UTILITY OF A SINGLE LATE-NIGHT PLASMA CORTISOL AND ACTH FOR THE DIAGNOSIS OF CUSHING SYNDROME

An Integrated Clinical Score to Predict Remission in Cushing's Disease

Objective

To derive a clinical score from parameters that favor remission of Cushing's disease (CD) after pituitary surgery.

Methods

This is an analysis of 11 clinical, hormonal, and post-operative parameters that each favored remission in a cohort of 145 patients with CD treated by trans-sphenoidal surgery (TSS). Each parameter was designated as a categorical variable (presence/absence), and several favorable parameters present for each patient were calculated. From this, a median parameter score (clinical score) of the entire cohort was derived, which was then compared to the event of remission/persistence of CD.

Results

The median number of favorable parameters present in the entire cohort was 3 (0-7). The significant count of patients in remission increased with the increasing number of parameters. The receiver-operator characteristic curve showed that the presence of ≥3 parameters was associated with remission in CD with a sensitivity of 84.2% and a specificity of 80%. Patients with a clinical score ≥3 had significantly higher remission rates (88.9%) than those who had persistent disease (27.3%; P = 0.001).

Conclusion

A clinical score of ≥3 predicts remission in CD treated by TSS; however, it requires validation in other large cohorts. Rather than assessing individual parameters to predict remission in CD, an integrated clinical score is a better tool for follow-up and patient counseling.

Remission in Cushing's disease is predicted by cortisol burden and its withdrawal following pituitary surgery

AIM

To ascertain the predictors of remission and relapse in patients of Cushing's disease (CD) undergoing pituitary transsphenoidal surgery (TSS).

METHODS

Patients with CD subjected to TSS over 35 years at a tertiary care center were included. Patients were grouped into remission and persistent disease at 1 year after surgery, and were further followed up for relapse. Demographic, clinical, biochemical, histological, radiological and post-operative follow-up parameters were analyzed.

RESULTS

Of the 152 patients of CD, 145 underwent TSS. Remission was achieved in 95 (65.5%) patients at 1 year. Patients in remission had shorter duration of symptoms prior to presentation (p = 0.009), more frequent presence of proximal myopathy (p = 0.038) and a tumor size of < 2.05 cm (p = 0.016) in comparison to those with persistent disease. Post-TSS, immediate post-operative 0800-h cortisol (< 159.85 nmol/L; p = 0.001), histological confirmation of tumor (p = 0.045), duration of glucocorticoid replacement (median 90 days; p = 0.001), non-visualization of tumor on MRI (p = 0.003), new-onset hypogonadism (p = 0.001), 3-month 0800-h cortisol (< 384.9 nmol/L; p = 0.001), resolution of diabetes (p = 0.001) and hypertension (p = 0.001), and recovery of hypothalamic-pituitary-adrenal axis (p = 0.018) favored remission. In logistic regression model, requirement of glucocorticoid replacement (p = 0.033), and resolution of hypertension post-TSS (p = 0.003) predicted remission. None of the parameters could predict relapse.

CONCLUSION

The study could ascertain the predictors of remission in CD. Apart from the tumor characteristics, surgical aspects and low post-operative 0800-h cortisol, the results suggest that baseline clinical parameters, longer glucocorticoid replacement, and resolution of metabolic complications post-TSS predict remission in CD. Long-term follow-up is essential to look for relapse.

Biochemical diagnosis of Cushing's disease: Screening and confirmatory testing

Due to the variable clinical features and its rarity diagnosis of Cushing's disease (CD) is often delayed. Clearly, awareness for CD needs to be raised, accompanied by the availability of simple and accurate screening tests. Late-night salivary cortisol (LNSC), 1 mg dexamethasone suppression test (DST), and urinary free cortisol (UFC) have all been extensively studied, demonstrating high sensitivity and specificity for the diagnosis of Cushing's syndrome. However, each of those well-established tests has its own distinctive features, making it preferable in specific clinical conditions and patient groups. To choose the most appropriate test in individual patients, an expert endocrinologist should be consulted. This review will discuss the pitfalls for each of those tests.

Etiology-, Sex-, and Tumor Size-Based Differences in Adrenocorticotropin-Dependent Cushing Syndrome

OBJECTIVE

To examine demographic, clinical, and biochemical differences in patients with adrenocorticotropin (ACTH)-dependent Cushing syndrome (CS) based on etiology, sex, and tumor size.

METHODS

This was a single-center study of 211 patients with ACTH-dependent CS followed for 35 years. Patients were stratified into 3 groups based on etiology: Cushing disease (CD)/transsphenoidal surgery, Cushing disease/total bilateral adrenalectomy (CD/TBA), and ectopic ACTH secretion (EAS). Patients were also stratified based on sex and tumor size (nonvisualized, microadenoma, and macroadenoma).

RESULTS

CD was the commonest cause of ACTH-dependent CS (190; 90%). Most patients presented in the third decade (median age, 29 years). Clinical features, cortisol, and ACTH were significantly greater in the EAS group. The CD/TBA group had more nonvisualized tumors (22% vs 8%; P = .000) and smaller tumor size (4 vs 6 mm; P = .001) compared with the CD/transsphenoidal surgery group. There was female predominance in CD (2.06:1) and male predominance in EAS (2:1). Men had shorter duration of symptoms (2 years; P = .014), were younger (23 years; P = .001), had lower body mass index (25.1 kg/m²; P = .000), and had more severe disease (low bone mineral density, hypokalemia). Macroadenomas were frequent (46; 24.2%), and ACTH correlated with tumor size in CD (r = 0.226; P = .005).

CONCLUSION

Our cohort presented at an earlier age than the Western population with a distinct, but slightly lower, female predilection. Patients with CD undergoing TBA had frequent negative imaging. Men had a clinical profile suggesting aggressive disease. Microadenoma and macroadenoma were difficult to distinguish on a clinicobiochemical basis.

Prevalence of Depression and Psychological Distress and Perturbations of Cortisol Dynamics in Attendants of Hospitalized Patients: An Observational Pilot Study

Background: Attendants of in-hospital patients are prone to undue stress resulting in depression, anxiety, melancholy and psychological distress. Hitherto available studies cater to attendants of patients admitted in critical care units and none have ventured to look into their cortisol dynamics. Herein, we have evaluated the magnitude of psychological distress and depression amongst ostensibly healthy attendants of non-critically ill patients and correlated them with cortisol dynamics. 

Methods: Non-critically ill patients admitted to the general medicine ward were chosen by purposive sampling and one attendant was selected from each patient. Those with known risk factors, psychiatric illnesses, chronic drug intake, addictions, and overweight/obesity were excluded. Psychological distress and depression were assessed using the General Health Questionnaire 12-items (GHQ-12) and the Patient Health Questionnaire (PHQ-9), respectively. Morning plasma cortisol, late-night plasma cortisol (LNPC), late-night salivary cortisol (LNSC), urinary free cortisol (UFC), and plasma cortisol after overnight 1 mg dexamethasone administration were measured. 

Results: After exclusion, 39 participants were recruited (M:F=2.3:1.6). The mean age was 34.1±11.4 years. The mean duration of stay in hospital ambience prior to recruitment was 16.2±1.2 days. Based on the PHQ-9 score, 55% of the participants had depression. Psychological distress prevailed in 13% of participants as per the GHQ-12 score. The median LNPC/LNSC was higher in participants with depression compared to those with no depression, however, there was no statistically significant difference. There was no significant correlation between GHQ-12/PHQ-9 scores and cortisol dynamics. 

Conclusions: Although depression is prevalent in about half of the patient attendants, cortisol dynamics remain largely unaltered over a short period of two to three weeks.

Neurocognitive Functions and Brain Volume in Patients with Endogenous Cushing's Syndrome Before and After Curative Surgery

INTRODUCTION

Cushing's syndrome (CS) leads to various neuropsychiatric manifestations due to structural and functional changes of the brain and contributes significantly in the impairment of health-related quality of life.

AIM AND OBJECTIVE

This study is conducted with aims to evaluate neurocognitive functions and brain volume in patients with endogenous Cushing's syndrome before and after curative surgery.

METHODS

The diagnosis of CS was made by clinical features, abnormal cortisol dynamics, ACTH levels, and imaging studies. Neuropsychiatric tests (Beck depression Index, Spatial span test, PGI memory scale, Color trail test, Verbal fluency test), and Brain volume (Bi-caudate and third ventricular diameter) were done before and after curative surgery.

RESULTS

Fifteen patients of CS were included for the study; all patients underwent curative surgery, neuropsychiatric assessment, and brain volume measurements. Nine patients were followed successfully till remission and repeat evaluation of these patients was done. Depression was the most common neuropsychiatric illness. Severity of depression positively correlated with 0800 h plasma cortisol and ACTH. Patients with higher severity of depression had maximum improvement after curative surgery. Significant decrease in the third ventricular, as well as bicaudate diameter, was observed after curative surgery (P < 0.01).

CONCLUSION

Neuropsychiatric functions and structural brain changes reverse after curative surgery in patients with endogenous CS, however, long term follow-up is required to know whether these changes reverse completely or not.

Accuracy of Laboratory Tests for the Diagnosis of Cushing Syndrome

CONTEXT

The diagnosis of Cushing syndrome (CS) can be challenging. It remains to be determined which diagnostic tests are the most accurate.

OBJECTIVE

To summarize the accuracy of diagnostic tests for CS using contemporary meta-analytic techniques (hierarchical models).

DATA SOURCES

PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systemic Reviews (inception until August 3, 2018).

STUDY SELECTION

Studies performed in adults that determined the accuracy of one or more diagnostic tests: overnight 1-mg dexamethasone suppression test (DST), 2-day low-dose DST (2d DST), 24-hour urinary free cortisol (UFC), late-night salivary cortisol (LNSC), midnight serum cortisol (MSC), and the dexamethasone-suppressed CRH (dex-CRH) and desmopressin (dex-DDAVP) tests.

DATA EXTRACTION

Two authors independently extracted data and performed methodological assessments.

DATA SYNTHESIS

One hundred thirty-nine studies (14 140 participants) were included in the analysis. The respective sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio (95% confidence interval [CI]) estimates include the following: DST 98.6% (96.9%-99.4%), 90.6% (86.4%-93.6%), 10.5 (7.2-15.3), and 0.016 (0.007-0.035); 2d DST 95.3% (91.3%-97.5%), 92.8% (85.7%-96.5%), 13.2 (6.47-27.1), and 0.051 (0.027-0.095); UFC 94.0% (91.6%-95.7%), 93.0% (89.0%-95.5%), 13.3 (8.47-21.0), and 0.065 (0.046-0.092); LNSC 95.8% (93.%-97.2%), 93.4% (90.7%-95.4%), 14.6 (10.3-20.7), and 0.045 (0.030-0.066); MSC 96.1% (93.5%-97.6%), 93.2% (88.1%-96.3%), 14.2 (7.96-25.2), and 0.042 (0.026-0.069); and dex-CRH 98.6% (90.4%-99.8%), 85.9% (67.6%-94.7%), 7.0 (2.80-17.6), and 0.016 (0.002-0.118). A single study evaluated dex-DDAVP. Meta-regression and a novel network meta-analytic approach suggest that DST is the most sensitive while UFC is the least sensitive.

CONCLUSIONS

All of the included diagnostic tests for CS are highly sensitive and specific. It appears that the DST is the most sensitive while the UFC is less sensitive. The specificity of all first-line tests appears comparable.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

Prolactin-adjusted ACTH Ratio in Predicting Lateralization of ACTH Source During Simultaneous Bilateral Inferior Petrosal Sinus Sampling in Patients with Cushing's Disease

INTRODUCTION

Prolactin-adjusted adrenocorticotropic hormone (ACTH) ratio is used to improve the diagnostic accuracy of bilateral inferior petrosal sinus sampling (BIPSS) for lateralization of pituitary adenoma.

OBJECTIVE

To study the use of prolactin for successful catheterization during BIPSS, the role of prolactin-normalized ACTH ratio for confirmation of Cushing's disease (CD) and prolactin-adjusted ACTH ratio in predicting the lateralization.

PATIENTS AND METHODS

BIPSS was done in patients with CD; prolactin-adjusted ACTH ratio was compared with intersinus ACTH ratio, magnetic resonance imaging, and intraoperative findings for localization of pituitary adenoma. Histopathology was taken as "gold standard" for the diagnosis of CD.

RESULTS

Eight patients underwent BIPSS. All the patients underwent transsphenoidal surgery. All these patients had proper venous sampling during BIPSS as determined by inferior petrosal sinus (IPS):Peripheral prolactin ratio of ≥1.8. Prolactin-normalized ACTH ratio of ≥1.3 was achieved in all the eight patients, which was consistent with the diagnosis of CD. Concordance of intersinus ACTH ratio ≥1.4 with the intraoperative findings was found in five of eight (62.5%) patients depicting correct lateralization. Concordance of prolactin-adjusted ACTH ratio with intraoperative findings was found in four of eight (50%) patients. Seven of eight patients had concordance of intersinus ACTH ratio with prolactin-adjusted ACTH ratio.

CONCLUSION

Prolactin is a useful marker for successful catheterization, confirming the diagnosis of CD during BIPSS, and prolactin-adjusted ACTH ratio does not add to the accuracy of lateralization of pituitary adenoma compared with intersinus ACTH ratio.