Is it worthwhile to screen patients with type 2 diabetes mellitus for subclinical Cushing's syndrome?

Who and how to screen for endogenous hypercortisolism in type 2 diabetes mellitus or obesity

PURPOSE

The current review aims to summarize and discuss the prevalence of confirmed hypercortisolism in patients with diabetes mellitus or obesity, analysing the screening tests used and their accuracy, in order to better identify whether patients with diabetes mellitus and obesity should be screened for Cushing's syndrome (CS) and how.

METHODS

A narrative review was performed including publications focusing on the current knowledge on prevalence of confirmed hypercortisolism in patients with type 2 diabetes mellitus (T2DM) or obesity and on screening tests used to detect CS.

RESULTS

The studies reviewed suggest that the prevalence of CS in patients with T2DM is variable, ranging from 0.6 to 9.3%. The most used screening test is the overnight cortisol after 1 mg of dexamethasone suppression test (DST), with a false positive rate ranging from 3.7 to 21%. The prevalence of CS among obese patients is generally about 1%, except for two studies which reported higher prevalence. For obese patients, 1 mg DST and late-night salivary cortisol are the most accurate screening tests for CS.

CONCLUSIONS

Clinical expertise remains the mainstay to identify which subjects should be screened for CS. The evaluation of the clinical stigmata of CS and the combination with clinical comorbidities typical of CS are the stronger predictors of CS. In addition, we could hypothesize that in patients with T2DM, overnight 1 mg DST is the more accurate screening test for CS. By contrast, in patients with obesity both LNSC and overnight 1 mg DST could be equally used for the screening of hypercortisolism.

Diagnostic dilemma in Cushing's syndrome: discrepancy between patient-reported and physician-assessed manifestations

PURPOSE

Early diagnosis and immediate treatment of Cushing's syndrome (CS) are critical for a better prognosis but remain a challenge. However, few comprehensive reports have focused on this issue or investigated whether patient-reported manifestations are consistent with physician-assessed symptoms of CS. This study aimed to clarify the differences in patient-reported and physician-assessed manifestations of signs and symptoms of CS that prevent early diagnosis.

METHODS

This single-center retrospective study included 52 patients with CS (16 with Cushing's disease and 36 with adrenal CS). Upon clinical diagnosis, medical records were used to independently review the patient-reported and physician-assessed manifestations of typical (such as purple striae and proximal myopathy) and nonspecific features (such as hirsutism and hypertension). The correlations and differences between the patient-reported and physician-assessed manifestations were then analyzed.

RESULTS

We observed a positive correlation between the total number of manifestations of nonspecific features reported by patients and those assessed by physicians, but not for typical features. Moreover, manifestations reported by the patients were less frequent than those assessed by physicians for typical features, leading to discrepancies between the two groups. In contrast, there were no differences in most nonspecific features between the patient-reported and physician-assessed manifestations. Notably, the concordance between patient-reported and physician-assessed manifestations of typical features was not associated with urinary free cortisol levels.

CONCLUSION

Regardless of disease severity, patients often do not complain of the typical features of CS that are crucial for formulating a diagnosis.

Comorbidities in Mild Autonomous Cortisol Secretion - A Clinical Review of Literature

Mild autonomous cortisol secretion (mACS) is a state of cortisol excess usually associated with existence of adrenal incidentaloma. Because of the lack of symptoms of the disease, the biochemical evaluation is the most important to determine a diagnosis. However, scientific societies have different diagnostic criteria for mACS, which makes the treatment of this disease and using results of original papers in daily practice more difficult. Chronic hypercortisolemic state, even if mild, may lead to diseases that are mostly connected with overt Cushing's syndrome. Some of them can cause a higher mortality of patients with mACS and those problems need to be addressed. In this review we describe the comorbidities associated with mACS: cardiovascular disorders, arterial hypertension, diabetes mellitus, insulin resistance, dyslipidemia, obesity, metabolic syndrome, non-alcoholic fatty liver disease, vertebral fractures and osteoporosis. The point of this paper is to characterise them and determine if and how these conditions should be managed. Two databases - PubMed and Web of Science were searched. Even though the evidence are scarce, this is an attempt to lead clinicians through the problems associated with this enigmatic condition.

Hidden hypercortisolism: a too frequently neglected clinical condition

PURPOSE

Classic Cushing's syndrome (CS) is a severe disease characterized by central obesity, hypertension, easy bruising, striae rubrae, buffalo hump, proximal myopathy and hypertricosis. However, several CS cases have also been reported with unusual or camouflaged manifestations. In recent years, several authors investigated the prevalence of "hidden hypercortisolism" (HidHyCo) among subjects affected with bone fragility, hypertension and type 2 diabetes mellitus (DM2). The prevalence of the HidHyCo is estimated to be much higher than that of classic CS. However, similarly to classic CS, HidHyCo is known to increase the risk of fractures, cardiovascular disease and mortality.

METHODS

We reviewed all published cases of unusual presentations of hypercortisolism and studies specifically assessing the HidHyCo prevalence in diabetic, osteoporotic and hypertensive patients.

RESULTS

We found 49 HidHyCo cases, in whom bone fragility, hypertension and diabetes were the presenting manifestations of an otherwise silent hypercortisolism. Amongst these cases, 34.7%, 32.7%, 6.1% and 19.0%, respectively, had bone fragility, hypertension, DM2 or hypertension plus DM2 as the sole clinical manifestations of HidHyCo. Overall, 25% of HidHyCo cases were of pituitary origin, and bone fragility was the very prevalent first manifestation among them. In population studies, it is possible to estimate that 1-4% of patients with apparent primary osteoporosis has a HidHyCo and the prevalence of this condition among diabetics ranges between 3.4 and 10%.

CONCLUSION

These data indicate that patients with resistant or suddenly worsening hypertension or DM2 or unexplainable bone fragility should be screened for HidHyCo using the most recently approved sensitive cut-offs.

When to suspect hidden hypercortisolism in type 2 diabetes: a meta-analysis

OBJECTIVE

Among patients with type 2 diabetes (T2D), the prevalence of hidden hypercortisolism (HidHyCo, formally called subclinical hypercortisolism or mild autonomous cortisol secretion) was estimated to be 2.2-12.1%. The aim of this study was to investigate whether the available literature helps to identify the characteristics of T2D patients more frequently associated with HidHyCo.

METHODS

A meta-analysis was performed using studies that assessed both the prevalence of HidHyCo in patients with T2D and the characteristics of these patients with and without HidHyCo. The DerSimonian and Laird (DSL) and the Hartung, Knapp, Sidik and Jonkman (HKSJ) methods were utilized.

RESULTS

Among the 18 available studies, 6 studies provided the necessary data. The association between HidHyCo and advanced T2D (based on the patients' description given in each study in presence of micro/ microvascular complications, or insulin treatment plus hypertension, or hypertension treated with ≥2 drugs), hypertension, insulin treatment and dyslipidemia was reported in 5 (2184 patients), 6 (2283 patients), 3 (1440 patients), and 3 (987 patients) studies, respectively. HidHyCo was associated with advanced T2D as assessed with both DSL (odds ratio, OR, 3.47, 95% Confidence Interval, 95%CI, 2.12-5.67) and HKSJ method (OR 3.60, 95%CI 2.03-6.41) and with the prevalence of hypertension or of insulin treatment as assessed by the DSL approach (OR 1.92, 95%CI 1.05-3.50 and OR 2.29, 95%CI 1.07-4.91, respectively), but not as assessed with HKSJ method.

CONCLUSIONS

Patients with advanced T2D have a higher prevalence of HidHyCo. These data inform about the selection of T2D patients for HidHyCo screening.

Hypercortisolism and altered glucose homeostasis in obese patients in the pre-bariatric surgery assessment

AIMS

Hypothalamus-pituitary-adrenal (HPA) axis hyperactivity was suggested to be associated with the metabolic syndrome (MS), obesity and diabetes. The aim of this study was to test whether hypercortisolism was associated with altered glucose homeostasis and insulin resistance, hypertension and dyslipidemia in a homogeneous population of obese patients.

MATERIALS/METHODS

In retrospective analysis of a set of data about obese patients attending the outpatient service of a single obesity centre between January 2013 and January 2020, 884 patients with BMI >30 kg/m² were segregated in two subgroups: patients with urinary free cortisol (UFC) higher than normal (UFC+; n = 129) or within the normal range (UFC-; n = 755).

RESULTS

The overall prevalence of UFC+ was 14.6% and double test positivity (morning cortisol >1.8 mcg/dL following overnight dexamethasone suppression test, ODST) was detected in 1.0% of patients. Prediabetes (OR 1.74; 95%CI 1.13-2.69; p = 0.012) and diabetes (OR 2.03; 95%CI 1.21-3.42; p = 0.008) were associated with higher risk of UFC+ when analysis was adjusted for confounding variables. Conversely, hypertension and dyslipidemia were not related to UFC+. Within the individuals with normal FPG and HbA1c, those with higher estimated insulin resistance (HOMA2-IR) maintained a higher risk of UFC+ (OR 2.84, 95%CI 1.06-7.63; p = 0.039) and this relationship was weakened only when the body fat percentage was included into the model.

CONCLUSIONS

In obese patients, hypercortisolism was more frequent across the entire spectrum of altered glucose homeostasis including the very early stages; this relation could not be detected for the other criteria of the MS, as waist, hypertension and atherogenic dyslipidemia.

Primary pigmented nodular adrenocortical disease (PPNAD): single centre experience

Background Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of Cushing's syndrome (CS) in childhood. We describe a case series of patients presenting at our centre along with a review of the literature. Methods A retrospective analysis of six index cases and one family were done for demographic features, hormonal profile, imaging findings, genetic mutation status, histopathologic findings and follow-up details. Diagnosis was based on biochemistry and confirmed with histopathology and or genetic mutation. All patients had suppressed 8 am adrenocorticotropic hormone (ACTH) (<10 pg/mL) despite evidence of hypercortisolism. Results The mean age in our cohort was 8.2 years (range 15 months to 20 years). All patients presented with overt CS, including one patient with cyclic Cushing's. Three patients had additional features of Carney complex (CNC). Imaging did not reveal any obvious mass lesions on computed tomography (CT), the classical beaded appearance was present in only two of the patients. Mutation analysis was positive in three patients. Five patients underwent bilateral adrenalectomy and had features of PPNAD on histopathology. Conclusions PPNAD is a rare cause of ACTH-independent CS in childhood and may signal underlying CNC. Patients with younger age of onset with overt CS may still have a mutation in the PRKAR1A gene and warrant genetic testing.

Autonomous hypercortisolism: definition and clinical implications

In current practice, an adrenal adenoma usually comes as an unexpected byproduct of an imaging study performed for unrelated reasons, without any prior suspect of adrenal disease. Therefore, these tumors currently represent a public health challenge because they are increasingly recognized due to the widespread use of high-resolution cross-sectional imaging for diagnostic purposes. In radiology series, the prevalence of adrenal adenomas increases steeply with age, from around 3% below the age of 50 years up to 10% in the ageing population. These tumors may have clinical relevance because they are able to secrete cortisol autonomously, independently from the pituitary control, in up to 20-30% of patients. In most of the cases the resulting cortisol excess is insufficient to produce a typical Cushing phenotype but may have clinical consequences, such as hypertension, diabetes, obesity, dyslipidemia and osteoporosis. Despite some controversy on the most effective diagnostic algorithm to define this subtle hypercortisolism, there is mounting evidence that a simple approach by using the 1-mg overnight dexamethasone suppression test (DST) may stratify patients for their cardiovascular risk. Cross-sectional, retrospective studies showed that patients with increasingly higher cortisol following DST have an adverse cardiovascular risk profile and are at increased risk of death. Therefore, also a subtle autonomous cortisol excess is associated with increased morbidity and mortality, mainly of cardiovascular origin.

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.

Update on the risks of benign adrenocortical incidentalomas

PURPOSE OF REVIEW

Recent studies highlighted the association between adrenocortical incidentalomas and several comorbidities. This review summarizes the most recent evidence showing the potential risks related to adrenocortical tumors classified as nonfunctioning adrenal incidentalomas (NFAIs) or associated with clinically autonomous cortisol secretion (ACS).

RECENT FINDINGS

Alterations in glucose metabolism are a common finding in patients with ACS (30% of the cases). As shown in nonrandomized trials, surgical treatment may improve or cure diabetes in 52% of patients. Cross-sectional studies showed that NFAIs are also associated with insulin resistance. In a recent long-term retrospective study, patients with NFAI were at increased risk of developing prediabetes/diabetes during follow-up. Similarly, a prospective study showed that the incidence of prediabetes was higher also in tumors converting from NFAI to ACS. Patients with ACS are at increased risk of cardiovascular events and related mortality. Some cardiovascular markers were altered in patients with NFAI, even if a cause-effect relationship is not readily evident. Finally, 13% of NFAIs have increased risk of developing ACS during long-term follow-up.

SUMMARY

Patients with NFAI are at increased risk of developing alterations of glucose metabolism, whereas those with ACS or NFAI who converted to ACS over time are at risk for cardiovascular diseases.

A Probabilistic Model for Cushing's Syndrome Screening in At-Risk Populations: A Prospective Multicenter Study

CONTEXT

Cushing's syndrome (CS) is challenging to diagnose. Increased prevalence of CS in specific patient populations has been reported, but routine screening for CS remains questionable. To decrease the diagnostic delay and improve disease outcomes, simple new screening methods for CS in at-risk populations are needed.

OBJECTIVE

To develop and validate a simple scoring system to predict CS based on clinical signs and an easy-to-use biochemical test.

DESIGN

Observational, prospective, multicenter.

SETTING

Referral hospital.

PATIENTS

A cohort of 353 patients attending endocrinology units for outpatient visits.

INTERVENTIONS

All patients were evaluated with late-night salivary cortisol (LNSC) and a low-dose dexamethasone suppression test for CS.

MAIN OUTCOME MEASURES

Diagnosis or exclusion of CS.

RESULTS

Twenty-six cases of CS were diagnosed in the cohort. A risk scoring system was developed by logistic regression analysis, and cutoff values were derived from a receiver operating characteristic curve. This risk score included clinical signs and symptoms (muscular atrophy, osteoporosis, and dorsocervical fat pad) and LNSC levels. The estimated area under the receiver operating characteristic curve was 0.93, with a sensitivity of 96.2% and specificity of 82.9%.

CONCLUSIONS

We developed a risk score to predict CS in an at-risk population. This score may help to identify at-risk patients in non-endocrinological settings such as primary care, but external validation is warranted.

Prevalence of subclinical hypercortisolism in type 2 diabetic patients from the Rio de Janeiro Type 2 Diabetes Cohort Study

AIMS

Subclinical hypercortisolism was reported to be more prevalent among diabetic, obese and hypertensive patients. Our primary aim was to investigate the prevalence of subclinical hypercortisolism in patients from the Rio de Janeiro Type 2 Diabetes (RIO-T2D) Cohort; and secondarily to assess its associated factors.

METHODS

From May 2013 to August 2014, 393 diabetic outpatients underwent overnight 1mg dexamethasone suppression test (DST). Patients with non-suppressive morning cortisol (≥1.8μg/dl) were further evaluated with nocturnal salivary cortisol, two readings >0.35μg/dl were considered confirmatory for subclinical hypercortisolism.

RESULTS

One-hundred twenty-eight patients (32.6%) failed to suppress morning cortisol, and in 33 patients (8.6%) subclinical hypercortisolism was confirmed. Independent correlates of a positive DST were older age (OR: 1.04; 95% CI: 1.01-1.07; p=0.007), number of anti-hypertensive drugs in use (OR: 1.26; 95% CI: 1.05-1.50; p=0.012), longer diabetes duration (OR: 1.03; 95% CI: 1.004-1.06; p=0.023), and presence of diabetic nephropathy (OR: 1.70; 95% CI: 1.01-2.87; p=0.047). Independent correlates of confirmed subclinical hypercortisolism were a greater number of anti-hypertensive medications (OR: 1.54; 95% CI: 1.14-2.06; p=0.004), shorter diabetes duration (OR: 0.92; 95% CI: 0.87-0.98; p=0.006), and increased aortic stiffness (OR: 2.81; 95% CI: 1.20-6.57; p=0.017); metformin use was protective (OR: 0.27; 95% CI: 0.10-0.73; p=0.010).

CONCLUSION

Patients with type 2 diabetes had a high prevalence of subclinical hypercortisolism, and its presence was associated with more severe hypertension and increased aortic stiffness.