Glucocorticoid Measurements in Health and Disease - Metabolic Implications and the Potential of 24-h Urine Analyses

Low Urinary Free Cortisol as a Risk Factor for Patients with Variceal Bleeding

Background and Objectives: Specificity and reliability issues of the current cortisol assessment methods lead to limitations on the accurate assessment of relative adrenal insufficiency. Although free cortisol provides a more accurate evaluation of adrenal cortisol production, the expense and time-consuming nature of these assays make them impractical for routine use. Research has, thus, focused on alternative methods, such as indirectly measuring free cortisol using Coolens' equation or directly assessing salivary cortisol concentration, which is considered a more favorable approach despite associated challenges like sampling issues and infection risks. The aim of this study was to explore correlations between 24 h urinary free cortisol (UFC), free plasma cortisol, serum total cortisol, and salivary cortisol as potential reliable indices of free cortisol in the setting of variceal bleeding. Additionally, we assessed the predictive value of UFC for 6-week mortality and 5-day treatment failure in patients with liver cirrhosis and variceal bleeding. Materials and Methods: A total of 40 outpatients with liver cirrhosis and variceal bleeding were enrolled. Free cortisol levels in serum, saliva, and urine were assessed using the electrochemiluminescence immunoassay method. For the measurement of plasma-free cortisol, a single quadrupole mass spectrometer was employed. The quantification of free cortisol was fulfilled by analyzing the signal response in the negative ESI-MS mode. Results: UFC was significantly correlated to free plasma cortisol. Negative correlations were demonstrated between UFC, the Child-Pugh (CP) score, and C reactive protein (CRP) levels. In the multivariate analysis, CP stage C was associated with 6-week mortality risk and portal vein thrombosis with 5-day treatment failure using Cox regression and binary logistic regression analyses, respectively. Patients who experienced rebleeding, infection, or death (or any combination of these events) presented with lower levels of UFC. Conclusions: This study suggests that low levels of UFC may impose a risk factor for patients with liver cirrhosis and variceal bleeding. The use of UFC as an index of adrenal cortisol production in variceal bleeding warrants further investigation.

Maternal hair cortisol concentrations and its association with increased insulin resistance in midpregnancy

PURPOSE

Stress and elevated maternal glycemia have negative effects on pregnancy. We evaluated the association of hair cortisol concentrations (HCC), a marker of chronic stress, with insulin resistance and gestational diabetes (GDM).

METHODS

In total, 527 women from Lima, Peru, provided a hair sample in the second trimester of their pregnancy to measure HCC using liquid chromatography-tandem mass spectrometry. Each 6 cm of hair captured HCC in early (T1=1-12 weeks) and midpregnancy (T2 = 13-24 weeks). GDM diagnosis was conducted in midpregnancy. Multivariable regression models adjusted for putative risk factorsincluding maternal sociodemographic factors, diabetes history, and hair characteristics, were used to estimate the association of HCC with GDM and various glycemic traits.

RESULTS

GDM was diagnosed in 122 (23%) women. Mean HCC across pregnancy was T1 = 3.7 (±3.4) pg/mg and T2 = 4.8 (±3.4) pg/mg. HCC was associated with increased log-transformed units of fasting insulin (T1 = 0.15 [0.03, 0.27], T2 = 0.17 [0.04, 0.30]), homeostasis model assessment for insulin resistance (T1 = 0.14 [0.01, 0.26], T2 = 0.17 [0.03, 0.30]), and homeostasis model assessment for β-cell function (T1 = 0.20 [0.05, 0.34], T2 = 0.20 [0.04, 0.36]), but not with GDM (T1 = 0.95 [0.63, 1.40], T2 = 1.11 [0.74, 1.67]).

CONCLUSIONS

Elevated maternal HCC was associated with abnormal insulin homeostasis in pregnancy. Dysregulation of the hypothalamic-pituitary-adrenal axis, as reflected by high HCC, may also contribute to insulin resistance syndrome in pregnancy.

Stimulated Parotid Saliva Is a Better Method for Depression Prediction

BACKGROUND

Saliva cortisol is considered to be a biomarker of depression prediction. However, saliva collection methods can affect the saliva cortisol level.

OBJECTIVE

This study aims to determine the ideal saliva collection method and explore the application value of saliva cortisol in depression prediction.

METHODS

30 depressed patients and 30 healthy controls were instructed to collect saliva samples in the morning with six collection methods. Simultaneous venous blood was collected. Enzyme-linked immunosorbent assay was used to determine the cortisol level. The 24-observerrated Hamilton depression rating scale (HAMD-24) was used to assess the severity of depression.

RESULTS

The significant differences in saliva cortisol levels depend on the saliva collection methods. The level of unstimulated whole saliva cortisol was most correlated with blood (r = 0.91). The stimulated parotid saliva cortisol can better predict depression. The area under the curve was 0.89. In addition, the saliva cortisol level of the depression patients was significantly higher than the healthy controls. The correlation between the cortisol level and the HAMD-24 score was highly significant. The higher the saliva cortisol level, the higher the HAMD-24 score.

CONCLUSIONS

All the above findings point to an exciting opportunity for non-invasive monitoring of cortisol through saliva.

Quantitation of six steroid hormones by ultra-performance liquid chromatography-tandem mass spectrometry in plasma and prefrontal cortex samples from rats with chronic unpredictable mild stress-induced depression

Steroid hormones such as glucocorticoids and their metabolites are closely related to mental diseases and neuroendocrine diseases. Quantitative analysis of these substances will help in understanding their roles in related research fields. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to detect the concentration of corticosterone (CORT) and its metabolites, progesterone (PROG) and testosterone in rat plasma and prefrontal cortex (PFC), and was applied to investigate the changes in hormones in rats with depression induced by chronic unpredictable mild stress (CUMS). The method was shown to be linear in the quantitation range for all analytes. Intra- and inter-day accuracy and precision were between 80% and 120%. Furthermore, we found that the level of CORT in plasma and PFC increased, whereas that of 11-dehydrocorticosterone (11-DHCORT) as well as the ratio of 11-DHCORT and CORT declined in rats with CUMS-induced depression. The trends of these changes in central PFC and peripheral plasma were consistent. In conclusion, this study successfully established an UPLC-MS/MS method for simultaneous measurement of CORT and its metabolites, PROG and testosterone in rat plasma and PFC, and applied it to rats with depression. The method could be further applied to the research of depression and diseases related to these steroid hormones.

Steroid Metabolism in Children and Adolescents With Obesity and Insulin Resistance: Altered SRD5A and 20α/20βHSD Activity

Alterations in glucocorticoid metabolism may contribute to the development of obesity and insulin resistance (IR). Obesity in turn affects the androgen balance. The peripheral metabolism of steroids is equally an important determinant of their bioavailability and activity. The aim of this study was to evaluate steroid metabolism in obese children and to define which enzyme alterations are associated with IR. Clinical characteristics and anthropometric measurements were determined in 122 obese children and adolescents (72 girls, 50 boys) aged 8 - 18 years. 26 of them (21.3%) were diagnosed with IR (13 boys, 13 girls). Routine laboratory tests were performed and 24h urinary steroid excretion profiles were analyzed by gas chromatography/mass spectrometry. Positive relationship between 5α-reductase (SRD5A) activity and IR was found. According to the androsterone to etiocholanolone (An/Et) ratio the activity of SRD5A was significantly increased in obese children with IR, but the difference remained insignificant once the 5α-dihydrotestosterone to testosterone (5αDHT/T) ratio was considered. Furthermore, this relationship persisted in boys but was not observed in girls. The activity of 20α-hydroxysteroid dehydrogenase (20αHSD) and 20β-hydroxysteroid dehydrogenase (20βHSD) was reduced only in obese girls with IR. Conclude, in the context of obese children and adolescents with IR, we surmise that increased SRD5A represents a compensatory mechanism to reduce local glucocorticoid availability. This phenomenon is probably different in the liver (restriction) and in the adipose tissue (expected increase in activity). We show significant changes in 20αHSD and 20βHSD activity in obese girls with IR, but it is difficult to clearly determine whether the activity of these enzymes is an indicator of the function in their ovaries or adrenal glands.

Co-occurring childhood maltreatment exposure and depressive symptoms in adulthood: Testing differential effects of stress dysregulation and perceived stress

Objectives: Objectives were to explore: 1) the association between sub-groups with different multi-type childhood maltreatment exposures and depressive symptoms in late adulthood, and 2) the mediating effects of dysregulated physiological stress system function and perceived stress in midlife on the aforementioned associations.Methods: Data come from the Biomarker project (n = 1,053) of the Midlife Development in the United States study. Latent profile analysis was used to identify sub-groups with differing childhood maltreatment type and chronicity. We then test our mediation hypothesis using a product of coefficients method procedure.Results: Two vulnerable sub-groups were identified (Class 2: Emotional and physical maltreatment class, n = 52, and Class 3: Sexual abuse class, n = 79) along with a normative sub-group (Class 1: Normative class, n = 922) comprising of a majority of adults. Both vulnerable sub-groups had higher levels of perceived stress in late adulthood. Perceived stress mediated the association between both vulnerable sub-groups and depressive symptoms. Physiological stress dysregulation mediated the association only between the emotional and physical maltreatment class and depressive symptoms in late adulthood.Conclusion: Therapeutic approaches targeted at prevention of perceived stress for both vulnerable sub-groups identified in this study and those targeting physiological dysregulation in addition for the emotional and physical maltreatment class could be critical for depressive symptom recovery.

Maternal Glucocorticoid Metabolism Across Pregnancy: A Potential Mechanism Underlying Fetal Glucocorticoid Exposure

CONTEXT

Across pregnancy, maternal serum cortisol levels increase up to 3-fold. It is not known whether maternal peripheral cortisol metabolism and clearance change across pregnancy or influence fetal cortisol exposure and development.

OBJECTIVES

The primary study objective was to compare maternal urinary glucocorticoid metabolites, as markers of cortisol metabolism and clearance, between the second and third trimester of pregnancy. Secondary objectives were to test associations of total maternal urinary glucocorticoid excretion, with maternal serum cortisol levels and offspring birth weight z score.

DESIGN, PARTICIPANTS, AND SETTING

A total of 151 women with singleton pregnancies, recruited from prenatal clinic at the Pittsburgh site of the Measurement of Maternal Stress (MOMS) study, had 24-hour urine collections during both the second and third trimesters.

RESULTS

Between the second and third trimester, total urinary glucocorticoid excretion increased (ratio of geometric means [RGM] 1.37, 95% CI 1.22-1.52, P < .001), and there was an increase in calculated 5β-reductase compared to 5α-reductase activity (RGM 3.41, 95% CI 3.04-3.83, P < .001). During the third trimester total urinary glucocorticoid excretion and serum cortisol were negatively correlated (r = -0.179, P = .029). Mean total urinary glucocorticoid excretion across both trimesters and offspring birth weight z score were positively associated (β = 0.314, P = .001).

CONCLUSIONS

The estimated activity of maternal enzymes responsible for cortisol metabolism change between the second and third trimester of pregnancy. Additionally, maternal peripheral metabolism and clearance of cortisol may serve as a novel mechanism affecting fetal cortisol exposure and growth.

Cortisol and 11 beta-hydroxysteroid dehydrogenase type 2 as potential determinants of renal citrate excretion in healthy children

BACKGROUND

In patients with Cushing disease, renal citrate excretion is reduced. A low urinary citrate concentration is a risk factor for nephrolithiasis. Since higher acid loading is one major determinant of reduced citrate excretion, we aimed to examine whether glucocorticoids still within the physiological range may already impact on urinary citrate excretion independently of acid-base status.

METHODS

Overall, 132 healthy prepubertal participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study who had collected two successive 24-h urine samples (at 1 and 2 years) before the start of their pubertal growth spurt were included in the study. Net acid excretion capacity (NAEC), urinary potential renal acid load (PRAL), creatinine, calcium, and various cortisol metabolites were measured in all samples. Glucocorticoid quantification was done by GC-MS and radioimmunoassay.

RESULTS

In regression models multivariable-adjusted for 24-h urinary PRAL, NAEC, creatinine and calcium, urinary free cortisol (UFF), 6β-hydroxycortisol, and 20α-dihydrocortisol showed significant inverse relationships (P ≤ 0.02) with 24-h renal citrate output. By contrast, the estimate of renal 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), i.e., the ratio of urinary free cortisone/UFF, associated positively with urinary citrate (P = 0.04).

CONCLUSIONS

In line with studies in hypercortisolic state, even moderately high cortisol levels in healthy children, still within the physiological range, may negatively impact on the kidney's citrate excretion. Besides, a higher 11β-HSD2 activity, favoring cortisol inactivation, is paralleled by an increased citrate excretion.

Measurement of urinary free cortisol by LC-MS-MS: adoption of a literature reference range and comparison with our current immunometric method

PURPOSE

One of the best indicators of adrenal gland dysfunction is the level of free cortisol measured in the 24-h urine (UFC) which faithfully reflects the level of biologically active serum cortisol not subjected to circadian variations. Liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is a sensitive, accurate and precise method recently available in routine laboratories that could remedy interference problems of immunoassays.

METHODS

In this study, a literature reference range for UFC measured by LC-MS-MS was verified, and UFC values measured by LC-MS-MS and immunoassay were compared. Immunometric UFC measurement was performed by ACCESS CORTISOL assay without preliminary extraction, using Beckman Coulter UniCel DxI 600 highly automated platform. Liquid chromatography-tandem mass spectrometry UFC measurement was performed by a home-made validated method using cortisol-D₄ as internal standard with preliminary deproteinization of urinary samples by centrifugal filter and injection on reverse-phase column. Cortisol was analyzed in positive ion mode with an ESI interface.

RESULTS

The reference interval from literature (11-70 μg/day) was confirmed by results obtained for healthy study group. Comparison study of the two methods highlighted a constant and proportional systematic error with a general tendency to overestimate results for the in-use method.

CONCLUSIONS

In conclusion, the direct immunometric method overestimates UFC results with respect to liquid chromatography-tandem mass spectrometry which represents the reference method. The literature reference range 11-70 μg/day was confirmed and can be adopted by our lab that will shift all UFC tests performed in routine to the mass spectrometry-based method, satisfying clinicians' request.

Co-twin relationship quality as a moderator of genetic and environmental factors on urinary cortisol levels among adult twins

Previous research has indicated that genetic and environmental factors shape physiological activity. Cortisol levels, in particular, have received significant attention, with studies indicating substantive heritability estimates across various sampling techniques. A related line of research has indicated that genetic and environmental factors that explain variability in cortisol levels may vary across context and experiences by way of gene-environment interactions (G × Es). Despite these findings, a limited number of studies have examined the extent to which interpersonal relationships may operate as a moderator. The current study focused on co-twin relationship quality as a source of moderation, as twins are more likely to have contact with one another and to form close, interpersonal relationships with their co-twin relative to singleton siblings. Using a sample of 298 adult twins from the National Survey of Midlife Development in the United States (MIDUS), we examined the extent to which genetic and environmental factors that explain variability in urinary cortisol levels varied across levels of co-twin relationship quality. The heritability of cortisol levels was greater and nonshared environmental influences were lower at greater levels of relationship quality. These findings suggest that the heritability of cortisol may vary across context, and positive relationships with others may moderate such factors.

Height Velocity defined metabolic Control in Children with Congenital Adrenal Hyperplasia using urinary GC-MS Analysis

BACKGROUND

Treatment of children with classic congenital adrenal hyperplasia (CAH) with glucocorticoids is a difficult balance between hypercortisolism and hyperandrogenism. Biochemical monitoring of treatment is not well defined. Achievement of a normal growth rate is the most important therapeutic goal.

METHODS

We retrospectively evaluated 123 24-h GC-MS urinary steroid metabolome analyses together with their corresponding one-year height velocity (HV) z-scores in 63 prepubertal children aged 7.2 ± 1.6 years with classic CAH due to 21-hydroxylase deficiency treated with hydrocortisone and fludrocortisone.

RESULTS

Multivariate linear mixed effects model analysis revealed a positive influence of CAH-specific z-scores of summed urinary androgen metabolites (B= 0.97 ± 0.20, t-value = 4.97, P < 0.0001) and a negative influence of the cortisol metabolite tetrahydrocortisol (B= -1.75 ± 0.79, t-value = -2.20, P = 0.03) on HV z-scores. ROC analysis demonstrated that adrenal androgen excess, defined as HV > 1.5 z, was best determined by a z-score of all urinary androgen metabolites of > 0.512 (accuracy 66.2%, sensitivity 57.1 %, specificity 74.4%, positive prediction values (PPV) 66.7%, negative prediction values (NPV) 65.9%). Tetrahydrocortisol excretion > 1480 µg/ m2 BSA/ d in conjunction with suppressed urinary androgen metabolites < 0.163 z indicated overtreatment, defined as HV < -1.5 z (accuracy 79.6 %, sensitivity 40.0 %, specificity 94.9%, PPV 75.0%, NPV 80.4%).

CONCLUSION

We could establish target values for urinary steroid metabolite excretions in children with CAH based on their growth rate. Urinary steroid metabolome analysis represents a highly suitable method for monitoring metabolic control in CAH children.

Impact of Two Forms of Daily Preventive Zinc or Therapeutic Zinc Supplementation for Diarrhea on Hair Cortisol Concentrations Among Rural Laotian Children: A Randomized Controlled Trial

Zinc supplementation has been shown to reduce the morbidity burden among young children, and may reduce chronic stress. Hair cortisol has been promoted as an indicator of chronic stress. We assessed the impact of different strategies for delivering supplementary zinc on hair cortisol concentrations (HCC) in young Laotian children and examined risk factors associated with HCC. In a randomized double-blind controlled trial (NCT02428647), children aged 6⁻23 mo were randomized to one of four intervention groups and followed for ~36 weeks: daily preventive zinc (PZ) tablets (7 mg/day), daily multiple micronutrient powder (MNP) sachets (containing 10 mg zinc and 14 other micronutrients), therapeutic zinc (TZ) supplements for diarrhea treatment (20 mg/day for 10 days) or daily placebo powder. HCC of 512 children was assessed at baseline and endline. ANCOVA and linear regression models were used to assess group differences in HCC and to examine the risk factors associated with HCC, respectively. At enrollment, mean HCC was 28.8 ± 43.9 pg/mg. In models adjusted for age at enrollment, health district, and baseline HCC there was no overall effect of the interventions on endline HCC and change in HCC. When controlling for additional predetermined covariates, there was a marginally significant effect on change in HCC (p = 0.075) with a slightly lower reduction of HCC in TZ compared to PZ (mean change (95% CI): -4.6 (-7.0; -2.3) vs. -9.4 (-11.7; -7.0) pg/mg; p = 0.053). At baseline, consumption of iron rich foods was negatively associated with HCC, whereas AGP (α1-acid glycoprotein) levels, elevated AGP and C-reactive protein and high soluble transferrin receptor were positively associated with HCC. In young Laotian children, MNP, PZ and TZ had no impact on HCC. The marginal difference in change in HCC between the PZ and TZ groups was too small to be considered of health significance.

Hair cortisol and the relationship with chronic pain and quality of life in endometriosis patients

Endometriosis is a chronic estrogen-dependent disease in which pelvic pain is the dominant symptom. The negative effects of endometriosis on the life of women with this disease can be a cause of stress. Stress levels can be measured in different ways, mostly reflecting acute stress responses. Hair cortisol measurements are a reflection of long-term systematic cortisol levels. In this study a first attempt is made to measure cortisol levels in hair of endometriosis patients in comparison with healthy controls. Moreover, it is explored whether chronic pain symptoms as well as different aspects of Health Related Quality of Life (HRQoL) are associated with hair cortisol levels in women with endometriosis. Results show that the mean hair cortisol level is significantly higher in women with endometriosis compared to healthy controls (p = 0.018). There is a positive correlation between hair cortisol level and HRQoL in patients but not in controls (Rho 0.426). The level of hair cortisol does not correlate with the reported pain intensity in patients (Rho -0.082). These results are indicative of an altered HPA-axis function in endometriosis patients, possibly caused by higher chronic stress level in these patients. Moreover, a potential explanation for the positive correlation of cortisol with the HRQoL in these patients is that patients with a high HRQoL have an adequate stress response by increasing their cortisol levels as a response to physical and emotional stress induced by the endometriosis.

5α-reductase activity in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

5α-reductase activity might be important during the development of polycystic ovary syndrome (PCOS). However, the changes of 5α-reductase activity in PCOS subjects and the relationship between 5α-reductase activity and body mass index (BMI), insulin resistance (IR) remain largely unknown.

METHODS

We performed a meta-analysis to examine 5α-reductase activity in women with PCOS; exploratory subgroup analyses were also performed.

RESULTS

Five articles (with 356 cases and 236 controls) reporting 5α-reductase activity in patients with PCOS were selected for the meta-analysis. We observed significantly higher ratios of 5αTHF/THF (5α-reduced tetrahydrocortisol to 5β-reduced tetrahydrocortisol) and An/Et (androsteroneto/etiocholanolone) levels, which were used to assess 5α-reductase activity, among the patients with PCOS, [standardized mean differences (SMD) =0.43, 95%confidence intervals (95%CI) =0.25-0.61, P < 0.00001; SMD = 0.86, 95% CI = 0.29-1.44, P = 0.003]. We observed significant heterogeneity between studies for An/Et (I² = 89% and P < 0.00001). According to the group analysis, women with PCOS exhibited increased 5α-reductase activity which was significantly associated with homeostasis model assessment of insulin resistance (HOMA-IR) regardless of obesity.

CONCLUSIONS

5α-reductase activity was enhanced in women with PCOS. Increased 5α-reductase activity in patients with PCOS was related to IR.

Stress assessment using hair cortisol of kangaroos affected by the lumpy jaw disease

The aim of this study was to objectively assess stress of kangaroos affected by lumpy jaw disease (LJD) using plasma and hair cortisol concentrations. The plasma and hair samples were collected from kangaroos with LJD and healthy controls. Collected hair samples were extracted with methanol after washing with isopropanol, following which they were processed with the cortisol enzyme immunoassay kit. The plasma cortisol concentration of LJD animals tended to be higher than that of the control. Ventral hair cortisol, but not dorsal hair, of LJD animals was significantly higher than that of the control. In conclusion, stress in kangaroos infected with LJD could be assessed by measuring ventral hair cortisol.

Stress-related and basic determinants of hair cortisol in humans: A meta-analysis

The analysis of hair cortisol concentrations (HCC) is a relatively new strategy to measure long-term cumulative cortisol levels, which is increasingly used in psychoneuroendocrinological research. Here, we conduct a first comprehensive meta-analysis of HCC research based on aggregated data from a total of 124 (sub)samples (66 independent studies; total N=10,289). We seek to answer two central questions: (i) Which covariates and basic features of HCC need to be considered in future research? (ii) What are the main determinants of HCC in terms of chronic stress exposure and mental health? Concerning basic characteristics, our findings identify several covariates to be considered (age, sex, hair washing frequency, hair treatment, oral contraceptive use), confirm a decline of HCC from the first to the second proximal 3cm hair segment, and show positive associations between HCC and short-term salivary cortisol measures. Regarding chronic stress, we show that stress-exposed groups on a whole exhibit 22% increased HCC. This long-term cortisol hypersecretion emerges particularly when stress is still ongoing at the time of study (+43% HCC) but is not present in conditions of past/absent stress (-9% HCC, n.s.). We also report evidence for 17%-reduced HCC in anxiety disorders, such as PTSD. Interestingly, no consistent associations with mood disorders and self-reports of perceived stress, depressiveness or social support are found. However, our findings reveal positive associations of HCC with stress-related anthropometric (body mass index, waist-to-hip ratio) and hemodynamic measures (systolic blood pressure). These meta-analytic results are discussed in the light of their practical implications and important areas for future inquiry are outlined.

The degree of urinary hypercortisolism is not correlated with the severity of cushing's syndrome

Cushing syndrome (CS) is characterized by increased morbidity and mortality compared to the general population. However, there are patients who have more clinical aggressive forms than others. Aim of the study is to evaluate whether the degree of hypercortisolism, defined by the number of times urinary free cortisol (UFC) levels exceed the upper limit of the normal range (ULN), is related to the worsening of phenotypic features, as well as metabolic and cardiovascular parameters, in a cohort of CS patients. A cross-sectional study was conducted on 192 patients with active CS, consecutively presenting at the outpatients' clinic of the University Hospitals of Ancona, Naples, and Palermo. Patients were grouped into mild (UFC not exceeding twice the ULN), moderate (2-5 times the ULN), and severe (more than 5 times the ULN) hypercortisolism. Thirty-seven patients (19.3 %) had mild, 115 (59.8 %) moderate, and 40 (20.9 %) severe hypercortisolism. A significant trend of increase among the three groups was demonstrated for 8-, 16-, and 24-h serum cortisol levels (p < 0.001) and serum cortisol after low dose of dexamethasone suppression test (p = 0.001). No significant trend of increase was found regarding phenotype and comorbidities. The degree of hypercortisolism by itself does not appear to be a sufficient parameter to express the severity of CS. Therefore, estimating the severity of CS according to biochemical parameters remains a challenge, while the clinical phenotype and the associated comorbidities might be more useful to assessing the severity of the CS.

High Glucocorticoid Response to 24-h-Shift Stressors in Male but Not in Female Physicians

Physicians' daily work is accompanied by emotional and physical stress, and 24-h shifts are considered to be a major stressor. Effects of stressors on the hypothalamic-pituitary-adrenal (HPA) axis can be evaluated by estimating the glucocorticoid excretion in urine samples. We characterized the impact of a 24-h working period on the urinary glucocorticoid excretion of physicians and focused on gender differences. 10 females and 12 male physicians collected 24-h urine samples during a 24-h shift ("on-duty") and on a free weekend ("off-duty") that were analyzed by gas chromatography-mass spectrometry. Urinary glucocorticoid excretion rates (GERs) were assessed by addition of the 24-h excretion rates per square meter body surface area for the seven major urinary cortisol and cortisone metabolites. Women showed generally lower glucorticoid excretion rates compared to men. Only male physicians had increased GERs on duty compared to off duty. As a measure of change between being on duty and off duty, the ratio GERs on duty/GERs off duty was significantly higher in males than in females. Thus, the 24-h shift stress factor generates diverging results between female and male subjects with activation of the HPA axis primarily in male physicians.

Steroid Metabolomic Disease Signature of Nonsyndromic Childhood Obesity

CONTEXT

The profile of urinary steroids as measured by gas chromatography-mass spectrometry defines a subject's "steroidal fingerprint."

OBJECTIVE

Here, we clustered steroidal fingerprints to characterize patients with nonsyndromic childhood obesity by "steroid metabolomic signatures."

HYPOTHESIS

Nonsyndromic obesity is a symptom of different diseases and conditions, some of them will have their own signature.

DESIGN

A total of 31 steroid metabolites were quantified by gas chromatography-mass spectrometry, and their excretion rates were z-transformed. Using MetaboAnalyst 3.0, we divided the subjects into 5 distinctive groups by k-means clustering. Steroidal fingerprints and clinical/biochemical data of patients in each cluster were analyzed.

PATIENTS

A total of 87 obese children (44 females), aged 8.5-17.9 years, were clinically characterized, and their 24-hour urine was collected.

RESULTS

Cluster 1 (n = 39, 21 females) had normal steroid profile. Cluster 2 (n = 20, 11 females) showed mild, nonspecific elevation of C19 and C21 steroids, females' resistance to polycystic ovary morphology, and hirsutism. Cluster 3 (n = 7 female), with relative 21-hydroxylase insufficiency, was characterized by partial or full polycystic ovary syndrome. Cluster 4 (n = 4 males), showed markedly elevated C21 steroids and imbalance in the 11β-hydroxysteroid dehydrogenase system, higher insulin, increased frequency of glucose/insulin index more than 0.3, γ-glutamyl transpeptidase activity, systolic blood pressure, and tendency to liver steatosis. Cluster 5 (n = 17, 5 females) had elevated dehydroepiandrosterone and 17-OH-pregnenolone metabolites, suggesting 3β-hydroxysteroid dehydrogenase insufficiency but no clinically unique phenotype. Z-score body mass index values were not significantly different between the clusters.

CONCLUSIONS

We defined a novel concept of disease-specific steroid metabolomic signature based on urinary steroidal gas chromatography-mass spectrometry. Clustering by software designed for metabolic data analysis reclassified childhood obesity into 5 groups with distinctive signatures; groups require further definition and may require cluster-specific therapeutic strategies.

Assessing cortisol from hair samples in a large observational cohort: The Whitehall II study

Hair cortisol concentrations (HCC) have been suggested to reflect long-term integrated cortisol levels, but most evidence of associations with co-variates is from small samples of healthy volunteers. The objective of this study was to describe the collection of hair samples in a large cohort study and report associations of demographic and health measures with HCC. We examined HCC measured from the 3cm hair segment near the scalp in 3507 participants (aged 59-83y) from The Whitehall II occupational cohort study of British civil servants. Hair samples were analysed using a column switching LC-APCI-MS/MS assay. Findings from mutually adjusted linear regression analyses revealed lower HCC in participants who reported use of hair dye [% difference (95%CI); -12.5 (-22.0, -1.9), p value=0.022] and evidence suggestive of differences by length of sample storage and seasonal variation. With regard to demographic variables, HCC was lower in women compared to men [-17.0 (-24.8, -8.4), p value <0.001] and higher in Black compared to other ethnic groups. Prevalent diabetes, use of systemic corticosteroids and cardiovascular medication were independently associated with higher HCC. With regard to health, depressive symptoms were associated with higher HCC [20.0 (8.1, 33.3), p value=0.001] following adjustment for physical disease and medication. We conclude that hair steroid analysis presents significant opportunities for assessing cortisol in large scale cohorts. Demographic factors, sample storage, season of collection and hair characteristics should be considered in future analyses. Health status, both mental and physical, is linked to HCC.

Endogenous glucocorticoid analysis by liquid chromatography-tandem mass spectrometry in routine clinical laboratories

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful analytical technique that offers exceptional selectivity and sensitivity. Used optimally, LC-MS/MS provides accurate and precise results for a wide range of analytes at concentrations that are difficult to quantitate with other methodologies. Its implementation into routine clinical biochemistry laboratories has revolutionised our ability to analyse small molecules such as glucocorticoids. Whereas immunoassays can suffer from matrix effects and cross-reactivity due to interactions with structural analogues, the selectivity offered by LC-MS/MS has largely overcome these limitations. As many clinical guidelines are now beginning to acknowledge the importance of the methodology used to provide results, the advantages associated with LC-MS/MS are gaining wider recognition. With their integral role in both the diagnosis and management of hypo- and hyperadrenal disorders, coupled with their widespread pharmacological use, the accurate measurement of glucocorticoids is fundamental to effective patient care. Here, we provide an up-to-date review of the LC-MS/MS techniques used to successfully measure endogenous glucocorticoids, particular reference is made to serum, urine and salivary cortisol.

Correspondence between hair cortisol concentrations and 30-day integrated daily salivary and weekly urinary cortisol measures

Characterization of cortisol production, regulation and function is of considerable interest and relevance given its ubiquitous role in virtually all aspects of physiology, health and disease risk. The quantification of cortisol concentration in hair has been proposed as a promising approach for the retrospective assessment of integrated, long-term cortisol production. However, human research is still needed to directly test and validate current assumptions about which aspects of cortisol production and regulation are reflected in hair cortisol concentrations (HCC). Here, we report findings from a validation study in a sample of 17 healthy adults (mean±SD age: 34±8.6 yrs). To determine the extent to which HCC captures cumulative cortisol production, we examined the correspondence of HCC, obtained from the first 1cm scalp-near hair segment, assumed to retrospectively reflect 1-month integrated cortisol secretion, with 30-day average salivary cortisol area-under-the curve (AUC) based on 3 samples collected per day (on awakening, +30min, at bedtime) and the average of 4 weekly 24-h urinary free cortisol (UFC) assessments. To further address which aspects of cortisol production and regulation are best reflected in the HCC measure, we also examined components of the salivary measures that represent: (1) production in response to the challenge of awakening (using the cortisol awakening response [CAR]), and (2) chronobiological regulation of cortisol production (using diurnal slope). Finally, we evaluated the test-retest stability of each cortisol measure. Results indicate that HCC was most strongly associated with the prior 30-day integrated cortisol production measure (average salivary cortisol AUC) (r=0.61, p=0.01). There were no significant associations between HCC and the 30-day summary measures using CAR or diurnal slope. The relationship between 1-month integrated 24-h UFC and HCC did not reach statistical significance (r=0.30, p=0.28). Lastly, of all cortisol measures, test-retest correlations of serial measures were highest for HCC (month-to-month: r=0.84, p<0.001), followed by 24-h UFC (week-to-week: r's between 0.59 and 0.68, ps<0.05) and then integrated salivary cortisol concentrations (week-to-week: r's between 0.38 and 0.61, p's between 0.13 and 0.01). These findings support the contention that HCC provides a reliable estimate of long-term integrated free cortisol production that is aligned with integrated salivary cortisol production measured over a corresponding one-month period.

Higher diet-dependent renal acid load associates with higher glucocorticoid secretion and potentially bioactive free glucocorticoids in healthy children

Metabolic acidosis induces elevated glucocorticoid (GC) levels. However, the influence of less strong daily acid loads on GCs is largely unexplored. To investigate this, we studied whether higher acid loads in children, fully within the normal range of habitual diets, associate with endogenous GCs. In a specific quasi-experimental design, we examined 200 6- to 10-year-old healthy participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study equally divided to either high or low 24-hour renal net acid excretion. Major urinary GC metabolites were analyzed by gas chromatography-mass spectrometry to assess daily adrenal GC secretion and metabolites of tissue cortisol catabolism (6β-hydroxycortisol and 20α-dihydrocortisol). Liquid chromatography-mass spectrometry was used to quantify urinary free cortisol and cortisone. After confounder adjustment, significant positive associations were unmasked for urinary potential renal acid load and net acid excretion with adrenal GC secretion, free cortisone, free cortisone plus cortisol, 6β-hydroxycortisol, and 20α-dihydrocortisol. An inverse association emerged for an enzymatic marker (5β-reductase) of irreversible GC inactivation. Our data suggest that existing moderate elevations in diet-dependent acid loads suffice to raise GCs and affect cortisol metabolism. Thus, potential detrimental effects of high acid loading appear to be mediated, in part, by increased GC activity via increased GC secretion and/or reduced GC inactivation. Higher cortisone levels, directly available for intracrine activation to cortisol may play a special role.

Glucocorticoid activity and metabolism with NaCl-induced low-grade metabolic acidosis and oral alkalization: results of two randomized controlled trials

Low-grade metabolic acidosis (LGMA), as induced by high dietary acid load or sodium chloride (NaCl) intake, has been shown to increase bone and protein catabolism. Underlying mechanisms are not fully understood, but from clinical metabolic acidosis interactions of acid-base balance with glucocorticoid (GC) metabolism are known. We aimed to investigate GC activity/metabolism under alkaline supplementation and NaCl-induced LGMA. Eight young, healthy, normal-weight men participated in two crossover designed interventional studies. In Study A, two 10-day high NaCl diet (32 g/d) periods were conducted, one supplemented with 90 mmol KHCO3/day. In Study B, participants received a high and a low NaCl diet (31 vs. 3 g/day), each for 14 days. During low NaCl, the diet was moderately acidified by replacement of a bicarbonate-rich mineral water (consumed during high NaCl) with a non-alkalizing drinking water. In repeatedly collected 24-h urine samples, potentially bioactive-free GCs (urinary-free cortisol + free cortisone) were analyzed, as well as tetrahydrocortisol (THF), 5α-THF, and tetrahydrocortisone (THE). With supplementation of 90 mmol KHCO3, the marker of total adrenal GC secretion (THF + 5α-THF + THE) dropped (p = 0.047) and potentially bioactive-free GCs were reduced (p = 0.003). In Study B, however, GC secretion and potentially bioactive-free GCs did not exhibit the expected fall with NaCl-reduction as net acid excretion was raised by 30 mEq/d. Diet-induced acidification/alkalization affects GC activity and metabolism, which in case of long-term ingestion of habitually acidifying western diets may constitute an independent risk factor for bone degradation and cardiometabolic diseases.

Psychogenic Stress in Hospitalized Dogs: Cross Species Comparisons, Implications for Health Care, and the Challenges of Evaluation

Simple Summary

The effects of stress on health outcomes in animals are well documented. Veterinary clinicians may be able to improve their patients’ care by better understanding how to recognize and reduce stress in those patients. This review will describe the physiology of the mammalian stress response and known health consequences of psychogenic, rather than physical, stress; as well as methods of measuring stress in animals. While the review will address stress in a range of domestic species, it will specifically focus on dogs.

Abstract

Evidence to support the existence of health consequences of psychogenic stress has been documented across a range of domestic species. A general understanding of methods of recognition and means of mitigation of psychogenic stress in hospitalized animals is arguably an important feature of the continuing efforts of clinicians to improve the well-being and health of dogs and other veterinary patients. The intent of this review is to describe, in a variety of species: the physiology of the stress syndrome, with particular attention to the hypothalamic-pituitary-adrenal axis; causes and characteristics of psychogenic stress; mechanisms and sequelae of stress-induced immune dysfunction; and other adverse effects of stress on health outcomes. Following that, we describe general aspects of the measurement of stress and the role of physiological measures and behavioral signals that may predict stress in hospitalized animals, specifically focusing on dogs.

Adrenal gland volume, intra-abdominal and pericardial adipose tissue in major depressive disorder

Major depressive disorder (MDD) is associated with an increased risk for the development of cardio-metabolic diseases. Increased intra-abdominal (IAT) and pericardial adipose tissue (PAT) have been found in depression, and are discussed as potential mediating factors. IAT and PAT are thought to be the result of a dysregulation of the hypothalamus-pituitary-adrenal axis (HPAA) with subsequent hypercortisolism. Therefore we examined adrenal gland volume as proxy marker for HPAA activation, and IAT and PAT in depressed patients. Twenty-seven depressed patients and 19 comparison subjects were included in this case-control study. Adrenal gland volume, pericardial, intraabdominal and subcutaneous adipose tissue were measured by magnetic resonance imaging. Further parameters included factors of the metabolic syndrome, fasting cortisol, fasting insulin, and proinflammatory cytokines. Adrenal gland and pericardial adipose tissue volumes, serum concentrations of cortisol and insulin, and serum concentrations tumor-necrosis factor-α were increased in depressed patients. Adrenal gland volume was positively correlated with intra-abdominal and pericardial adipose tissue, but not with subcutaneous adipose tissue. Our findings point to the role of HPAA dysregulation and hypercortisolism as potential mediators of IAT and PAT enlargement. Further studies are warranted to examine whether certain subtypes of depression are more prone to cardio-metabolic diseases.

Higher glucocorticoid secretion in the physiological range is associated with lower bone strength at the proximal radius in healthy children: importance of protein intake adjustment

Whether higher production of glucocorticoids (GCs) within the physiological range may already be affecting bone status in healthy children is unknown. Because dietary protein intake affects both bone and GCs, we examined the association of urinary measures of glucocorticoid status and cortical bone in healthy non-obese children, after particularly controlling for protein intake. Proximal forearm bone parameters were measured by peripheral quantitative computed tomography (pQCT). Subjects studied (n = 175, 87 males, aged 6 to 18 years) had two 24-hour urine samples collected: the first sample at 1 year before bone measurement, and the second sample at the time of bone measurement. Major urinary GC metabolites were measured by mass spectrometry and summed to assess daily adrenal GC secretion (∑C21). Urinary free cortisol (UFF) and cortisone (UFE) were summed to assess potentially bioactive free GCs (UFF + UFE). After controlling for several covariates and especially urinary nitrogen (the biomarker of protein intake) cortisol secretion ∑C21 was inversely associated with all analyzed pQCT measures of bone quality. ∑C21 also predicted a higher endosteal and lower periosteal circumference, explaining both a smaller cortical area and (together with lower BMD) a lower strength-strain-index (SSI). UFF + UFE, UFE itself, and a urinary metabolite-estimate of 11beta-hydroxysteroid dehydrogenase type1 (11beta-HSD1) activity showed corresponding reciprocal associations (p < 0.05) with BMD and bone mineral content, but not with SSI and bone geometry variables. In conclusion, higher GC levels, even within the physiological range, appear to exert negative influences on bone modeling and remodeling already during growth. Our physiological data also suggest a relevant role of cortisone as the direct source for intracrine-generated cortisol by bone cell 11beta-HSD1.

24 h urinary free cortisol in large-scale epidemiological studies: short-term and long-term stability and sources of variability

BACKGROUND

Function of the hypothalamus-pituitary-adrenal (HPA) axis has been associated with several somatic and psychiatric health problems. The amount of free cortisol excreted in the urine during 24h (24-h UFC) has often been used as a proxy for HPA-axis function. Reference values for 24-h UFC and their stability in the short and long term, as well as sources of variability, are largely lacking.

METHODS

This study was performed in a general population cohort. Participants collected 24-h UFC on two consecutive days (T1), and repeated this collection approximately 2 years later (T2). Cortisol in urine was measured using LC-MS/MS. Height and weight were measured at the research facilities; glomerular filtration rate was estimated using creatinine clearance. Psychological distress (General Health Questionnaire), smoking, alcohol use and exercise were measured by means of questionnaires.

RESULTS

24-h UFC stability on a day-to-day basis was 0.69 (T1, N=1192) and 0.72 (T2, N=963) (both p<0.001). Long-term stability as indicated by correlation between 2-day averages of T1 and T2 was 0.60 (N=972, p<0.001). Multivariable linear regression analysis revealed that 24-h UFC was predicted by urine volume (standardized beta 0.282 (T1, N=1556) and 0.276 (T2, N=1244); both p<0.001) and glomerular filtration rate (standardized beta 0.137 (T1) and 0.179 (T2); both p<0.001), while also sex explained a small part (standardized beta for female sex -0.057 (T1) and -0.080 (T2); both p<0.05).

CONCLUSION

24-h UFC is moderately stable both in the short and the long term. The effects of urine volume and glomerular filtration rate on 24-h UFC are much stronger than those of sex.

Diminished 11β-hydroxysteroid dehydrogenase type 2 activity is associated with decreased weight and weight gain across the first year of life

CONTEXT

Low birth weight is associated with adverse metabolic outcome in adulthood. Exposure to glucocorticoid (GC) excess in utero is associated with decreased birth weight, but the prospective longitudinal relationship between GC metabolism and growth has not been examined.

OBJECTIVE

We have hypothesized that changes in GC metabolism leading to increased availability may impair growth.

DESIGN

This was a prospective, longitudinal study with clinical measurements and 24-hour urinary steroid metabolite analysis at 1, 4, 12, 26, and 52 weeks after delivery in mothers and their babies.

SETTING

The study was conducted with observations and samples collected in the volunteers' own homes.

PARTICIPANTS

Healthy mothers and newborn babies/infants participated in the study.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

Urinary steroid metabolite excretion quantified by gas chromatography/mass spectroscopy across the first year of life in relation to change in weight was measured.

RESULTS

The total production of the GC metabolites quantified increased across the first year of life. Markers of 11β-hydroxysteroid dehydrogenase type 1 activity increased from the age of 3 months as did those of 5α-reductase activity. After correcting for confounding variables, low markers of 11β-hydroxysteroid dehydrogenase type 2 activity was associated with reduced absolute weight and decreased weight gain over the first year of life. In the mothers, 5α-reductase activity was low at birth and progressively increased to normal over the first 6 months postpartum.

CONCLUSIONS

Increased GC exposure as a consequence of reduced 11β-hydroxysteroid dehydrogenase type 2 activity is likely to be a critical determinant of growth in early life. This not only highlights the central role of GCs and their metabolism, but also emphasizes the need for detailed longitudinal analyses.

11β Hydroxysteroid dehydrogenase type 2 and dietary acid load are independently associated with blood pressure in healthy children and adolescents

BACKGROUND

The reduced activity of 11β hydroxysteroid dehydrogenase type 2 (11βHSD2) contributes to elevated blood pressure (BP) in clinical syndromes, but its effect on BP in the physiologic range is unclear.

OBJECTIVES

We examined the association of 11βHSD2 activity with BP in healthy children independent of known BP-related dietary and other factors and determined whether the diet-dependent acid load may constitute a dietary factor related to BP.

DESIGN

We conducted a cross-sectional analysis in 267 healthy children (age range: 4-14 y) who provided a 24-h urine sample, a parallel 3-d weighed dietary record, and 1-3 BP measurements ±1.5 y around the urine collection. The ratio of urinary free cortisone to cortisol measured by using a radioimmunoassay was used as an index for 11βHSD2. Urinary net acid excretion and the urinary and dietary potential renal acid load (PRAL) were used to predict the diet-dependent acid load. The PRAL was calculated as the sum of major mineral nonbicarbonate anions minus the sum of mineral cations. Sex-, age- and height-independent SD scores (SDSs) of systolic and diastolic BP were used as outcomes in linear regression analyses.

RESULTS

11βHSD2 was inversely associated with systolic BP SDSs in basic models and in analyses adjusted for body size, maternal BP, breastfeeding, and dietary intakes of total energy, salt, and fruit and vegetables (P = 0.03). In models that included indexes of dietary acid load instead of fruit and vegetables, all 3 acid-load biomarkers were significantly (P = 0.006-0.02) directly related to systolic BP.

CONCLUSION

A lower 11βHSD2 activity and higher dietary acid load may independently contribute to higher systolic BP in healthy children.

Molecular genetics of the adrenocortical axis and breeding for robustness

The concept of robustness refers to the combination of a high production potential and a low sensitivity to environmental perturbations. The importance of robustness-related traits in breeding objectives is progressively increasing toward the production of animals with a high production level in a wide range of climatic conditions and production systems, together with a high level of animal welfare. Current strategies to increase robustness include selection for "functional traits," such as skeletal and cardiovascular integrity, disease resistance, and mortality at various stages. It is also possible to use global evaluation of sensitivity to the environment (eg reaction norm analysis or canalization), but these techniques are difficult to implement in practice. The glucocorticoid hormones released by the adrenal cortex exert a wide range of effects on metabolism, the cardiovascular system, inflammatory processes, and brain function, for example. Protein catabolism toward energy production and storage (lipids and glycogen) supports their pivotal role in stress responses aiming at the adaptation and survival of individuals under strong environmental pressure. Large individual variations have been described in adrenocortical axis activity, with important physiopathological consequences. In terms of animal production, higher cortisol levels have negative effects on growth rate and feed efficiency and increase the fat:lean ratio of carcasses. On the contrary, cortisol has positive effects on functional traits and adaptation. Intense selection for lean tissue growth and more generally high protein output during the past decades has concomitantly reduced cortisol production, which may be responsible for the negative effects of selection on functional traits. In this paper, we review experimental evidence suggesting that the balance between production and functional traits was modified in favor of improved robustness by selecting animals with higher adrenocortical axis activity, as well as the molecular genetic tools that can be used to fine-tune this objective.

Breeding for robustness: the role of cortisol

Robustness in farm animals was defined by Knap as 'the ability to combine a high production potential with resilience to stressors, allowing for unproblematic expression of a high production potential in a wide variety of environmental conditions'. The importance of robustness-related traits in breeding objectives is progressively increasing towards the production of animals with a high production level in a wide range of climatic conditions and production systems, together with a high level of animal welfare. Current strategies to increase robustness include selection for 'functional traits', such as skeletal and cardiovascular integrity, disease resistance and mortality in various stages. It is also possible to use global evaluation of sensitivity to the environment (e.g. reaction norm analysis or canalization), but these techniques are difficult to implement in practice. The hypothalamic-pituitary-adrenocortical (HPA) axis is the most important stress-responsive neuroendocrine system. Cortisol (or corticosterone) released by the adrenal cortices exerts a large range of effects on metabolism, the immune system, inflammatory processes and brain function, for example. Large individual variations have been described in the HPA axis activity with important physiopathological consequences. In terms of animal production, higher cortisol levels have negative effects on growth rate and feed efficiency and increase the fat/lean ratio of carcasses. On the contrary, cortisol has positive effects on traits related to robustness and adaptation. For instance, newborn survival was shown to be directly related to plasma cortisol levels at birth, resistance to bacteria and parasites are increased in animals selected for a higher HPA axis response to stress, and tolerance to heat stress is better in those animals that are able to mount a strong stress response. Intense selection for lean tissue growth during the last decades has concomitantly reduced cortisol production, which may be responsible for the negative effects of selection on piglet survival. One strategy to improve robustness is to select animals with higher HPA axis activity. Several sources of genetic polymorphism have been described in the HPA axis. Hormone production by the adrenal cortices under stimulation by adrenocorticotropin hormone is a major source of individual differences. Several candidate genes have been identified by genomic studies and are currently under investigation. Bioavailability of hormones as well as receptor and post-receptor mechanisms are also subject to individual variation. Integration of these different sources of genetic variability will allow the development of a model for marker-assisted selection to improve animal robustness without negative side effects on production traits.

Salivary cortisol in ambulatory assessment--some dos, some don'ts, and some open questions

The impact of stress on health and disease is an important research topic in psychosomatic medicine. Because research on hypothalamic-pituitary-adrenal (HPA) axis regulation under controlled laboratory studies lacks ecological validity, it needs to be complemented by a research program that includes momentary ambulatory assessment. The measurement of salivary cortisol offers the possibility to trace the free steroid hormone concentrations in ambulant settings. Therefore, in this article, we first discuss the role of salivary cortisol in ambulatory monitoring. We start with a brief description of HPA axis regulation, and we then consider cortisol assessments in other organic materials, followed by a presentation of common salivary markers of HPA axis regulation suitable for ambulatory assessment. We further provide an overview on assessment designs and sources of variability within and between subjects (intervening variables), acknowledge the issue of (non)compliance, and address statistical aspects. We further give an overview of associations with psychosocial and health-related variables relevant for ambulatory assessment. Finally, we deal with preanalytical aspects of laboratory salivary cortisol analysis. The relative simplicity of salivary cortisol assessment protocols may lead to an overoptimistic view of the robustness of this method. We thus discuss several important issues related to the collection and storage of saliva samples and present empirical data on the stability of salivary cortisol measurements over time.

Prepubertal glucocorticoid status and pubertal timing

CONTEXT

Whether prepubertal glucocorticoid status impacts on the timing of puberty is not clear.

OBJECTIVE

The objective of the study was to examine the relationship between prepubertal glucocorticoid status and early or late pubertal markers, independent of adrenarchal and nutritional status.

DESIGN AND PARTICIPANTS

Prospective cohort study of healthy Caucasian children (n = 111, 56 boys) who provided both 24-h urine samples and weighed dietary records 1 and 2 yr before the start of pubertal growth spurt [age at take-off (ATO)].

MEASUREMENTS

Major urinary glucocorticoid and androgen metabolites determined by gas chromatography-mass spectrometry analysis were summed to assess daily overall cortisol (ΣC21) and adrenal androgen secretion; urinary free cortisol and cortisone measured by RIA were summed (UFF+UFE) as an indicator of potentially bioactive free glucocorticoids.

MAIN OUTCOMES

The main outcomes included ATO, age at peak height velocity, age at menarche/voice break, ages at Tanner stage 2 for breast (girls) and genital (boys) development, and pubic hair.

RESULTS

In girls ΣC21, but not UFF+UFE, was associated with pubertal markers after adjusting for overall adrenal androgen, urinary nitrogen, and body fat. Girls with higher ΣC21 (fourth quartile) reached ATO 0.7 yr (P = 0.01) and menarche 0.9 yr later (P = 0.006) than girls with lower ΣC21 (first quartile). The ΣC21 tended to be also positively associated with age at Tanner stage 2 for breast (P = 0.1), Tanner stage 2 for pubic hair (P = 0.1), and age at peak height velocity (P = 0.06). In boys, neither the ΣC21 nor UFF+UFE was related to pubertal timing.

CONCLUSION

An individually higher prepubertal glucocorticoid secretion level, even in physiological range, appears to delay early and late pubertal timing of healthy girls, particularly their onset of pubertal growth spurt and menarche.

Urine volume dependency of specific dehydroepiandrosterone (DHEA) and cortisol metabolites in healthy children

Urine volume should be considered as a confounder when using urinary free cortisol (UFF) and cortisone (UFE) to assess glucocorticoid (GC) status. We aimed to examine whether adrenal androgen (AA) metabolites may be also affected by urine volume in healthy children. To compare the flow dependence of GC and AA metabolites, specific GC metabolites were examined. In 24-h urine samples of 120 (60 boys) healthy children (4-10 yr), steroid profiles were determined by GC-MS analysis, UFF and UFE by radioimmunoassay. To assess daily AA and GC secretion rates, 7 quantitatively most important AA (∑C19) and GC (∑C21) metabolites were summed. Sum of DHEA and its 16α-hydroxylated metabolites were denoted as DHEA&M. Association of urine volume with AA (∑C19, DHEA&M, DHEA, 16α-hydroxy-DHEA, 3β,16α,17β-androstenetriol) and GC (∑C21, UFF, UFE, 6β-hydroxycortisol, 20α-dihydrocortisol) were examined in linear regression models. Among the examined AA metabolites, 16α-hydroxy-DHEA (β=0.56, p<0.0001) and DHEA (β=0.43, p=0.05) showed relatively strong association with urine volume. A trend was seen for ∑C19 (β=0.23, p=0.08), but not for DHEA&M (p>0.1). Regarding GC metabolites, urine volume showed a stronger association with cortisol's direct metabolites, i.e., cortisone, 6β-hydroxycortisol and 20α-dihydrocortisol (β=0.4-0.6, p<0.01) than with cortisol itself (β=0.28, p<0.05). ∑C21 was not associated with urine volume. In conclusion, like UFF and UFE, renal excretion of DHEA, 16α-hydroxy-DHEA, 6β-hydroxycortisol, and 20α-dihydrocortisol may also depend on urine volume. The intrarenal production of the latter three and cortisone might explain their relative strong water-flow-dependency. Total AA or GC secretion marker appears not to be relevantly confounded by urine volume.

Associations between job strain and the cortisol/DHEA-S ratio among management and nonmanagement personnel

OBJECTIVE

To assess associations between the main, nonlinear, and interactive effects of the demand-control-support (DCS) model and the cortisol/dehydroepiandrosterone sulfate (DHEA-S) ratio, a biomarker of psychophysical well-being.

METHODS

Subjects were 596 employees from all occupational levels of a German airplane manufacturing plant. Multiple regression models controlling for age and gender were computed separately for employees with (n = 103) and without (n = 493) management responsibilities.

RESULTS

Among employees without management responsibilities, the dimensions of the DCS model did not predict the cortisol/DHEA-S ratio. In contrast, among employees with management responsibilities, both linear and nonlinear job demand effects explained a substantial fraction of the cortisol/DHEA-S variance. Increasing levels of job demands were associated with decreasing cortisol/DHEA-S ratios (linear effect) with the quartile of moderately high levels of job demands representing an optimal level. Furthermore, we observed a significant nonlinear effect with job control and a significant interaction between job demands and job control among employees with management responsibilities. These results suggest a beneficial effect associated with moderate levels of job control. This may be due to a buffering effect against adverse levels of job demands (interactive effect) and the independent association with decreased cortisol/DHEA-S ratios (nonlinear effect).

CONCLUSION

This is the first study that provides evidence that the DCS model is associated with the cortisol/DHEA-S ratio. Among employees with management responsibilities, moderate levels of job control may help managers to cope effectively with job demands and may induce a favorable cortisol/DHEA-S ratio.

Profiling oestrogens and testosterone in human urine by stable isotope dilution/benchtop gas chromatography-mass spectrometry

Oestrogens, such as oestrone (E(1)), 17β-oestradiol (E(2)), oestriol (E(3)) and their biologically active metabolites 2-methoxyoestrone (2-MeOE(1)), 2-hydroxyoestradiol (2-OHE(2)) 16-ketooestradiol (16-OE(2)), 16-epioestriol (16-epiE(3)), as well as testosterone (T) play an important role in physiological and pathological developmental processes during human development. We therefore aimed at developing an isotope dilution/bench top gas chromatography-mass spectrometry (ID/GC-MS) method, based on benchtop GC-MS, for the simultaneous determination ('profiling') of the above analytes in children. The method consisted of equilibration of urine (5 ml) with a cocktail containing stable isotope-labelled analogues of the analytes as internal standards ([2,4-(2)H(2)]E(1), [2,4,16,16-(2)H(4)]E(2), [2,4,17-(2)H(3)]E(3), [16,16,17-(2)H(3)]T, [1,4,16,16-(2)H(4)]2-MeOE(1), [1,4,16,16,17-(2)H(5)]2-OHE(2), [2,4,15,15,17-(2)H(5)]16-OE(2) and [2,4-(2)H(2)]16-epiE(3)). Then, solid-phase extraction (C(18) cartridges), enzymatic hydrolysis (sulphatase from Helix pomatia (type H-1)), re-extraction, purification by anion exchange chromatography and derivatisation to trimethylsilyl ethers followed. The samples were analysed by GC-MS (Agilent GC 6890N/5975MSD; fused silica capillary column 25 m × 0.2 mm i.d., film 0.10 μm). Calibration plots were linear and showed excellent reproducibility with coefficients of determination (r(2)) between 0.999 and 1.000. Intra- and inter-assay coefficients of variation (CV) were <2.21% for all quantified metabolites. Sensitivity was highest for 2-OHE(2) (0.25 pg per absolute injection: signal-to-noise ratio (S/N)=3) and lowest for 16-epiE(3) (2 pg per absolute injection: S/N=2.6), translating into corresponding urine sample analyte concentrations of 0.025 ng ml(-1) and 0.2 ng ml(-1), respectively. Accuracy - determined in a two-level spike experiment - showed relative errors ranging between 0.15% for 16-OE(2) and 11.63% for 2-OHE(2). Chromatography showed clear peak shapes for the components analysed. In summary, we describe a practical, sensitive and specific ID/GC-MS assay capable of profiling the above-mentioned steroids in human urine from childhood onwards.

Biological mechanisms related to the effectiveness of guided imagery for chronic pain

Specific aims of this pilot study were to (a) determine the effect of a guided imagery (GI) intervention over an 8-week period on pain and pain disability in a sample of persons with chronic noncancer pain (CNCP) and (b) analyze the mediating effects of neuroendocrine and neuroimmune functioning on the effectiveness of GI on outcome variables. A simple interrupted time-series design (12-week period) was used. GI was introduced at Week 4 and used daily by 25 participants for the remaining 8 weeks. Measures of pain and pain disability were obtained at the beginning of the study period and at six repeated 2-week intervals. Measures of hypothalamic-pituitary-adrenal (HPA) axis activation (plasma cortisol), immune-mediated analgesia (lymphocyte subset counts and proliferation), and immune-mediated hyperalgesia (interleukin-1β) were obtained at the beginning of the study and at Week 11. Usual pain levels were lower after the introduction of GI at Week 4 (Wilks' λ = 52.31; df = 2, 22; p = .000). Pain disability levels were lower after the introduction of GI at Week 4 (Wilks' λ = 5.98; df = 6, 18; p = .001). Correlation coefficients between change scores of dependent variables and mediating variables were not significant. GI was effective in reducing pain intensity and pain disability over an 8-week period; however, the results did not support the expected effects of decreased HPA axis activation, improved immune-mediated analgesia, and reduced immune-mediated hyperalgesia in mediating these outcomes. These findings may be related to procedural and theoretical issues and limitations related to the study design.

Brief review: glucocorticoid excretion in obesity

Cortisol secretion and glucocorticoid excretion rates are regularly increased in obesity and associate with indices of body size and visceral adiposity. Different mechanisms may underlie the elevated urinary excretion rates of cortisol metabolites in obesity. In the present brief overview, potential mechanisms are discussed, paying special attention to cortisol metabolism. Besides, potential confounding factors in the evaluation of urinary glucocorticoid excretion are highlighted.

Steroid assays in paediatric endocrinology

Most steroid disorders of the adrenal cortex come to clinical attention in childhood and in order to investigate these problems, there are many challenges to the laboratory which need to be appreciated to a certain extent by clinicians. The analysis of sex steroids in biological fluids from neonates, over adrenarche and puberty present challenges of specificities and concentrations often in small sample sizes. Different reference ranges are also needed for interpretations. For around 40 years, quantitative assays for the steroids and their regulatory peptide hormones have been possible using immunoassay techniques. Problems are recognised and this review aims to summarise the benefits and failings of immunoassays and introduce where tandem mass spectrometry is anticipated to meet the clinical needs for steroid analysis in paediatric endocrine investigations. It is important to keep a dialogue between clinicians and the laboratory, especially when any laboratory result does not make sense in the clinical investigation.

Glucocorticoids and body fat associated with renal uric acid and oxalate, but not calcium excretion, in healthy children

In patients with hypercortisolism, who are frequently obese, the prevalence of elevated urinary excretion rates of the potential lithogenic factors (calcium, oxalate, and uric acid) is increased. We examined whether the 24-hour urinary excretion rates of calcium, oxalate, and uric acid are already associated with body fat and endogenous glucocorticoids in healthy free-living children, taking relevant nutritional and acid-base factors into account. Urinary analyte excretions were determined in 24-hour urine samples of 300 healthy children aged 4 to 14 years. Potentially bioactive free glucocorticoids were assessed as urinary free cortisol + urinary free cortisone. Associations of glucocorticoids and percentage body fat with the outcome variables were examined in regression models adjusted for sex, height, growth velocity, urinary volume, net acid excretion, and relevant nutritional factors. Percentage body fat and urinary free cortisol + urinary free cortisone explained most of the growth-independent variation of urinary uric acid and also a relevant part of oxalate, but none of calcium. Net acid excretion, an indicator of endogenous acid production, and dietary protein, salt, and fiber intakes were also variably associated with the outcomes urinary calcium, oxalate, and uric acid. In conclusion, body fatness and potentially bioactive free glucocorticoids (even in the physiologic range) appear to affect urinary excretion rates of oxalate and uric acid, whereas urinary calcium output is more strongly related to dietary factors in healthy children. Our data provide the first in vivo-based evidence that the obesity- or hypercortisolism-associated urolithiasis may be a pathophysiologic continuation of the corresponding endocrine metabolic variations in healthy children.