Copeptin Levels Before and After Transsphenoidal Surgery for Cushing Disease: A Potential Early Marker of Remission.

Context: Arginine-vasopressin and CRH act synergistically to stimulate secretion of ACTH. There is evidence that glucocorticoids act via negative feedback to suppress arginine-vasopressin secretion. Objective: Our hypothesis was that a postoperative increase in plasma copeptin may serve as a marker of remission of Cushing disease (CD). Design: Plasma copeptin was obtained in patients with CD before and daily on postoperative days 1 through 8 after transsphenoidal surgery. Peak postoperative copeptin levels and Δcopeptin values were compared among those in remission vs no remission. Results: Forty-four patients (64% female, aged 7-55 years) were included, and 19 developed neither diabetes insipidus (DI) or syndrome of inappropriate anti-diuresis (SIADH). Thirty-three had follow-up at least 3 months postoperatively. There was no difference in peak postoperative copeptin in remission (6.1 pmol/L [4.3-12.1]) vs no remission (7.3 pmol/L [5.4-8.4], P = 0.88). Excluding those who developed DI or SIADH, there was no difference in peak postoperative copeptin in remission (10.2 pmol/L [6.9-21.0]) vs no remission (5.4 pmol/L [4.6-7.3], P = 0.20). However, a higher peak postoperative copeptin level was found in those in remission (14.6 pmol/L [±10.9] vs 5.8 (±1.4), P = 0.03]) with parametric testing. There was no difference in the Δcopeptin by remission status. Conclusions: A difference in peak postoperative plasma copeptin as an early marker to predict remission of CD was not consistently present, although the data point to the need for a larger sample size to further evaluate this. However, the utility of this test may be limited to those who develop neither DI nor SIADH postoperatively.

Liver findings in patients with Carney complex, germline PRKAR1A pathogenic variants, and link to cardiac myxomas.

This study aimed to evaluate liver involvement in patients with Carney complex (CNC) based on a large cohort and to analyze any germline PRKAR1A genotype-phenotype association of liver disease. The study included 83 patients with CNC, followed between 1995 and 2018 at a tertiary research center. We reviewed liver images, recorded types and number of lesions and analyzed per genotype: all patients were sequenced for the PRKAR1A gene. A total of 29/83 patients (24.0%) had liver radiological findings. Patients with liver lesion had a significantly higher rate of pathogenic variants detected in the PRKAR1A gene (72.4 vs 38.9%, P = 0.005, respectively). Patients with a pathogenic variant detected on germline PRKAR1A analysis had a higher risk for having a liver lesion compared with patients with wild-type (WT) PRKAR1A alleles (21/42 (50.0%) vs 8/41 (19.5%), respectively, P = 0.004). Among patients with liver lesions, those with a nonsense PRKAR1A pathogenic-variant had more liver lesions (7/7) than among those with other pathogenic-variant types (8/22, P = 0.001). In multivariable analysis, detection of liver lesion(s) was associated with an odds ratio of 5.2 for cardiac myxomas (95% CI 1.55-17.49, P = 0.008). In conclusion, patients with CNC, particularly with a PRKAR1A pathogenic variant, have a higher rate of liver lesions. Additionally, liver lesions are associated with a high risk for cardiac myxomas in this population.

Computerized Analysis of Brain MRI Parameter Dynamics in Young Patients With Cushing Syndrome-A Case-Control Study.

BACKGROUND: Young patients with Cushing Syndrome (CS) may develop cognitive and behavioral alterations during disease course. METHODS: To investigate the effects of CS on the brain, we analyzed consecutive MRI scans of patients with (n = 29) versus without CS (n = 8). Multiple brain compartments were processed for total and gray/white matter (GM/WM) volumes and intensities, and cortical volume, thickness, and surface area. Dynamics (last/baseline scans ratio per parameter) were analyzed versus cortisol levels and CS status (persistent, resolved, and non-CS). RESULTS: Twenty-four-hour urinary free cortisol (24hUFC) measurements had inverse correlation with the intensity of subcortical GM structures and of the corpus callosum, and with the cerebral WM intensity. 24hUFC dynamics had negative correlation with volume dynamics of multiple cerebral and cerebellar structures. Patients with persistent CS had less of an increase in cortical thickness and WM intensity, and less of a decrease in WM volume compared with patients with resolution of CS. Patients with resolution of their CS had less of an increase in subcortical GM and cerebral WM volumes, but a greater increase in cortical thickness of frontal lobe versus controls. CONCLUSION: Changes in WM/GM consistency, intensity, and homogeneity in patients with CS may correlate with CS clinical consequences better than volume dynamics alone.

Somatic PRKAR1A Gene Mutation in a Nonsyndromic Metastatic Large Cell Calcifying Sertoli Cell Tumor.

Large cell calcifying Sertoli cell tumors (LCCSCTs) are rare testicular tumors, representing <1% of all testicular neoplasms. Almost 40% of patients with LCCSCTs will present in the context of an inherited tumor predisposition condition, such as Carney complex (CNC) or Peutz-Jeghers syndrome. We report the case of a 42-year-old man who had presented with a right testicular mass, and was diagnosed with metastatic LCCSCT. The patient underwent radical orchiectomy, achieving initial remission of his disease. However, lymph node and hepatic metastases were identified. He received chemotherapy without response, and he died of complications of his disease 4 years after the initial diagnosis. Genetic analysis of the tumor and a lymph node metastasis identified a somatic frameshift mutation in the PRKAR1A gene (c.319delG, p.E107fs*22). The mutation was predicted to result in premature termination of the PRKAR1A protein and, thus, not be expressed at the protein level, consistent with other PRKAR1A nonsense mutations. The patient was extensively screened for signs of CNC, but he had no stigmata of the complex. To the best of our knowledge, the present report is the first of a somatic mutation in the PRKAR1A gene shown to be associated with a seemingly sporadic case of LCCSCT. Somatic PRKAR1A mutations are rare in sporadic tumors, and it is unknown whether this mutation was causative of LCCSCT in our patient who did not have CNC, or contributed to the malignancy of the tumor, which might have been caused by additional mutations.

A novel mutation in the glucocorticoid receptor gene as a cause of severe glucocorticoid resistance complicated by hypertensive encephalopathy.

BACKGROUND: Glucocorticoid resistance syndrome (GRS) is caused by mutations of the glucocorticoid receptor (coded by the NR3C1 gene) and presents with signs of mineralocorticoid and/or androgen excess. PATIENT: A female patient presented at the age of almost 3 years with hypertensive and hypoglycemic seizure. She was diagnosed with GRS and was treated with antihypertensive medications and dexamethasone. She was later found to have MRI findings of punctuate microinfarcts at the basal ganglia, left thalamus and pons, possibly associated with uncontrolled hypertension. Increase of the dexamethasone dose up to 14 mg/day resulted in sufficient control of her symptoms. RESULTS: Two mutations in the NR3C1 gene were identified: a novel mutation in exon 2 (p.E198X), and a previously described mutation in exon 8 (p.R714Q). CONCLUSION: GRS may present with life-threatening complications; this is the first report of hypertensive encephalopathy in association with GRS. Successful management of patients might require high doses of dexamethasone to control blood pressure.

Lipoprotein particles in patients with pediatric Cushing disease and possible cardiovascular risks.

BACKGROUND: Cardiovascular (CV) complications are the most significant cause of mortality in adults with Cushing disease (CD); little is known about CV risk factors in children with CD. Measurement of lipoprotein particles by nuclear magnetic resonance (NMR) spectroscopy is a novel technology to assess CV risk. The objective of the current study is to analyze the NMR lipid profile in pediatric CD patients before and 1 year after remission. METHODS: NMR lipid profile was obtained via the Vantera NMR analyzer, using frozen serum samples from 33 CD patients (mean age 13.8 ± 4.0 years) evaluated between 1997 and 2017 at the National Institutes of Health (NIH) Clinical Center (CC). RESULTS: GlycA (glycosylated acute-phase proteins), triglyceride-rich particles (TRLP medium and very small sizes), low-density lipoprotein (LDL) particles (LDLP total and large size), high-density lipoprotein (HDL) particles (HDLP total, medium and small sizes), total cholesterol, LDL-cholesterol, HDL-cholesterol, GlycA inflammatory biomarker, and apolipoprotein B and apolipoprotein A1 (ApoA1) concentrations showed statistically significant changes after remission of CD (p < 0.05). CONCLUSION: In our study population, most of the lipid variables improved post-CD remission, with the exception of HDL and ApoA1, indicating that NMR lipoprotein profile may be a helpful tool in assessing the CV risk in pediatric patients with CD.

Aortic pulse wave velocity in children with Cushing syndrome: A window into a marker of early cardiovascular disease.

OBJECTIVE: To investigate early signs of cardiovascular arterial remodelling in paediatric patients with Cushing syndrome (CS) in comparison with normative values from healthy children. STUDY DESIGN: The metrics used to assess cardiac health were from thoracic aorta and carotid MRI. Scans were performed on 18 children with CS (mean: 12.5 ± 3.1 years, range: 6.0-16.8 years, 10 female). Pulse wave velocity (PWV), aortic distensibility (AD) and carotid intima-media thickness (cIMT), well-validated measurements of cardiac compromise, were measured from the images and compared to normative age-matched values where available. RESULTS: Patients with CS had significantly higher PWV compared to age-adjusted normal median control values (4.0 ± 0.7 m/s vs. 3.4 ± 0.2 m/s, respectively, P = 0.0115). PWV was positively correlated with midnight plasma cortisol (r = 0.56, P = 0.02). Internal and common cIMT were negatively correlated with ascending AD (r = -0.75, P = 0.0022, r = -0.69, P = 0.0068, respectively). CONCLUSION: Pulse wave velocity data indicate that paediatric patients with CS have early evidence of cardiovascular remodelling. The results suggest the opportunity for monitoring as these changes begin in childhood.

Optical Imaging Technology: A Useful Tool to Identify Remission in Cushing Disease After Surgery.

We recently reported the use of optical imaging technology to quantify facial plethora in endogenous Cushing syndrome (CS). In the present study, we studied a larger cohort of patients with Cushing disease (CD) and examined water content fraction as well as blood volume fraction as bio-optic markers for determining the efficacy of this methodology as a predictor of lasting remission after surgery for CS. We imaged 49 patients before and after transsphenoidal surgery (TSS) for Cushing disease (CD); 22 patients were also seen at 3-6 months, and 13 patients 12 months post-operatively. On all patients, we used multi-spectral imaging (MSI) to evaluate hemodynamic distributions as well as water content at a specific area of the face. We found a decrease in blood volume fraction after vs. before surgical treatment in the tested facial area in 37 of the 40 patients, as determined with biochemical markers (p<0.001). All patients that were followed up for up to 12 months showed the same decrease from preoperative values and they remained in remission from CD. We conclude that MSI can be used for the evaluation of remission from CD, at least in the immediate post-operative period and up to one year after surgery. The use of this technology can supplement biochemical and other testing for the evaluation of the various treatment modalities available for patients with CD.

Postoperative Diabetes Insipidus and Hyponatremia in Children after Transsphenoidal Surgery for Adrenocorticotropin Hormone and Growth Hormone Secreting Adenomas.

OBJECTIVES: To define the incidence and risk factors of postoperative sodium alterations in pediatric patients undergoing transsphenoidal surgery (TSS) for adrenocorticotropic hormone and growth hormone secreting pituitary adenomas. STUDY DESIGN: We retrospectively reviewed 160 patients ≤18 years of age who had TSS for pituitary adenomas at our institution from 1999 to 2017. Variables included daily serum sodium through postoperative day 10, urine specific gravity, and medications administered. We examined associations between sex, repeat surgery, manipulation of the posterior pituitary (PP), tumor invasion into the PP, tumor type and size, cerebrospinal fluid (CSF) leak, lumbar drain insertion, body mass index, puberty, and development of diabetes insipidus (DI) or syndrome of inappropriate antidiuretic hormone secretion (SIADH). RESULTS: Mean age was 12.9 ± 3.4 years (female = 81). Patients had adrenocorticotropic hormone (150/160) and growth hormone (10/160) producing adenomas. Forty-two (26%) patients developed DI. Among the 37 of 160 who required desmopressin acutely, 13 of 37 required it long term. Risk of long-term need for desmopressin was significantly higher in patients who had CSF leak 9 of 48 (P = .003), lumbar drain 6 of 30 (P = .019), manipulation 11 of 50 (P < .001), or invasion 4 of 15 (P = .022) of the PP. Sixty patients developed hyponatremia, 19 because of SIADH, 39 to hypotonic fluids and 2 to cerebral salt wasting syndrome. Patients with SIADH were placed on fluid restriction; 1 received salt tablets. CONCLUSIONS: Among 160 children who underwent TSS for pituitary adenomas, the incidence of DI and SIADH after TSS was 26% and 14%, respectively. Combined risk factors for DI and/or SIADH include female sex, manipulation of and/or tumor invasion into the PP, and CSF leak or lumbar drain. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00001595 and NCT00060541.

Incidence of Autoimmune and Related Disorders After Resolution of Endogenous Cushing Syndrome in Children.

Glucocorticoids are widely used for immunosuppression in autoimmune diseases. After the resolution of hypercortisolemia, the immune system recovers allowing for autoimmune diseases to manifest. Here we investigated the presence of autoimmune and related diseases that developed after cure of endogenous Cushing syndrome (CS) in children. We identified 129 children who were diagnosed and successfully treated for endogenous CS at the National Institutes of Health from 1997 until 2017, and who were followed for at least 6 months after treatment. We performed a retrospective chart review analysis to identify the presence of autoimmune or related diseases after cure. Ten children were diagnosed with a new autoimmune or related disorder after resolution of hypercortisolemia. This results in a frequency of 7.8% of our pediatric CS population. The identified patients had a shorter duration of hypercortisolemia prior to diagnosis, but did not otherwise differ from the remaining patients. The various identified diseases were: celiac disease (n=1), psoriasis (n=1), Hashimoto thyroiditis (n=1), Graves disease (n=1), optic neuritis (n=2), skin hypopigmented lesions/vitiligo (n=2), allergic rhinitis/asthma (n=1), and neuropathy responding to glucocorticoid treatment (n=1). The reported time between the treatment of CS and diagnosis of autoimmune disorder ranged from 6 to 19 months. The presence of autoimmune or related diseases might be masked by the hypercortisolemic state in endogenous CS. After resolution of hypercortisolemia, the presentation of new autoimmune diseases or recurrence of previously known autoimmune conditions should be considered when concerning symptoms arise.

Decreased lymphocytes and increased risk for infection are common in endogenous pediatric Cushing syndrome.

BackgroundHypercortisolemia results in changes of the immune system and elevated infection risk, but data on the WBC changes in pediatric Cushing syndrome (CS) are not known. We describe the changes of the WBC lineages in pediatric endogenous hypercortisolemia, their associations with the markers of disease severity, and the presence of infections.MethodsWe identified 197 children with endogenous CS. Clinical and biochemical data were recorded. Sixty-six children with similar age and gender, and normocortisolemia served as controls.ResultsThe absolute lymphocyte count of CS patients was significantly lower than that of controls, while the total WBC and the absolute neutrophil counts were significantly higher. These changes correlated with several markers of CS severity and improved after resolution of hypercortisolemia. Infections were identified in 35 patients (17.8%), and their presence correlated to elevated serum morning cortisol, midnight cortisol, and urinary free cortisol levels, as well as with the decrease in absolute lymphocyte count.ConclusionsChildren with endogenous CS have abnormal WBC counts, which correlate with the severity of CS, and normalize after cure. Infections are common in this population; clinicians should be aware of this complication of CS and have low threshold in diagnosis and treating infections in CS.

Failure to Thrive in the Context of Carney Complex.

BACKGROUND/AIMS: Carney complex (CNC) is a rare syndrome associated with multiple tumors and several other unique manifestations. We describe the clinical, genetic, and laboratory findings in a cohort of patients with CNC and failure to thrive (FTT). METHODS: A retrospective case series of pediatric patients with CNC presenting with FTT. RESULTS: We describe a patient with infantile Cushing syndrome (CS) who presented with severe FTT and liver disease; the patient was subsequently diagnosed with CNC. This led to the realization that at least 10 other patients with CNC and FTT have been investigated in the last 22 years at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Four of those had primary pigmented nodular adrenocortical disease (PPNAD), 2 had cardiac myxomas, and 3 had liver disease. CONCLUSION: Pediatric patients with CNC may present with FTT whose primary cause is variable and includes CS due to PPNAD, hepatic involvement, and other manifestations of CNC. FTT due to liver disease and/or other causes is a unique new presentation of this rare syndrome with which clinicians need to be familiar.

Management of primary aldosteronism in patients with adrenal hemorrhage following adrenal vein sampling: A brief review with illustrative cases.

The authors describe the clinical investigation of two cases of primary aldosteronism with adrenal hemorrhage (AH) following adrenal vein sampling. A literature review was conducted regarding the medical management of primary aldosteronism in patients with AH following adrenal vein sampling. Guidelines on the management of primary aldosteronism with AH following adrenal vein sampling are lacking. The two patients were followed with serial imaging to document resolution of AH and treated medically with excellent blood pressure response. Resolution of AH was achieved, but a repeat adrenal vein sampling was deferred given the increased morbidity risk associated with a repeat procedure.

Obesity and the diagnostic accuracy for primary aldosteronism.

The effects of body mass index on the diagnostic accuracy of primary aldosteronism (PA) are inconsistent and yet important considering the high prevalence and frequent co-occurrence of obesity and hypertension. The current study included 59 adult patients who underwent a stepwise evaluation for PA, using aldosterone to renin ratio for case detection and plasma aldosterone concentration after saline suppression test and/or 24-hour urinary aldosterone after oral sodium loading for case confirmation. Body mass index had a quadratic (U-shaped) correlation with plasma aldosterone concentration, plasma renin activity, aldosterone to renin ratio, and plasma aldosterone concentration after saline suppression test. Among patients with a body mass index ≥30 kg/m2 , the aldosterone to renin ratio yielded lower case detection accuracy of PA. We conclude that obesity results in a nonlinear correlation with plasma aldosterone concentration, plasma renin activity, and aldosterone to renin ratio, which affects the accuracy of case detection for PA. Patients with a body mass index ≥30 kg/m2 are less accurately identified as having PA when saline suppression and/or oral salt loading tests are used for case confirmation.

3D Volumetric Measurements of GH Secreting Adenomas Correlate with Baseline Pituitary Function, Initial Surgery Success Rate, and Disease Control.

There is scarce data on the clinical utility of volume measurement for growth hormone (GH)-secreting pituitary adenomas. The current study objective was to assess the association between pituitary adenoma volumes and baseline endocrine evaluation, initial surgical success rate, and disease control among patients with acromegaly. A retrospective cohort study was conducted at a clinical research center including patients with acromegaly due to GH-secreting pituitary adenomas. Baseline hormonal evaluation and adenoma characteristics according to MRI were collected. Volumetric measurements of pituitary adenomas were performed using a semi-automated lesion segmentation and tumor-volume assessment tools. Rates of post-operative medical treatment, radiation therapy, and re-operation were gathered from the patients' medical records. Twenty seven patients (11 females) were included, median age 21.0 years (interquartile range 29 years, range 3-61 years). Patients harboring adenomas with a volume <2 000 mm3 had higher chance to achieve disease remission [94.1% (n=16) vs. 50.0% (n=4), p<0.05]. Adenoma volumes positively correlated with baseline plasma GH levels before and after oral glucose administration, and with plasma IGF-I and PRL levels. Adenoma volume had negative correlation with morning plasma cortisol levels. Finally, patients harboring larger adenomas required 2nd surgery and/or medical treatment more often compared with subjects with smaller adenomas. Accurate 3D volume measurement of GH-secreting pituitary adenomas may be used for the prediction of initial surgery success and for disease control rates among patients with a GH-secreting pituitary adenomas and performs better than standard size assessments.

Circadian Plasma Cortisol Measurements Reflect Severity of Hypercortisolemia in Children with Different Etiologies of Endogenous Cushing Syndrome.

BACKGROUND: The utility of circadian cortisol variation in estimating the degree of hypercortisolemia in different forms of endogenous Cushing syndrome (CS) has not been evaluated in children yet. METHODS: A retrospective cohort study, including children who underwent surgery due to CS (n = 115), was divided into children with a pituitary adenoma (Cushing disease) (n = 88), primary adrenal CS (n = 21), or ectopic adrenocorticotropin- or corticotropin-releasing hormone (ACTH-/CRH)-secreting tumors (n = 6). Circadian plasma cortisol measurements were obtained at 11: 30 p.m. and at midnight, and at 7: 30 and 8: 00 a.m. The ratios between the morning and late-night concentrations were calculated. RESULTS: Plasma cortisol early-morning and midnight (AM/PM) ratios negatively correlated with 24-h urinary free cortisol (UFC) collections among the full study population and in each of the individual etiologies. Plasma ACTH concentrations positively correlated with plasma cortisol AM/PM ratios among patients with ACTH-independent CS. Finally, patients with primary pigmented nodular adrenocortical disease showed no correlation between UFC collections and the plasma cortisol AM/PM ratio, in contrast with other etiologies for primary adrenal CS, which showed a strong negative correlation between them. CONCLUSION: Our study shows the association between the plasma cortisol AM/PM ratio and the degree of hypercortisolemia in children with CS.

Pediatric Cushing disease: disparities in disease severity and outcomes in the Hispanic and African-American populations.

BackgroundLittle is known about the contribution of racial and socioeconomic disparities to severity and outcomes in children with Cushing disease (CD).MethodsA total of 129 children with CD, 45 Hispanic/Latino or African-American (HI/AA) and 84 non-Hispanic White (non-HW), were included in this study. A 10-point index for rating severity (CD severity) incorporated the degree of hypercortisolemia, glucose tolerance, hypertension, anthropomorphic measurements, disease duration, and tumor characteristics. Race, ethnicity, age, gender, local obesity prevalence, estimated median income, and access to care were assessed in regression analyses of CD severity.ResultsThe mean CD severity in the HI/AA group was worse than that in the non-HW group (4.9±2.0 vs. 4.1±1.9, P=0.023); driving factors included higher cortisol levels and larger tumor size. Multiple regression models confirmed that race (P=0.027) and older age (P=0.014) were the most important predictors of worse CD severity. When followed up a median of 2.3 years after surgery, the relative risk for persistent CD combined with recurrence was 2.8 times higher in the HI/AA group compared with that in the non-HW group (95% confidence interval: 1.2-6.5).ConclusionOur data show that the driving forces for the discrepancy in severity of CD are older age and race/ethnicity. Importantly, the risk for persistent and recurrent CD was higher in minority children.

Coagulation Profile in Patients with Different Etiologies for Cushing Syndrome: A Prospective Observational Study.

Previous studies reported a higher prevalence of venous-thromboembolic events among patients with Cushing disease (CD) compared to those with ACTH-independent Cushing syndrome (CS) from adrenal sources. The objective of the current study was to evaluate the coagulation profile of patients with CS from different etiologies. A prospective observational study was conducted at a clinical research center. The study included adult patients admitted for evaluation of suspected CS (n=85), that were divided into 3 groups: CD (n=22), ACTH-independent CS from an adrenal tumor/hyperplasia (adrenal CS, n=21), and a control group consisting of subjects with negative screening for CS (rule-out CS, n=42). Coagulation profiles were drawn before and 8.5±4.3 months after surgery (trans-sphenoidal or adrenalectomy, n=18), and included fibrinogen, Factor VIII (FVIII), von Willebrand factor antigen (vWF:Ag), plasminogen activator inhibitor-1 (PAI-1), antithrombin III (ATIII), Protein C (PC), Protein S (PS), α2-antiplasmin (α2AP), and aPTT measurements. Patients with CD had higher baseline mean cortisol levels, ATIII activity and vWF:Ag levels compared with adrenal CS. Differences in ATIII activity and vWF:Ag levels remained even after controlling for BMI, and ATIII after also controlling for 24-h urinary free cortisol collections. Our study showed for the first time the differences in coagulation profiles between various etiologies of CS. We assume that the higher cortisol burden among CD patients may explain the differences found in the coagulation profile as well as the higher risk for VTE compared with primary adrenal CS patients.

Hair cortisol in the evaluation of Cushing syndrome.

PURPOSE: Hair cortisol evaluation has been used to help detect patients with suspected Cushing syndrome. Our goal was to correlate segmental hair cortisol with biochemical testing in patients with Cushing syndrome and controls. This study was a prospective analysis of hair cortisol in confirmed Cushing syndrome cases over 16 months. METHODS: Thirty-six subjects (26.5 ± 18.9 years, 75% female, and 75% Caucasian) were analyzed by diurnal serum cortisol, 24 h urinary free cortisol corrected for body surface area (UFC/BSA), and 24 h urinary 17-hydroxysteroids corrected for creatinine (17OHS/Cr). Thirty patients were diagnosed with Cushing syndrome, and six were defined as controls. 3-cm hair samples nearest to the scalp, cut into 1-cm segments (proximal, medial, and distal), were analyzed for cortisol by enzyme immunoassay and measured as pmol cortisol/g dry hair. Hair cortisol levels were compared with laboratory testing done within previous 2 months of the evaluation. RESULTS: Proximal hair cortisol was higher in Cushing syndrome patients (266.6 ± 738.4 pmol/g) than control patients (38.9 ± 25.3 pmol/g) (p = 0.003). Proximal hair cortisol was highest of all segments in 25/36 (69%) patients. Among all subjects, proximal hair cortisol was strongly correlated with UFC/BSA (r = 0.5, p = 0.005), midnight serum cortisol (r = 0.4, p = 0.03), and 17OHS/Cr, which trended towards significance (r = 0.3, p = 0.06). CONCLUSIONS: Among the three examined hair segments, proximal hair contained the highest cortisol levels and correlated the most with the initial biochemical tests for Cushing syndrome in our study. Further studies are needed to validate proximal hair cortisol in the diagnostic workup for Cushing syndrome.