) biochemical success, and 92.9% (26 of 28 patients) who underwent single-port partial adrenalectomy and 100% (13 of 13 patients) who underwent multi-port partial adrenalectomy showed complete long-term (median 5.5 years) biochemical success. No complications were observed with single-port adrenalectomy. CONCLUSION: Single-port partial adrenalectomy is feasible after selective adrenal venous sampling for unilateral aldosterone-producing adenomas, with shorter operative and laparoscopic times and a high rate of complete biochemical success.

Association Between Aldosterone and Hypertension Among Patients With Overt and Subclinical Hypercortisolism.

Introduction: Hypertension is one of the most common clinical features of patients with overt and subclinical hypercortisolism. Although previous studies have shown the coexistence of autonomous cortisol and aldosterone secretion, it is unclear whether aldosterone plays a role in hypertension among patients with hypercortisolism. Therefore, we examined the associations of plasma aldosterone concentrations (PACs) with hypertension among patients with overt and subclinical hypercortisolism. Methods: This single-center retrospective cohort study included patients with adrenal tumor and serum cortisol levels after 1-mg dexamethasone suppression test >1.8 µg/dL (50 nmol/L). Using multivariable regression models adjusting for baseline characteristics, we investigated the association of PACs with systolic blood pressure and postoperative improvement of hypertension after the adrenalectomy. Results: Among 89 patients enrolled in this study (median age, 51 years), 21 showed clinical signs of Cushing syndrome (overt hypercortisolism) and 68 did not show clinical presentations (subclinical hypercortisolism). We found that higher PACs were significantly associated with elevated systolic blood pressure among patients with subclinical hypercortisolism (adjusted difference [95% CI] = +0.59 [0.19-0.99], P = 0.008) but not among those with overt hypercortisolism. Among 33 patients with subclinical hypercortisolism and hypertension who underwent adrenalectomy, the postoperative improvement of hypertension was significantly associated with higher PACs at baseline (adjusted risk difference [95% CI] = +1.45% [0.35-2.55], P = 0.01). Conclusion: These findings indicate that aldosterone may contribute to hypertension among patients with subclinical hypercortisolism. Further multi-institutional and population-based studies are required to validate our findings and examine the clinical effectiveness of the intervention targeting aldosterone for such patients.

Safety and feasibility of radiofrequency ablation using bipolar electrodes for aldosterone-producing adenoma: a multicentric prospective clinical study.

Evaluation of feasibility and safety of percutaneous radiofrequency ablation using bipolar radiofrequency devices in a prospective multicenter cohort of patients with benign aldosterone-producing adenoma. A total of five institutions participated. CT-guided percutaneous RFA was performed for patients diagnosed as APA. The safety of the procedure was evaluated using the Common Terminology Criteria for Adverse Events. During the 84-day follow-up period, serial changes in plasma aldosterone concentration and plasma renin activity were measured. The percentage of patients with normalized hormonal activity after the procedure, was calculated with 95% confidence intervals. Forty patients were enrolled, and two patients were excluded for cerebral hemorrhage and no safe puncture root. In another patients, RFA was tried, but an intraprocedural intercostal arterial injury occurred. Consequently, RFA was completed in thirty-seven patients (20 men, 17 women; mean age, 50.4 ± 10.0 year). The tumor size was 14.8 ± 3.8 mm. The treatment success rate of the ablation was 94.6% (35/37), and a 2nd session was performed in 2.7% (1/37) patients. Grade 4 adverse events were observed in 4 out of 38 sessions (10.5%). The normalization of plasma aldosterone concentration or aldosterone-renin ratio was 86.5% (72.0-94.1: 95% confidence interval) on day 84. Percutaneous CT-guided RFA for APA using a bipolar radiofrequency system was safe and feasible with clinical success rate of 86.5% on day 84.

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.

Cortisol Co-Secretion and Clinical Usefulness of ACTH Stimulation Test in Primary Aldosteronism: A Systematic Review and Biases in Epidemiological Studies.

The hypothalamus-pituitary-adrenal (HPA) axis plays an important role in primary aldosteronism. Aldosterone biosynthesis is regulated not only by angiotensin II in the renin-angiotensin-aldosterone system, but also by adrenocorticotropic hormone (ACTH), one of the key components of the HPA axis. Although previous studies have reported cortisol cosecretion in primary aldosteronism, particularly aldosterone-producing adenoma (APA), the clinical relevance of such aldosterone and cortisol cosecretion from APA and hypertension or other metabolic disorders has not been fully established. Several somatic mutations including KCNJ5 and CACNA1D are known to induce autonomous production of aldosterone in APA, and the aldosterone responsiveness to ACTH may vary according to each mutation. The ACTH stimulation test has been reported to be a useful tool to distinguish the subtypes of primary aldosteronism (e.g., unilateral vs bilateral) in some studies, but it has not been commonly applied in clinical practice due to limited evidence. Given the recent advancement of imaging, omics research, and computational approach, it is important to summarize the most updated evidence to disentangle the potential impact of cortisol excess in primary aldosteronism and whether the ACTH stimulation test needs to be considered during the diagnostic process of primary aldosteronism. In this article, we conducted a systematic review of epidemiological studies about (i) cortisol cosecretion in primary aldosteronism and (ii) the ACTH stimulation test for the diagnosis of primary aldosteronism (including subtype diagnosis). Then, we discussed potential biases (e.g., confounding bias, overadjustment, information bias, selection bias, and sampling bias) in the previous studies and introduced some advanced epidemiological/statistical methods to minimize these limitations. A better understanding of biases and epidemiological perspective on this topic would allow us to produce further robust evidence and balanced discussion about the causal mechanisms involving the HPA axis and clinical usefulness of the ACTH stimulation test among patients with primary aldosteronism.

Efficacy and safety of esaxerenone (CS-3150), a newly available nonsteroidal mineralocorticoid receptor blocker, in hypertensive patients with primary aldosteronism.

Mineralocorticoid receptor (MR) blockers are very beneficial for patients with hypertension and primary aldosteronism (PA). We investigated the efficacy and safety of a newly available nonsteroidal MR blocker, esaxerenone, in Japanese patients with hypertension and PA. A multicenter, open-label study was conducted in Japan between October 2016 and July 2017. Patients with hypertension and PA received 12 weeks of treatment with esaxerenone, initiated at 2.5 mg/day and escalated to 5 mg/day during week 2 or 4 of treatment, based on individual response. The only other permitted antihypertensive therapies were stable dosages of a Ca2+ channel blocker or α-blocker. The primary efficacy outcome was a change in sitting systolic and diastolic blood pressure (SBP/DBP) from baseline to the end of treatment. Forty-four patients were included; dose escalation to 5 mg/day was implemented for 41 of these patients. Significant decreases in SBP and DBP were observed (point estimates [95% confidence interval] -17.7 [-20.6, -14.7] and -9.5 [-11.7, -7.3] mmHg, respectively; both p < 0.0001 at the end of treatment). Significant BP reductions were evident from week 2 and continued through to week 8; BP remained stable until week 12. The antihypertensive effect of esaxerenone on SBP was significantly greater in females and in patients receiving monotherapy. The major drug-related adverse events were serum K+ increase and estimated glomerular filtration rate decrease (both 4.5%, n = 2); no gynecomastia or breast pain was observed. We conclude that esaxerenone is a potent MR blocker with favorable efficacy and safety profiles in patients with hypertension and PA.

Precise Mapping of Intra-Adrenal Aldosterone Activities Provides a Novel Surgical Strategy for Primary Aldosteronism.

Segmental selective adrenal venous sampling (sAVS) elucidates an intraadrenal aldosterone activity map (IAMap), which allows us to design a novel surgical treatment strategy for patients with primary aldosteronism. We evaluated the usefulness of sAVS by analyzing 278 patients with whom we had prospectively used IAMap using the criteria of sAVS for surgical indication between 2009 and 2015. We evaluated its diagnostic accuracy using pathological and postsurgical biochemical and clinical outcomes. One hundred twenty and 158 patients were diagnosed with unilateral and bilateral disease, respectively, through sAVS. The concordance of lateralization diagnosis with computed tomography imaging was 66.6%. Among the unilateral patients, we performed partial adrenalectomy in 68 patients whose IAMap showed focal aldosterone hypersecretion from computed tomography-detectable tumor in the affected adrenal gland. All of them achieved complete biochemical success 1 year after surgery. Furthermore, 25 of 158 bilateral disease patients underwent surgical resection because they were preoperatively diagnosed as bilateral aldosterone-producing adenomas by IAMap. These cases showed complete or partial biochemical success (28.0% and 72.0%, respectively); 36.0% showed complete clinical success. Pathological studies demonstrated that all 145 resected specimens possessed aldosterone-producing adenoma or multiple nodules (132 and 13 cases, respectively), and none showed diffuse hyperplasia. IAMap accurately diagnosed both bilateral and unilateral aldosterone-producing adenomas and diffuse hyperplasia before surgery. sAVS allows a novel surgical strategy for selected PA patients with favorable outcomes.

Genetics of aldosterone-producing adenomas with pathogenic KCNJ5 variants.

Somatic variants in genes that regulate intracellular ion homeostasis have been identified in aldosterone-producing adenomas (APA). Although the mechanisms leading to an increased aldosterone production in APA cells has been well studied, the molecular events that cause cell proliferation and tumor formation are poorly understood. In the present study, we have performed whole exome sequencing (WES) to characterize the landscape of somatic alterations in a homogeneous series of APA with pathogenic KCNJ5 variants. In the WES analysis on eleven APA, 84 exonic somatic events were called by 3 different somatic callers. Besides the KCNJ5 gene, only two genes (MED13 and ZNF669) harbored somatic variants in more than one APA. Unlike adrenocortical carcinomas, no chromosomal instability was observed by the somatic copy-number alteration and loss of heterozygosity analyses. The estimated tumor purity ranged from 0.35 to 0.67, suggesting a significant proportion of normal cell infiltration. Based on the results of PureCN analysis, the KCNJ5 variants appear to be clonal. In conclusion, in addition to KCNJ5 somatic pathogenic variant, no significant somatic event that would obviously explain proliferation or tumor growth was observed in our homogeneous cohort of KCNJ5-mutated APA. The molecular mechanisms causing APA growth and tumorigenesis remain to be elucidated.

Changes in glucose metabolism based on 75-g oral glucose tolerance tests before and after surgery for adrenal Cushing's syndrome.

Adrenal Cushing's syndrome (CS) is caused by cortisol-producing adrenal adenoma and is frequently accompanied by glucose metabolism disorders, which are characterized by increased insulin resistance and insufficient ß-cell compensation. However, considering the rarity of CS, few studies have assessed whether the glucose metabolism disorders could be ameliorated by surgical treatment. In this case series, we evaluated glucose metabolism before and after surgery in 11 patients (10 women and 1 man) who underwent unilateral adrenalectomy for overt adrenal CS between 2005 and 2016. Patients with pre-diagnosed diabetes mellitus (DM) were excluded. Pre- and post-operative 75-g oral glucose tolerance tests were performed. Cortisol secretion decreased significantly after surgery (median 24-h urinary free cortisol: 582.0 µg/day [interquartile range: 321.0-743.0 µg/day] to 31.3 µg/day [23.6-40.6 µg/day], p = 0.001). The results of the OGTT generally improved after surgery (normal glucose tolerance/impaired glucose tolerance/DM: 2/8/1 to 8/3/0), with significant decreases in the immunoreactive insulin and glucose levels. We also found a decrease in the median homeostatic model assessment of insulin resistance (2.4 [1.4-2.8] to 1.0 [0.6-1.1], p = 0.002), and increases in the median Matsuda index (3.0 [2.3-4.5] to 8.2 [6.3-11.4], p < 0.001), median insulinogenic index (0.70 [0.22-1.51] to 1.22 [0.78-1.64], p = 0.08), and median disposition index (609.1 [237.8-1,095.2] to 1,286.0 [1,034.6-1,857.6], p = 0.002). These findings indicate that adrenalectomy for adrenal CS without overt DM may help ameliorate glucose metabolism disorders, and improve both insulin resistance and insulin secretion.

Aldosterone and 18-Oxocortisol Coaccumulation in Aldosterone-Producing Lesions.

Primary aldosteronism is a secondary hypertensive disease caused by autonomous aldosterone production that often caused by an aldosterone-producing adenoma (APA). Immunohistochemistry of aldosterone synthase (CYP11B2) shows the presence of aldosterone-producing cell clusters (APCCs) even in non-primary aldosteronism adult adrenal cortex. An APCC-like structure also exists as possible APCC-to-APA transitional lesions (a speculative designation) in primary aldosteronism adrenals. However, whether APCCs produce aldosterone or 18-oxocortisol, a potential serum marker of APA, remains unknown because of lack of technology to visualize adrenocorticosteroids on tissue sections. To address this obstacle, in this study, we used highly sensitive Fourier transform ion cyclotron resonance mass spectrometry to image various adrenocorticosteroids, including 18-oxocortisol, in adrenal tissue sections from 8 primary aldosteronism patients with APCC (cases 1-4), possible APCC-to-APA transitional lesions (case 5), and APA (cases 6-8). Further analyses by tandem mass spectrometry imaging allowed us to differentially visualize aldosterone from cortisone, which share identical mass-to-charge ratio value ( m/z). In conclusion, these advanced imaging techniques revealed that aldosterone and 18-oxocortisol coaccumulated within CYP11B2-expressing lesions. These imaging outcomes along with a growing body of aldosterone research led us to build a progressive development hypothesis of an aldosterone-producing pathology in the adrenal glands.

Aldosterone Suppression by Dexamethasone in Patients With KCNJ5-Mutated Aldosterone-Producing Adenoma.

Context: Aldosterone biosynthesis is regulated principally by ACTH and gene mutations as well as by angiotensin II and serum potassium. In addition, previous studies have reported the potential effects of KCNJ5 mutations in aldosterone-producing adenoma (APA) on cardiovascular diseases. However, responsiveness to ACTH in APAs according to potassium inwardly rectifying channel, subfamily J, member 5 (KCNJ5) mutations remains unknown. Objective: To investigate KCNJ5 genotype-specific differences in aldosterone biosynthesis in response to ACTH stimulation. Design and Setting: A cross-sectional study through retrieval of clinical records. Participants: One hundred forty-one patients aged ≥20 years with APA were examined. Main Outcome Measures: Associations between KCNJ5 mutations and clinical parameters reflecting the renin-angiotensin system [saline infusion test (SIT)] and ACTH pathways [dexamethasone suppression test (DST)]. Results: KCNJ5 mutations were detected in 107 cases. In the crude comparison, patients with mutations in KCNJ5 had higher plasma aldosterone concentrations (PACs) both at baseline and after the SIT. PAC after the DST showed a significant inverse association with KCNJ5 genotypes after controlling for age, sex, tumor size, and PAC after the SIT. Immunohistochemical analysis of 101 cases revealed more abundant immunoreactivity of CYP11B1 and CYP17 in the KCNJ5-mutated group than in the KCNJ5 wild-type group. Conclusion: This report of marked suppression of PAC by dexamethasone in patients with KCNJ5-mutated APAs indicates that such APAs respond to endogenous ACTH more readily than APAs in nonmutated cases. Further molecular and epidemiologic studies are required to validate our results and clarify the clinical effectiveness of the DST for predicting KCNJ5 mutations before adrenalectomy.

A Unique Case of Renovascular Hypertension due to Fibromuscular Dysplasia in an Extra-renal Artery.

A 33-year-old man was admitted to our hospital to undergo an evaluation to determine the cause of secondary hypertension. Computerized tomography angiography (CTA) showed bilateral multiple renal arteries with significant stenosis of the right extra-renal artery due to fibromuscular dysplasia and segmental impairment of renal perfusion. Although the plasma aldosterone concentration and plasma renin activity were within the normal ranges, percutaneous balloon dilatation of the stenotic lesion resolved his hypertension, leading to a diagnosis of renovascular hypertension caused by segmental renal ischemia due to extra-renal artery stenosis. CTA should be considered during the examination of patients with early-age hypertension, even if the plasma renin activity is not sufficiently elevated.

KCNJ5 mutation as a predictor for resolution of hypertension after surgical treatment of aldosterone-producing adenoma.

OBJECTIVE: To investigate the effect of KCNJ5 mutations on the cure of hypertension in patients with aldosterone-producing adenoma (APA) after unilateral adrenalectomy. METHODS: Our study included 142 patients with APA, who were detected with an endocrinological abnormality and diagnosed with hypertension, as confirmed by pathological analysis. We sequenced KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1 from APA tissue samples, and performed a retrospective analysis to determine correlations between wild-type or mutated KCNJ5 and patient clinical characteristics. RESULTS: Somatic KCNJ5 mutations were identified in 106 of 142 patients with APA, 136 of whom had resolution of hyporeninemic-hyperaldosteronemia 1 year after surgery. Of the 136 patients, 81 patients had resolution of hypertension ('Cured group' vs. 'Improved group'). We found increased prevalence of KCNJ5 mutations in the Cured group compared to the Improved group (85.2% vs. 60.0%, respectively; P = 0.002), which was associated with younger age, shorter duration of hypertension, fewer antihypertensive medications, lower BMI, higher aldosterone level, higher estimated glomerular filtration rate, and milder vascular complications. In both groups we found that harbouring a KCNJ5 mutation, taking fewer antihypertensive medications, and the duration of hypertension were independently associated with resolution of hypertension by unilateral adrenalectomy. In patients with KCNJ5-mutated APA, left ventricular hypertrophy was significantly decreased by surgical treatment in patients from either Cured or Improved groups, although those patients with wild-type KCNJ5 showed no change. CONCLUSIONS: Testing for KCNJ5 mutations in young patients with APA may provide a prognostic indication for resolution of hypertension and severity of vascular complications.

Evaluation of Cortisol Production in Aldosterone-Producing Adenoma.

Aldosterone-producing adenoma (APA) is sometimes accompanied with subclinical hypercortisolism. We investigated the ability of cortisol production in APA, both clinically and pathologically. A retrospective cohort study was conducted at Yokohama Rosai Hospital from 2009 to 2016. Thirty patients with APA and serum cortisol levels during the 1 mg dexamethasone suppression test (F-DST)<3.0 µg/dl were included. We evaluated the 1) difference between pre-adrenalectomy F-DST (pre-F-DST) and post-adrenalectomy F-DST (ΔF-DST), 2) correlation between ∆F-DST and pre-F-DST, tumour size determined by CT, and type of adrenalectomy (total or partial), and 3) relationship between the ratio of F-DST divided by tumour size (ΔF-DST/pre-F-DST/mm) and immunoreactivity of CYP17A1, CYP11B1, and CYP11B2. The median [interquartile range] age was 48 [38-58] years. We found a significant decrease in F-DST after adrenalectomy [before: 1.4 (1.1-1.8); after: 0.9 (0.6-1.2); p<0.001]. Additionally, a significant correlation was found for ΔF-DST and both pre-F-DST (Spearman, ρ=-0.68, p<0.001) and tumour size (ρ=-0.51, p 0.005). No significant difference was found in ΔF-DST between total and partial adrenalectomy. CYP17A1 and CYP11B1 were positive in 21 (100%) and 17 (81%) adenomas, respectively. CYP17A1 immunoreactivity in the tumour was significantly related with ΔF-DST/pre-F-DST/mm (p 0.049). F-DST significantly decreased after adrenalectomy, and most of the adenomas were immunohistochemically positive for CYP17A1 and CYP11B1 as well as CYP11B2. We should consider the possibility of autonomous cortisol production as well as hyperaldosteronism in the evaluation and treatment of APA patients.

A Novel Method: Super-selective Adrenal Venous Sampling.

Primary aldosteronism (PA) and subclinical Cushing's syndrome (SCS) are conditions in which the adrenal glands autonomously produce excessive amounts of aldosterone and cortisol, respectively. The conventional adrenal venous sampling (cAVS) method collects blood samples from both adrenal central veins and is useful for identifying the laterality of excess hormone production in a unilateral lesion(s), as documented in PA cases. In cAVS, plasma cortisol concentrations (PCCs) are used to normalize plasma aldosterone concentrations (PACs). A novel "super-selective" adrenal venous sampling (ssAVS) method was developed using a micro-catheter, which collects blood samples from adrenal tributary veins (TVs). PACs in ssAVS samples do not require PCC normalization because samples contain a limited amount of systemic venous blood, if any. The ssAVS method enabled segmental lesion(s) to be detected in both adrenal glands, which may be treated by bilateral adrenalectomy, thereby sparing lesion-free segment(s). Right and left adrenals typically have three TVs each, i.e., the superior, lateral, and inferior TVs in the right adrenal as well as the superior-median, superior-lateral, and lateral TVs in the left adrenal. In the ssAVS method, specific parent catheters and a technique to handle them are required, and have been described herein. Furthermore, ssAVS results from three cases of PA are presented: bilateral aldosterone-producing adenoma (APA) (Case #1), left APA and right possible cortisol-producing adenoma causing SCS (Case #2), and idiopathic hyperaldosteronism in which bilateral adrenal segments produced excessive amounts of aldosterone (Case #3). The ssAVS method is not difficult for expert angiographers, and, thus, is recommended worldwide to treat PA cases for which cAVS does not represent a viable surgical treatment option.

Aldosterone excess may inhibit insulin secretion: A comparative study on glucose metabolism pre- and post-adrenalectomy in patients with primary aldosteronism.

Conflicting data have been published on the effects of aldosterone excess on glucose metabolism. Specifically, there are limited data on whether adrenalectomy in patients with aldosterone-producing adenomas (APA) can improve glucose metabolism. In this study we evaluated changes in glucose metabolism, before and after surgery for APA. The subjects were 61 patients treated with unilateral adrenalectomy, localized by adrenal venous sampling. A 75g-oral glucose tolerance test (OGTT) was performed before and 1 year after adrenalectomy. Patients with diabetes mellitus or a serum cortisol level >3 µg/dL after a 1 mg dexamethasone suppression test, were excluded. Using the 75g-OGTT data, insulin secretion and insulin resistance (or sensitivity) indices were calculated. The results showed that immunoreactive insulin levels during the OGTT increased significantly after adrenalectomy, whereas plasma glucose levels, before and after surgery, were comparable. The insulinogenic index significantly increased after surgery (0.5 [0.4-0.8] to 0.8 [0.4-1.1], p < 0.001). The disposition index remained largely unchanged (806.2 [489.4-1,138.9] to 686.6 [479.4-922.1], p = 0.25). The homeostatic model assessment of insulin resistance increased significantly (1.0 [0.6-1.5] to 1.5 [1.0-2.2], p < 0.001) and the ISImatsuda decreased significantly (6.9 [4.5-10.4] to 5.2 [3.4-7.9], p < 0.001). Changes in these indices were not correlated with changes in potassium and aldosterone levels before and after surgery. In conclusion, insulin secretion increased after adrenalectomy for APA, indicating that aldosterone excess inhibits insulin secretion. However, because of a parallel increase in insulin resistance, plasma glucose levels remained unchanged.

Somatic KCNJ5 mutation occurring early in adrenal development may cause a novel form of juvenile primary aldosteronism.

We report a case of non-familial juvenile primary aldosteronism (PA). Super-selective adrenal venous sampling identified less aldosterone production in the right inferior adrenal segment than others. Bilateral adrenalectomy sparing the segment normalized blood pressure and improved PA. Both adrenals had similar histologies, consisting of a normal adrenal cortex and aldosterone synthase-positive hyperplasia/adenoma. An aldosterone-driving KCNJ5 mutation was detected in the lesions, but not in the histologically normal cortex. After taking into account that the two adrenal glands displayed a similar histological profile, as well as the fact that hyperplastic lesions in both glands exhibited a common KCNJ5 mutation, we conclude that the specific mutation may have occurred at an adrenal precursor mesodermal cell, at an early stage of development; its daughter cells were mixed with non-mutant cells and dispersed into both adrenal glands, resulting into a form of the condition known as genetic mosaicism.

Immunohistochemistry of aldosterone synthase leads the way to the pathogenesis of primary aldosteronism.

Our group previously purified human and rat aldosterone synthase (CYP11B2 and Cyp11b2, respectively) from their adrenals and verified that it is distinct from steroid 11ß-hydroxylase (CYP11B1 or Cyp11b1), the cortisol- or corticosterone-synthesizing enzyme. We now describe their distributions immunohistochemically with specific antibodies. In rats, there is layered functional zonation with the Cyp11b2-positive zona glomerulosa (ZG), Cyp11b1-positive zona fasciculata (ZF), and Cyp11b2/Cyp11b1-negative undifferentiated zone between the ZG and ZF. In human infants and children (<12 years old), the functional zonation is similar to that in rats. In adults, the adrenal cortex remodels and subcapsular aldosterone-producing cell clusters (APCCs) replace the continuous ZG layer. We recently reported possible APCC-to-APA transitional lesions (pAATLs) in 2 cases of unilateral multiple adrenocortical micro-nodules. In this review, we present 4 additional cases of primary aldosteronism, from which the extracted adrenals contain pAATLs, with results of next generation sequencing for these lesions. Immunohistochemistry for CYP11B2 and CYP11B1 has become an important tool for the diagnosis of and research on adrenocortical pathological conditions and suggests that APCCs may be the origin of aldosterone-producing adenoma.

Guanosine triphosphate can directly regulate cortisol production by activating Ca(2+)-messenger systems in bovine adrenal fasciculata cells.

Adenosine triphosphate (ATP) is known to stimulate cortisol production in vitro, however, the effect of guanosine triphosphate (GTP) on cortisol production is not known. We studied the effect of GTP on cortisol production and investigated the regulation of intracellular signal transduction systems, including the cyclic AMP-dependent and Ca(2+)-messenger systems, in bovine adrenal fasciculata cells. GTP clearly induced cortisol biosynthesis but only to a level less than half the adrenocorticotropic hormone (ACTH)-induced maximum. The binding site for [γ-(35)S]-GTPγS was shown to differ completely from that for ATP and also from those for Gs and Gi, as indicated by the fact that binding was not influenced by pretreatment with cholera toxin and pertussis toxin. GTP significantly increased cytosolic calcium ([Ca(2+)]i) and inositol 1, 4, 5-triphosphate without affecting cyclic AMP formation. GTP-induced cortisol production was suppressed by H-9 and Calphostin C (specific protein kinase C inhibitors) but not by H-8 and KT5720 (specific inhibitors of cyclic AMP-dependent protein kinase), suggesting that GTP activates cortisol biosynthesis possibly via a protein kinase C-dependent pathway. Extracellular calcium may be essential for GTP activity since GTP-induced cortisol production was almost completely suppressed in its absence. In conclusion, it can be postulated that GTP-induced steroid secretion in bovine adrenal fasciculata cells is under paracrine or autocrine control.

Clinical and Steroidogenic Characteristics of Aldosterone-Producing Adenomas With ATPase or CACNA1D Gene Mutations.

OBJECT: This comparative study clarified the clinical characteristics and in vitro steroidogenic activities of aldosterone-producing adenomas (APAs) harboring ATPase or CACNA1D gene mutations. DESIGN AND PATIENTS: Genetic testing was performed on 159 unilateral APAs. Somatic ATPase and CACNA1D gene mutations were analyzed in 42 APA tissues without KCNJ5 gene mutations. RESULTS: ATP1A1, ATP2B3, and CACNA1D mutations were detected in one, four, and four patients, respectively. Compared with patients without KCNJ5, ATPase, or CACNA1D mutations (wild type), ATPase mutations tended to have more severe hyperaldosteronism and smaller tumors; those with CACNA1D mutations had clinical characteristics and tumor sizes similar to those with wild-type genes. APAs with ATPase mutations were composed mainly of compact eosinophilic tumor cells, whereas CACNA1D mutations resulted in predominantly clear tumor cells. Aldosterone production in APA cells with ATP2B3 mutations were more responsive to dibutyryl cAMP, whereas those with CACNA1D mutations were more responsive to adrenocorticotropic hormone than the wild-type cells. CONCLUSION: APAs with ATPase mutations demonstrated a potentially severe primary aldosteronism phenotype, whereas those with CACNA1D mutations displayed characteristics similar to wild-type APAs. The status of stimulated aldosterone production was also different according to the cell types, suggesting that the regulatory effects of adrenocorticotropic hormone on aldosterone synthesis could possibly vary according to the intracellular signaling involved in hormone production.