Urinary Free Cortisol Concentrations Research Articles

Transition to a market economy and chronic psychosocial stress in northern Laos: An exploratory study of urinary free cortisol in rural residents.

The indigenous population in northern Laos has experienced a transition from self-sufficiency to a market-oriented economy, which may have brought about unprecedented chronic psychosocial stress. This study examined the association between the transition to a market economy and urinary free cortisol (UFC) concentration as a stress biomarker among rural residents of three villages with different degrees of integration into the market economy. An interview survey and urine sample collection were conducted in August 2018 and March 2019. We measured the UFC concentration in spot urine samples collected in the morning from participants aged 20-60 years (n = 168) using an enzyme-linked immunosorbent assay. Multiple linear regression analysis was performed to examine differences in UFC concentrations among villages by sex, with time of arrival for the survey, age, and body mass index included as covariates. The UFC concentration was higher in men living in the village with the highest degree of integration into the market economy than in those in the two villages with a lower dependence on cash, possibly linking increased stress levels with a change in employment type. This trend was not observed in women. Socioeconomic changes incidental to a transition to a market economy may increase the stress levels of men in northern Laos.

Effect of external sleep disturbance on sleep architecture in perimenopausal and postmenopausal women

Objective This study aimed to use external sleep disturbance as a model to evaluate sleep architecture in climacteric women before and after menopausal hormone therapy (MHT). Methods Seventeen perimenopausal and 18 postmenopausal women underwent a polysomnography protocol: an adaptation night, a reference night and a sleep disturbance night with one hand loosely tied to the bed for blood sampling. The sleep architecture of the reference and disturbance nights were compared. The 24-h urinary free cortisol concentration (UFC) was measured. The procedure was repeated after 6 months on MHT or placebo. Results Fifteen perimenopausal and 17 postmenopausal women completed the study. The perimenopausal and postmenopausal groups were combined. During external sleep disturbance, sleep was shorter and more fragmented; with less stage 2, slow-wave and rapid eye movement (REM) sleep and more wake time and awakenings, both at baseline and after the treatment period. Compared to the placebo group, sleep disturbance was minor for women on MHT: sleep was not shortened and the amount of slow-wave sleep did not decrease. Increased 24-h UFC was observed only during MHT. Conclusions Sleep in climacteric women is easily disturbed, leading to shorter and more fragmented sleep with less deep sleep and REM sleep. Six months of MHT attenuates the observed sleep disturbance.

Consumption of a fermented dairy beverage improves hippocampal-dependent relational memory in a randomized, controlled cross-over trial

ABSTRACT Objectives: We aimed to determine whether consumption of a fermented dairy beverage containing probiotic microorganisms influences negative mood states, stress, and hippocampal memory performance in healthy adults. Methods: Adults (25-45 yrs, N = 26) free of gastrointestinal and mental illness were enrolled in a single-blind, randomized, controlled, crossover trial. Participants completed testing prior to and after 4-week consumption, with a 2–4 week washout between treatments of: (1) 8 oz of a dairy-based fermented beverage containing 25–30 billion colony forming units of live and active kefir cultures or (2) 8 oz isocaloric, non-fermented, 1% low-fat lactose-free dairy-based control beverage. Hippocampal-dependent relational memory was assessed using a spatial reconstruction task. Negative mood states of depression and anxiety were assessed using the Depression Anxiety Stress Scales-42 (DASS-42). Pooled 24-hour urine samples were analyzed using an enzyme-linked immunosorbent assay to determine urinary free-cortisol (UFC) concentrations. Fecal microbiota composition was assessed using 16S rRNA gene sequencing. Results: Lactobacillus was increased by 235% following fermented dairy consumption compared to the control (p < .01). Furthermore, the fermented dairy beverage improved performance on two metrics of relational memory, misplacement (p = .04) and object-location binding (p = .03). UFC and DASS-42 scores (all p’s > .08) were not significantly changed by either arm of the intervention. No correlations were observed between the change in Lactobacillus and memory performance. Conclusions: Fermented dairy consumption increased the presence of certain microorganisms in the gut and improved relational memory in healthy adults. However, the benefits observed for relational memory were not related to changes in Lactobacillus. Trial registration: ClinicalTrials.gov identifier: NCT02849275.

The diagnostic utility of late night salivary cortisol (LNSF) and cortisone (LNSE) in Cushing's syndrome.

Measurement of late night salivary cortisol (LNSF) is useful in the identification of cyclical Cushing's syndrome (CS); the usefulness of its metabolite cortisone (late night salivary cortisone, LNSE) is less well described. The aim of this study was to determine the utility of measuring LNSE in patients with confirmed CS compared with other diagnostic tests and to analyse serial LNSF measurements for evidence of variable hormonogenesis. This was a retrospective observational study including patients with confirmed CS in whom LNSF and LNSE were measured. Twenty-three patients with confirmed CS were included, 21 with Cushing's disease. LNSF had a sensitivity of 92%, LNSE 87% and combined LNSF/LNSE 94% per sample. Four patients had cyclical hormonogenesis, when the definition of one trough and two peaks was applied to LNSF measurements, anda fifth patient fell just outside the criteria. Six patients had evidence of variable hormonogenesis, defined as doubling of LNSF concentration on serial measurements. Sensitivity of 24-h urinary free cortisol (UFC) was 89% per collection. Sixteen patients had simultaneous measurements of LNSF and UFC; in three patients, they provided discordant results. LNSF appears more sensitive than LNSE and UFC in the diagnosis of CS, combining LNSF and LNSE results leads to superior sensitivity. Half of our cohort had evidence of cyclical or variable hormonogenesis. Fluctuations in LNSF did not always correlate with changes in UFC concentration, emphasising the importance of performing more than one screening test, particularly if pretest clinical suspicion is high.

Relationship Between Urine Hydration Indices and 24 Hour Urinary Cortisol Concentration (P24-006-19)

ObjectivesThe aim of this study was to investigate the relationship between urine specific gravity (USG) and color (UC), and 24-hour urinary free cortisol (UFC) concentrations in an adult population. MethodsAdult participants aged 26–45 years (N = 51, 33 females) were recruited from the central Illinois area. Participants collected their urine over a 24-hour period. Pooled urine samples were analyzed for USG and color. UFC concentration was measured using an enzyme-linked immunosorbent assay. Whole-body adiposity (%Fat) was assessed via dual energy x-ray absorptiometry (DXA). Pearson and Spearman correlations were conducted to assess bivariate relations between variables. Age and sex were also included as covariates in partial correlation analyses. ResultsPearson correlations revealed a positive association between UFC concentrations and hydration biomarkers in both the 24-hour pooled (r = 0.57, P < 0.01) and FMU samples (r = 0.71, P < 0.01). These associations persisted following adjustment for age, %Fat. Additionally, Spearman correlations revealed a positive relationship between UFC concentrations and 24-hour pooled urine color (rho = 0.45, P = 0.01). ConclusionsGreater urine concentration, as indicated by elevated USG and color, was related to higher UFC concentrations. Additional experimental work is necessary to determine the extent to which changes in water intake contribute to urinary cortisol and other markers of stress. Funding SourcesUSDA National Institute of Food and Agriculture, Hatch Project 1,009,249.

The Effect of Prebiotic Consumption on the Gastrointestinal Microbiota of Healthy Adults: A Randomized, Controlled, Crossover Trial (P20-015-19)

ObjectivesChronic stress is recognized as a contributing factor in health conditions such as depression, anxiety, and sleep disturbances. Prebiotic consumption, which changes the gastrointestinal microbiota in a way that benefits host health, is one potential treatment being explored to alleviate these conditions. Accordingly, we aimed to determine the effects of fructooligosaccharide (FOS) and galactooligosaccharide (GOS) consumption on changes in the gastrointestinal (GI) microbiota and biological and behavioral markers of stress among adults. MethodsA randomized, controlled, double-blind, crossover trial was conducted in healthy adults (n = 24) between 25 and 45 years of age. Participants consumed two study beverages in a counter balanced order: 1) 8 oz per day 1% Lactaid (control) and 2) 8 oz of 1% Lactaid with 5 g FOS and 5 g GOS (prebiotic). Each study beverage was consumed daily for 4-weeks with a 2 to 4-week washout between study periods. Fecal samples were collected at the beginning and end of each period. Following fecal DNA extraction, the V4 region of the 16S rRNA gene was amplified. Sequencing was performed on an Illumina HiSeq. Sequence data were analyzed with DADA2 and QIIME 2. Taxonomy was assigned with the GreenGenes 13_8 99% OTU reference database. Statistical analyses were conducted in SAS 9.4 using linear mixed modeling with time, treatment, and the time by treatment interaction as fixed effects and participant and period as random effects. ResultsPrebiotic consumption increased the relative abundance of Bifidobacterium (P = 0.01) compared to the control group. In addition, there was an increase observed in the relative abundance of Erysipelotrichaceae Clostridium (P = 0.04) in the prebiotic group and a decrease in the control group. In contrast, there was a decrease observed in the relative abundance of Prevotella (P = 0.004) in the prebiotic group and an increase in the control group. ConclusionsThese results demonstrate that FOS and GOS induce changes in the GI microbiota of healthy adults. Ongoing analyses include an examination of the relationships between 24-hour urinary free cortisol concentrations, a potential biological marker of stress, and relative abundance of microbes examined in the current study. Funding SourcesUSDA National Institute of Food and Agriculture, Hatch project 1009249.

Efficacy and safety of once-monthly pasireotide in Cushing's disease: a 12 month clinical trial

Cushing's disease is a rare debilitating endocrine disorder for which few prospective interventional studies have been done. We report results of the first phase 3 trial assessing long-acting intramuscular pasireotide in patients with Cushing's disease. In this phase 3 clinical trial we recruited patients aged 18 years or older with persistent, recurrent, or de-novo (non-surgical candidates) Cushing's disease who had a mean urinary free cortisol (mUFC) concentration (from three 24 h samples) of 1·5-5·0 times the upper limit of normal (ULN), a normal or greater than normal morning plasma adrenocorticotropic hormone concentration, and a pituitary source of Cushing's syndrome, from 57 sites across 19 countries. Exclusion criteria included previous pasireotide treatment, mitotane therapy within 6 months, and pituitary irradiation within 10 years. We randomly allocated patients 1:1 (block size of four) using an interactive-response-technology system to intramuscular pasireotide 10 mg or 30 mg every 4 weeks for 12 months (in the core phase). We stratified randomisation by screening mUFC concentration (1·5 to <2·0 × ULN and 2·0-5·0 × ULN). The dose could be uptitrated (from 10 mg to 30 mg or from 30 mg to 40 mg) at month 4 if the mUFC concentration was greater than 1·5 × ULN, and at month 7, month 9, or month 12 if the mUFC concentration was greater than 1·0 × ULN. Investigators, patients, site personnel, and those assessing outcomes were masked to dose group allocation. The primary endpoint was the proportion of patients in each group with an mUFC concentration of less than or equal to the ULN at month 7. Efficacy analyses were based on intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01374906. Between Dec 28, 2011, and Dec 9, 2014, we randomly allocated 150 patients to receive pasireotide 10 mg (74 [49%] patients) or 30 mg (76 [51%] patients). The primary efficacy endpoint was met by 31 (41·9% [95% CI 30·5-53·9]) of 74 patients in the 10 mg group and 31 (40·8% [29·7-52·7]) of 76 in the 30 mg group. The most common adverse events were hyperglycaemia (36 [49%] in the 10 mg group and 36 [47%] in the 30 mg group), diarrhoea (26 [35%] and 33 [43%]), cholelithiasis (15 [20%] and 34 [45%]), diabetes mellitus (14 [19%] and 18 [24%]), and nausea (15 [20%] and 16 [21%]). Serious adverse events suspected to be study drug related were reported in eight (11%) patients in the 10 mg group and four (5%) in the 30 mg group. Two (3%) patients in the 30 mg group died during the study (pulmonary artery thrombosis and cardiorespiratory failure); neither death was judged to be related to the study drug. Long-acting pasireotide normalised mUFC concentration in about 40% of patients with Cushing's disease at month 7 and had a similar safety profile to that of twice-daily subcutaneous pasireotide. Long-acting pasireotide is an efficacious treatment option for some patients with Cushing's disease who have persistent or recurrent disease after initial surgery or are not surgical candidates, and provides a convenient monthly administration schedule. Novartis Pharma AG.

Psychological vulnerability to stress in carriers of congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Carriers of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) demonstrate increased secretion of cortisol precursors following ACTH stimulation, suggestive of impaired cortisol production and compensatory increases in hypothalamic corticotropin-releasing hormone (CRH) secretion. Both cortisol and CRH have behavioral effects, and hypothalamic CRH hypersecretion has been associated with chronic states of anxiety and depression. We performed an endocrinologic and psychological evaluation in carriers of 21-OHD and matched control subjects. We recruited 29 parents of children with classic CAH (14 males, 15 females; age (mean±SD): 41.8±5.7 yr), and hence 21-OHD carriers, and 13 normal subjects (5 males, 8 females; age: 43.8±6.1 yr). All subjects underwent a formal ovine (o) CRH stimulation test with measurement of ACTH, cortisol, 17-hydroxyprogesterone (17-OHP) and androstenedione concentrations, which was preceded by determination of 24-hour urinary free cortisol (UFC) excretion. Psychometric assessment was performed by administering the State-Anxiety (STAI 1) and Trait-Anxiety (STAI 2) Inventory, Beck Depression Inventory, Symptom Checklist-90R and Temperament and Character Inventory. Carriers of 21-OHD had significantly higher 17-OHP concentrations following oCRH stimulation and higher STAI 1 (47.6±5.6 vs. 43.3±5.4, P=0.023) scores than control subjects. Mean 24-hour UFC concentrations were positively correlated with paranoid ideation (r=0.435; P=0.023) and psychoticism (r=0.454; P=0.017). Stepwise multiple linear regression analysis revealed that the single independent predictor of STAI 1 was peak stimulated 17-OHP concentrations (β: 0.055, SE: 0.023, R2: 0.290, P=0.031). Carriers of 21-OHD may be predisposed to the development of anxiety disorders.

Cabergoline for Cushing’s disease: a large retrospective multicenter study

The efficacy of cabergoline in Cushing's disease (CD) is controversial. The aim of this study was to assess the efficacy and tolerability of cabergoline in a large contemporary cohort of patients with CD. We conducted a retrospective multicenter study from thirteen French and Belgian university hospitals. Sixty-two patients with CD received cabergoline monotherapy or add-on therapy. Symptom score, biological markers of hypercortisolism and adverse effects were recorded. Twenty-one (40%) of 53 patients who received cabergoline monotherapy had normal urinary free cortisol (UFC) values within 12 months (complete responders), and five of these patients developed corticotropic insufficiency. The fall in UFC was associated with significant reductions in midnight cortisol and plasma ACTH, and with clinical improvement. Compared to other patients, complete responders had similar median baseline UFC (2.0 vs 2.5xULN) and plasma prolactin concentrations but received lower doses of cabergoline (1.5 vs 3.5 mg/week, P < 0.05). During long-term treatment (>12 months), cabergoline was withdrawn in 28% of complete responders because of treatment escape or intolerance. Overall, sustained control of hypercortisolism was obtained in 23% of patients for 32.5 months (19-105). Nine patients on steroidogenesis inhibitors received cabergoline add-on therapy for 19 months (1-240). Hypercortisolism was controlled in 56% of these patients during the first year of treatment with cabergoline at 1.0 mg/week (0.5-3.5). About 20-25% of CD patients are good responders to cabergoline therapy allowing long-term control of hypercortisolism at relatively low dosages and with acceptable tolerability. No single parameter, including the baseline UFC and prolactin levels, predicted the response to cabergoline.

Urinary free cortisol and androgens in the population—Hormone interactions and the relationship with body composition and bone status

ObjectiveAbnormal secretion of thyroid hormones, growth hormone, cortisol and androgens influences body composition. We hypothesised that higher cortisol excretion, in combination with higher androgen and IGF-I concentrations, had a synergistic, favourable effect on body mass and bone. Design, patients and methodsThis was a cross-sectional study on a population sample of 290 women and 93men. The mean age was 65.4±7.2yearsinwomen and 59.7±10.0yearsinmen. Body composition was assessed with bioimpedance, and skeletal health with calcaneal quantitative ultrasound and fracture rate. The influence of urinary free cortisol (UFC), serum DHEAs (women), testosterone (men), free T4andIGF-I on the outcome was studied with regression analyses adjusted for age and body mass index. ResultsIn women, higher concentrations of UFC, DHEAs, IGF-I and lower free T4, were associated with higher fat-free mass. Only a higher UFC concentration was associated with favourable calcaneal measurements. In men, higher testosterone was associated with higher fat-free mass and lower fat mass. Higher IGF-I concentration, but not UFC, was independently associated with higher fat-free mass in men. Interaction analyses did not reveal any additive effects of hormones on body composition or bone in either sex. In both men and women, only age was associated with osteoporotic fractures. ConclusionSerum concentrations of androgens together with IGF-I were positively associated with body composition in both sexes. Urinary cortisol was positively associated with fat-free mass and bone status in women only. Increasing age, but not hormones, was the major determinant of osteoporotic fractures in this population sample.

Incidentally Discovered Aldosterone and Cortisol Cosecreting Adrenal Cortical Adenoma

A substantial proportion of adrenal incidentalomas demonstrates subtle hormonal hypersecretion; however, adenomas that cosecrete aldosterone and cortisol are rare. We here report a case of an adrenal mass that was incidentally detected on a computed tomography scan in a 57-year-old man. The patient had a 10-year history of diabetes mellitus and a 5-year history of hypertension. Evaluation revealed hyperaldosteronemia with an elevated plasma aldosterone-to-renin ratio, hypokalemia, unsuppressed cortisol after dexamethasone administration, and elevated urinary free cortisol concentration. The appearance of the right adrenalectomy specimen indicated adrenal adenoma. Postoperatively, the blood glucose and blood pressure control improved and the urinary cortisol and aldosterone-to-renin ratio normalized. A complete endocrine evaluation in patients with incidentally discovered adrenal masses should be performed, even if the patient has a long-standing history of hypertension and diabetes, to avoid any

Relationships Between 24-Hour Urinary Free Cortisol Concentrations and Metabolic Syndrome in Obese Children

Clinical features of Metabolic Syndrome (MetS) and Cushing's Syndrome are similar, suggesting a pathogenetic role of hypothalamus-pituitary-adrenal axis in MetS. The aim of the study was to determine whether MetS diagnosis and specific clusters of MetS components (waist circumference, dyslipidemia, hypertension, and impaired glucose metabolism) are associated with serum cortisol (SC) or 24-h urinary free cortisol (UFC) levels. We conducted cross-sectional analyses of data from our obesity cohort. We studied 264 obese children (age, 11.0 ± 2.8 years; male, 48%; BMI, 28.2 ± 5.4 kg/m(2)). We examined UFC, SC, homeostasis model assessment (HOMA), and features of MetS (waist circumference, blood pressure, fasting lipids, and glucose). Slightly increased UFC concentrations were measured in 30.7% of the children. Obese children with MetS had significantly (P = .003) higher UFC levels compared with obese children without MetS. Girls demonstrated significantly higher UFC concentrations compared with boys independent of pubertal stage. UFC and SC levels were significantly related to features of MetS, but the associations were stronger for UFC. In multivariate analyses adjusted for age, sex, and body mass index, none of the features of MetS but HOMA index was correlated with UFC, whereas SC demonstrated no significant association to any parameter of MetS or HOMA. Our findings support the hypothesis that changes in the hypothalamus-pituitary-adrenal axis are related to MetS in obesity. UFC seems to be a suitable marker for this relationship. Norm values for UFC adapted to obese children may help to avoid unnecessary dexamethasone suppression tests.

Factitious Cushing's syndrome masquerading as Cushing's disease

Factitious Cushing's syndrome is extremely rare. The diagnosis is challenging as cross-reactivity of synthetic corticosteroids or their metabolites in immunoassay measurements of plasma or urinary cortisol can make distinguishing between true and factitious Cushing's syndrome difficult. Adrenocorticotropin (ACTH) is usually suppressed in factitious Cushing's syndrome. A 54-year-old woman presented with clinical and biochemical features of Cushing's syndrome and an unsuppressed ACTH concentration. She denied recent exogenous corticosteroid use. Initial investigations revealed a markedly elevated urinary free cortisol, mildly elevated midnight salivary cortisol and normal morning cortisol concentration. Plasma ACTH was not suppressed at 13 ng/l (RR 10-60 ng/l). A pituitary MRI was normal, but inferior petrosal sinus sampling (IPSS) revealed a post corticotrophin releasing hormone ACTH ratio >20:1 in the left petrosal sinus. Ketoconazole therapy amplified discordance between the urinary free and morning plasma cortisol concentrations. Further investigation of this discordance using high-pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) revealed a urinary free cortisol excretion of only 20 nmol/24 h, but prednisolone excretion of 16,200 nmol/24 h. Factitious Cushing's syndrome can mimic endogenous ACTH-dependent hypercortisolism during initial investigations and IPSS. This case highlights the importance of (i) recognizing the significance of discordant results; (ii) using an ACTH assay capable of reliably differentiating ACTH-dependent from ACTH-independent Cushing's syndrome; and (iii) appreciating that IPSS is only useful to localize the source of ACTH in confirmed ACTH-dependent Cushing's syndrome. In this case, measurement of corticosteroids by HPLC-MS/MS was essential in reaching the correct diagnosis.

Combined Aldosterone and Cortisol Secretion by Adrenal Incidentaloma

A 70-year-old woman was referred to the authors' unit following hospitalization for cardiac failure, high urinary free cortisol concentrations and severe hypokaliemia. A computed tomography scan of the abdomen showed an adrenal adenoma. The 24-hour urinary free cortisol values were high and plasma cortisol levels failed to suppress following 1 mg dexamethasone test. Aldosterone to plasma renin activity ratio was also pathologic, confirmed by saline load. She showed no symptoms of glucocorticoid excess. She was diagnosed with combined primary hyperaldosteronism and Cushing's syndrome. Cases of adrenal incidentalomas co-secreting cortisol and aldosterone are rare; they should be addressed in patients undergoing adrenal surgery for Conn's syndrome to avoid adrenal insufficiency after removal of the tumor.

Effect of therapeutic doses of mometasone furoate on cortisol levels in children with mild asthma

Corticosteroids are the foundation of pharmacologic treatment for children with asthma. However, high-dose inhaled corticosteroid treatment can cause hypothalamic-pituitary-adrenal (HPA) axis suppression. We investigated the effect of three doses of mometasone furoate administered via dry-powder inhaler (MF-DPI) on the HPA axis in children. Fifty children (6-11 years) with mild asthma of > or =6 months' duration were randomized to MF-DPI, 100 (n = 13), 200 (n = 13), or 400 micrograms b.i.d. (n = 12), or placebo (n = 12) for 29 days. The primary end point was change from baseline in the 12-hour area under the plasma-cortisol-concentration-time curve (AUC). Secondary parameters included plasma cortisol response to cosyntropin stimulation and 24-hour urinary free cortisol concentrations. Compared with placebo, AUC changes associated with treatments of MF-DPI, 100 or 200 micrograms b.i.d., were not significant, whereas a significant change was observed with MF-DPI, 400 micrograms b.i.d. (27%; p = 0.05). Responses to cosyntropin stimulation and urinary cortisol measurements were similar to placebo with all MF-DPI doses. All regimens were well tolerated. MF-DPI did not have a significant effect on plasma or urinary cortisol levels at doses up to 200 micrograms b.i.d. in children with mild asthma. Higher MF-DPI doses may potentially suppress the HPA axis.

Measurement of urinary free cortisol by tandem mass spectrometry and comparison with results obtained by gas chromatography-mass spectrometry and two commercial immunoassays

Determination of urinary free cortisol (UFC) is an important adjunct for the assessment of adrenal function. In this study, we have analysed cortisol concentrations in urine samples by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and two immunoassays. The results were compared with GC-MS. The interference of cortisol ring-A metabolites in immunoassays was also assessed. The GC-MS technique involved solvent extraction, LH-20 clean-up and derivatization. Only solid-phase extraction procedure was used for LC-MS/MS. The samples were analysed in positive electro-spray ionization mode, monitoring the transitions for cortisol and deuterated-cortisol at m/z 363.3 > 121.2 and m/z 365.3 > 122.2, respectively. Immunoassays were performed according to the manufacturer's instructions. When compared with GC-MS results both immunoassays (Coat-A-Count; approximately 1.9-fold, Centaur; approximately 1.6-fold) overestimated UFC concentrations. Cortisol ring-A dihydro- and tetrahydrometabolites contribute significantly to this overestimation. There was no interference by these metabolites in either GC-MS or LC-MS/MS methods. The sensitivity of the LC-MS/MS procedure was 2 nmol/L and the intra- and inter-assay variations were <5% in each quality-control sample. The comparison of the UFC results achieved by assaying the study samples with GC-MS and LC-MS/MS indicated that the agreement between the two methods was excellent (LC-MS/MS = 1.0036GC-MS - 0.0841; r2 = 0.9937). The interference of cortisol ring-A metabolites in immunoassays contribute to overestimation of UFC concentrations. The LC-MS/MS procedure had the sensitivity, specificity, linearity, precision and accuracy for the determination of UFC concentrations. The method is suitable for routine use provided that method-dependant reference values are established.

Gamma Knife surgery for Cushing's disease

In this study the authors address the efficacy and safety of Gamma Knife surgery (GKS) in patients with adrenocorticotropic hormone-secreting pituitary adenomas. A review of data collected from a prospective GKS database between January 1990 and March 2005 was performed in patients with Cushing's disease. All but one patient underwent resection for a pituitary tumor, without achieving remission. Successful endocrine outcome after GKS was defined as a normal 24-hour urinary free cortisol (UFC) concentration posttreatment after a minimum of 1 year of follow up. Patient records were also evaluated for changes in tumor volume, development of new hormone deficiencies, visual acuity, cranial nerve neuropathies, and radiation-induced imaging changes. Ninety evaluable patients had undergone GKS, with a mean endocrine follow-up duration of 45 months (range 12-132 months). The mean dose, to the tumor margin was 23 Gy (median 25 Gy). Normal 24-hour UFC levels were achieved in 49 patients (54%), with an average time of 13 months after treatment (range 2-67 months). In the 49 patients in whom a tumor was visible on the planning magnetic resonance (MR) image, a decrease in tumor size occurred in 39 (80%), in seven patients there was to change in size, and tumor growth occurred in three patients. Ten patients (20%) experienced a relapse of Cushing's disease after initial remission; the mean time to recurrence was 27 months (range 6-60 months). Seven of these patients underwent repeated GKS, with three patients achieving a second remission. New hormone deficiencies developed in 20 patients (22%), with hypothyroidism being the most common endocrinopathy after GKS. Five patients experienced new visual deficits or third, fourth, or sixth cranial nerve deficits; two of these patients had undergone prior conventional fractionated radiation therapy, and four of them had received previous GKS. Radiation-induced changes were observed on MR images in three patients; one had symptoms attributable to these changes. Gamma Knife surgery is an effective treatment for persistent Cushing's disease. Adenomas with cavernous sinus invasion that are not amenable to resection are treatable with the Gamma Knife. A second GKS treatment appears to increase the risk of cranial nerve damage. These results demonstrate the value of combining two neurosurgical treatment modalities-microsurgical resection and GKS-in the management of pituitary adenomas.

Specificity assessment of immunoassay kits for determination of urinary free cortisol concentrations

Background In immunoassay kits for determination of urinary free cortisol (UFC) concentrations, the results vary markedly from kit to kit, so we compared in this study the reaction specificity among 4 commercially available immunoassay kits to determine the applicability of these assays in routine determination of UFC concentrations. Method Using 4 commercially available kits, cross-reaction was investigated. In addition, urine samples were fractionated by HPLC to investigate endogenous immunoreactive cortisol responses. HPLC fractions were subjected to gas chromatography-mass spectrometry (GCMS) to identify substances causing inter-kit assay discrepancies. Results Among the 4 kits, cortisol Kit “TFB” (Immunotech; IOT-RIA method) showed the lowest cross-reaction (2.5%) for prednisolone. Furthermore, on HPLC, 87.8% of the reaction of the entire fraction was seen in the fractions corresponding to the elution position of standard cortisol with the IOT-RIA method; this was the highest percentage among the 4 kits. GCMS revealed that the substance that showed a cross-reaction with the other 3 kits was 5α-tetrahydrocortisol (5α-THF) glucuronide. Conclusions The IOT-RIA method was found to be the most specific for UFC. The other 3 commercially available kits showed cross-reaction with a conjugate of 5α-THF, found to be one of the causes of inter-kit assay discrepancies.

Polycythemia as the first manifestation of Cushing’s disease

A 39-yr-old man presented to our hospital with unexplained erythrocytosis and hypertension. His follow-up for erythrocytosis had begun 2 yr earlier in another hospital and he had been diagnosed with polycythemia rubra vera. On admission to our hospital he was hypertensive (165/95 mmHg) and, except for the presence of moon-like face and facial plethora, his physical examination was normal. His hemoglobin concentration was 19.2 g/dl, and hematocrit was 58.9% with an increased red blood cell mass of 58 ml/kg as measured by radioisotope (Cr51). Blood film, other hematological indices except for elevated leukocyte alkaline phosphatase score, arterial gas analysis, and examination of aspirated bone marrow were all normal. An abdominal ultrasonography showed no evidence of splenomegaly. A diagnosis of probable secondary erythrocytosis was made. Early-morning serum cortisol and 24-h urinary free cortisol concentration as well as serum ACTH were high. Serum cortisol was not suppressed by low-dose dexamethasone, but suppressed by high-dose dexamethasone. Pituitary magnetic resonance imaging showed no lesion. After inferior petrosal sinus sampling suggesting right-central ACTH secretion, the patient underwent transnasal-transsphenoidal pituitary adenomectomy. Both hypercortisolemia and erythrocytosis regressed completely after the adenomectomy. After the operation, the patient's hemoglobin concentration and hematocrit decreased steadily, and 1 month post-adenomectomy his hemoglobin is 14.9 g/dl and hematocrit 44.8%. Thus, Cushing's syndrome should be a routine part of evaluation of unexplained polycythemia.

Urinary-Free Cortisol in Hispanic and Non-Hispanic Children with Mild Asthma and Nonasthmatic Normals

Urinary free cortisol (UFC) concentration is one of the most sensitive indicators of systemic effect of glucocorticoids. The purpose of this study was to determine normal UFC values in healthy children and children with mild asthma in a population of Hispanic and non-Hispanics. Healthy children (n = 64) and children with mild asthma (n = 36), 6 to 16 years old were recruited and admitted to a Clinical Research Center for an observed 24-hour urine collection. No differences were found for UFC (corrected or uncorrected) between healthy and patients with mild asthma or between Hispanic and non-Hispanics. The reference values for UFC/creatinine (Cr), presented as 10th–90th percentile of the mean, were 44.5 µg/g (28.3–70.4) for children with mild asthma and 44.2 µg/g (29.0–55.5) for healthy patients. Significant correlations were found between UFC and age, weight, and height. When UFC was corrected for Cr, the correlation with age and weight disappeared. When UFC was corrected for body surface area (BSA), the correlation with height and weight disappeared. Corrected UFC for Cr offers an index that is independent of age and weight of pediatric patients with no difference between Hispanics and white non-Hispanics. (Pediatr Asthma Allergy Immunol 2006; 19[2]:100–105.)