Zuzana Krátká

BACKGROUND: Current guidelines and consensus documents recommend withdrawal of mineralocorticoid receptor antagonists (MRAs) before primary aldosteronism (PA) subtyping by adrenal vein sampling (AVS), but this practice can cause severe hypokalemia and uncontrolled high blood pressure. Our aim was to investigate if unilateral PA can be identified by AVS during MRA treatment. METHODS: We compared the rate of unilateral PA identification between patients with and without MRA treatment in large data sets of patients submitted to AVS while off renin-angiotensin system blockers and β-blockers. In sensitivity analyses, the between-group differences of lateralization index values after propensity score matching and the rate of unilateral PA identification in subgroups with undetectable (≤2 mUI/L), suppressed (P =0.001) and showed a higher rate of adrenal nodules (82% versus 67%; P =0.022) and adrenalectomy (72% versus 54%; P =0.01). However, they exhibited no significant differences in commonly used AVS indices and the area under the receiving operating characteristic curve of lateralization index, both under unstimulated conditions and postcosyntropin. Several sensitivity analyses confirmed these results in propensity score matching adjusted models and in patients with undetectable, or suppressed or unsuppressed renin levels. CONCLUSIONS: At doses that controlled blood pressure and potassium levels, MRAs did not preclude the identification of unilateral PA at AVS. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01234220.

BACKGROUND: Adrenaline-producing tumors are mostly characterized by a sudden release of catecholamines with episodic symptoms. Noradrenergic ones are usually less symptomatic and characterized by a continuous overproduction of catecholamines that are released into the bloodstream. Their effects on the cardiovascular system can thus be different. The aim of this study was to determine the prevalence of cardiovascular complications by catecholamine phenotype. METHODS: We retrospectively analyzed data on the prevalence of cardiovascular events in 341 consecutive patients with pheochromocytoma and paraganglioma treated from 1995 to 2023. Biochemical catecholamine phenotype was determined based on plasma or urinary catecholamines and metanephrines. RESULTS: According to the phenotype, 153 patients had noradrenergic pheochromocytoma and paraganglioma and 188 had adrenergic pheochromocytoma and paraganglioma. In the whole sample, the incidence of serious cardiovascular complications was 28% (95 patients), with no difference between the phenotypes or sexes. The noradrenergic phenotype had significantly more atherosclerotic complications (composite end point of type 1 myocardial infarction and symptomatic peripheral artery disease; odds ratio, 3.58 [95% CI, 1.59–8.83]; P =0.003), while the adrenergic phenotype more often had type 2 myocardial infarction and takotsubo-like cardiomyopathy (OR, 0.24 [95% CI, 0.09–0.57]; P =0.002). These changes remained even after adjustment for conventional risk factors of atherosclerosis. CONCLUSIONS: We found a 28% incidence of cardiovascular complications in a consecutive group of patients with pheochromocytoma and paraganglioma. Patients presenting with a noradrenergic phenotype have a higher incidence of atherosclerotic complications, while the adrenergic phenotype is associated with a higher incidence of acute myocardial damage due to takotsubo-like cardiomyopathy.

BACKGROUND: Adrenal venous sampling is recommended for the identification of unilateral surgically curable primary aldosteronism but is often clinically useless, owing to failed bilateral adrenal vein cannulation. OBJECTIVES: To investigate if only unilaterally selective adrenal vein sampling studies can allow the identification of the responsible adrenal. METHODS: Among 1625 patients consecutively submitted to adrenal vein sampling in tertiary referral centers, we selected those with selective adrenal vein sampling results in at least one side; we used surgically cured unilateral primary aldosteronism as gold reference. The accuracy of different values of the relative aldosterone secretion index (RASI), which estimates the amount of aldosterone produced in each adrenal gland corrected for catheterization selectivity, was examined. RESULTS: We found prominent differences in RASI values distribution between patients with and without unilateral primary aldosteronism. The diagnostic accuracy of RASI values estimated by the area under receiver operating characteristic curves was 0.714 and 0.855, respectively, in the responsible and the contralateral side; RASI values >2.55 and ≤0.96 on the former and the latter side furnished the highest accuracy for detection of surgically cured unilateral primary aldosteronism. Moreover, in the patients without unilateral primary aldosteronism, only 20% and 16% had RASI values ≤0.96 and >2.55. CONCLUSIONS: With the strength of a large real-life data set and use of the gold reference entailing an unambiguous diagnosis of unilateral primary aldosteronism, these results indicate the feasibility of identifying unilateral primary aldosteronism using unilaterally selective adrenal vein sampling results. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01234220.

The new clinical prediction score (SCORE) has been recently proposed for primary aldosteronism (PA) subtyping prior to adrenal vein sampling (AVS). This study aimed to compare that SCORE with previously published scores and their validation using a cohort of patients at our center who had had positive SIT confirming PA and had been diagnosed with either bilateral PA according to AVS or unilateral PA if biochemically cured after an adrenalectomy. Final diagnoses were used to evaluate the diagnostic performance of the proposed clinical prediction tools. Only Kamemura’s model (with a maximum score of 4 points) and Kobayashi’s score (with a maximum score of 12 points) reached 100% reliability for prediction of bilateral PA; however, with sensitivity of only 3%. On the other hand, the values of SCORE = 3 (with sensitivity of 48%), the SPACE score ≥18 (with sensitivity of 35%), the Kobayashi’s score ≤2 (with sensitivity of 28%), and the Kocjan’s score = 3 (with sensitivity of 28%) were able to predict unilateral PA with 100% probability. Furthermore, Umakoshi’s and Young’s models both reached 100% reliability for a unilateral PA with score = 4 and both predictive factors together respectively; however, the sensitivity was lower compared with previous models; 4% and 14%, respectively. None of the clinical prediction tools applied to our cohort predicted unilateral and bilateral subtypes together with the expected high diagnostic performance, and therefore can only be used for precisely defined cases.

The overproduction of catecholamines in pheochromocytoma/paraganglioma (PPGL) induces a hypermetabolic state. The aim of this study was to evaluate the incidence of a hypermetabolic state and differences in substrate metabolism in consecutive PPGL patients divided by catecholamine phenotype. Resting energy expenditure (REE) and respiratory quotient (RQ) were measured in 108 consecutive PPGL patients and 70 controls by indirect calorimetry. Hypermetabolic state was defined according to the Mifflin St. Jeor Equation as a ratio above 110%. Hypermetabolic state was confirmed in 70% of PPGL patients, regardless of phenotype. Older age, prevalence of diabetes mellitus and arterial hypertension were correlated with hypermetabolic PPGL as compared to normometabolic form. Analysis according to overproduced catecholamine showed differences in VCO₂ (p < 0.05) and RQ (p < 0.01) and thus different substate metabolism between phenotypes in hypermetabolic form of PPGL. Lipid utilization was higher in the adrenergic phenotype (p = 0.001) and positively associated with the percentage of REE ratio (R = 0.48, p < 0.001), whereas the noradrenergic phenotype preferentially oxidizes carbohydrates (P = 0.001) and is correlated with the percentage of REE ratio (R = 0.60, p < 0.001). Hypermetabolic state in PPGL is a common finding in both catecholamine phenotypes. Hypermetabolic PPGL patients are older and suffer more from diabetes mellitus and arterial hypertension. Under basal conditions, the noradrenergic type preferentially metabolizes carbohydrates, whereas the adrenergic phenotype preferentially metabolizes lipids.

Purpose: Adrenal venous sampling (AVS) performed to distinguish unilateral and bilateral primary aldosteronism (PA) is invasive and poorly standardized. This study aimed to identify non-invasive characteristics that can select the patients with unilateral PA who could bypass AVS before surgery. Methods: A single-center study collected a total of 450 patients with PA. Development and validation cohorts included 242 and 208 patients. The AVS was successful in 150 and 138 patients from the cohorts, and the unilateral PA was found in 96 and 94 patients, respectively. Clinical factors independently associated with lateralized AVS in multivariable logistic regression were used to construct a unilateral PA prediction score (SCORE). Results: The proposed SCORE was calculated as a sum of the prevalence of adrenal nodule on computed tomography (2 points) and plasma/serum aldosterone concentration ≥ 165 ng/L after the saline infusion test (SIT) (1 point). Importantly, the SCORE = 3 points identified 48% of unilateral PA patients with a specificity of 100% in the development cohort. The zero rate of false-positive classifications was preserved with the same cut-off value in the validation cohort. Conclusions: AVS could be omitted before surgery in patients with typical Conn´s adenoma provided the aldosterone concentration ≥ 165 ng/L after the SIT.

Background: Brown adipose tissue (BAT) is a therapeutic target to combat obesity and related disorders. Pheochromocytoma and functional paraganglioma (PPGL) are associated with activated BAT due to catecholamine excess. Our aim was to evaluate BAT activity by gene profile and assess its relation to clinical characteristics and overproduced catecholamine. Methods: mRNA expression of 15 genes in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) was measured via RT-PCR in 25 patients with PPGL and 14 controls undergoing cholecystectomy. Results: We found in VAT of PPGL higher expression of UCP1 (p < 0.001), CEBPB, PPARGC1A (both p < 0.001), PRDM16 (p = 0.069) and DIO2 (p = 0.005). UCP1 expression correlated only with norepinephrine levels and its metabolite. UCP1 expression, among others, correlated negatively with BMI, age and positively with HDLc levels. Dominance of BAT or BeAT markers was not assessed in PPGL. In SAT of PPGL, we found higher expression of ADRB3, CIDEA (both p < 0.05), and PPARGC1A (p = 0.001), but not UCP1. Conclusion: We demonstrate signs of UCP1-dependent norepinephrine-induced thermogenesis connected with higher expression of DIO2, PPARGC1A, CEBPB and PRDM16 in retroperitoneal VAT of PPGL and its relations to circulating HDLc and triglycerides levels. However, no direct relationship with increased basal energy metabolism measured by calorimetry was found.

Many of the patients with primary aldosteronism (PA) are denied curative adrenalectomy because of limited availability or failure of adrenal vein sampling. It has been suggested that adrenal vein sampling can be omitted in young patients with a unilateral adrenal nodule, who show a florid biochemical PA phenotype. As this suggestion was based on a very low quality of evidence, we tested the applicability and accuracy of imaging, performed by computed tomography and/or magnetic resonance, for identification of unilateral PA, as determined by biochemical and/or clinical cure after unilateral adrenalectomy. Among 1625 patients with PA submitted to adrenal vein sampling in a multicenter multiethnic international study, 473 were ≤45 years of age; 231 of them had exhaustive imaging and follow-up data. Fifty-three percentage had a unilateral adrenal nodule, 43% had no nodules, and 4% bilateral nodules. Fifty-six percentage (n=131) received adrenalectomy and 128 were unambiguously diagnosed as unilateral PA. A unilateral adrenal nodule on imaging and hypokalemia were the strongest predictors of unilateral PA at regression analysis. Accordingly, imaging allowed correct identification of the responsible adrenal in 95% of the adrenalectomized patients with a unilateral nodule. The rate raised to 100% in the patients with hypokalemia, who comprised 29% of the total, but fell to 88% in those without hypokalemia. Therefore, a unilateral nodule and hypokalemia could be used to identify unilateral PA in patients ≤45 years of age if adrenal vein sampling is not easily available. However, adrenal vein sampling remains indispensable in 71% of the young patients, who showed no nodules/bilateral nodules at imaging and/or no hypokalemia. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01234220.

Context: Impaired diurnal blood pressure (BP) variability is related to higher cardiovascular risk. Objective: To assess diurnal variability of BP and its relation to target organ damage (TOD) and catecholamine phenotype in a consecutive sample of pheochromocytoma/paraganglioma (PPGL). Design: We included 179 patients with PPGL All patients underwent 24 hours of ambulatory BP monitoring to determine dipping status. Differences in plasma metanephrine or urine adrenaline were used to distinguish catecholamine biochemical phenotype. To evaluate TOD, renal functions, presence of left ventricle hypertrophy (LVH), and the subgroup (n = 111) carotid-femoral pulse wave velocity (PWV) were assessed. Structural equation modeling was used to find the relationship among nocturnal dipping, catecholamine phenotype, and TOD parameters. Results: According to the nocturnal dipping, patients were divided into the three groups: dippers (28%), nondippers (40%), and reverse dippers (32%). Reverse dippers were older (P < 0.05), with a higher proportion of noradrenergic (NA) phenotype (P < 0.05), a higher prevalence of diabetes mellitus (P < 0.05), and sustained arterial hypertension (P < 0.01) and its duration (P < 0.05), as opposed to the other groups. All parameters of TOD were more pronounced only in reverse dippers compared with nondippers and dippers. The presence of NA phenotype (=absence of adrenaline production) was associated with reverse dipping and TOD (LVH and PWV). Conclusions: Patients with reverse dipping had more substantial TOD compared with other groups. The NA phenotype plays an important role, not only in impaired diurnal BP variability but also independently from dipping status in more pronounced TOD of heart and vessels.

Fibroblast growth factor 21 (FGF21) is a hepatokine with beneficial effects on metabolism. Our aim was to evaluate the relationship between the serum FGF21, and energy and glucose metabolism in 40 patients with pheochromocytoma/functional paraganglioma (PPGL), in comparison with 21 obese patients and 26 lean healthy controls. 27 patients with PPGL were examined one year after tumor removal. Basic anthropometric and biochemical measurements were done. Energy metabolism was measured by indirect calorimetry (Vmax-Encore 29N). FGF21 was measured by ELISA. FGF21 was higher in PPGL than in controls (174.2 (283) pg/mL vs. 107.9 (116) pg/mL; p < 0.001) and comparable with obese (174.2 (283) pg/mL vs. 160.4 (180); p = NS). After tumor removal, FGF21 decreased (176.4 (284) pg/mL vs. 131.3 (225) pg/mL; p < 0.001). Higher levels of FGF21 were expressed, particularly in patients with diabetes. FGF21 positively correlated in PPGL with age (p = 0.005), BMI (p = 0.028), glycemia (p = 0.002), and glycated hemoglobin (p = 0.014). In conclusion, long-term catecholamine overproduction in PPGL leads to the elevation in serum FGF21, especially in patients with secondary diabetes. FGF21 levels were comparable between obese and PPGL patients, despite different anthropometric indices. We did not find a relationship between FGF21 and hypermetabolism in PPGL. Tumor removal led to the normalization of FGF21 and the other metabolic abnormalities.