Cushing’s syndrome in a clinic population with diabetes

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.

Etiology, baseline clinical profile and comorbidities of patients with Cushing's syndrome at a single endocrinological center

PURPOSE

The aim of this study was to compare phenotype of patients with pituitary, adrenal and ectopic CS and identify the differences regarding biochemical parameters, clinical presentations, and comorbidities in CS patients who were diagnosed at the single endocrinological center in Wroclaw.

METHODS

The study population involved 64 patients with CS (53 women and 11 men) diagnosed in Department of Endocrinology, Diabetes and Isotope Therapy in 2000-2018. Patients were divided into three etiologic groups: pituitary dependent-CS (P-CS) (64%), adrenal dependent CS (A-CS) (25%), and CS from an ectopic source (E-CS) (11%).

RESULTS

Percentage of men in the A-CS group was significantly higher than in the other etiologic groups. ACTH, UFC, and cortisol in DST were significantly higher in E-CS group compare to P-CS and A-CS (p < 0.05). Mean potassium level in E-CS group was significantly lower than in P-CS and A-CS (p < 0.05). Median of time elapsed to diagnosis was significantly lower in the E-CS group compared with either the P-CS and the A-CS group (p < 0.01). The most frequently symptoms in CS patients were skin alterations (82.8%), weight gain (81.2%), and hypertension (81.2%).

CONCLUSIONS

The epidemiology of CS is changing toward a growing proportion of A-CS. All patients with E-CS presented a profound hypokalemia. Salient hypokalemia could be a biochemical marker more suggestive for E-CS rather than P-CS. The incidence of diabetes is more frequent in E-CS group than in P-CS and A-CS groups.

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.

Tissue sodium accumulation and peripheral insulin sensitivity in maintenance hemodialysis patients

BACKGROUND

Recent data suggest that sodium (Na⁺ ) is stored in the muscle and skin without commensurate water retention in maintenance hemodialysis (MHD) patients. In this study, we hypothesized that excessive Na⁺ accumulation would be associated with abnormalities in peripheral insulin action.

METHODS

Eleven MHD patients and eight controls underwent hyperinsulinemic-euglycemic-euaminoacidemic clamp studies to measure glucose (GDR) and leucine disposal rates (LDR), as well as lower left leg ²³ Na magnetic resonance imaging to measure Na⁺ concentration in the muscle and skin tissue.

RESULTS

The median GDR and LDR levels were lower, and the median muscle Na⁺ concentration was higher in MHD patients compared with controls. No significant difference was found regarding skin Na⁺ concentration between group comparisons. Linear regression revealed inverse relationships between muscle Na⁺ concentration and GDR and LDR in MHD patients, whereas no relationship was observed in controls. There was no association between skin Na⁺ content and GDR or LDR in either MHD patients or controls.

CONCLUSIONS

These data suggest that excessive muscle Na⁺ content might be a determinant of IR in MHD patients, although the causality and mechanisms remain to be proven.

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.

DIAGNOSIS OF ENDOCRINE DISEASE: Differentiation of pathologic/neoplastic hypercortisolism (Cushing's syndrome) from physiologic/non-neoplastic hypercortisolism (formerly known as pseudo-Cushing's syndrome)

Endogenous hypercortisolism (Cushing's syndrome) usually implies the presence of a pathologic condition caused by either an ACTH-secreting neoplasm or autonomous cortisol secretion from a benign or malignant adrenal neoplasm. However, sustained or intermittent hypercortisolism may also accompany many medical disorders that stimulate physiologic/non-neoplastic activation of the HPA axis (formerly known as pseudo-Cushing's syndrome); these two entities may share indistinguishable clinical and biochemical features. A thorough history and physical examination is often the best (and sometimes only) way to exclude pathologic/neoplastic hypercortisolism. The presence of alcoholism, renal failure, poorly controlled diabetes and severe neuropsychiatric disorders should always raise suspicion that the presence of hypercortisolism may be related to physiologic/non-neoplastic Cushing's syndrome. As late-night salivary cortisol and low-dose dexamethasone suppression have good sensitivity and negative predictive value, normal studies exclude Cushing's syndrome of any form. However, these tests have imperfect specificity and additional testing over time with clinical follow-up is often needed. When there is persistent diagnostic uncertainty, secondary tests such as the DDAVP stimulation test and the dexamethasone-CRH test may provide evidence for the presence or absence of an ACTH-secreting tumor. This review will define and characterize the numerous causes of physiologic/non-neoplastic hypercortisolism and provide a rational clinical and biochemical approach to distinguish it from pathologic/neoplastic hypercortisolism (true Cushing's syndrome).

Increased salt consumption induces body water conservation and decreases fluid intake

BACKGROUND

The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions.

METHODS

Over the course of 2 separate space flight simulation studies of 105 and 205 days' duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance.

RESULTS

A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion.

CONCLUSION

Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion.

FUNDING

Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO, Coppenrath und Wiese, ENERVIT, HIPP, Katadyn, Kellogg, Molda, and Unilever.

Incidence of Cushing's syndrome in patients with significant hypercortisoluria

OBJECTIVE

To investigate the incidence of Cushing's syndrome (CS) in patients with significant hypercortisoluria and the performance of urinary free cortisol (UFC) screening.

DESIGN

Retrospective file review.

METHODS

The computerized database of a publicly funded health maintenance organization (HMO) in Israel was searched for all patients who underwent 24-h UFC testing in 2005-2014 with a result of more than twice the upper limit of normal (ULN). The patients' medical files were reviewed for a subsequent diagnosis of CS by an expert endocrinologist. Findings were evaluated for patterns in CS diagnosis and UFC testing over time.

RESULTS

Of 41 183 individuals tested, 510 (1.2%) had UFC >2× ULN (214 >3× ULN). Eighty-five (16.7%) individuals were diagnosed with CS (63 female and mean age 47.2 ± 15.1 years), mainly Cushing's disease (55.3%) or adrenal Cushing's syndrome (37.6%). The number of UFC tests increased steadily, from 1804 in 2005 to 6464 in 2014; yet, the resultant detection rate of CS remained generally stable. The calculated incidence of CS in the general HMO-insured population based only on the patients identified in the present cohort was 4.5 new cases/million/year (median 4.9/million/year, range 1.7-5.9/million/year), which was also relatively stable. The most common reason for referral for UFC screening was obesity. Of the 148 patients before bariatric surgery with UFC >2× ULN, 2 were diagnosed with CS.

CONCLUSIONS

The incidence of CS is higher than previously suggested. The consistently increasing number of UFC tests being performed has not been accompanied by a similar increase in CS detection rate. The expected yield of routine UFC testing before bariatric surgery is low.

DIAGNOSIS OF ENDOCRINE DISEASE: Prevalence of hypercortisolism in type 2 diabetes patients: a systematic review and meta-analysis

OBJECTIVE

Type 2 diabetes (T2D) and Cushing's syndrome (CS) share clinical characteristics, and several small studies have recorded a high prevalence of hypercortisolism in T2D, which could have therapeutic implications. We aimed to assess the prevalence of endogenous hypercortisolism in T2D patients.

DESIGN

Systematic review and meta-analysis of the literature.

METHODS

A search was performed in SCOPUS, MEDLINE, and EMBASE for original articles assessing the prevalence of endogenous hypercortisolism and CS in T2D. Data were pooled in a random-effect logistic regression model and reported with 95% confidence intervals (95% CI).

RESULTS

Fourteen articles were included, with a total of 2827 T2D patients. The pooled prevalence of hypercortisolism and CS was 3.4% (95% CI: 1.5-5.9) and 1.4% (95 CI: 0.4-2.9) respectively. The prevalence did not differ between studies of unselected patients and patients selected based on the presence of metabolic features such as obesity or poor glycemic control (P = 0.41 from meta-regression). Imaging in patients with hypercortisolism (n = 102) revealed adrenal tumors and pituitary tumors in 52 and 14% respectively.

CONCLUSIONS

Endogenous hypercortisolism is a relatively frequent finding in T2D, which may have therapeutic implications.

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.

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.

Recommendations of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism for the diagnosis of Cushing's disease in Brazil

Although it is a rare condition, the accurate diagnosis and treatment of Cushing's disease is important due to its higher morbidity and mortality compared to the general population, which is attributed to cardiovascular diseases, diabetes mellitus and infections. Screening for hypercortisolism is recommended for patients who present multiple and progressive clinical signs and symptoms, especially those who are considered to be more specific to Cushing's syndrome, abnormal findings relative to age (e.g., spinal osteoporosis and high blood pressure in young patients), weight gain associated with reduced growth rate in the pediatric population and for those with adrenal incidentalomas. Routine screening is not recommended for other groups of patients, such as those with obesity or diabetes mellitus. Magnetic resonance imaging (MRI) of the pituitary, the corticotropin-releasing hormone (CRH) test and the high-dose dexamethasone suppression test are the main tests for the differential diagnosis of ACTH-dependent Cushing's syndrome. Bilateral and simultaneous petrosal sinus sampling is the gold standard method and is performed when the triad of initial tests is inconclusive, doubtful or conflicting. The aim of this article is to provide information on the early detection and establishment of a proper diagnosis of Cushing's disease, recommending follow-up of these patients at experienced referral centers. Arch Endocrinol Metab. 2016;60(3):267-86.

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

Variable prevalence of subclinical Cushing's syndrome (SCS) has been reported in patients with type 2 diabetes mellitus (T2DM), making the need for screening in this population uncertain. It is unknown if this variability is solely due to study-related methodological differences or a reflection of true differences in ethnic predisposition. The objective of this study is to explore the prevalence of SCS in Asian Indian patients with T2DM. In this prospective single center study conducted in a tertiary care referral center, 993 T2DM outpatients without any discriminatory clinical features (easy bruising, facial plethora, proximal muscle weakness, and/or striae) of hypercortisolism underwent an overnight 1 mg dexamethasone suppression test (ODST). ODST serum cortisol ≥1.8 μg/dl was considered positive, and those with positive results were subjected to 48 h, 2 mg/day low dose DST (LDDST). A stepwise evaluation for endogenous hypercortisolism was planned for patients with LDDST serum cortisol ≥1.8 μg/dl. Patients with positive ODST and negative LDDST were followed up clinically and re-evaluated a year later for the development of clinically evident Cushing's syndrome (CS). In this largest single center study reported to date, we found 37 out of 993 (3.72%) patients had ODST serum cortisol ≥1.8 μg/dl. None of them had LDDST cortisol ≥1.8 μg/dl, nor did they develop clinically evident CS over a follow-up period of 1 year. Specificity of ODST for screening of CS was 96.3% in our cohort. None of the T2DM outpatients in our cohort had SCS, hence cautioning against routine biochemical screening for SCS in this cohort. We suggest screening be based on clinical suspicion only.

Cushing's syndrome: epidemiology and developments in disease management

Cushing’s syndrome is a rare disorder resulting from prolonged exposure to excess glucocorticoids. Early diagnosis and treatment of Cushing’s syndrome is associated with a decrease in morbidity and mortality. Clinical presentation can be highly variable, and establishing the diagnosis can often be difficult. Surgery (resection of the pituitary or ectopic source of adrenocorticotropic hormone, or unilateral or bilateral adrenalectomy) remains the optimal treatment in all forms of Cushing’s syndrome, but may not always lead to remission. Medical therapy (steroidogenesis inhibitors, agents that decrease adrenocorticotropic hormone levels or glucocorticoid receptor antagonists) and pituitary radiotherapy may be needed as an adjunct. A multidisciplinary approach, long-term follow-up, and treatment modalities customized to each individual are essential for optimal control of hypercortisolemia and management of comorbidities.

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

Cushing's syndrome may be more frequent in some specific patient groups such as type 2 diabetes and obesity. The aim of this study was to investigate the prevalence of Cushing's syndrome in outpatients with type 2 diabetes with poor glycemic control despite at least 3-months insulin therapy. Outpatients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite receiving at least 3-months long insulin treatment (insulin alone or insulin with oral antidiabetics) were included. Patients with classic features of Cushing's syndrome were excluded. Overnight 1 mg dexamethasone suppression test (DST) was performed as a screening test. A total of 277 patients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite insulin therapy were included. Two of the 277 patients with type 2 diabetes were diagnosed with Cushing's syndrome (0.72 %). Hypertension was statistically more frequent in the patients with cortisol levels ≥1.8 μg/dL than the patients with cortisol levels <1.8 μg/dL after overnight 1 mg DST (p = 0.041). Statistically significant correlation was determined between cortisol levels after 1 mg DST and age, daily insulin dose (r = 0.266 and p < 0.001, r = 0.163 and p = 0.008, respectively). According to our findings, the prevalence of Cushing's syndrome among patients with type 2 diabetes with poor glycemic control despite insulin therapy is much higher than in the general population. The patients with type 2 diabetes with poor glycemic control despite at least three months of insulin therapy should be additionally tested for Cushing's syndrome if they have high dose insülin requirements.

Routine screening for Cushing's syndrome is not required in patients presenting with hirsutism

CONTEXT

Prevalence of Cushing's syndrome (CS) in patients presenting with hirsutism is not well known.

OBJECTIVE

Screening of CS in patients with hirsutism.

SETTING

Referral hospital.

PATIENTS AND OTHER PARTICIPANTS

This study was carried out on 105 patients who were admitted to the Endocrinology Department with the complaint of hirsutism.

INTERVENTION

All the patients were evaluated with low-dose dexamethasone suppression test (LDDST) for CS.

MAIN OUTCOME MEASURE

Response to LDDST in patients presenting with hirsutism.

RESULTS

All the patients had suppressed cortisol levels following low-dose dexamethasone administration excluding CS. The etiology of hirsutism was polycystic ovary syndrome in 79%, idiopathic hirsutism in 13%, idiopathic hyperandrogenemia in 6%, and nonclassical congenital hyperplasia in 2% of the patients.

CONCLUSION

Routine screening for CS in patients with a referral diagnosis of hirsutism is not required. For the time being, diagnostic tests for CS in hirsute patients should be limited to patients who have accompanying clinical stigmata of hypercortisolism.

Prevalence and associated factors of subclinical hypercortisolism in patients with resistant hypertension

BACKGROUND

Subclinical hypercortisolism is a secondary cause of hypertension that had never been evaluated in resistant hypertensive patients, a subgroup of general hypertensive individuals with an expected high prevalence of secondary hypertension.

METHODS

Four hundred and twenty-three patients with resistant hypertension and ages up to 80 years were screened for the presence of subclinical hypercortisolism by morning serum cortisol after a midnight 1 mg dexamethasone suppression test (DST). Those with morning cortisol of at least 50  nmol/l had hypercortisolism confirmed by two salivary cortisol of at least 3.6  nmol/l collected at 2300  h. Statistical analysis included bivariate tests between those with positive and negative screening test and with and without confirmed hypercortisolism, and logistic regressions to assess their independent correlates.

RESULTS

One hundred and twelve patients (prevalence 26.5%, 95% confidence interval 22.0-31.9%) had the screening test positive for suspected hypercortisolism. None had overt Cushing syndrome. Patients with positive screening were older, more frequently males, had higher prevalences of diabetes and target-organ damage and higher nighttime SBPs than patients with normal screening test results. Thirty-four patients (total prevalence 8.0%, 95% confidence interval: 5.7-11.2%) had confirmed hypercortisolism. Independent correlates of a positive DST were older age (P = 0.007), male sex (P = 0.012) and presence of cardiovascular diseases (P = 0.002) and chronic kidney disease (P = 0.016). Correlates of confirmed subclinical hypercortisolism were older age (P = 0.020), diabetes (P = 0.06) and a nondipping pattern on ambulatory blood pressure monitoring (P = 0.04).

CONCLUSION

Patients with resistant hypertension had a relatively high prevalence of subclinical hypercortisolism, and its presence is associated with several markers of worse cardiovascular prognosis.

Glucose metabolism in patients with subclinical Cushing's syndrome

This clinical review will summarize the available data regarding the effect of either physiological or increased glucocorticoid concentrations on glucose metabolism and insulin-sensitivity, in order to clarify the role, if any, of subclinical Cushing's syndrome (SCS), a status of altered hypothalamic-pituitary-adrenal axis secretion in the absence of the classical signs or symptoms of overt cortisol excess, in patients with adrenal incidentalomas (AI) and diabetes mellitus type 2. Focusing on patients with SCS associated to AI, while there is convincing evidence in the literature that even a mild hyper cortisolemia is associated with alterations of glucose metabolism, evidence is insufficient to conclude that the simple correction of chronic, even mild, hypercortisolism can completely revert metabolic, mainly glycemic alterations. At the same time, considering the variability of the prevalence of Cushing's syndrome in patients with diabetes mellitus type 2 reported in the literature, no agreement does exist whether screening for CS can be useful and recommended in those patients.

Cushing's syndrome: diagnosis and surveillance using salivary cortisol

This short review summarizes the use of late-night salivary cortisol measurement in the diagnosis of Cushing's syndrome, in the evaluation of patients with adrenal incidentalomas, and in monitoring of post-operative patients, with a focus on the different assay methodologies currently in common use. The focus is on recent studies identified by literature searches using Ovid Medline and Google Scholar as well as analysis of several recent review articles on the topic. Measurement of late night salivary cortisol (LNSC) has an excellent sensitivity and specificity for the diagnosis of Cushing's syndrome regardless of the assay methodology used. Immunoassays have the advantage of simplicity, low cost, and small sample volume requirement, while liquid chromatography-tandem mass spectrometry has the advantage of a high specificity for cortisol and the ability to measure cortisone. The overnight dexamethasone suppression test appears to be superior to LNSC measurement in the evaluation of patients with adrenal incidentalomas. LNSC measurement is an excellent approach to monitor post-operative Cushing's disease patients for surgical failure or recurrence. Salivary cortisol is most useful as the initial test when Cushing's syndrome is suspected and for periodic patient monitoring after pituitary surgery for Cushing's disease.

Do patients with type 2 diabetes mellitus have an increased prevalence of Cushing's syndrome?

Many clinical features are common for patients with type 2 diabetes mellitus (T2DM) and Cushing's syndrome (CS) such as central obesity, hypertension and dyslipidaemia. Patients with CS often have T2DM. Because T2DM is much more frequent than CS, it is possible that some patients with T2DM have increased production of cortisol and thus represent patients with CS. The aim of this review was to evaluate the prevalence of CS in patients with T2DM. A search was performed in PubMed and Medline. We found seven prospective studies, two case-control studies and two cross-sectional studies. The difficulties in diagnosing subclinical CS is discussed. The most frequent tests for diagnosing CS, late-night salivary cortisol, 1-mg dexamethasone suppression test and urinary free cortisol are discussed and put in relation to the results of the literature found. The observed prevalence of CS in patients with T2DM varies widely between the different studies, ranging from 0-9.4%. This may be due to patient selection, differences in test methodology (including choice of test), cutoff values and different cortisol assays. The true prevalence of CS in T2DM has not been determined. We need more studies investigating the prevalence of CS in T2DM patients. There is a need for developing more specific tests for diagnosing CS in patients with only slightly elevated cortisol secretion and subclinical CS. We suggest that examination for hypercortisolism should only be performed in T2DM patients with a cushingoid appearance and hypertension or truncal obesity or dyslipidaemia.

Clinical review: Diagnosis and treatment of subclinical hypercortisolism

CONTEXT

Subclinical hypercortisolism (SH) is a condition of biochemical cortisol excess without the classical signs or symptoms of overt hypercortisolism. It is thought to be present in the 5-30% of patients with incidentally discovered adrenal mass (adrenal incidentalomas), which in turn are found in 4-7% of the adult population. Therefore, SH has been suggested to be present in 0.2-2.0% of the adult population. Some studies suggested that this condition is present in 1-10% of patients with diabetes or established osteoporosis. The present manuscript reviews the literature on diagnostic procedures and the metabolic effect of the recovery from SH.

EVIDENCE ACQUISITION

A PubMed search was used to identify the available studies. The most relevant studies from 1992 to November 2010 have been included in the review.

EVIDENCE SYNTHESIS

The available data suggest that SH may be associated with chronic complications, such as hypertension, diabetes mellitus, overweight/obesity, and osteoporosis. The available intervention studies suggest that the recovery from SH may lead to the improvement of hypertension and diabetes mellitus. A retrospective study suggests that this beneficial effect could be predicted before surgery.

CONCLUSIONS

SH is suggested to be associated with some chronic complications of overt cortisol excess. Recovery from this condition seems to improve these complications. However, a large, prospective, randomized study is needed to confirm this hypothesis and to establish the best diagnostic approach to identify patients with adrenal incidentalomas who can benefit from surgery.

Prevalence of endocrine diseases in morbidly obese patients scheduled for bariatric surgery: beyond diabetes

BACKGROUND

Bariatric surgery allows stable body weight reduction in morbidly obese patients. In presurgical evaluation, obesity-related co-morbidities must be considered, and a multidisciplinary approach is recommended. Precise guidelines concerning the endocrinological evaluation to be performed before surgery are not available. The aim of this study was to evaluate the prevalence of common endocrine diseases in a series of obese patients scheduled for bariatric surgery.

METHODS

We examined 783 consecutive obese subjects (174 males and 609 females) aged 18-65 years, who turned to the obesity centre of our department from January 2004 to December 2007 for evaluation before bariatric surgery. Thyroid, parathyroid, adrenal and pituitary function was evaluated by measurement of serum hormones. Specific imaging or supplementary diagnostic tests were performed when indicated.

RESULTS

The overall prevalence of endocrine diseases, not including type 2 diabetes mellitus, was 47.4%. The prevalence of primary hypothyroidism was 18.1%; pituitary disease was observed in 1.9%, Cushing syndrome in 0.8%, while other diseases were found in less than 1% of subjects. Remarkably, the prevalence of newly diagnosed endocrine disorders was 16.3%.

CONCLUSIONS

A careful endocrinological evaluation of obese subjects scheduled for bariatric surgery may reveal undiagnosed dysfunctions that require specific therapy and/or contraindicate the surgical treatment in a substantial proportion of patients. These results may help to define the extent of the endocrinological screening to be performed in obese patients undergoing bariatric surgery.

Pros and cons of screening for occult Cushing syndrome

Systematic screening studies performed mainly in patients with diabetes mellitus have revealed an unexpectedly high prevalence of occult Cushing syndrome. Such studies may provide a rationale for systematically screening obese patients with type 2 diabetes mellitus. However, a screening strategy is only justified if it is supported by enough evidence of its efficacy and if the benefits will outweigh drawbacks. To date, the natural history of occult Cushing syndrome and its possible effect on long-term morbidity are unknown. The clinical spectrum of occult Cushing syndrome and its relatively low prevalence may potentially negatively affect the performance of endocrine tests used to diagnose overt Cushing syndrome and generate false positives. Whether the cure of occult Cushing syndrome favorably influences clinical outcomes and is more beneficial than treatment of diabetes mellitus and cardiovascular risk factors with currently available pharmacological tools remains to be demonstrated. Last, the acceptability of a screening program by professionals and the health-care system in terms of workload and costs is highly questionable. Thus, an assessment of the indications for and against screening for occult Cushing syndrome on the basis of currently available data suggests that, to date, the cons surpass the pros.

Micellar electrokinetic chromatography for the determination of cortisol in urine samples in view of biomedical studies

An MEKC method used for the determination of cortisol in urine was developed and elaborated. In turn, the measurements of urinary free cortisol provided the diagnostic information for excess adrenal production of cortisol. MEKC realized by the addition of anionic surfactant SDS to the buffer solution was demonstrated to be the appropriate mode for the separation of cortisol and dexamethasone was used as internal standard. A buffer solution composed of 10 mM sodium tetraborate and 50 mM SDS at pH 8.8 was used. The MEKC assay was evaluated by analyzing a series of urine samples containing cortisol in variable concentrations. The proposed method was validated for specificity, linearity, LODs and LOQs, precision and trueness. The LOQ for cortisol equaled 5 ng/mL. The method was selective and reliable for identification and can detect changes of endogenous levels of cortisol in urine under different stress situations.

Cushing's syndrome: why is diagnosis so difficult?

Practicing and perfecting the art of medicine demands recognition that uncertainty permeates all clinical decisions. When delivering clinical care, clinicians face a multiplicity of potential diagnoses, limitations in diagnostic capacity, and "sub-clinical" disease identified by tests rather than by clinical manifestations. In addition, clinicians must recognize the rapid changes in scientific knowledge needed to guide decisions. Cushing's syndrome is one of several disorders in which there may be considerable difficulty and delay in diagnosis. This article describes a current model of clinical reasoning, some of its challenges, and the application of the principles of clinical epidemiology to meet some of those challenges.

Is there value in routine screening for Cushing's syndrome in patients with diabetes?

CONTEXT

Subclinical Cushing's syndrome has been described among diabetic populations in recent years, but no consensus has emerged about the value of screening.

METHODS

We enrolled 201 consecutive patients attending our diabetes clinic and 79 controls. Patients with at least two of the following three criteria were offered screening using a 2300 h salivary cortisol test: glycosylated hemoglobin of at least 7%, body mass index of at least 25 kg/m(2), and a history of hypertension or blood pressure of at least 140/90 mm Hg. Results are expressed as mean +/- sem.

RESULTS

Mean nighttime salivary cortisol levels were similar in the two groups (8.5 +/- 1.0 nmol/liter for diabetic patients vs. 5.8 +/- 1.0 nmol/liter for controls). Forty-seven patients (23%) had a value of at least 10 nmol/liter, which was set as a conservative threshold above which further investigation would be performed. Thirty-five (75%) agreed to further testing with a 1-mg overnight dexamethasone test. Of the remaining 12 patients, 10 were followed up clinically for at least 1 yr, and no evidence was found of the syndrome evolving. In 28 patients, serum cortisol suppressed to 60 nmol/liter or less. Of the seven patients who failed this test, four agreed to a 2 mg/d 48-h dexamethasone test, with serum cortisol suppressing to 60 nmol/liter or less in all four. Three declined this test but had normal 24-h urinary free cortisol levels. No patient had clinical features of hypercortisolism.

CONCLUSIONS

The 1-3% detection rates of three recently published series have not been realized at our center where we studied a group using criteria making patients more likely to have hypercortisolism. Our results do not support the validity of screening patients without clinical features of Cushing's syndrome in the diabetes clinic.

Incidentally discovered pituitary masses: pituitary incidentalomas

With the widespread use of computed tomography and MRI, the incidental discovery of pituitary incidentalomas is increasing in frequency. The most common cause of a pituitary mass is a pituitary adenoma (90% of all pituitary masses); however, the differential diagnosis remains extensive. The challenge is to distinguish those that can or will cause morbidity/mortality from those that will not. Opinions on approaching management of these lesions vary. This article will review current data regarding the prevalence, natural history and potential morbidity associated with this entity and describe an epidemiological approach based on four questions: does an incidental mass put the patient at increased risk for an adverse outcome? Can individuals with treatable syndromes be accurately diagnosed? Is the treatment of these syndromes more effective in presymptomatic patients? And do the beneficial effects of presymptomatic detection and treatment of these patients justify the costs incurred? We recommend the following approach: recognizing that one size does not fit all and that the approach should be tailored to the needs of the particular case. If the mass was discovered on a computed tomography, an enhanced MRI is recommended. Detailed history and physical examination should be carried out to look for signs of functional or 'subclinically' functional tumor. Size and structure should be assessed, especially proximity to the optic chiasm. Laboratory evaluation with a serum prolactin for small tumors is cost effective, other lab testing is indicated if metabolic problems are present. Care should be taken to assess for hypopituitarism, clinically and biochemically, if the mass is large, that is, more than 1 cm, visual field testing is also recommended. Note that the vast majority of patients with pituitary incidentalomas that are microadenomas die with them, not from them.