Cushing's syndrome in type 2 diabetes patients with poor glycemic control

COEXISTENCE OF PHEOCHROMOCYTOMA AND HYPERCORTISOLEMIA. DIAGNOSTIC DIFFICULTIES

OBJECTIVE

Aim: Our study aimed to present diagnostic problems in the case of hypercortisolism, pheochromocytoma, hypertension, type 2 diabetes, and chronic kidney disease.

PATIENTS AND METHODS

Materials and Methods: Description of a patient with resistant hypertension admitted to the Department of Endocrinology for hormonal diagnostics. The results of hormonal tests and imaging tests before the procedure were analyzed, and the patient's condition was checked after the procedure. The analysis was extended with a literature review, considering the diagnostic problems in the described case. Electronic databases were the primary way to search, mainly MEDLINE and PubMed. We described a case of a 61-year-old woman diagnosed with right adrenal pheochromocytoma, hypercortisolemia, chronic kidney disease, drug-resistant hypertension, type 2 diabetes, and hypercholesterolemia. During hospitalization in the Department of Endocrinology, i.a., imaging tests and tests to assess adrenal function were performed. During the diagnostic process, a decision was made to perform surgical treatment of the pheochromocytoma, resulting in clinical improvement of the patient's condition.

CONCLUSION

Conclusions: The described case presents diagnostic problems endocrinologists face in the coexistence of several diseases. Often, the diagnosis to make a final diagnosis is complicated, hindered by the patient's multi-morbidity, as well as by the medications taken. There are few studies analyzing the coexistence of the diseases as described by us and their impact on the results of diagnostic tests that would facilitate the diagnosis.

Assessment of the diagnostic performance of the 1 mg dexamethasone suppression test in class 3 obese patients

Objective. This study was aimed to evaluate the prevalence of Cushing’s syndrome and the diagnostic performance of the 1 mg dexamethasone suppression test in class 3 obese patients.

Methods. Anthropometric measurements and other laboratory data, including 1 mg dexamethasone suppression test of 753 class 3 obese patients, who applied to the Endocrinology and Metabolism Outpatient Clinic for the pre-bariatric surgery evaluation between 2011 and 2020, were evaluated retrospectively.

Results. An abnormal response to the 1 mg dexamethasone suppression test (cortisol ≥1.8 mcg/dl) was observed in 24 patients and the presence of Cushing’s syndrome was confirmed by additional tests in 6 patients. The prevalence of abnormal dexamethasone suppression test was 3.18% and the prevalence of Cushing’s syndrome 0.79%. The specificity value was determined as 97.5% for 1 mg dexamethasone suppression test with cortisol threshold value ≥1.8 mcg/dl.

Conclusions. The prevalence of Cushing’s syndrome was found to be low in class 3 obese patients and 1 mg of dexamethasone suppression test had a very sufficient performance for Cushing’s syndrome screening in this patient group.

Assessment of 1 mg Dexamethasone Suppression Test in Patients with Obesity Before Bariatric Surgery

PURPOSE

This study aims to examine the prevalence of Cushing's syndrome (CS) in class 3 obese patients before bariatric surgery.

MATERIALS AND METHODS

The data of 1037 class 3 obese patients admitted to the endocrinology outpatient clinic for endocrinological evaluation before bariatric surgery between 2012 and 2019were reviewed retrospectively. One milligram dexamethasone suppression test (DST) was used for the evaluation of hypercortisolism in all cases and cutoff accepted as 1.8 μg/dL.

RESULTS

The mean body mass index (BMI) was 48 ± 8.9 kg/m² and age was 42 ± 10 years with female preponderance (F/M: 799/238] being observed in this cohort. Insufficient cortisol suppression was found in 40 patients; confirmed hypercortisolemia was detected in 8 patients. The prevalence of pathologic DST was 3.85% and 0.77% in confirmed hypercortisolism. The specificity for 1-mg DST with the cutoff 1.8 μg/dL was calculated as 96.8%.

CONCLUSION

Hypercortisolism prevalence was found to be low, and 1 mg DST is a sufficient test for the screening of CS in class 3 obese patients evaluated before bariatric surgery.

Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.

Six controversial issues on subclinical Cushing's syndrome

Subclinical Cushing's syndrome is a condition of hypercortisolism in the absence of signs specific of overt cortisol excess, and it is associated with an increased risk of diabetes, hypertension, fragility fractures, cardiovascular events and mortality. The subclinical Cushing's syndrome is not rare, being estimated to be between 0.2-2 % in the adult population. Despite the huge number of studies that have been published in the recent years, several issues remain controversial for the subclinical Cushing's syndrome screening, diagnosis and treatment. The Altogether to Beat Cushing's syndrome Group was founded in 2012 for bringing together the leading Italian experts in the hypercortisolism-related diseases. This document represents the Altogether to Beat Cushing's syndrome viewpoint regarding the following controversial issues on Subclinical Cushing's syndrome (SCS): (1) Who has to be screened for subclinical Cushing's syndrome? (2) How to screen the populations at risk? (3) How to diagnose subclinical Cushing's syndrome in patients with an adrenal incidentaloma? (4) Which consequence of subclinical Cushing's syndrome has to be searched for? (5) How to address the therapy of choice in AI patients with subclinical Cushing's syndrome? (6) How to follow-up adrenal incidentaloma patients with subclinical Cushing's syndrome surgically or conservatively treated? Notwithstanding the fact that most studies that faced these points may have several biases (e.g., retrospective design, small sample size, different criteria for the subclinical Cushing's syndrome diagnosis), we believe that the literature evidence is sufficient to affirm that the subclinical Cushing's syndrome condition is not harmless and that the currently available diagnostic tools are reliable for identifying the majority of individuals with subclinical Cushing's syndrome.

Diabetes in Cushing Disease

PURPOSE OF REVIEW

This review focuses on the pathophysiological and clinical aspects of diabetes mellitus occurring in patients with Cushing disease (CD).

RECENT FINDINGS

Insulin resistance and impairment in insulin secretion are both involved in the pathogenesis of glucocorticoid-induced diabetes. Correction of glucocorticoid excess does not always resolve abnormalities of glucose homeostasis, and correction of hyperglycaemia is specifically required. In fact, insulin resistance may persist even after correction of glucocorticoid excess and diabetes needs to be treated for long term. On the other hand, emerging drugs used in the treatment of CD, such as the novel somatostatin analog pasireotide, may have direct effects on glucose homeostasis regardless of control of cortisol excess. Diabetes mellitus is a frequent and early complication of CD with important diagnostic, prognostic and therapeutic implications. Specifically, diagnosis of CD in patients with diabetes may be difficult due to potential misinterpretation of markers of cortisol hypersecretion. Moreover, diabetes mellitus is often difficult to be controlled in CD requiring a careful and dedicated therapeutic approach. Finally, the coexistence of diabetes may influence the therapeutic decision making in CD, since drugs used in this setting may variably influence glucose homeostasis regardless of control of hypercortisolism.

The degree of urinary hypercortisolism is not correlated with the severity of cushing's syndrome

Cushing syndrome (CS) is characterized by increased morbidity and mortality compared to the general population. However, there are patients who have more clinical aggressive forms than others. Aim of the study is to evaluate whether the degree of hypercortisolism, defined by the number of times urinary free cortisol (UFC) levels exceed the upper limit of the normal range (ULN), is related to the worsening of phenotypic features, as well as metabolic and cardiovascular parameters, in a cohort of CS patients. A cross-sectional study was conducted on 192 patients with active CS, consecutively presenting at the outpatients' clinic of the University Hospitals of Ancona, Naples, and Palermo. Patients were grouped into mild (UFC not exceeding twice the ULN), moderate (2-5 times the ULN), and severe (more than 5 times the ULN) hypercortisolism. Thirty-seven patients (19.3 %) had mild, 115 (59.8 %) moderate, and 40 (20.9 %) severe hypercortisolism. A significant trend of increase among the three groups was demonstrated for 8-, 16-, and 24-h serum cortisol levels (p < 0.001) and serum cortisol after low dose of dexamethasone suppression test (p = 0.001). No significant trend of increase was found regarding phenotype and comorbidities. The degree of hypercortisolism by itself does not appear to be a sufficient parameter to express the severity of CS. Therefore, estimating the severity of CS according to biochemical parameters remains a challenge, while the clinical phenotype and the associated comorbidities might be more useful to assessing the severity of the CS.

Serum but not salivary cortisol levels are influenced by daily glycemic oscillations in type 2 diabetes

Diurnal salivary and plasma cortisol variations are considered valid expression of circadian cortisol rhythmicity. The aim of this study was to assess the reliability of salivary and plasma cortisol and if glycemia and glycemic oscillations may interfere with their concentration. Forty-seven type 2 diabetic patients and 31 controls were studied for glycemic profile and diurnal salivary and plasma cortisol variations on two contemporary samples taken at 08:00 a.m.-11:00 p.m (Late Night, LN). Glucose variability was evaluated in diabetic patients by considering the standard deviation of blood glucose (BGSD) readings, by calculating the mean amplitude of glycemic excursions (MAGEs) and continuous overlapping net glycemic action (CONGA). A significant correlation between LN serum cortisol and morning fasting glycemia (r = 0.78; p = 0.004) was observed in T2DM group but not in the control group (r = 0.09; p = 0.74). While LN serum cortisol significantly correlated with CONGA in diabetic patients (r = 0.50; p < 0.001), LN salivary cortisol did not correlate with any indices of glucose variability. Moreover, a highly significant correlation between LN salivary and LN serum cortisol concentrations was found in control group (r = 0.80; p < 0.001) but not in diabetic patients (r = 0.07; p = 0.62). This study shows for the first time that LN salivary rather than plasma cortisol may give information on the dynamics of adrenal function of type 2 diabetic patients, as it is not significantly influenced by glycemic variations. However, our preliminary results need to be confirmed by further studies with more complete evaluations including many more patients.

Lack of significant association between type 2 diabetes mellitus with longitudinal change in diurnal salivary cortisol: the multiethnic study of atherosclerosis

Cross-sectional association has been shown between type 2 diabetes and hypothalamic-pituitary-adrenal (HPA) axis dysregulation; however, the temporality of this association is unknown. Our aim was to determine if type 2 diabetes is associated with longitudinal change in daily cortisol curve features. We hypothesized that the presence of type 2 diabetes may lead to a more blunted and abnormal HPA axis profile over time, suggestive of increased HPA axis dysregulation. This was a longitudinal cohort study, including 580 community-dwelling individuals (mean age 63.7 ± 9.1 years; 52.8 % women) with (n = 90) and without (n = 490) type 2 diabetes who attended two MultiEthnic Study of Atherosclerosis Stress ancillary study exams separated by 6 years. Outcome measures that were collected were wake-up and bedtime cortisol, cortisol awakening response (CAR), total area under the curve (AUC), and early, late, and overall decline slopes. In univariate analyses, wake-up and AUC increased over 6 years more in persons with as compared to those without type 2 diabetes (11 vs. 7 % increase for wake-up and 17 vs. 11 % for AUC). The early decline slope became flatter over time with a greater flattening observed in diabetic compared to non-diabetic individuals (23 vs. 9 % flatter); however, the change was only statistically significant for wake-up cortisol (p-value: 0.03). Over time, while CAR was reduced more, late decline and overall decline became flatter, and bedtime cortisol increased less in those with as compared to those without type 2 diabetes, none of these changes were statistically significant in adjusted models. We did not identify any statistically significant change in cortisol curve features over 6 years by type 2 diabetes status.

Cushing’s disease: the clinical features, diagnostics, differential diagnostics, and methods of treatment

The present guidelines on diagnostics, differential diagnostics, and methods of treatment of Cushing’s disease have been developed by a group of Russian specialists.