Identification of risk loci for primary aldosteronism in genome-wide association studies

Unilateral adrenalectomy in bilateral adrenal hyperplasia with primary aldosteronism

Disclosure: N. Patel: None. A.N. Mukhtar: None. P. Shooliz: None. 15% of adrenal adenomas are considered functional with most secreting one hormone. However, 14% of aldosterone producing adenomas (APAs) will co-secrete cortisol (Orrega & Chorny, 2020). In patients with APAs over the age of 35 without co-secretion, the next step is adrenal vein sampling (AVS). This case highlights the importance of recognizing APAs with co-secretion of cortisol without a completely suppressed Adrenocorticotropic hormone (ACTH) and the next steps in management. We present a 67 year old male with a history of hypertension and hypokalemia who presented with a left sided 3.3 centimeter (cm) adrenal nodule with non contrast attenuation of 29 Hounsfield units, 73% absolute washout value, and 55% relative washout value likely representing an adrenal adenoma. Laboratory testing supported APA diagnosis, with an elevated plasma aldosterone concentration (13.3ng/dl), suppressed renin (0.2ng/ml/hr), and increased 24 hour urine aldosterone excretion (28 μg/24 hours) with sodium of 212 mmol/24 hour. Testing for co-secretion of cortisol was confirmed by inappropriately high levels of cortisol at 5.3μg/dl after the dexamethasone suppression test. Patient’s morning ACTH levels were fluctuating from low-normal at 10 μg/dl to 27 μg/dl with normal serum cortisol level of 17.2 μg/dl. Given the above results, AVS was not completed and the patient underwent a left sided adrenalectomy with pathology revealing an 4.3cm adrenocortical adenoma. Postoperatively, after a few days, the patient became normotensive with resolution of hypokalemia. 1 week post operative aldosterone was 1 ng/dl, renin was 2.37 ng/ml/hr, and morning cortisol was 9 μg/dl. APAs greater than 2.4cm have a high probability of co-secretion of cortisol and a dexamethasone suppression test is recommended to rule out subclinical Cushing’s syndrome. Though our patient had varying levels of ACTH, with the larger size and low ACTH levels, as low as 10, pituitary cause was less likely. In APA with cortisol co-secretion, AVS is unnecessary due to 20% risk of misclassifying unilateral disease as bilateral adrenal hyperplasia (BAH), since cosyntropin infusion can falsely suppress lateralization. A patient diagnosed with BAH without co-secretion undergoes medical management rather than an adrenalectomy. However, in patients with an APA and co-secretion of cortisol that have BAH or a contralateral adrenal micronodule, the treatment is surgery to treat the hypercortisolism making AVS unnecessary. Patients with an APA that co-secretes cortisol require stress dose steroids intraoperatively followed by a taper to prevent a life threatening adrenal crisis. Overall this case illustrates the importance of diagnosing APAs that co-secrete cortisol as this leads to essential management changes. Presentation: Monday, July 14, 2025

Caution About the Overdiagnosis of Primary Aldosteronism

Hiperaldosteronismo primario: análisis de una serie de 54 pacientes

Scintigraphic localization of adrenal lesions in primary aldosteronism

In primary aldosteronism (PA) the differentiation of unilateral aldosterone-producing adenomas (APA) from bilateral adrenal hyperplasia (BAH) is usually performed by adrenal venous sampling (AVS) and/or computed tomography (CT). CT alone often lacks the sensitivity to identify micro-APAs. Our objectives were to establish if steroid profiling could be useful for the identification of patients with micro-APAs and for the development of an online tool to differentiate micro-APAs, macro-APAs and BAH. The study included patients with PA (n = 197) from Munich (n = 124) and Torino (n = 73) and comprised 33 patients with micro-APAs, 95 with macro-APAs, and 69 with BAH. Subtype differentiation was by AVS, and micro- and macro-APAs were selected according to pathology reports. Steroid concentrations in peripheral venous plasma were measured by liquid chromatography-tandem mass spectrometry. An online tool using a random forest model was built for the classification of micro-APA, macro-APA and BAH. Micro-APA were classified with low specificity (33%) but macro-APA and BAH were correctly classified with high specificity (93%). Improved classification of micro-APAs was achieved using a diagnostic algorithm integrating steroid profiling, CT scanning and AVS procedures limited to patients with discordant steroid and CT results. This would have increased the correct classification of micro-APAs to 68% and improved the overall classification to 92%. Such an approach could be useful to select patients with CT-undetectable micro-APAs in whom AVS should be considered mandatory.

In this issue of The Journal of Clinical Hypertension, Grillo and colleagues1 demonstrated that blood pressure (BP) variability (BPV) as determined by ambulatory BP monitoring (ABPM) was greater for patients with primary aldosteronism and those with essential hypertension in comparison to patients with no hypertension. The clinical implications of their findings are significant as they demonstrate another important subgroup of patients who are at increased risk for target organ damage from BPV. In addition, these investigators provide more evidence of the clinical utility of ABPM in diagnosing BPV in at-risk patient populations. There is growing evidence from both short-term (24-hour) and long-term assessments that BPV is associated with a higher risk for stroke, myocardial infarction, and kidney disease in patients with essential hypertension.2, 3 A study of 169 hypertensive patients showed that short-term BPV was associated with increased risk for left ventricular hypertrophy, increased carotid artery intimal-media thickness, and albuminuria, and prognosis was related to the number of sites of target organ damage.4 Similarly, Tatasciore and colleagues5 demonstrated increased carotid intima-media thickness and left ventricular mass in patients with greater BPV. These findings were specific for systolic BPV while awake and were independent of mean awake BP levels.5 Long-term BPV with measurements spanning weeks, months, or years is typically assessed by patient home BP monitoring or clinic BP measurements.2 As with short-term BPV, long-term BPV has also been associated with an increased risk of target organ damage in patients with essential hypertension.2 In multiple studies, patients with greater long-term variability in their home BP measurements had a higher prevalence of cardiovascular and kidney damage2, 6 and a higher risk of cardiovascular events and mortality.2, 7-10 Significantly compounding the cardiovascular risk of BPV, hypertensive patients with primary aldosteronism appear to be even more vulnerable to target organ damage compared with patients with only essential hypertension. A study of cardiovascular outcomes compared patients with primary aldosteronism from solitary adenomas or bilateral adrenal hyperplasia with patients who had essential hypertension.11 These cardiovascular events included stroke, myocardial infarction, atrial fibrillation, and echocardiographic and electrocardiographic evidence of left ventricular hypertrophy.11 The investigators found that patients with primary aldosteronism experienced more cardiovascular events than patients with essential hypertension.11 Importantly, the excess cardiovascular event burden in the primary aldosteronism patient group was independent of BP control.11 In a subsequent study, Catena and colleagues12 showed that the prevalence of cardiovascular events was significantly greater in a group of patients with primary aldosteronism (35%) than in patients with essential hypertension (11%). This excess cardiovascular complication burden was also independent and out of proportion to the patient's BP.12 Although both of these studies did not specifically evaluate BPV, it is certainly possible that the findings of Grillo and colleagues, which implicated BPV and target organ damage, is a causative factor for the increased cardiovascular events found in patients with primary aldosteronism. Given the increased risk of target organ damage associated with BPV, it may become critical that clinicians now consider another metric to assess whether their hypertensive patients are receiving optimal antihypertensive treatment; it is now not enough to just achieve a BP below a recommended threshold. A substantial body of clinical research has demonstrated that BPV is a significant causative factor in target organ damage even when BP is adequately controlled with medical therapies. For patients with primary aldosteronism who are already more vulnerable to target organ damage than patients with essential hypertension, BPV may be an even more important factor to measure. As Grillo and colleagues demonstrated in this study, ABPM is a well-suited and useful tool to assess BPV in patients with primary aldosteronism. Currently, the use of ABPM is limited and typically confined to the diagnosis of white-coat hypertension, episodic hypertension, resistant hypertension, and hypotensive symptoms while taking antihypertensive medications and autonomic dysfunction.13-15 However, we suggest that ABPM also be considered as a tool to evaluate the extent of BPV in patients with primary aldosteronism and to determine the effectiveness of an antihypertensive regimen. Finally, the authors discuss potential mechanisms for BPV. We are left concluding that there is much more to learn, including whether the fluctuations in BP are incurring injury or simply reflecting an aspect of target organ changes. Does the fact that one finds BPV in patients with primary aldosteronism offer any clues? Certainly volume expansion is a mediator of the increase in BP in primary aldosteronism and it would seem unlikely that volume per se would vary enough to account for the BPV. A volume-expanded state, however, could sensitize BP to changes in, for example, sympathetic tone. It would be interesting to know how much BPV might decrease following removal of an adrenal tumor that produced aldosterone. An underlying role for aldosterone in the development of hypertensive states as well as hypertensive complications seem to continually widen.

Dickkopf 3 (Dkk3) is a secreted protein belonging to the Dkk family and encoded by the orthologous gene of REIC. Dkk3/REIC is expressed by mouse and human adrenal glands, but the understanding of its roles in this organ is still limited. To determine the functions of Dkk3 in the mouse adrenal gland, we first identified that the mouse Dkk3 protein is N-glycosylated in the adrenal gland as well as in the brain. We performed proteome analysis on adrenal glands from Dkk3-null mice, in which exons 5 and 6 of the Dkk3 gene are deleted. Twodimensional polyacrylamide gel electrophoresis of adrenal proteins from wild-type and Dkk3-null mice revealed 5 protein spots whose intensities were altered between the 2 genotypes. Mass spectrometry analysis of these spots identified binding immunoglobulin protein (BiP), an endoplasmic reticulum (ER) chaperone. To determine whether mouse Dkk3 is involved in the unfolded protein response (UPR), we carried out a reporter assay using ER-stress responsive elements. Forced expression of Dkk3 resulted in the induction of distinct levels of reporter expression, showing the UPR initiated by the ER membrane proteins of activating transcription factor 6 (ATF6) and inositol-requring enzyme 1 (IRE1). Thus, it is possible that Dkk3 is a physiological ER stressor in the mouse adrenal gland.

Observational studies have reported associations between primary aldosteronism (PA) and cardiovascular outcomes, including coronary artery diseases (CAD), congestive heart failure (CHF), and stroke. However, establishing causality remains a challenge due to the lack of randomized controlled trial data on this topic. We thus aimed to investigate the causal relationship between PA and the risk of developing CAD, CHF, and stroke. Cross-ancestry meta-analysis of genome-wide association studies combining East Asian and European ancestry (1560 PA cases and 742 139 controls) was conducted to identify single-nucleotide variants that are associated with PA. Then, using the identified genetic variants as instrumental variables, we conducted the 2-sample Mendelian randomization analysis to investigate the causal relationship between PA and incident CAD, CHF, and stroke among both East Asian and European ancestry. Summary association results were extracted from large genome-wide association studies consortia. Our cross-ancestry meta-analysis of East Asian and European populations identified 7 genetic loci significantly associated with the risk of PA, for which the genes nearest to the lead variants were CASZ1, WNT2B, HOTTIP, LSP1, TBX3, RXFP2, and NDP. Among the East Asian population, the pooled odds ratio estimates using these 7 genetic instruments of PA were 1.07 (95% CI, 1.03-1.11) for CAD, 1.10 (95% CI, 1.01-1.20) for CHF, and 1.13 (95% CI, 1.09-1.18) for stroke. The results were consistent among the European population. Our 2-sample Mendelian randomization study revealed that PA had increased risks of CAD, CHF, and stroke. These findings highlight that early and active screening of PA is critical to prevent future cardiovascular events.

It has been suggested that there might be a pathophysiological link and overlap between primary aldosteronism (PA) and obstructive sleep apnea (OSA). Therefore, in a prospective study, we evaluated the frequency of PA in hypertensive patients suspected of having OSA. We included 207 consecutive hypertensive patients (mean age 53.2 ± 12.1 years, 133 M, 74 F) referred for polysomnography on the basis of one or more of the following clinical features: typical OSA symptoms, resistant or difficult-to-treat hypertension, diabetes, or cardiovascular disease. PA was diagnosed based on thew saline infusion test. Moderate-to-severe OSA was diagnosed in 94 patients (45.4% of the whole group). PA was diagnosed in 20 patients with OSA (21.3%) compared with 9 patients in the group without OSA (8.0%; P = .006). PA was also frequent in patients in whom symptoms of OSA were a sole indication for PA screening (15.4%) and in patients with and without resistant hypertension (24.5% and 17.8%, respectively). Most patients with PA and OSA were diagnosed with bilateral adrenal hyperplasia (18 patients, 90%). There were no major differences in clinical characteristics between patients with OSA with PA and those without PA. In multivariate models, moderate-to-severe OSA predicted the presence of PA (odds ratio 2.89, P = .018). Patients with clinically important moderate-to-severe OSA are characterized by a relatively high frequency of PA. Our results support the recommendations to screen patients with moderate-to-severe OSA for PA, regardless of the presence of other indications for PA screening.

To describe the magnetic resonance (MR) imaging features of the adrenal glands in primary hyperaldosteronism and assess MR imaging in the detection and characterization of aldosterone-producing adenoma (APA). The authors retrospectively reviewed the cases of 20 patients (13 female and seven male patients; age range, 14-67 years; median age, 46 years) with primary hyperaldosteronism who underwent 1.5-T MR imaging between 1995 and 1998. All patients underwent transverse T1- and T2-weighted imaging, and chemical shift imaging was performed in 17 patients. Imaging results were correlated with findings at biochemical testing, venous sampling, or surgery. Among the 20 patients, 10 (50%) had APA and 10 (50%) bilateral adrenal hyperplasia (BAH). In the detection of APA, MR imaging had a sensitivity of 70%, specificity of 100%, and accuracy of 85%. APAs (mean size, 20 x 16 mm) were iso- or hypointense relative to the liver on T1-weighted images and slightly hyperintense on T2-weighted images. With chemical shift imaging, the signal intensity decreased on the out-of-phase images in six of seven (86%) patients with APA and in eight of nine (89%) patients with BAH. MR imaging has a high specificity in the detection of APA. As with nonhyperfunctioning adenoma, APA and BAH show evidence of intracellular lipid at chemical shift imaging.

Primary aldosteronism comprises 2 main subtypes: unilateral aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia. Somatic KCNJ5 mutations are found in APA at a prevalence of around 40% that drive and sustain aldosterone excess. Somatic APA mutations have been described in other genes (CACNA1D, ATP1A1, and ATP2B3) albeit at a lower frequency. Our objective was to identify genotype-specific steroid profiles in adrenal venous (AV) and peripheral venous (PV) plasma in patients with APAs. We measured the concentrations of 15 steroids in AV and PV plasma samples by liquid chromatography-tandem mass spectrometry from 79 patients with confirmed unilateral primary aldosteronism. AV sampling lateralization ratios of steroids normalized either to cortisol or to DHEA+androstenedione were also calculated. The hybrid steroid 18-oxocortisol exhibited 18- and 16-fold higher concentrations in lateralized AV and PV plasma, respectively, from APA with KCNJ5 mutations compared with all other APA combined together (P<0.001). Lateralization ratios for the KCNJ5 group were also generally higher. Strikingly, we demonstrate that a distinct steroid signature can differentiate APA genotype in AV and PV plasma. Notably, a 7-steroid fingerprint in PV plasma correctly classified 92% of the APA according to genotype. Prospective studies are necessary to translate these findings into clinical practice and determine if steroid fingerprinting could be of value to select patients with primary aldosteronism who are particularly suitable candidates for adrenal venous sampling because of a high probability of having an APA.

Idiopathic hyperaldosteronism (IHA) due to bilateral adrenal hyperplasia is the most common subtype of primary aldosteronism (PA). The pathogenesis of IHA is still unknown, but the bilateral disease suggests a potential predisposing genetic alteration. Heterozygous germline mutations of armadillo repeat containing 5 (ARMC5) have been shown to be associated with hypercortisolism due to sporadic primary bilateral macronodular adrenal hyperplasia and are also observed in African-American PA patients. We investigated the presence of germline ARMC5 mutations in a group of PA patients who had bilateral computed tomography-detectable adrenal alterations. We sequenced the entire coding region of ARMC5 and all intron/exon boundaries in 39 patients (37 Caucasians and 2 black Africans) with confirmed PA (8 unilateral, 27 bilateral and 4 undetermined subtype) and bilateral adrenal lesions. We identified 11 common variants, 5 rare variants with a minor allele frequency <1% and 2 new variants not previously reported in public databases. We did not detect by in silico analysis any ARMC5 sequence variations that were predicted to alter protein function. In conclusion, ARMC5 mutations are not present in a fairly large series of Caucasian patients with PA associated to bilateral adrenal disease. Further studies are required to definitively clarify the role of ARMC5 in the pathogenesis of adrenal nodules and aldosterone excess in patients with PA.

Nonaldosterone mineralocorticoids, such as deoxycorticosterone (DOC) and 18-hydroxy-DOC, have been reported to be elevated in some patients with primary aldosteronism (PA). Since DOC is a probable precursor of a more potent mineralocorticoid, 19-nor-deoxycorticosterone (19-nor-DOC), this study evaluated urinary free (UF) 19-nor-DOC excretion in 6 patients with PA and compared the results to those from 11 patients with low renin hypertension (LRH) and 7 normotensive subjects. PA was due to either an aldosterone-producing adenoma (APA; 4 patients) or bilateral adrenal hyperplasia (2 patients) diagnosed by adrenal venous catheterization or surgery. Compared to LRH subjects, patients with PA had a higher mean blood pressure (137 +/- 9 vs. 114 +/- 3 mm Hg), a lower plasma potassium level (3.1 +/- 0.2 vs. 3.9 +/- 0.1 meq/1) and greater renin suppression (0.3 +/- 0.1 vs. 0.6 +/- 0.1 ng angiotensin I/ml . h). UF 19-nor-DOC levels were elevated in PA subjects compared to those in normotensives (3,716 +/- 1,517 vs. 428 +/- 112 ng/day) but not compared to those in LRH patients (1,237 +/- 471). Two patients with APA had distinctly elevated UF 19-nor-DOC levels (11,137 and 7,744 ng/day), but another APA patient had the lowest value (305 ng/day). UF 19-nor-DOC positively correlated with the aldosterone secretion rate in PA (r = 0.75) but not LRH subjects. In conclusion, this study demonstrates that patients with PA may have elevated levels of UF 19-nor-DOC which are proportional to the aldosterone excess and could be a contributing factor to the hypertension, hypokalamia, and excess mineralocorticoid activity of this disease.

Accumulating evidence suggests a link between adrenocortical zona glomerulosa and parathyroid gland through mechanisms that remain unexplored. To test the hypothesis that in vivo angiotensin II blockade affects PTH secretion in patients with hypertension and that aldosterone and angiotensim II directly stimulate PTH secretion ex vivo. We investigated the changes of serum PTH levels induced by oral captopril (50 mg) administration in patients with primary essential hypertension (EH) and with primary aldosteronism (PA) caused by bilateral adrenal hyperplasia (BAH) or aldosterone-producing adenoma (APA), the latter before and after adrenalectomy. We also exposed primary cultures of human parathyroid cells from patients with primary hyperparathyroidism to angiotensin II (10-7 M) and/or aldosterone (10-7 M). Captopril lowered PTH levels (in nanograms per liter) both in patients with EH (n = 63; 25.9 ± 8.3 baseline vs 24.4 ± 8.0 postcaptopril, P < 0.0001) and in patients with APA after adrenalectomy (n = 27; 26.3 ± 11.6 vs 24.0 ± 9.7 P = 0.021). However, it was ineffective in patients with full-blown PA caused by APA and BAH. In primary culture of human parathyroid cells, both aldosterone (P < 0.001) and angiotensin II (P = 0.002) markedly increased PTH secretion from baseline, by acting through mineralocorticoid receptor and angiotensin type 1 receptor, as these effects were abolished by canrenone and irbesartan, respectively. These results collectively suggest an implication of the renin-angiotensin-aldosterone system in PTH regulation in humans, at least in PTH-secreting cells obtained from parathyroid tumors. Moreover, they further support the concept that mild hyperparathyroidism is a feature of human PA that is correctable with adrenalectomy.