Cardiovascular Outcomes of KCNJ5 Mutated Aldosterone-Producing Adenoma: A Systematic Review.

BACKGROUND: While clinical features of KCNJ5-mutated aldosterone-producing adenoma (APA) have been reported, evidence of its clinical outcomes is lacking. We aimed to synthesize available literature about the associations between KCNJ5 mutation with cardiovascular and metabolic outcomes among patients with APA. METHODS: In this systematic review of observational studies, MEDLINE and Embase were searched through August 2022. Two independent authors screened the search results and extracted data from eligible observational studies investigating cardiovascular or metabolic outcomes between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs. Risk of Bias In Non-randomized Studies of Interventions was used to assess the quality of the included studies. RESULTS: A total of 573 titles/abstracts were screened and after the expert opinion of the literature, full text was read in 20 titles/abstracts, of which 12 studies were included. Across 3 studies comparing the baseline or change in the cardiac function between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs, all studies reported the association between impaired cardiac functions and KCNJ5 mutation status. Among 6 studies evaluating the cure of hypertension after surgery, all studies showed that KCNJ5 mutation was significantly associated with the cure of hypertension. In quality assessment, 7 studies were at serious risk of bias, while the remaining studies were at moderate risk of bias. CONCLUSIONS: This systematic review provided evidence of the significant association between KCNJ5 mutation and unfavorable cardiovascular outcomes in patients with primary aldosteronism. Further research is needed to improve the quality of evidence on this topic and elucidate the underlying mechanisms of the potential burden of KCNJ5 mutation.

Adrenal venous sampling criteria for chemiluminescent enzyme immunoassay as a preferable alternative to radioimmunoassay in primary aldosteronism.

Plasma aldosterone concentration (PAC) was routinely measured using radioimmunoassay (RIA); however, the RIA kit was discontinued in March 2021 in Japan. This study examined PAC conversion in adrenal venous sampling (AVS) and AVS criteria when measured using chemiluminescent enzyme immunoassay (CLEIA). PAC of 415 adrenal venous blood samples from AVS (including segmental AVS) of 63 patients with primary aldosteronism was measured using RIA (Spac-S aldosterone kit; Fujirebio Inc.) and CLEIA (Lumipulse Presto Aldosterone; Fujirebio Inc.). PAC of 70 AVS samples was also measured using liquid chromatography-mass spectrometry (LC-MS/MS, ASKA Pharma Medical Co., Ltd.). PAC conversion formulas were determined for each AVS sample assay. PAC measured using CLEIA was significantly correlated with that measured using RIA (correlation coefficient = 0.971). The PAC conversion formula was PAC (CLEIA) = PAC (RIA) × 0.772 - 1,199 pg/mL. The PAC of 14,000 pg/mL in RIA was equivalent to 9,613 pg/mL in CLEIA. PAC measured using CLEIA was also correlated with that measured using LC-MS/MS, and the PAC conversion formula was PAC (CLEIA, pg/mL) = 0.97 × PAC (LC-MS/MS, pg/mL) + 211. The inter-assay coefficient of variability (CV) was 1.1-1.3% and intra-assay CV was 1.0-1.7%, measured using CLEIA. The PAC conversion formula for AVS samples was obtained using CLEIA and RIA, and the conversion formula was different from that for peripheral blood. PAC values measured by CLEIA showed preferable accuracy and high concordance with those measured by LC-MS/MS, even in AVS samples. The study outcomes are useful for interpreting AVS results using non-RIA measurement methods.

Determination of three C18-oxygenated steroids in adrenal lesion segments in primary aldosteronism by super-selective adrenal venous sampling and LC/ESI-MS/MS.

Super-selective adrenal venous sampling (ssAVS) can collect the adrenal tributary venous blood in the aldosterone (ALD)-hypersecreting segments in primary aldosteronism. The concentrations of the C18-oxygenated steroids, especially 18-oxocortisol (18-oxoF), in the lesion segments might be more useful indices than those in the peripheral or adrenal central veins (current candidate indexes) for the differential diagnosis of unilateral ALD-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). To verify this hypothesis, we developed a liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for simultaneously quantifying ALD, 18-oxoF and 18-hydroxycortisol in the adrenal tributary venous serum sample collected by ssAVS (ssAVS serum) and compared their concentrations between APA and BAH patients. Only deproteinization was required for a 10 µl sample prior to the LC/ESI-MS/MS analysis. Endogenous corticoids did not interfere with the quantifications, and the intra-assay and interassay precisions (≤ 8.3%) and accuracies (94.2-102.7%) were acceptable. The clinical study revealed that the 18-oxoF concentration was significantly higher in the ALD-producing tumor tissues (from APA patients) than in the hyperplastic tissues (from BAH patients). However, in conclusion, the 18-oxoF concentration in the ssAVS serum sample can be a rough indication but cannot be decisive for the differential diagnosis between APA and BAH owing to the significant individual difference.

The utility of zebrafish cardiac arrhythmia model to predict the pathogenicity of KCNQ1 variants.

Genetic testing for inherited arrhythmias and discriminating pathogenic or benign variants from variants of unknown significance (VUS) is essential for gene-based medicine. KCNQ1 is a causative gene of type 1 long QT syndrome (LQTS), and approximately 30% of the variants found in type 1 LQTS are classified as VUS. We studied the role of zebrafish cardiac arrhythmia model in determining the clinical significance of KCNQ1 variants. We generated homozygous kcnq1 deletion zebrafish (kcnq1del/del) using the CRISPR/Cas9 and expressed human Kv7.1/MinK channels in kcnq1del/del embryos. We dissected the hearts from the thorax at 48 h post-fertilization and measured the transmembrane potential of the ventricle in the zebrafish heart. Action potential duration was calculated as the time interval between peak maximum upstroke velocity and 90% repolarization (APD90). The APD90 of kcnq1del/del embryos was 280 ± 47 ms, which was significantly shortened by injecting KCNQ1 wild-type (WT) cRNA and KCNE1 cRNA (168 ± 26 ms, P < 0.01 vs. kcnq1del/del). A study of two pathogenic variants (S277L and T587M) and one VUS (R451Q) associated with clinically definite LQTS showed that the APD90 of kcnq1del/del embryos with these mutant Kv7.1/MinK channels was significantly longer than that of Kv7.1 WT/MinK channels. Given the functional results of the zebrafish model, R451Q could be reevaluated physiologically from VUS to likely pathogenic. In conclusion, functional analysis using in vivo zebrafish cardiac arrhythmia model can be useful for determining the pathogenicity of loss-of-function variants in patients with LQTS.

Node-by-node diagnosis for multiple ipsilateral nodules by segmental adrenal venous sampling in primary aldosteronism.

OBJECTIVES: In patients with primary aldosteronism (PA), multiple adrenocortical nodules may be present on the surgical side. The aim of this study was to clarify the pathological diagnosis and the node-by-node diagnostic capability of segmental adrenal venous sampling (sAVS). DESIGN: Retrospective study. PATIENTS: A total of 162 patients who underwent adrenalectomy following sAVS were studied. MEASUREMENTS: Multiple nodules on the surgical side were extracted while referring to contrast-enhanced computed tomography images. We also performed a detailed histopathological analysis of the resected specimens from patients undergoing sAVS, which included immunohistochemistry for CYP11B2. RESULTS: In 11 (6.8%) patients, two to three nodules were detected on the surgical side. All patients were diagnosed by sAVS with at least one aldosterone-producing adenoma (APA) for localized aldosterone elevation in tributaries. Seven patients showed a lateralization index value of ≥4 after ACTH stimulation. Histopathologically and clinically, two patients had two or three CYP11B2-positive APAs, and the other nine patients both APAs and non-APAs. The positive predictive value of the most suspected APA, that is, the drainer that showed the highest aldosterone level by sAVS, was 11/11 (100%, 95% confidence interval [CI]: 71.5%-100%), while that for the second and third suspected APA was 3/7 (42.9%, 95% CI: 9.9%-81.6%), and they were significantly different (p = .01). Further, the positive predictive value of non-APA was 4/4 (100%, 95% CI: 39.8%-100%). CONCLUSIONS: The sAVS could correctly diagnose the aldosterone production in multiple ipsilateral adrenal nodules.

Anatomical Variations of the Left Adrenal Vein Encountered During Venous Sampling.

PURPOSE: To identify anatomical variations in the left adrenal vein (LAV) and to evaluate the role of preprocedural contrast-enhanced computed tomography (CT) planning. METHODS: The length of the left adrenal central vein (LACV), the vessel that receives blood from all tributaries of the left adrenal gland, was measured using venograms of patients who had undergone adrenal venous sampling (AVS) for the diagnosis of primary aldosteronism between October 2017 and December 2019. The anatomical variants of the LAV were described and classified. Contrast-enhanced CT was used to evaluate the detection rate of the following: (a) confluence of the left inferior phrenic vein and the LAV and (b) the last tributary flowing into the LAV. RESULTS: In total, 311 patients (143 men, 168 women; mean age: 49.3 years ± 11.0) were enrolled. Of them, 9 (2.9%) patients had anatomical variants lacking a LACV. In patients with a LACV (n = 302), the venographic LACV length was 9.0 mm ± 3.9 (<1 mm in 9 patients). The detection rate of the confluence of the left inferior phrenic vein and LAV, as determined using contrast-enhanced CT, was high (96.2%), whereas that of the last tributary flowing into the LAV was low (0.8%). In 4 of 18 patients with short or absent LACV, the variant was visualized using contrast-enhanced CT. CONCLUSIONS: In some patients, the LACV is absent or short, which is an anatomical variation. Understanding venographic anatomical variations can help avoid misleading results resulting from a suboptimal sampling site in AVS. For some subtypes, contrast-enhanced CT may also help in planning the AVS procedure.

Comparison and commutability study between standardized liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and chemiluminescent enzyme immunoassay for aldosterone measurement in blood.

A commutability confirmation test for the blood aldosterone measurement was performed on liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) as a designated comparison method (DCM) and four chemiluminescent enzyme immunoassay (CLEIA) measurement procedures based on metrological traceability. A conventional radioimmunoassay (RIA) and two measurement procedures of CLEIA which obtains RIA equivalent values were also compared. The relationship between the DCM value and the CLEIA value with respect to 120 pg/mL of the RIA value, which is the screening criterion of primary aldosteronism (PA) was clarified. For the correlation test, 75 samples of patient serum and plasma were used. Regression analysis revealed that the standardized LC-MS/MS and four CLEIA measurement procedures were in good agreement. This is the effect of measurement specificity and calibration using by certified reference material (CRM). The median of the LC-MS/MS corresponding to 120 pg/mL of RIA was 48.5 pg/mL. In the mean of standardized four CLEIA values corresponding to the 48.5 pg/mL of LC-MS/MS value was 47.51 pg/mL and the standard deviation (SD) was 2.93 pg/mL. However, the correlation between the RIA value and the RIA equivalent of the two measurement procedures by CLEIA differed depending on the measurement procedure. This is due to the influence of RIA measurement performance. Standardized CLEIA measurements are suitable for routine measurement procedure. When converting the LC-MS/MS equivalent value by the standardized CLEIA to the conventional RIA value, it is necessary to use the conversion formula.

Clinical Translationality of KCNJ5 Mutation in Aldosterone Producing Adenoma.

Hypertension due to primary aldosteronism poses a risk of severe cardiovascular complications compared to essential hypertension. The discovery of the KCNJ5 somatic mutation in aldosteroene producing adenoma (APA) in 2011 and the development of specific CYP11B2 antibodies in 2012 have greatly advanced our understanding of the pathophysiology of primary aldosteronism. In particular, the presence of CYP11B2-positive aldosterone-producing micronodules (APMs) in the adrenal glands of normotensive individuals and the presence of renin-independent aldosterone excess in normotensive subjects demonstrated the continuum of the pathogenesis of PA. Furthermore, among the aldosterone driver mutations which incur excessive aldosterone secretion, KCNJ5 was a major somatic mutation in APA, while CACNA1D is a leading somatic mutation in APMs and idiopathic hyperaldosteronism (IHA), suggesting a distinctive pathogenesis between APA and IHA. Although the functional detail of APMs has not been still uncovered, its impact on the pathogenesis of PA is gradually being revealed. In this review, we summarize the integrated findings regarding APA, APM or diffuse hyperplasia defined by novel CYP11B2, and aldosterone driver mutations. Following this, we discuss the clinical implications of KCNJ5 mutations to support better cardiovascular outcomes of primary aldosteronism.

The Primary Aldosteronism Surgical Outcome Score for the Prediction of Clinical Outcomes After Adrenalectomy for Unilateral Primary Aldosteronism.

OBJECTIVE: To develop a prediction model for clinical outcomes after unilateral adrenalectomy for unilateral primary aldosteronism. SUMMARY BACKGROUND DATA: Unilateral primary aldosteronism is the most common surgically curable form of endocrine hypertension. Surgical resection of the dominant overactive adrenal in unilateral primary aldosteronism results in complete clinical success with resolution of hypertension without antihypertensive medication in less than half of patients with a wide between-center variability. METHODS: A linear discriminant analysis model was built using data of 380 patients treated by adrenalectomy for unilateral primary aldosteronism to classify postsurgical clinical outcomes. The total cohort was then randomly divided into training (280 patients) and test (100 patients) datasets to create and validate a score system to predict clinical outcomes. An online tool (Primary Aldosteronism Surgical Outcome predictor) was developed to facilitate the use of the predictive score. RESULTS: Six presurgical factors associated with complete clinical success (known duration of hypertension, sex, antihypertensive medication dosage, body mass index, target organ damage, and size of largest nodule at imaging) were selected based on classification performance in the linear discriminant analysis model. A 25-point predictive score was built with an optimal cut-off of greater than 16 points (accuracy of prediction = 79.2%; specificity = 84.4%; sensitivity = 71.3%) with an area under the curve of 0.839. CONCLUSIONS: The predictive score and the primary aldosteronism surgical outcome predictor can be used in a clinical setting to differentiate patients who are likely to be clinically cured after surgery from those who will need continuous surveillance after surgery due to persistent hypertension.

Survey of the current status of subclinical coronavirus disease 2019 (COVID-19).

OBJECTIVES: We investigated relationships between subclinical COVID-19 (coronavirus disease 2019) and background factors. METHODS: We determined SARS-CoV-2 antibody (IgG) prevalence in 1603 patients, doctors, and nurses in 65 medical institutions in Kanagawa Prefecture, Japan and investigated their background factors. Antibodies (IgG) against SARS-CoV-2 were analyzed by Immunochromatographic test. RESULTS: The 39 subjects (2.4%) were found to be IgG antibody-positive: 29 in the patient group (2.9%), 10 in the doctor/nurse group (2.0%), and 0 in the control group. After adjustment for age, sex, and the antibody prevalence in the control group, antibody prevalence was 2.7% in the patient group and 2.1% in the doctor/nurse group. There was no significant difference between the antibody-positive subjects and the antibody-negative subjects in any background factors investigated including overseas travel, contact with overseas travelers, presence/absence of infected individuals in the living area, use of trains 5 times a week or more, BCG vaccination, and use of ACE inhibitor and ARB. CONCLUSIONS: Antibody prevalence in the present survey at medical institution is higher than that in Tokyo and in Osaka measured by the government suggesting that subclinical infections are occurring more frequently than expected. No background factor that influenced antibody-positive status due to subclinical infection was identified.

Tandem Mass Spectrometry Imaging Reveals Distinct Accumulation Patterns of Steroid Structural Isomers in Human Adrenal Glands.

Visualizing tissue distribution of steroid hormones is a promising application of MALDI mass spectrometry imaging (MSI). On-tissue chemical derivatization using Girard's T reagent has enhanced the ionization efficiency of steroids. However, discriminating between structural isomers with distinct bioactivities remains a challenge. Herein, we used ion trap MS/tandem MS (MS3) to distinguish a mineralcorticoid aldosterone (Aldo) and a glucocorticoid cortisol (F), from their structural isomers. Our method is also useful to detect hybrid steroids (18-hydroxycortisol [18-OHF] and 18-oxocortisol) with sufficient signal-to-noise ratio. The clinical applicability of the tandem MS method was evaluated by analyzing F, Aldo, and 18-OHF distributions in human adrenal glands. In such clinical specimens, small Aldo-producing cell clusters (APCCs) were identified and were first found to produce a high level of Aldo and not to contain F. Moreover, a part of APCCs produced 18-OHF, presumably converted from F by APCC-specific CYP11B2 activity. Catecholamine species were also visualized with another derivatization reagent (TAHS), and those profiling successfully discriminated pheochromocytoma species. These tandem MSI-methods, coupled with on-tissue chemical derivatization has proven to be useful for detecting low-abundance steroids, including Aldo and hybrid steroids and thus identifying steroid hormone-producing lesions.

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.

Comparative study of the effects of ipragliflozin and sitagliptin on multiple metabolic variables in Japanese patients with type 2 diabetes: A multicentre, randomized, prospective, open-label, active-controlled study.

In the present randomized study, we assessed the efficacy of ipragliflozin compared with sitagliptin in 124 Japanese patients with type 2 diabetes. Sodium-glucose co-transporter-2 inhibitor-naïve and incretin-related agent-naïve patients were randomly assigned to receive additional 50 mg ipragliflozin or sitagliptin. The primary endpoint was the proportion of participants with >0.5% decrease in glycated haemoglobin (HbA1c) without body weight gain at 12 weeks. For secondary endpoints, we measured several biomarkers related to metabolic changes. After 12 weeks, 53.9% of participants in the ipragliflozin and 42.9% in the sitagliptin group reached the primary endpoint (P = 0.32). Decreases in homeostatic model assessment of insulin resistance, body fat percentage and skeletal muscle mass index, and increases in free fatty acids, ketone body concentration and HDL cholesterol levels were greater in the ipragliflozin group. Increases in homeostatic model assessment of ß-cell function and decreases in proinsulin-to-insulin ratio were greater in the sitagliptin group. No serious adverse events occurred in either group. In conclusion, ipragliflozin had beneficial effects on fat reduction, insulin resistance and lipid metabolism, while sitagliptin had beneficial effects on ß-cell function.

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.

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.

Clinical Utility of the Adrenocorticotropin Stimulation Test with/without Dexamethasone Suppression for Definitive and Subtype Diagnosis of Primary Aldosteronism.

The adrenocorticotropin (ACTH) stimulation test (AST) has been reported to be useful for diagnosing primary aldosteronism (PA), particularly for differentiating PA subtypes under 1-mg dexamethasone suppression (DS). The aim of our study was to clarify the effect of 1-mg DS on AST results. A retrospective cohort study was conducted using data for 48 patients (PA: 30/48). We estimated the difference in plasma aldosterone concentration (PAC) responsiveness to ACTH stimulation with single (AST alone) and combined (AST under 1-mg DS) tests within the same patient. We compared the diagnostic accuracy of these two tests for PA and the laterality of hyperaldosteronism. We found no differences in PAC responsiveness to ACTH stimulation between single and combined tests, and observed a significant positive linear relationship (30 min, R² = 0.75, p-value < 0.01). Both tests showed the highest diagnostic accuracy for PA following 30 min of ACTH stimulation. The ability to detect the laterality of hyperaldosteronism was inconsistent and differed according to the two definitions: lateralization ratio and the absolute aldosterone levels in adrenal venous sampling. PAC responsiveness to ACTH stimulation was similar for AST with and without 1-mg DS. AST can be performed under both conditions with similar accuracy to detect PA.

Efficacy and Safety of the Dipeptidyl Peptidase-4 Inhibitor Sitagliptin on Atherosclerosis, ß-Cell Function, and Glycemic Control in Japanese Patients with Type 2 Diabetes Mellitus Who are Treatment Naïve or Poorly Responsive to Antidiabetes Agents: A Multicenter, Prospective Observational, Uncontrolled Study.

BACKGROUND: Sitagliptin, a dipeptidyl peptidase-4 inhibitor, is widely used in patients with type 2 diabetes. However, the pleiotropic effects of sitagliptin is not well understood. OBJECTIVE: To assess the clinical efficacy and safety of sitagliptin on atherosclerosis, ß-cell function, and glycemic control in Japanese patients with type 2 diabetes. METHODS: A prospective observational study of 270 patients with type 2 diabetes mellitus was carried out. Patients (aged 64.3 [12.4] years, body mas index 25.2 [4.3]) with glycated hemoglobin >6.9% (52 mmol/mol) or fasting plasma glucose >130 mg/dL were treated with sitagliptin for 12 months. The primary end point was glycated hemoglobin level changes from baseline to 3 months. The secondary end points included changes in several biomarkers related to inflammation and ß-cell function from baseline to 3 months, as well as changes in glycated hemoglobin level from baseline to 12 months. RESULTS: Glycated hemoglobin levels were significantly lower in patients treated with sitagliptin for 3 months than at baseline (8.1% [1.4%]-7.3% [1.2%]) (65 [16.9]-56 [13.1] mmol/mol]) (P < 0.0001), which continued after 12 months (7.4% [1.3%]) (56 [15.2] mmol/mol) (P < 0.0001). In addition, a marker of vascular-specific inflammation, pentraxin-3, and a marker of ß-cell function (proinsulin/insulin ratio), respectively, were lower after treatment with sitagliptin for 3 months than at baseline (1.88 [0.78]-1.65 [0.63] ng/mL [P = 0.0038] and 0.20 [0.14]-0.17 [0.11] [P = 0.01], respectively). On the other hand, a biomarker reflecting whole body inflammation; that is, high-sensitivity C-reactive protein level, was unchanged. Adverse events occurred in 14 patients (5.18%). CONCLUSIONS: Sitagliptin may have beneficial effects on vascular inflammation and ß-cell function in Japanese patients with type 2 diabetes. Pentraxin-3 may be an early predictive marker for detecting the antiatherosclerotic effects of dipeptidyl peptidase-4.

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.

Extraordinarily high aldosterone, 901.0 ng/dL, in a patient with primary aldosteronism: an insight into the underlying mechanism.

A 43-yr-old hypertensive male was admitted due to hypokalemia (1.8 mEq/L) and renal dysfunction (eGFR, 20.0 mL/min/1.73 m2). His plasma aldosterone was 901.0 ng/dL, plasma renin activity 5.7 ng/mL/hr, and aldosterone/renin activity ratio 158. Angiotensin II (AII) was 0.7 pg/mL, ACTH <1.0 pg/mL, and cortisol 21.6 µg/dL. Liquid chromatography-tandem mass spectrometry analysis showed that aldosterone (104 times the control) as well as its precursors were significantly elevated in the patient's plasma. A left adrenal (4-cm-diameter) tumor with 131I-Adosterol uptake was found and removed. Four days later, plasma aldosterone and renin activity had dropped to 7.73 ng/dL and 1.6 ng/mL/hr, respectively. However, they rose to 24.0 ng/dL and 10.9 ng/mL/hr, respectively, by Day 102. Nevertheless, magnetic resonance angiography found no evidence of a renovascular lesion. The tumor was a benign adrenocortical adenoma composed predominantly of clear cells positive for 17α-hydroxylase, [hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerases], and aldosterone synthase. A quantitative real-time polymerase chain reaction analysis of the tumor cells revealed that expression of the gene encoding aldosterone synthase was 85 times the control level. In addition, the tumor cells harbored G151R mutation of the inward rectifying potassium channel subfamily j, member 5 gene. The striking overexpression of aldosterone synthase by the tumor cells was considered the primary mechanism for the extravagant overproduction of aldosterone in this case. This overexpression may have resulted from integration of signals from AII and forced membrane depolarization due to the potassium channel mutation.