The acute effects of hydrocortisone on cardiac electrocardiography, action potentials, intracellular calcium, and contraction: The role of protein kinase C

Tumor enlargement in adrenal incidentaloma is related to glaucoma: a new prognostic feature?

PURPOSE

The uncertainty on the management of small adrenal incidentalomas (AIs) still represents a challenge in real clinical practice. Considering the lack of knowledge on risk factors implicated in tumour enlargement, the aim of this study was to identify risk factors for morphological changes during follow-up of adrenal incidentalomas (AIs).

METHODS

We retrospectively evaluated demographic, clinical, radiological and biochemical parameters of 153 AIs (2007-2021). Patients with histological diagnosis of metastases or pheochromocytoma were excluded. To detect risk factors for tumor enlargement, diseases associated with AIs were included if their prevalence was higher than 2%. Patients were divided into two groups (A: radiological stability; B: tumor enlargement defined as > 5 mm/year in the main diameter).

RESULTS

Group A: 89.5% and group B: 10.5%, mean follow-up 38.6 ± 6.9 months (range 6-240). Tumor enlargement when occurred was within 36 months of follow-up. In group B high body weight (p < 0.03), dehydroepiandrosterone sulfate (DHEAS) (p < 0.05) and direct renin concentration (DRC) (p < 0.04) were higher than group A, while aldosterone levels were lower; moreover, considering comorbidities, glaucoma and dysglycemia (p < 0.01 for both) had higher prevalence in group B. Glaucoma and dysglycemia were independent predictors of enlargement. Patients affected by glaucoma, atrial fibrillation, dysglycemia had a lower dimensional change-free survival than non-affected.

CONCLUSIONS

Glaucoma might be a novel risk factor for AI enlargement. If subtle undetectable cortisol hypersecretion has a role is a topic for further research.

Analysis of the effect of cortisone on the QT interval

BACKGROUND

Cardiac death caused by malignant arrhythmias is very prevalent. Prolongation of the QT interval is a relevant aspect in arrhythmia mechanisms. Prior studies have revealed that the QTc interval could be shortened by cortisone. Moreover, in an animal model of long QT syndrome, cortisone treatment shortens the ventricular action potential duration. The present study investigated the effect of methylprednisolone (MPS) on the QTc interval in cardiovascularly healthy humans.

METHODS

Patients who had just been diagnosed with multiple sclerosis receiving MPS therapy were analysed prospectively. Demographic data, laboratory values, anti-arrhythmic medication and baseline and follow-up ECGs were extracted from the patients' medical records.

RESULTS

Seventy-eight patients were included. The mean ± standard deviation age was 47 ± 15 years. The values of the electrolytes were normal. All patients were treated with MPS for 3 or 5 days. The heart rate increased at the beginning of MPS therapy and decreased during the subsequent period. ECG measurements showed that the QTc interval was prolonged at the beginning of MPS therapy and shortened over the course of treatment. The longest QTc intervals were obtained by calculation with Bazett's formula.

CONCLUSIONS

In humans, cortisone shortens the QTc interval over time. The analysis indicates a cumulative effect of cortisone that lasts longer. The results of our pilot study reveal that cortisone might be added to therapeutic strategies in patients with long QT syndromes. Further clinical studies have to be carried out to analyze potential clinical options.

New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation

Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.

Activation of PKCα participates in the reduction of Ikur in atrial myocytes induced by tumour necrosis factor-α

The atrial-specific ultra-rapid delayed rectifier K⁺ current (Ikur) plays an important role in the progression of atrial fibrillation (AF). Because inflammation is known to lead to the onset of AF, we aimed to investigate whether tumour necrosis factor-α (TNF-α) played a role in regulating Ikur and the potential signalling pathways involved. Whole-cell patch-clamp and biochemical assays were used to study the regulation and expression of Ikur in myocytes and in tissues from left atrial appendages (LAAs) obtained from patients with sinus rhythm (SR) or AF, as well as in rat cardiomyocytes (H9c2 cells) and mouse atrial myocytes (HL-1 cells). Ikur current density was markedly reduced in atrial myocytes from AF patients compared with SR controls. Reduction of Kv1.5 protein levels was accompanied by increased expression of TNF-α and protein kinase C (PKC)α activation in AF patients. Treatment with TNF-α dose-dependently reduced Ikur and protein expression of Kv1.5 but not Kv3.1b in H9c2 cells and HL-1 cells. TNF-α also increased activity of PKCα. Specific PKCα inhibitor Gö6976 alleviated the reduction in Ikur induced by TNF-α, but not the reduction in Kv1.5 protein. TNF-α was involved in the electrical remodelling associated with AF, probably by depressing Ikur in atrial myocytes via activation of PKCα.

Prevalence and Incidence of Atrial Fibrillation in a Large Cohort of Adrenal Incidentalomas: A Long-Term Study

CONTEXT

Chronic glucocorticoids excess leads to morphological and functional cardiac alterations, a substrate for arrhythmias. Autonomous cortisol secretion (ACS) in adrenal incidentalomas is a model of chronic endogenous hypercortisolism.

OBJECTIVE

To investigate prevalence and incidence of atrial fibrillation (AF) in a large cohort of patients with ACS.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

Patients evaluated between 1990 and 2018 for adrenal incidentalomas (n = 632), without pheochromocytoma, primary aldosteronism, Cushing syndrome, congenital adrenal hyperplasia, and adrenal malignancy. Cortisol after 1-mg dexamethasone suppression test < or > 50 nmol/L defined nonsecreting tumors (NST) (n = 420) and ACS (n = 212), respectively.

INTERVENTION

Assessment of AF at baseline (n = 632) and during a median follow-up of 7.7 years retrospectively (NST, n = 249; ACS, n = 108). Comparison with general population.

MAIN OUTCOME MEASURE

Prevalence and incidence of AF.

RESULTS

AF prevalence was higher in patients with ACS (8.5%) than NST (3.1%, P = 0.003) and the general population (1.7%; P < 0.001 vs ACS, P = 0.034 vs NST). The age-adjusted rate ratio to the general population was 1.0 for NST and 2.6 for ACS. AF was associated with ACS (odds ratio, 2.40; 95% confidence interval [CI], 1.07-5.39; P = 0.035). The proportion of patients with AF at last evaluation was higher in ACS (20.0%) than NST (11.9%; P = 0.026). ACS showed a higher risk of incident AF than NST (hazard ratio, 2.95; 95% CI, 1.27-6.86; P = 0.012), which was associated with post-dexamethasone cortisol (hazard ratio, 1.15; 95% CI, 1.07-1.24; P < 0.001), independently of known contributing factors.

CONCLUSIONS

Patients with adrenal incidentalomas and ACS are at risk of AF. Electrocardiogram monitoring may be recommended during follow-up.

Neutrophil: lymphocyte ratio is positively associated with subclinical diabetic cardiomyopathy

BACKGROUND

Subclinical diabetic cardiomyopathy (DCM) occurs frequently in asymptomatic subjects with Type 2 diabetes mellitus (T2DM). The direct association between the immune system and DCM with effective biomarkers has been demonstrated in previous studies.

METHODS

Five hundred seven subjects with T2DM were recruited from April 2018 to October 2019 and divided into T2DM with cardiac dysfunction (DCM) group and T2DM without cardiac dysfunction (non-DCM) group. The relationship between the quartiles of Neutrophil: lymphocyte ratio (NLR) and subclinical DCM was evaluated by using adjusted logistic regression models.(covariates: age, sex, BMI, duration of diabetes, and hyperlipidemia).

RESULTS

Blood NLR was significantly upregulated in DCM group compared to non-DCM group (P = 0.05). Then the adjusted odds ratio (95% CI) of the highest NLR quartile was 14.32 (2.92-70.31) compared with the lowest quartile of NLR after multiple adjusted (P < 0.001). However, there was no significant relation between neutrophil and lymphocyte counts and the occurrence of DCM in T2DM patients.

CONCLUSIONS

This study demonstrated that NLR was associated with the occurrence of subclinical DCM, suggesting that NLR may be a biomarker for predicting DCM with effectiveness and accuracy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR1900027080) . Registered 30 October 2019. Retrospectively registered: www.medresman.org.