Active Cushing's Syndrome Research Articles

Left ventricular subclinical systolic myocardial dysfunction assessed by speckle-tracking in patients with Cushing's syndrome.

Two-dimensional speckle tracking echocardiography is a novel ultrasound technique, which can detect early subclinical myocardial dysfunction with high sensitivity. The purpose of this study was to explore the value of speckle tracking echocardiography in the evaluation of subclinical myocardial injury in patients with Cushing's syndrome. 35 patients with Cushing's syndrome and 29 healthy controls matched for age, sex, BMI, and systolic blood pressure were included in the study. All subjects were assessed using both conventional Doppler echocardiography and speckle tracking echocardiography. Among patients, they were further divided into inactive group (n = 7) and active group (n = 28) based on cortisol levels. Trend analysis was used among patients in different disease activity. Correlation analysis and linear regression analysis were used to explore influence factors related to subclinical myocardial dysfunction. Left ventricular ejection fraction value showed no statistical difference between patients Cushing's syndrome and control group. However, GLS and LVSD, show significant differences in Cushing's syndrome group. Also, among active Cushing's syndrome group, inactive Cushing's syndrome group and control group, GLS (-15.4 ± 3.0 vs -18.1 ± 3.1 vs-19.4 ± 2.4, P < 0001) and LVSD (48.9 ± 21.5 vs 43.5 ± 17.9 vs 28.5 ± 8.3, P < 0001) changed significantly with the disease activity status. In addition, GLS and LVSD were both linearly corrected with 24-hour urinary cortisol level. GLS and LVSD are sensitive parameters in detecting and monitoring subclinical myocardial systolic dysfunction in patients with Cushing's syndrome. Myocardial injury is linearly correlated with cortisol level, which can be partially reversed after the biochemical control of cortisol.

Challenges in the postsurgical recovery of cushing syndrome: glucocorticoid withdrawal syndrome.

Glucocorticoid withdrawal syndrome is a challenging clinical phenomenon that can complicate the postsurgical recovery of Cushing syndrome. It is characterized by physical tolerance and dependence to supraphysiologic glucocorticoid exposure during active Cushing syndrome followed by the abrupt decline in cortisol levels after surgical treatment. The symptoms of glucocorticoid withdrawal often overlap with those of postoperative adrenal insufficiency and can be difficult for patients to cope with and for clinicians to treat. This mini review will discuss the clinical characteristics, pathophysiology, and management of glucocorticoid withdrawal syndrome while highlighting recent data in the field.

Unique Gene Expression Signature in Periadrenal Adipose Tissue Identifies a High Blood Pressure Group in Patients With Cushing Syndrome.

Cushing syndrome (CS) is a rare disease caused by excess cortisol levels with high cardiovascular morbidity and mortality. Hypertension in CS promotes hypercortisolism-associated cardiovascular events. Adipose tissue is a highly plastic tissue with most cell types strongly affected by the excess cortisol exposure. We hypothesized that the molecular and cellular changes of periadrenal adipose tissue in response to cortisol excess impact systemic blood pressure levels in patients with CS. We investigated gene expression signatures in periadrenal adipose tissue from patients with adrenal CS collected during adrenal surgery. During active CS we observed a downregulation of gene programs associated with inflammation in periadrenal adipose tissue. In addition, we observed a clustering of the patients based on tissue gene expression profiles into 2 groups that differed in blood pressure levels (CS low blood pressure and CS high blood pressure). The 2 clusters showed significant differences in gene expression pattens of the renin-angiotensin-aldosterone-system. Renin was the strongest regulated gene compared with control patients and its expression correlated with increased blood pressure observed in our patients with CS. In the CS high blood pressure group, systemic renin plasma levels were suppressed indicative of an abnormal blood pressure associated with periadrenal adipose tissue renin-angiotensin-aldosterone-system activation. Here, we show for the first time a relevant association of the local renin-angiotensin-aldosterone-system and systemic blood pressure levels in patients with CS. Patients from the CS high blood pressure group still had increased blood pressure levels after 6 months in remission, highlighting the importance of local tissue effects on long-term systemic effects observed in CS.

Increased Plasma Leptin and Agouti-Related Peptide May Be Related To Sleep Alterations In Patients With Active Cushing's Syndrome

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Cardiovascular complications of Cushings syndrome: Impact on morbidity and mortality.

Cardiovascular complications of Cushings syndrome: Impact on morbidity and mortality.

ENDOCRINOLOGY IN THE TIME OF COVID-19: Management of Cushing's syndrome.

Clinical evaluation should guide those needing immediate investigation. Strict adherence to COVID-19 protection measures is necessary. Alternative ways of consultations (telephone, video) should be used. Early discussion with regional/national experts about investigation and management of potential and existing patients is strongly encouraged. Patients with moderate or severe clinical features need urgent investigation and management. Patients with active Cushing's syndrome, especially when severe, are immunocompromised and vigorous adherence to the principles of social isolation is recommended. In patients with mild features or in whom a diagnosis is less likely, clinical re-evaluation should be repeated at 3 and 6 months or deferred until the prevalence of SARS-CoV-2 has significantly decreased; however, those individuals should be encouraged to maintain social distancing. Diagnostic pathways may need to be very different from usual recommendations in order to reduce possible exposure to SARS-CoV-2. When extensive differential diagnostic testing and/or surgery is not feasible, it should be deferred and medical treatment should be initiated. Transsphenoidal pituitary surgery should be delayed during high SARS-CoV-2 viral prevalence. Medical management rather than surgery will be the used for most patients, since the short- to mid-term prognosis depends in most cases on hypercortisolism rather than its cause; it should be initiated promptly to minimize the risk of infection in these immunosuppressed patients. The risk/benefit ratio of these recommendations will need re-evaluation every 2–3 months from April 2020 in each country (and possibly local areas) and will depend on the local health care structure and phase of pandemic.

COVID-19 and Cushing's syndrome: recommendations for a special population with endogenous glucocorticoid excess

COVID-19 and Cushing's syndrome: recommendations for a special population with endogenous glucocorticoid excess

The relationship of mitochondrial dysfunction and the development of insulin resistance in Cushing's syndrome.

PurposeCushing’s syndrome is characterized by metabolic disturbances including insulin resistance. Mitochondrial dysfunction is one pathogenic factor in the development of insulin resistance in patients with obesity. We explored whether mitochondrial dysfunction correlates with insulin resistance and other metabolic complications.Patients and methodsWe investigated the changes of mRNA expression of genes encoding selected subunits of oxidative phosphorylation system (OXPHOS), pyruvate dehydrogenase (PDH) and citrate synthase (CS) in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM) and mitochondrial enzyme activity in platelets of 24 patients with active Cushing’s syndrome and in 9 of them after successful treatment and 22 healthy control subjects.ResultsPatients with active Cushing’s syndrome had significantly increased body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR) and serum lipids relative to the control group. The expression of all investigated genes for selected mitochondrial proteins was decreased in SCAT in patients with active Cushing’s syndrome and remained decreased after successful treatment. The expression of most tested genes in SCAT correlated inversely with BMI and HOMA-IR. The expression of genes encoding selected OXPHOS subunits and CS was increased in PM in patients with active Cushing’s syndrome with a tendency to decrease toward normal levels after cure. Patients with active Cushing’s syndrome showed increased enzyme activity of complex I (NQR) in platelets.ConclusionMitochondrial function in SCAT in patients with Cushing’s syndrome is impaired and only slightly affected by its treatment which may reflect ongoing metabolic disturbances even after successful treatment of Cushing’s syndrome.

Quality of Life in Cushing's disease: A long term issue?

The purpose of this review is to describe how quality of life (QoL) is impaired in patients with hypercortisolism due to Cushing's syndrome of any aetiology, including pituitary-dependent Cushing's disease. It is worse in active disease, but improvement after successful therapy is often incomplete, due to persistent physical and psychological co-morbidities, even years after endocrine “cure”. Physical symptoms like extreme fatigability, central obesity with limb atrophy, hypertension, fractures, and different skin abnormalities severely impair the affected patients’ everyday life. Psychological and cognitive problems like bad memory, difficulties to concentrate and emotional distress, often associated with anxiety and depression, make it difficult for many patients to overcome the aftermath of treated Cushing's syndrome. Recent studies have shown diffuse structural abnormalities in the central nervous system during active hypercortisolism, thought to be related to the wide distribution of glucocorticoid receptors throughout the brain. Even though they improve after treatment, normalization is often not complete. Shortening the exposure to active Cushing's syndrome by reducing the often long delay to diagnosis and promptly receiving effective treatment is highly desirable, together with preparing the patient for the difficult periods, especially after surgery. In this way they are prepared for the impairments they perceive in every day life, and live with the hope of later improvement, which can be therapeutic in many instances.

Translational evidence of prothrombotic and inflammatory endothelial damage in Cushing syndrome after remission.

Sustained evidence from observational studies indicates that after remission of Cushing syndrome (CS) a cardiovascular risk phenotype persists. Here, we performed a translational study in active CS and CS in remission (RCS) to evaluate the subclinical cardiometabolic burden and to explore the direct pro-inflammatory and prothrombotic potential of their sera on the endothelium in an in vitro translational atherothrombotic cell model. Cross sectional study. The groups were (n=9/group): I. RCS; II. Active CS (ACS) and III. Controls (CTR), all matched for age, body mass index, sex, without other hormonal deficits. We evaluated in vivo: cardiometabolic profile; endothelial markers (sVCAM-1, NO); endothelial dysfunction (FMD); intima-media thickness and body composition (DEXA). In vitro endothelial cells (EC) were exposed to sera taken from the different subjects to evaluate inflammatory EC response (tisVCAM) and thrombogenicity of the generated extracellular matrix (ECM): von Willebrand factor (VWF) and platelet reactivity. Three of the 9 RCS subjects were on glucocorticoid replacement therapy (GC-RT). Patients on GC-RT had a shorter period of time in stable remission. In vivo analysis ACS showed typically metabolic features, while cardiometabolic markers reached statistical significance for RCS only for Hs-CRP (P<.01). In vitro:EC exposed to ACS and RCS sera displayed increased tisVCAM-1 (P<.01 for ACS and P<.05 for RCS vs CTR), VWF (P<.01 for ACS and P<.05 for RCS vs CTR) and platelet adhesion on ECM (P<.01 for ACC and P<.05 for RCS vs CTR). No statistically significant differences were observed between GC-RT RSC and RCS without GC-RT. The sera of premenopausal women with CS in remission, without atherothrombotic disease, contain circulatory endothelial deleterious factors with a direct thrombogenic and pro-inflammatory endothelial effect that could increase cardiovascular risk.

Vascular Health in Patients in Remission of Cushing's Syndrome Is Comparable With That in BMI-Matched Controls.

In active Cushing's syndrome (CS), patients suffer from endothelial dysfunction and premature atherosclerosis. However, it is uncertain to what extent vascular health recovers after long-term remission. This is highly relevant because this topic relates to future development of cardiovascular disease. The objective of the study was to investigate whether micro- and macrovascular health is impaired after long-term remission of CS in patients with no or adequately treated comorbidities. This was a cross-sectional case-control study in two tertiary referral centers. Sixty-three patients (remission of CS for ≥ 4 y) and 63 healthy, well-matched controls were compared. In group A (58 patients and 58 controls), serum biomarkers associated with endothelial dysfunction, intima media thickness, pulse wave velocity, and pulse wave analysis were studied. In group B (14 patients and 14 controls), endothelium-dependent and -independent vasodilatation was studied in conduit arteries (flow mediated dilation of the brachial artery) and forearm skeletal muscle resistance arteries (vasodilator response to intraarterial acetylcholine, sodium-nitroprusside, and NG-monomethyl-L-arginine using venous occlusion plethysmography). There were no significant differences between the outcome measures of vascular health of patients and controls in groups A and B. The vascular health of patients in long-term remission of CS seems to be comparable with that of healthy gender-, age-, and body mass index-matched controls, provided that the patients have no, or adequately controlled, comorbidities. Therefore, the effects of hypercortisolism per se on the vasculature may be reversible. This accentuates the need for the stringent treatment of metabolic comorbidities in these patients.

Glucocorticoid Regulation of Food-Choice Behavior in Humans: Evidence from Cushing's Syndrome.

The mechanisms by which glucocorticoids regulate food intake and resulting body mass in humans are not well-understood. One potential mechanism could involve modulation of reward processing, but human stress models examining effects of glucocorticoids on behavior contain important confounds. Here, we studied individuals with Cushing's syndrome, a rare endocrine disorder characterized by chronic excess endogenous glucocorticoids. Twenty-three patients with Cushing's syndrome (13 with active disease; 10 with disease in remission) and 15 controls with a comparably high body mass index (BMI) completed two simulated food-choice tasks (one with “explicit” task contingencies and one with “probabilistic” task contingencies), during which they indicated their objective preference for viewing high calorie food images vs. standardized pleasant, unpleasant, and neutral images. All participants also completed measures of food craving, and approximately half of the participants provided 24-h urine samples for assessment of cortisol and cortisone concentrations. Results showed that on the explicit task (but not the probabilistic task), participants with active Cushing's syndrome made fewer food-related choices than participants with Cushing's syndrome in remission, who in turn made fewer food-related choices than overweight controls. Corroborating this group effect, higher urine cortisone was negatively correlated with food-related choice in the subsample of all participants for whom these data were available. On the probabilistic task, despite a lack of group differences, higher food-related choice correlated with higher state and trait food craving in active Cushing's patients. Taken together, relative to overweight controls, Cushing's patients, particularly those with active disease, displayed a reduced vigor of responding for food rewards that was presumably attributable to glucocorticoid abnormalities. Beyond Cushing's, these results may have relevance for elucidating glucocorticoid contributions to food-seeking behavior, enhancing mechanistic understanding of weight fluctuations associated with oral glucocorticoid therapy and/or chronic stress, and informing the neurobiology of neuropsychiatric conditions marked by abnormal cortisol dynamics (e.g., major depression, Alzheimer's disease).

Body composition and bone mineral density in women with Cushing's syndrome in remission and the association with common genetic variants influencing glucocorticoid sensitivity.

Adverse body compositional features and low bone mineral density (BMD) are the characteristic of patients with active Cushing's syndrome (CS). The aim of this study was to evaluate body composition and BMD in women with CS in long-term remission and the influence of polymorphisms in genes affecting glucocorticoid (GC) sensitivity on these end-points. This was a cross-sectional, case-controlled study, including 50 women previously treated for CS and 50 age and gender-matched controls. Median (interquartile range) remission time was 13 (5-19) years. Body composition and BMD were measured with dual-energy X-ray absorptiometry. Five polymorphisms in four genes associated with GC sensitivity were analysed using TaqMan or Sequenom single-nucleotide polymorphism genotyping. Patients with CS in remission had increased abdominal fat mass (P<0.01), whereas BMD was not significantly different at any site between patients and controls. In patients, the NR3C1 Bcl1 polymorphism was associated with reduced total (P<0.05) and femur neck BMD (P<0.05). The polymorphism rs1045642 in the ABCB1 gene was associated with increased abdominal fat mass (P<0.05) and decreased appendicular skeletal muscle mass (P<0.05). GC replacement was associated with reduced total BMD (P<0.01), BMD at lumbar spine (P<0.05) and increased abdominal fat (P<0.01). Ongoing GC replacement therapy together with polymorphisms in two genes related with GC sensitivity is associated with abdominal obesity and adverse skeletal health in patients with CS in long-term remission.

Cardiac structure and function in Cushing's syndrome: a cardiac magnetic resonance imaging study.

Background:Patients with Cushing's syndrome have left ventricular (LV) hypertrophy and dysfunction on echocardiography, but echo-based measurements may have limited accuracy in obese patients. No data are available on right ventricular (RV) and left atrial (LA) size and function in these patients.Objectives:The objective of the study was to evaluate LV, RV, and LA structure and function in patients with Cushing's syndrome by means of cardiac magnetic resonance, currently the reference modality in assessment of cardiac geometry and function.Methods:Eighteen patients with active Cushing's syndrome and 18 volunteers matched for age, sex, and body mass index were studied by cardiac magnetic resonance. The imaging was repeated in the patients 6 months (range 2–12 mo) after the treatment of hypercortisolism.Results:Compared with controls, patients with Cushing's syndrome had lower LV, RV, and LA ejection fractions (P < .001 for all) and increased end-diastolic LV segmental thickness (P < .001). Treatment of hypercortisolism was associated with an improvement in ventricular and atrial systolic performance, as reflected by a 15% increase in the LV ejection fraction (P = .029), a 45% increase in the LA ejection fraction (P < .001), and an 11% increase in the RV ejection fraction (P = NS). After treatment, the LV mass index and end-diastolic LV mass to volume ratio decreased by 17% (P < .001) and 10% (P = .002), respectively. None of the patients had late gadolinium myocardial enhancement.Conclusion:Cushing's syndrome is associated with subclinical biventricular and LA systolic dysfunctions that are reversible after treatment. Despite skeletal muscle atrophy, Cushing's syndrome patients have an increased LV mass, reversible upon correction of hypercortisolism.

Small cerebellar cortex volume in patients with active Cushing's syndrome

Cushing's syndrome (CS) is associated with neuropsychological deficits. As the cerebellum plays a key role in neuropsychological functions it may be affected in CS. The aim of this study was to investigate whether patients with CS have a smaller cerebellar volume than healthy controls, and to analyse whether cerebellar volume is associated with neuropsychological performance and clinical parameters. A cross-sectional study was performed. Thirty-six CS patients (15 with active CS and 21 with CS in remission) and 36 controls matched for age, sex, and education underwent neuropsychological testing, quality of life assessment, clinical evaluation, and magnetic resonance imaging brain scan. Cerebellar volumes (white matter and cortex, bilateral) were calculated using FreeSurfer Software. Patients with active CS showed smaller bilateral cerebellar cortex volumes than controls (left, P=0.035 and right, P=0.034), as well as a trend toward smaller right cerebellar cortex volumes than patients in remission CS (P=0.051). No differences were observed in the volume of cerebellar white matter between the three groups. Both right and left cerebellar cortex volumes correlated negatively with triglyceride levels (right: r=-0.358, P=0.002 and left: r=-0.317, P=0.005) and age at diagnosis (right: r=-0.433, P=0.008 and left: r=-0.457, P=0.005). Left cerebellar cortex volume also correlated positively with visual memory performance (r=0.245, P=0.038). Right cerebellar cortex volume positively correlated with quality-of-life scores (r=0.468, P=0.004). The cerebellar cortex volume is smaller in active CS patients than in controls. This finding is associated with poor visual memory and quality of life and is mostly pronounced in patients with higher triglyceride levels and older age at diagnosis.

Long-Term Cognitive Impairments and Attentional Deficits in Patients with Cushing's Disease and Cortisol-Producing Adrenal Adenoma in Remission

Cognitive function is impaired in patients with active Cushing's syndrome (CS). The aim was to study cognitive function in patients with CS in long-term remission. We conducted a cross-sectional, case-controlled, single center study. Fifty-five patients previously treated for Cushing's disease (n = 43) and cortisol-producing adrenal adenoma (n = 12) and 55 controls matched for age, gender, and educational level participated in the study. Working memory, attention, information-processing speed, verbal fluency, and reading speed were studied using standardized neuropsychological testing and alerting, orienting, and executive control using the Attentional Network Test. Fatigue impact scale and the comprehensive psychopathological rating scale were used to evaluate fatigue and affective disorder. Median (interquartile range) duration of remission was 13 (5-19) yr and the mean ± SD age at follow-up was 54 ± 14 yr. Compared to controls, patients had a higher score on the fatigue impact scale, indicating greater burdens of fatigue, and a higher score on the comprehensive psychopathological rating scale subscales for depression and anxiety. In a multivariate analysis, attention, spatial orienting, alerting, working memory, verbal fluency, and reading speed were all diminished in comparison to controls, independent of scores for affective disorder and fatigue. No overall difference in outcome was seen between patients in long-term remission for Cushing's disease and cortisol-producing adrenal adenoma. Patients with CS in remission have impaired cognitive function that cannot be explained by the coexistence of affective disorder or chronic fatigue. The pattern of cognitive and attentional deficits suggests a more global involvement of the brain function than has previously been suggested.

Anthropometric measures and fasting insulin levels in children before and after cure of Cushing syndrome

Children with Cushing syndrome present with growth delay and excess adiposity that tends to be generalized rather than centripetal. There are no prospective studies of this phenotype as it evolves before and after treatment in children. The aims of this study were to evaluate children prior to and one-year after surgical cure compared to controls and to determine fasting insulin levels and their possible association with waist circumference and waist-height ratio, pre- and post-cure of Cushing syndrome. 30 children with Cushing syndrome were evaluated prior to and one-year post-treatment and compared to 14 age and body mass index-matched controls. Only triceps skin fold z- score showed a significant difference between patients with active Cushing syndrome and controls. A positive correlation between fasting insulin levels and waist circumference z- score was found for children with Cushing syndrome; this association persisted one-year following cure. Unlike adults affected with Cushing syndrome, upper arm muscle area of children with Cushing syndrome did not differ from obese children without Cushing syndrome. The persistence of a positive correlation between waist circumference and fasting insulin despite remission of Cushing syndrome suggests that children with a history of Cushing syndrome may have an increased risk for adverse long-term effects of increased abdominal fat mass.

Overt Immune Dysfunction after Cushing's Syndrome Remission: A Consecutive Case Series and Review of the Literature

Autoimmune diseases frequently improve during active Cushing's syndrome. Several studies have reported new onset or exacerbation of these conditions upon cortisol normalization. Our objective was to investigate the incidence and clinical characteristics of patients with autoimmune or allergic diseases after Cushing's syndrome remission. Consecutive cases of confirmed Cushing's syndrome were characterized. A review of the literature was conducted to identify previous descriptions of immune dysfunction upon remission and evidence of the hypothalamic-pituitary-adrenal axis influence on the immune system. Among 66 patients who achieved Cushing's syndrome remission, the incidence of immune dysfunction was 16.7%, where eight cases (72.7%) were noted for the first time and three (27.3%) were exacerbated. All had an ACTH-dependent cause. Glucocorticoids reduce proinflammatory cytokines and interact with other transcription factors affecting T cell and mast cell survival. Hypercortisolism induces a state of immunosuppression. After Cushing's syndrome remission, rebound immunity frequently results in overt conditions extending beyond thyroid dysfunction.

Cardiac dysfunction is reversed upon successful treatment of Cushing's syndrome

In patients with active Cushing's syndrome (CS), cardiac structural and functional changes have been described in a limited number of patients. It is unknown whether these changes reverse after successful treatment. We therefore evaluated the changes in cardiac structure and dysfunction after successful treatment of CS, using more sensitive echocardiographic parameters (based on two-dimensional strain imaging) to detect subtle changes in cardiac structure and function. In a prospective study design, we studied 15 consecutive CS patients and 30 controls (matched for age, sex, body surface area, hypertension, and left ventricular (LV) systolic function). Multidirectional LV strain was evaluated by two-dimensional speckle tracking strain imaging. Systolic (radial thickening, and circumferential and longitudinal shortening) and diastolic (longitudinal strain rate at the isovolumetric relaxation time (SR(IVRT))) parameters were measured. At baseline, CS patients had similar LV diameters but had significantly more LV hypertrophy and impaired LV diastolic function, compared to controls. In addition, CS patients showed impaired LV shortening in the circumferential (-16.5+/-3.5 vs -19.7+/-3.4%, P=0.013) and longitudinal (-15.9+/-1.9 vs -20.1+/-2.3%, P<0.001) directions and decreased SR(IVRT) (0.3+/-0.15 vs 0.4+/-0.2/ s, P=0.012) compared to controls. After normalization of corticosteroid excess, LV structural abnormalities reversed, LV circumferential and longitudinal shortening occurred, and SR(IVRT) normalized. CS induces not only LV hypertrophy and diastolic dysfunction but also subclinical LV systolic dysfunction, which reverses upon normalization of corticosteroid excess.

Bone turnover in patients with endogenous Cushing’s syndrome before and after successful treatment

We investigated bone turnover and its restoration in a large number of patients in the active phase and after cure of endogenous Cushing's syndrome. Furthermore, the usefulness of serum osteocalcin and collagen breakdown products as potential markers of active Cushing's syndrome was also evaluated. Suppressed bone formation is one of the most characteristic features of Cushing's syndrome (CS). Despite numerous previous reports, many aspects of the disturbed bone metabolism of these patients are unexplored. In this study, we investigated the time course of bone marker changes after the cure of CS as well as correlations between bone markers and serum cortisol concentrations. Eighty-seven patients with CS were studied. Patients were followed up to 48 months after surgical cure. Serum osteocalcin (OC) and collagen breakdown products (CTX) were measured with immunochemiluminescence method and compared to the results of 161 healthy controls. OC showed a negative, while CTX displayed a positive correlation with serum cortisol. Patients with diabetes mellitus and myopathy had significantly lower serum OC levels compared to those without these complications. The area under the curve of OC obtained by receiver-operating characteristics analysis for the discrimination of patients with CS from healthy controls was 0.9227. Postoperative OC increased rapidly from the first few days or weeks reaching its maximum at the sixth month and remained stable after the 24th postoperative month. Our study demonstrated significant correlations between serum cortisol and both bone formation and resorption markers in the active phase of CS. We propose that OC may serve as a sensitive biologic marker of glucocorticoid activity in endogenous CS during its active phase and it may reflect the clinical cure of the disease.