Clinical review: The pathogenetic role of cortisol in the metabolic syndrome: a hypothesis

Monosodium l-glutamate-obesity onset is associated with disruption of central control of the hypothalamic-pituitary-adrenal axis and autonomic nervous system

The hypothalamic-pituitary-adrenal axis (HPA) exerts important catabolic peripheral effects and influences autonomic nervous system (ANS)-mediated processes. Impaired negative-feedback control or reduced HPA axis sensitivity and altered ANS activity appear to be associated with the development and maintenance of obesity. In the present study, we examined the hypothesis that the central HPA axis is dysregulated favouring ANS disbalance in monosodium l-glutamate (MSG)-induced rat obesity. Glucose homeostasis, corticosterone, leptin and ANS electrical activity were evaluated. Adult MSG-induced obese rats exhibited fasting hyperinsulinaemia, insulin resistance, glucose intolerance, hypercorticosteronaemia, hyperleptinaemia and altered ANS activity. A decrease in food intake was observed during corticotrophin-releasing hormone (CRH) treatment in both control and MSG-treated rats. By contrast, food intake was significantly elevated in control rats treated with dexamethasone (DEXA), whereas no alterations were observed following DEXA treatment in MSG-induced obese rats. After DEXA injection, an increase in fasting insulin and glucose levels, associated with insulin resistance, was seen in both groups. As expected, there was a decrease of parasympathetic activity and an increase of sympathetic nervous activity in CRH-treated control animals and the opposite effect was seen after DEXA treatment. By contrast, there was no effect on ANS activity in MSG-rats treated with CRH or DEXA. In conclusion, impairment of the HPA axis can lead to disbalance of ANS activity in MSG-treated rats, contributing to the establishment and maintenance of obesity.

Effects of interleukin-1 antagonism on cortisol levels in individuals with obesity: a randomized clinical trial

BACKGROUND

Anti-inflammatory treatment with interleukin-1 (IL-1) antagonism decreases both cortisol and adrenocorticotropin hormone (ACTH) levels in individuals with obesity in short term. However, it remains unknown whether these effects persist upon prolonged treatment.

METHODS

In this double-blind, parallel-group trial involving patients with features of the metabolic syndrome, 33 patients were randomly assigned to receive 100 mg of anakinra (recombinant human IL-1 receptor antagonist) subcutaneously twice-daily and 34 patients to receive placebo for 4 weeks. For this analysis, change in cortisol and ACTH levels from baseline to 4 weeks were predefined end points of the trial.

RESULTS

The mean age was 54 years, baseline cortisol levels were 314 nmol/L (IQR 241-385) and C-reactive protein (CRP) levels were 3.4 mg/L (IQR 1.7-4.8). Treatment with anakinra led to a significant decrease in cortisol levels at day 1 when compared to placebo with an adjusted between-group difference of 28 nmol/L (95% CI, -7 to -43; P = 0.03). After 4 weeks, the cortisol-lowering effect of anakinra was attenuated and overall was statistically not significant (P = 0.72). Injection-site reactions occurred in 21 patients receiving anakinra and were associated with higher CRP and cortisol levels.

CONCLUSIONS

IL-1 antagonism decreases cortisol levels in male patients with obesity and chronic low-grade inflammation on the short term. After prolonged treatment, this effect is attenuated, probably due to injection-site reactions (ClinicalTrials.gov, NCT02672592).

Application of ELISA Technique and Human Microsomes in the Search for 11β-Hydroxysteroid Dehydrogenase Inhibitors

The metabolic syndrome is defined by impaired carbohydrate metabolism and lipid disorders and often accompanied by hypertension, all of which will lead to obesity and insulin resistance. Glucocorticoids play a regulatory role in the metabolism of proteins, lipids, and carbohydrates. There is growing evidence for a role of glucocorticoids in the development of the metabolic syndrome. The most important factor that regulates the access of endogenous glucocorticoids to receptors after release of glucocorticoids and their diffusion into the cytoplasm of target cells is the steroid metabolism involving a microsomal enzyme, 11β-hydroxysteroid dehydrogenase (11β-HSD). The changes in intracellular glucocorticoid metabolism in the pathogenesis of obesity indicate the participation of modulation by 11β-HSD1, which may represent a new therapeutic target for the treatment of diseases such as type 2 diabetes, visceral obesity, or atherosclerosis. The aim of our study was to determine the fast and effective method to assess inhibition activity of compounds in relation with 11β-hydroxysteroid dehydrogenase. The material for this study was human liver and kidney microsomes. In this study we used ELISA technique using 96-well microplates coated with antibodies which were specific for analyzed enzymes. The method can quickly and efficiently measure the inhibition of both 11β-HSD1 and 11β-HSD2. This method can be used to search for and determine inhibitors of this enzyme. Cortisone and cortisol were used as the substrates for corresponding enzyme assays. Furthermore, 3-N-allyl-2-thiouracil derivatives were used by us for comparison purposes in developing the method, although, due to their structure, those derivatives have not previously been considered as potential inhibitors of 11β-HSD1. 3-N-Allyl-2-thiouracil derivatives are a group worth considering, because by modifying their structure (e.g., by introducing other substituents into the pyrimidine ring) it will be possible to obtain an increase in the activity of compounds in this regard. In conclusion, this study shows an efficient and fast method of determining inhibition activity of compounds in relation with 11β-hydroxysteroid dehydrogenase.

The association of morning serum cortisol with glucose metabolism and diabetes: The Jackson Heart Study

BACKGROUND

Serum cortisol levels have been associated with type 2 diabetes (T2D). However, the role of cortisol in glycemia and T2D is not fully elucidated among African Americans (AAs). We hypothesized that among AAs morning serum cortisol would be positively associated with glycemic measures and prevalent T2D.

METHODS

We examined the cross-sectional association of baseline morning serum cortisol with fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function (HOMA-β), and prevalent T2D in the Jackson Heart Study. Linear regression models were used to examine the association of log-transformed cortisol with glycemic traits, stratified by T2D status. Logistic regression was used to examine the association of log-transformed cortisol with prevalent T2D. Models were adjusted for age, sex, education, occupation, systolic blood pressure, waist circumference, physical activity, smoking, beta-blocker/hormone replacement medications and cortisol collection time.

RESULTS

Among 4,206 AAs (mean age 55 ± 13 years, 64% female), 19% had prevalent T2D. A 100% increase in cortisol among participants without diabetes was associated with 2.7 mg/dL (95% CI: 2.0, 3.3) higher FPG and a 10.0% (95% CI: -14.0, -6.0) lower HOMA-β with no significant association with HbA1c or HOMA-IR. In participants with diabetes, a 100% increase in cortisol was associated with a 23.6 mg/dL (95% CI: 13.6, 33.7) higher FPG and a 0.6% (95% CI: 0.3, 0.9) higher HbA1c. Among all participants, quartile 4 vs. 1 of cortisol was associated with a 1.26-fold (95% CI: 1.75, 2.91) higher odds of prevalent T2D.

CONCLUSION

Higher morning serum cortisol was associated with higher FPG and lower β-cell function among participants without T2D and higher FPG and HbA1c in participants with diabetes. Among all participants, higher cortisol was associated with higher odds of T2D. These findings support a role for morning serum cortisol in glucose metabolism among AAs.

Prevention of complications from use of conventional immunosuppressants: a critical review

Synthetic immunosuppressive drugs are largely used in immune-related renal diseases and in kidney transplantation. Most of these drugs have a low therapeutic index (the ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective), which means that the drug should be dosed carefully and the patient monitored frequently. In this review, we consider the categories of synthetic immunosuppressive agents more frequently and conventionally used in clinical nephrology: glucocorticoids, Aalkylating agents (cyclophosphamide, chlorambucil), purine synthesis inhibitors (azathioprine, mycophenolate salts) and calcineurin inhibitors (cyclosporine, tacrolimus). For each category the possible side effects will be reviewed, the general and specific measures to prevent or treat the adverse events will be suggested, and the more common mistakes that may increase the risk of toxicity will be described. However, the efficacy and safety of immunosuppressive agents depend not only on the pharmacologic characteristics of single drugs but can be influenced also by the clinical condition and genetic characteristics of the patient, by the typology and severity of the underlying disease and by the interaction with other concomitantly used drugs.

Simultaneous Determination of Total Cortisol and Cortisone in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Method Development, Validation and Preliminary Clinical Application

Background:

Cortisol as a major glucocorticosteroid product of the adrenal cortex which has been recognized as a stress biomarker in evaluating stress related disorders for a long time. Plasma concentration of cortisol and its metabolite cortisone are usually changed in physiological and psychological tension, anxiety and depression. In order to study these changes properly, we need a sensitive, accurate and reproducible assay for plasma cortisol and cortisone determination. </P><P> Objective: The aim of this study was to develop a sensitive and robust method for the determination of total cortisol and cortisone in human plasma using mass spectrometry.

Methods:

A fast, sensitive and selective liquid chromatography-tandem mass spectrometry (LCMS/ MS) method was developed, validated, and then the levels of cortisol and cortisone were determined. Plasma samples cleanup procedure was composed of two steps: the first was a protein precipitation with 1 % formic acid in acetonitrile, and the second was an on-line solid phase extraction (SPE). Afterwards, cortisol and cortisone were separated using a C18 ACQUITY UPLC BEHTM column with a gradient elution. The mobile phase A was 0.1 % formic acid in water, the mobile phase B was 0.1 % methanol. For the detection we used a XEVO TQ-S mass spectrometer operating in the ESI positive mode.

Results:

The time of analysis was 6.5 minutes and the quantification range was 5-600 ng/mL for cortisol and cortisone, with > 94% recovery for all analytes (cortisol, cortisone and internal standards). The method was validated according to the EMA guideline for bioanalytical method validation.

Conclusion:

A simple and sensitive LC-MS/MS method was developed and validated for measurement of cortisol and cortisone in human plasma. Our findings indicate that the proposed analytical method is suitable for routine analysis.

An Okinawan-based Nordic diet improves glucose and lipid metabolism in health and type 2 diabetes, in alignment with changes in the endocrine profile, whereas zonulin levels are elevated

The Okinawan-based Nordic diet has been developed to improve glucose metabolism. The aim of the present study was to summarize all anthropometric, subjective, and biochemical findings obtained following two different studies investigating this diet. The diet was administered i) as a single breakfast to healthy volunteers and ii) as a 12-week dietary intervention to patients with type 2 diabetes. The degree of satiety, sweet cravings, gastrointestinal symptoms, and health-related quality of life were estimated. Weight and blood pressures of participants were measured, and analyses including circulating levels of inflammatory and metabolic biomarkers, hormones, and short-chain fatty acids (SCFA), and microbial diversity and amount of Enterobacteriaceae in feces, were performed. A single breakfast of the diet increased satiety (P<0.001), improved glucose homeostasis (P<0.001), and lowered levels of glucose-dependent insulinotropic polypeptide (GIP) (P=0.002), compared with a standard breakfast. A 12-week intervention in type 2 diabetes increased satiety and decreased sweet cravings, at the same time as health-related quality of life and gastrointestinal symptoms were improved. There were reductions in body mass index (P<0.001), waist circumference (P<0.001), and levels of glucose (P<0.001), cholesterol (P<0.001), and triglycerides (P=0.009), in alignment with the endocrine profile. These improvements were maintained at follow-up 16 weeks later, along with lower levels of ghrelin (P=0.012), polypeptide YY (P=0.002), and visfatin (P=0.021), compared with the parameters recorded at the study start. Levels of haptoglobin, interleukin-18 and thrombocytes were lowered, whereas some other inflammatory biomarkers were unaffected and zonulin levels elevated. Gut microbiota and SCFAs levels were mainly unaffected. The mechanisms governing the anthropometric and metabolic improvements appear to be mediated through alterations in the endocrine profile, yet not in the gut microbiota.

Expression and activity of the cortisol-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 is tissue and species-specific

The microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) interconverts glucocorticoid receptor-inert cortisone (11-dehydrocorticosterone in rodents) to its receptor-active form cortisol (corticosterone in rodents). Thus, 11β-HSD1 amplifies glucocorticoid action at the tissue level. According to the current literature, dysregulation of glucocorticoid signaling may contribute to the pathogenesis of the metabolic syndrome in which regeneration of cortisol by 11β-HSD1 may be an important factor. This is why the enzyme has been very intensely investigated as a potential therapeutic target to treat metabolic complications such as obesity and diabetes type 2. However, due to controversial results from the various animal and human studies as well as from different findings with regard to tissue-specific expression and activity, the varied results unfortunately do not yield a consistent picture. Therefore, the precise role of 11β-HSD1 in the development of complications associated with the metabolic syndrome has still not been deciphered yet. Overall, the prominent role of this enzyme in the pathogenesis of the metabolic syndrome becomes more and more dubious and therefore further studies are necessary to clarify its role finally. This short review gives an overview on the main contradicting findings on the role of 11β-HSD1 in the development of visceral obesity and diabetes type 2.

Metabolic and Endocrine Consequences of Bariatric Surgery

Obesity is one of the most serious worldwide epidemics of the twenty-first century according to the World Health Organization. Frequently associated with a number of comorbidities, obesity threatens and compromises individual health and quality of life. Bariatric surgery (BS) has been demonstrated to be an effective treatment to achieve not only sustained weight loss but also significant metabolic improvement that goes beyond mere weight loss. The beneficial effects of BS on metabolic traits are so widely recognized that some authors have proposed BS as metabolic surgery that could be prescribed even for moderate obesity. However, most of the BS procedures imply malabsorption and/or gastric acid reduction which lead to nutrient deficiency and, consequently, further complications could be developed in the long term. In fact, BS not only affects metabolic homeostasis but also has pronounced effects on endocrine systems other than those exclusively involved in metabolic function. The somatotropic, corticotropic, and gonadal axes as well as bone health have also been shown to be affected by the various BS procedures. Accordingly, further consequences and complications of BS in the long term in systems other than metabolic system need to be addressed in large cohorts, taking into account each bariatric procedure before making generalized recommendations for BS. In this review, current data regarding these issues are summarized, paying special attention to the somatotropic, corticotropic, gonadal axes, and bone post-operative health.

Developmental influences on stress response systems: Implications for psychopathology vulnerability in adolescence

The adolescent transition is marked by increases in stress exposure and significant maturation of neural and hormonal stress processing systems. Variability in the development of these systems during adolescence may influence the risk for stress-related psychopathology. This paper aims to review the developmental maturation of the HPA axis and related stress regulation systems, and demonstrate how interference in this adaptive developmental process may increase the risk for negative outcomes. We argue that the developmental maturation of the HPA axis aims to improve the regulatory capacity of the axis in order to more adaptively respond to these increases in stress reactivity. Additionally, we review evidence that sex differences in the development of the HPA and related axes may contribute to sex differences in the risk for stress-related psychopathology. Finally, we discuss how contextual factors, such as early trauma and obesity may alter the development of HPA axis during the adolescence transition and how alterations of normative development increase the risk for stress-related disorders.

Insulin translates unfavourable lifestyle into obesity

Lifestyle factors conferring increased diabetes risk are associated with elevated basal insulin levels (hyperinsulinaemia). The latter predicts later obesity in children and adolescents.A causal role of hyperinsulinaemia for adipose tissue growth is probable because pharmacological reduction of insulin secretion lowers body weight in people who are obese. Genetic inactivation of insulin gene alleles in mice also lowers their systemic insulin levels and prevents or ameliorates high-fat diet-induced obesity. Hyperinsulinaemia causes weight gain because of a physiological property of insulin. Insulin levels that are on the high side of normal, or which are slightly elevated, are sufficient to suppress lipolysis and promote lipogenesis in adipocytes. The effect of insulin on glucose transport or hepatic glucose production requires six or two times higher hormone levels, respectively.It seems justified to suggest a lifestyle that avoids high insulin levels in order to limit anabolic fat tissue activity.

Steroid profiling in nails using liquid chromatography-tandem mass spectrometry

The retrospective analysis of endogenous steroid hormones in nails can be used to elucidate endocrine diseases and thus help with their diagnosis and treatment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) based method was developed for the simultaneous identification and quantification of 12 steroid hormones (aldosterone, cortisone, cortisol, corticosterone, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, dehydroepiandrosterone (DHEA), 17α-hydroxyprogesterone (17-OHP), dihydrotestosterone (DHT) and progesterone) in human fingernails. Steroid hormones were extracted from 0.5 mg to 10 mg pulverized nail clippings by methanolic extraction, followed by a liquid-liquid extraction. The analysis was conducted with LC-MS/MS in electrospray ionization positive mode. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, matrix effect, recovery and robustness. It was successfully applied for steroid profiling in nails of mothers and their infants where cortisol, cortisone, testosterone, progesterone, androstenedione and 11-deoxycorticosterone could be detected. Furthermore, it could be shown that there is no significant difference in concentrations between left and right hand for cortisol, cortisone and progesterone. A positive linear correlation between cortisol and cortisone in nails was found. In conclusion, it could be shown that nails are a suitable matrix for the retrospective monitoring of cumulative steroid hormone levels.

Obesity, perceived weight discrimination, and hair cortisol: a population-based study

BACKGROUND AND PURPOSE

Stigmatization of individuals with obesity is pervasive and may act as a psychological stressor. The present study examined whether perceived weight discrimination mediated the relationship between obesity and cortisol, an objective marker of chronic stress, in a population-based sample.

METHODS

Data were from the English Longitudinal Study of Ageing (n = 1872). Height and weight were objectively measured in 2008/09. Experiences of weight-related discrimination were reported via questionnaire in 2010/11. Hair cortisol concentrations were determined from the scalp-nearest 2 cm hair segment in 2012/13. Mediation analyses tested the role of perceived weight discrimination in the associations between obesity and BMI and hair cortisol concentration, adjusting for age, sex, ethnicity, socio-economic status, smoking status, depression and hair-related factors.

RESULTS

Obesity, BMI and perceived weight discrimination were positively related to hair cortisol (all p <  .01). Perceived weight discrimination significantly mediated associations between obesity and hair cortisol (β = 0.021, SE = 0.007, 95% CI 0.007-0.036) and BMI and hair cortisol (β = 0.001, SE = 0.0004, 95% CI 0.0004-0.002), accounting for 19% of the total effect of obesity and 23% of the total effect of BMI on hair cortisol.

CONCLUSIONS

Perceived weight discrimination is an important mediator of the association between obesity and cortisol. Interventions combating weight stigma and discrimination or promoting strategies for coping with stress could help to lessen the psychological and physiological burden of obesity.

Links between HPA axis and adipokines: clinical implications in paradigms of stress-related disorders

INTRODUCTION

In the human organism, a constant interplay exists between the stress system [which includes the activity of the hypothalamic-pituitary-adrenal (HPA) axis] and the adipose tissue. This interplay is mediated by hormones of the HPA axis such as corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and glucocorticoids (GCs) and adipokines secreted by the adipose tissue.

AREAS COVERED

In this critical review, the bi-directional interactions between HPA axis and the most studied adipokines such as leptin and adiponectin, as well as the pro-inflammatory adipocytokines tumor necrosis factor (TNF) and interleukin (IL) 6 are presented. Furthermore, these interactions are described in normalcy as well as in specific clinical paradigms of stress-related disorders such as eating disorders, hypothalamic amenorrhea, and stress-related endogenous hypercortisolism states. Wherever new therapeutic strategies emerge, they are presented accordingly.

EXPERT COMMENTARY

Additional research is needed to clarify the mechanisms involved in the interplay between the HPA axis and the adipose tissue. Research should be focused, in particular, on the development of new therapeutic means targeting dysfunctional adipose tissue in stress-related situations.

Obesity and sleep disturbance: the chicken or the egg?

Epidemiological studies suggested an association between obesity and sleep disturbances. Obstructive sleep apnea is the most prevalent type of obesity-related sleep disorder that lead to an increased risk for numerous chronic health conditions. In addition the increased visceral adipose tissue might be responsible for the secretion of inflammatory cytokines that could contribute to alter the sleep-wake rhythm. Unhealthy food characterized by high consumption of fat and carbohydrate seems to negatively influence the quality of sleep while diet rich of fiber is associated to more restorative and deeper sleep. Although obesity could cause through several pathogenetic mechanisms an alteration of sleep, it has been reported that subjects suffering from sleep disorders are more prone to develop obesity. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep increase the risk of developing obesity. Experimental sleep restriction also causes physiological, hormonal and food behavioral changes that promote a positive energy balance and a compensatory disproportionate increase in food intake, decrease in physical activity, and weight gain. Thus, the aim of this review is to provide observational evidence on the association of obesity with sleep disturbances and viceversa with emphasis on possible pathophysiological mechanisms (hormonal and metabolic) that link these two pathological conditions.

Should Cushing's Syndrome be Considered as a Disease with High Cardiovascular Risk in Relevant Guidelines?

A considerable amount of data supports a 1.8-7.4-fold increased mortality associated with Cushing's syndrome (CS). This is attributed to a high occurrence of several cardiovascular disease (CVD) risk factors in CS [e.g. adiposity, arterial hypertension (AHT), dyslipidaemia and type 2 diabetes mellitus (T2DM)]. Therefore, practically all patients with CS have the metabolic syndrome (MetS), which represents a high CVD risk. Characteristically, despite a relatively young average age, numerous patients with CS display a 'high' or 'very high' CVD risk (i.e. risk of a major CVD event >20% in the following 10 years). Although T2DM is listed as a condition with a high CVD risk, CS is not, despite the fact that a considerable proportion of the CS population will develop T2DM or impaired glucose tolerance. CS is also regarded as a risk factor for aortic dissection in current guidelines. This review considers the evidence supporting listing CS among high CVD risk conditions.

Does sleep deprivation increase the vulnerability to acute psychosocial stress in young and older adults?

Sleep loss and psychosocial stress often co-occur in today's society, but there is limited knowledge on the combined effects. Therefore, this experimental study investigated whether one night of sleep deprivation affects the response to a psychosocial challenge. A second aim was to examine if older adults, who may be less affected by both sleep deprivation and stress, react differently than young adults. 124 young (18-30 years) and 94 older (60-72 years) healthy adults participated in one of four conditions: i. normal night sleep & Placebo-Trier Social Stress Test (TSST), ii. normal night sleep & Trier Social Stress Test, iii. sleep deprivation & Placebo-TSST, iv. sleep deprivation & TSST. Subjective stress ratings, heart rate variability (HRV), salivary alpha amylase (sAA) and cortisol were measured throughout the protocol. At the baseline pre-stress measurement, salivary cortisol and subjective stress values were higher in sleep deprived than in rested participants. However, the reactivity to and recovery from the TSST was not significantly different after sleep deprivation for any of the outcome measures. Older adults showed higher subjective stress, higher sAA and lower HRV at baseline, indicating increased basal autonomic activity. Cortisol trajectories and HRV slightly differed in older adults compared with younger adults (regardless of the TSST). Moreover, age did not moderate the effect of sleep deprivation. Taken together, the results show increased stress levels after sleep deprivation, but do not confirm the assumption that one night of sleep deprivation increases the responsivity to an acute psychosocial challenge.

Children's stress-related reports and stress biomarkers interact in their association with metabolic syndrome risk

The purpose was to examine the cross-sectional associations of stress-related reports and stress biomarkers with metabolic syndrome (MetS) risk in children while also testing the interaction between stress biomarkers and stress reports. In 353 children (5-10 years old, 7.9% overweight/obese), MetS risk was measured by blood pressure, waist circumference, glucose homeostasis, triglycerides, and high-density cholesterol. Stress was measured by stress-related reports (events, emotions, and internalizing/externalizing problems) and two biomarkers: salivary cortisol (total-day and morning output) and heart rate variability (percentage of consecutive normal RR intervals differing more than 50 ms and low-to-high-frequency ratio). Cross-sectional regression analyses with z scored total MetS risk as outcome were adjusted for age, sex, and socio-economic status. Only internalizing problems were directly related to a higher MetS risk score (β = 0.236). Cortisol and heart rate variability were significant moderators: High cortisol morning output resulted in a positive (unfavourable) report-MetS relationship (β = 0.259-0.552), whereas low percentage of consecutive normal RR intervals differing more than 50 ms resulted in a negative (favourable) report-MetS relationship (β = -0.298) and low low-to-high-frequency ratio in a positive (unfavourable) report-MetS relationship (β = 0.478). In conclusion, stress can sometimes be a disadvantageous factor in metabolic health of otherwise healthy children. The cortisol biomarker seems relevant because metabolic risk was highest when stress-related reports were accompanied by high morning cortisol output.

Basal cortisol levels and metabolic syndrome: A systematic review and meta-analysis of observational studies

OBJECTIVE

To perform a qualitative synthesis (systematic review) and quantitative analysis (meta-analysis) to summarize the evidence regarding the relationship between basal cortisol levels and metabolic syndrome (MetS) in adults.

METHODS

A systematic search was performed in the PubMed, Embase, and PsycINFO databases for observational studies on the association between basal cortisol levels and MetS. The quality of individual studies was assessed by the Newcastle-Ottawa score. A random effects model was used to report pooled quantitative results and the I2 statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias.

RESULTS

Twenty-six studies (19 cross-sectional and seven case-control) met the inclusion criteria for the systematic review. The majority was classified as having a low risk of bias and used established criteria for the diagnosis of MetS. Twenty-one studies provided data on basal cortisol levels as continuous values and were included in the meta-analysis; they comprised 35 analyses and 11,808 subjects. Pooled results showed no significant difference in basal cortisol levels between subjects with and without MetS (standardized mean difference [SMD] = 0.02, 95% confidence interval [CI]=-0.11 to 0.14). There was high heterogeneity between the studies when all comparisons were considered (I2 = 83.1%;p < 0.001). Paradoxically, meta-analysis of studies evaluating saliva samples showed no significantly lower basal cortisol levels among subjects with MetS (SMD=-0.18, 95% CI=-0.37 to 0.01), whereas those studies that evaluated serum samples (SMD = 0.11, 95% CI=-0.02 to 0.24) and urine samples (SMD = 0.73, 95% CI=-0.40 to 1.86) showed no significantly higher basal cortisol levels among subjects with MetS. In the subgroup and meta-regression analyses, a significant difference in basal cortisol levels was observed according to study design, population base, age, gender, cortisol level assessment method, and study quality.

CONCLUSION

This systematic review and meta-analysis does not reveal any association between basal cortisol levels and MetS based on results of observational studies. The results of a random-effect meta-analysis showed no significant difference in basal cortisol levels between subjects with and without MetS. The present findings should be considered in order to help future studies.

Educational Disparities in Risk for Metabolic Syndrome

BACKGROUND

The objective of this study was to evaluate the relationship between educational level as a surrogate marker of socioeconomic status and the risk of developing metabolic syndrome (MetS).

METHODS

Study subjects were 1915 Korean adults (1193 women and 722 men) who participated in a cohort study. Educational level was categorized into two groups: (1) high education (more than 12 years of education), and (2) low education (less than 12 years of education). MetS was defined according to diagnostic criteria of the National Cholesterol Education Program (NCEP-III) and the International Diabetes Federation (IDF). Multiple logistic regression analysis and Cox proportional hazard analysis were performed to evaluate cross-sectional and prospective association between MetS or MetS components and educational level after adjusting for covariates.

RESULTS

The overall prevalence of MetS at baseline was 15.0% in women and 20.4% in men. Incidence of MetS over 4.52 years was 16.6 per 1000 person-year in women and 27.6 per 1000 person-year in men. The prevalence and incidence of MetS were higher in the low educational group than those in the high educational group in both sexes. At baseline, the risk of MetS (odds ratio [OR]: 1.63, 95% confidence interval [CI]: 1.05-2.53 for NCEP criteria; OR: 2.30, 95% CI: 1.41-3.76 for IDF criteria) and abdominal obesity (OR: 2.62, 95% CI: 1.75-3.93) were higher in less educated women compared with those in more educated women. In men, there was no association between Mets or MetS components and educational level. Over 4.6 years of follow-up, the risk of developing MetS in women in the low education group (hazard ratio [HR]: 1.95, 95% CI: 1.12-3.50 for NCEP criteria; HR: 2.36, 95% CI: 1.14-4.86 for IDF criteria) was significantly higher than that in the high education group. In men, low education significantly increased the risk of developing impaired fasting glucose (HR: 1.95, 95% CI: 1.12-3.40).

CONCLUSION

An inverse association between educational level and MetS was found in Korean women, suggesting that socioeconomic disparities might increase the risk of MetS development, especially in women.

Stress-related eating, mindfulness, and obesity

OBJECTIVE

This study explored how experiences of stress in adulthood, including the occurrence of stressful life events and psychosocial strains in various life domains, might be related to stress-related eating and indicators of obesity, including body mass index (BMI) and waist circumference.

METHOD

Cross-sectional data were examined from 3,708 adults in the Midlife in the U.S. study (MIDUS II).

RESULTS

Hierarchical regression analyses indicated that experiences of stress were associated with higher BMI and waist circumference, even after controlling for age, annual household income, education level, race, and sex, although the additional variance accounted for was small. A nonparametric bootstrapping approach indicated that stress-related eating mediated the association between experiences of stress and indicators of obesity. Moderated-mediation analyses indicated that the relationship between experiences of stress and stress-related eating was amplified for women and individuals with obesity in comparison to men and individuals without obesity. Mindfulness did not moderate the experiences of stress and stress-related eating association.

CONCLUSIONS

These results provide further evidence of the contributions of psychosocial factors to chronic disease risk. (PsycINFO Database Record

A comparative study on cardiovascular disease risk factors in Korean adults according to clinical depression status

This study was conducted to compare the association between depression and cardiovascular disease risk factors among Korean adults. This study was based on the data from the Korea National Health and Nutrition Examination Survey conducted in 2012-2014. Using a multivariable logistic regression model, we calculated odds ratios (ORs) and 95% confidence intervals (CIs). A total of 10,359 subjects aged 19-64 years were selected, and 432 subjects (74 men, 358 women) were included in the physician-diagnosed depression group. Several cardiovascular risk factors were associated with higher odds of clinical depression. For men, high waist circumference (≥91.3 cm) and body mass index (≥25.0 kg/m²) were significantly associated with increased odds of depression, and high physical activity (≥50 MET h/week) was associated with decreased odds of depression. Men with dyslipidemia and metabolic syndrome had 2.43-fold and 2.0-fold higher odds of depression than those without the diseases. For women, current smokers had 2.25-fold higher odds of depression than nonsmokers, and frequent alcohol drinkers (≥4 times/week) also had 2.88-fold higher odds of depression than nondrinkers. Korean adults with clinical depression had a higher prevalence of some risk factors for cardiovascular diseases than those without depression.

Theophylline suppresses interleukin-6 expression by inhibiting glucocorticoid receptor signaling in pre-adipocytes

Adipose tissues in obese individuals are characterized by a state of chronic low-grade inflammation. Pre-adipocytes and adipocytes in this state secrete pro-inflammatory adipokines, such as interleukin 6 (IL-6), which induce insulin resistance and hyperglycemia. Theophylline (1,3-dimethylxanthine) exerts anti-inflammatory effects, but its effects on pro-inflammatory adipokine secretion by pre-adipocytes and adipocytes have not been examined. In this study, we found that theophylline decreased IL-6 secretion by 3T3-L1 pre-adipocytes and mouse-derived primary pre-adipocytes. The synthetic glucocorticoid dexamethasone (DEX) induced IL-6 expression in 3T3-L1 pre-adipocytes, and this effect was suppressed by theophylline at the mRNA level. Knockdown of CCAAT/enhancer binding protein (C/EBP) δ inhibited DEX-induced IL-6 expression, and theophylline suppressed C/EBPδ expression. Furthermore, theophylline suppressed transcriptional activity of the glucocorticoid receptor (GR) through suppression of nuclear localization of GR. In vivo, glucocorticoid corticosterone treatment (100 μg/mL) increased fasting blood glucose and plasma IL-6 levels in C57BL/6 N mice. Theophylline administration (0.1% diet) reduced corticosterone-increased fasting blood glucose, plasma IL-6 levels, and Il6 gene expression in adipose tissues. These results show that theophylline administration attenuated glucocorticoid-induced hyperglycemia and IL-6 production by inhibiting GR activity. The present findings indicate the potential of theophylline as a candidate therapeutic agent to treat insulin resistance and hyperglycemia.

Feeding Obese Diabetic Mice a Genistein Diet Induces Thermogenic and Metabolic Change

Obesity is associated with elevated plasma levels of glucocorticoids and reduced levels of thyroid hormones, both known to effect food intake and energy expenditure. Furthermore, tissue specific glucocorticoid metabolism is altered in obesity, increasing insulin resistance and cardiometabolic risk. The goal of this study was to examine whether these metabolic disturbances can be prevented with the isoflavone genistein in the ob/ob mouse, a model that resembles the phenotype in human obesity. Male ob/ob mice, aged 5 weeks, were fed either a genistein-rich diet (600 mg/kg) or a genistein-free diet for 4 weeks. ob/ob mice weighed 70% more than lean controls. While there was no effect of genistein on body weight, food consumption during weeks 3 and 4 was significantly increased in genistein-fed mice. This was associated with increases in body temperature and plasma levels of triiodothyronine (T3), suggesting a thermogenic effect. The hypercorticosteronism observed in the ob/ob mouse was reduced with genistein treatment. This effect was accompanied by a decrease in protein expression of renal 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) without changes in hepatic 11β-HSD1. Our results suggest that a diet containing genistein can have beneficial effects on energy expenditure, T3 production, and corticosterone status in the ob/ob mouse model of obesity.

Age moderates the association between social integration and diurnal cortisol measures

Social integration is defined as the degree to which an individual participates in a broad range of social relationships. Although measures of social integration vary across studies, it is often assessed as the number of social roles (e.g., parent, friend, student, volunteer) that an individual reports actively participating in. More socially integrated individuals tend to be healthier than those less socially integrated, but the biological mechanisms through which this occurs remain unclear. One possibility is that social integration might alter the function of the hypothalamic-pituitary-adrenal axis, of which cortisol is a key product, and in turn influence a broad range of health outcomes. This study examined the association between social integration and two indices of cortisol in a community sample of 680 healthy men and women aged 18-55. Because the social roles held by younger individuals may be more numerous yet superficial than those held by older individuals, this study also tested the hypothesis that these associations could be moderated by age such that lower levels of integration would be associated with cortisol dysregulation for older but not younger individuals in our sample. Participants provided salivary cortisol samples during waking hours on three days that were used to calculate diurnal cortisol levels and slopes. Increased social integration was associated with lower cortisol AUC among older (ages 35-55) but not younger (ages 18-34) individuals in our sample. Moreover, while increased social integration was associated with steeper diurnal cortisol slopes regardless of age, this association was strongest among older individuals. Differences in health behaviors, affect, and psychological stress did not mediate these associations. The results of this study support cortisol as a candidate biological mechanism through which increased social integration is associated with better physical health among older individuals.

Alignments of endocrine, anthropometric, and metabolic parameters in type 2 diabetes after intervention with an Okinawa-based Nordic diet

Background

An Okinawa-based Nordic diet with moderately low carbohydrate content and high fat and protein content has been shown to improve anthropometry and metabolism in type 2 diabetes.

Objective

The objectives of this study were to measure plasma or serum levels of hormones regulating energy metabolism and metabolic control, that is, cholecystokinin (CCK), Cortisol, C-peptide, ghrelin, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, leptin, plasminogen activator inhibitor-1 (PAI-1), polypeptide YY (PYY), resistin, and visfatin after this diet intervention, and to determine partial correlations between hormonal levels and anthropometric and metabolic responses.

Design

A total of 30 patients (17 women) with type 2 diabetes, mean age 57.5 ± 8.2 years, and body mass index (BMI) 29.9 ± 4.1 kg/m² were served the diet for 12 weeks. Fasting hormones were measured by Luminex and enzyme–linked immunosorbent assay (ELISA) before study start and after 12 and 28 weeks, along with anthropometric and metabolic parameters.

Result

The levels of CCK (P = 0.005), cortisol (P = 0.015), C-peptide (P = 0.022), glucagon (P = 0.003), GLP-1 (P = 0.013), GIP (P < 0.001), insulin (P = 0.004), leptin (P < 0.001), and PYY (P < 0.001) were lowered after dietary intervention. These reduced levels only remained for PYY at week 28 (P = 0.002), when also ghrelin (P = 0.012) and visfatin (P = 0.021) levels were reduced. Changes of glucose values correlated with changed levels of C-peptide and PYY (P < 0.001), insulin (P = 0.002), and PAI-1 (P = 0.009); changes of triglyceride values with changed levels of C-peptide, insulin, and PYY (P < 0.001) and PAI-1 (P = 0.005); changes of insulin resistance with changes of leptin levels (P = 0.003); and changes of BMI values with changed levels of C-peptide, insulin, and leptin (P < 0.001).

Conclusions

Okinawa-based Nordic diet in type 2 diabetes has significant impact on the endocrine profile, which correlates with anthropometric and metabolic improvements.

Traumatic Brain Injury: At the Crossroads of Neuropathology and Common Metabolic Endocrinopathies

Building on the seminal work by Geoffrey Harris in the 1970s, the neuroendocrinology field, having undergone spectacular growth, has endeavored to understand the mechanisms of hormonal connectivity between the brain and the rest of the body. Given the fundamental role of the brain in the orchestration of endocrine processes through interactions among neurohormones, it is thus not surprising that the structural and/or functional alterations following traumatic brain injury (TBI) can lead to endocrine changes affecting the whole organism. Taking into account that systemic hormones also act on the brain, modifying its structure and biochemistry, and can acutely and chronically affect several neurophysiological endpoints, the question is to what extent preexisting endocrine dysfunction may set the stage for an adverse outcome after TBI. In this review, we provide an overview of some aspects of three common metabolic endocrinopathies, e.g., diabetes mellitus, obesity, and thyroid dysfunction, and how these could be triggered by TBI. In addition, we discuss how the complex endocrine networks are woven into the responses to sudden changes after TBI, as well as some of the potential mechanisms that, separately or synergistically, can influence outcomes after TBI.

Acute anti-obesity effects of intracerebroventricular 11β-HSD1 inhibitor administration in diet-induced obese mice

The hypothalamus is the regulatory centre of both appetite and energy balance and endoplasmic reticulum (ER) stress in the hypothalamus is involved in the pathogenesis of obesity. Recently, inhibition of 11 β hydroxysteroid dehydrogenase type1 (11β-HSD1) was reported to have an anti-obesity effect by reducing fat mass. However, the link between the role of 11β-HSD1 in the hypothalamus and obesity has yet to be determined. In the present study, embryonal primary hypothalamic neurones and high-fat diet (HFD) fed mice were used to investigate the anorexigenic effects of 11β-HSD1 inhibitors both in vitro and in vivo. In hypothalamic neurones, carbenoxolone (a non selecitve 11β-HSD inhibitor) alleviated ER stress and ER stress-induced neuropeptide alterations. In HFD mice, i.c.v. administration of carbenoxolone or KR67500 (nonselective and selective 11β-HSD1 inhibitors, respectively) was associated with less weight gain compared to control mice for 24 hours after treatment, presumably by reducing food intake. Furthermore, glucose regulated protein (Grp78), spliced X-box binding protein (Xbp-1s), c/EBP homologous protein (chop) and ER DnaJ homologue protein (Erdj4) expression was decreased in the hypothalami of mice administrated 11β-HSD1 inhibitors compared to controls. Conversely, the phosphorylation of protein kinase B (PKB/Akt), signal transducer and activator of transcription 3 (Stat3), mitogen-activated protein kinase (MAPK/ERK) and S6 kinase1 (S6K1) in the hypothalamus was induced more in mice treated using the same regimes. In conclusion, acute 11β-HSD1 inhibition in the hypothalamus could reduce food intake by decreasing ER stress and increasing insulin, leptin, and mammalian target of rapamycin complex 1 (mTORC1) signalling.

Metabolic syndrome and its components among Korean submariners: a retrospective cross-sectional study

PURPOSE

Metabolic syndrome (MetS) is a cluster of inter-related risk factors for cardiovascular disease and diabetes. Although submariners tend to be exposed to unhealthy environmental factors, such as a confined work environment, physical inactivity, and circadian disruption, little is known regarding whether the risks of MetS and its components are associated with submarine service. The present study aimed to evaluate the risks of MetS and its components among submariners.

METHODS

A total of 5090 subjects (513 submariners and 4577 non-submariners) were included in the present study. We calculated the age-standardized and age-specific prevalences of MetS. The associations between submarine service and the risks of MetS and its components were evaluated using logistic regression analysis after adjusting for age, service rank, and lifestyle factors.

RESULTS

The age-standardized prevalences of MetS were 17.6 and 15.1% among submariners and non-submariners, respectively. Compared to non-submariners, submariners had higher risks of MetS (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.02, 1.68), low high-density lipoprotein cholesterol (OR 1.73, 95% CI 1.36, 2.20), and impaired fasting glucose (OR 1.46, 95% CI 1.21, 1.76). When we stratified the subjects according to physical activity, an increased risk of elevated blood pressure associated with submarine service was evident only in the subgroup with moderate or vigorous physical activity (P for interaction = 0.006).

CONCLUSION

Submariners had higher risks of MetS and some MetS components, compared to non-submariners. These findings suggest that special efforts are needed to prevent and manage MetS among individuals who are expected to be exposed to submarine environment.

Metabolic syndrome in psychiatry: advances in understanding and management

Metabolic syndrome comprises a number of cardiovascular risk factors that increase morbidity and mortality. The increase in incidence of the syndrome among psychiatric patients has been unanimously demonstrated in recent studies and it has become one of the greatest challenges in psychiatric practice. Besides the use of psychotropic drugs, factors such as genetic polymorphisms, inflammation, endocrinopathies and unhealthy lifestyle contribute to the association between metabolic syndrome and a number of psychiatric disorders. In this article, we review the current diagnostic criteria for metabolic syndrome and propose clinically useful guidelines for psychiatrists to identify and monitor patients who may have the syndrome. We also outline the relationship between metabolic syndrome and individual psychiatric disorders, and discuss advances in pharmacological treatment for the syndrome, such as metformin.

LEARNING OBJECTIVES

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Glucocorticoids Suppress the Browning of Adipose Tissue via miR-19b in Male Mice

Physiological levels of glucocorticoids (GCs) are required for proper metabolic control, and excessive GC action has been linked to a variety of pandemic metabolic diseases. MicroRNA (miRNA)-19b plays a critical role in the pathogenesis of GC-induced metabolic diseases. This study explored the potential of miRNA-based therapeutics targeting adipose tissue. Our results showed that overexpressed miR-19b in stromal vascular fraction (SVF) cells derived from subcutaneous adipose tissue had the same effects as dexamethasone (DEX) treatment on the inhibition of adipose browning and oxygen consumption rate. The inhibition of miR-19b blocked DEX-mediated suppression of the expression of browning marker genes as well as the oxygen consumption rate in differentiated SVF cells derived from subcutaneous and brown adipose tissue. Overexpressed miR-19b in SVF cells derived from brown adipose tissue had the same effects as DEX treatment on the inhibition of brown adipose differentiation and energy expenditure. Glucocorticoids transcriptionally regulate the expression of miR-19b via a GC receptor-mediated direct DNA binding mechanism. This study confirmed that miR-19b is an essential target for GC-mediated control of adipose tissue browning. It is hoped that the plasticity of the adipose organ can be exploited in the next generation of therapeutic strategies to combat the increasing incidence of metabolic diseases, including obesity and diabetes.

A systematic review and meta-analysis of the impact of mineralocorticoid receptor antagonists on glucose homeostasis

BACKGROUND

Spironolactone, a nonselective mineralocorticoid receptor antagonist (MRA), may have a deleterious effect on glycemia. The objective of this review was to assess current knowledge on MRAs' influence (spironolactone, eplerenone, and canrenone) on glucose homeostasis and the risk of diabetes.

METHOD

A systematic review was conducted using the Medline database on articles published from 1946 to January 2017 that studied the effects of MRAs on any glucose-related endpoints, without any restrictions regarding the participants' characteristics.Study design, patient population, dose and duration of intervention, and the quantitative results on glycemic markers were extracted, interpreted for result synthesis, and evaluated for sources of bias. From the articles included in the qualitative analysis, a select number were used in a meta-analysis on studies having measured glycated hemoglobin (HbA1c) or risk of diabetes.

RESULTS

Seventy-two articles were selected from the Medline database and references of articles. Results on spironolactone were heterogeneous, but seemed to be disease-specific. A potential negative effect on glucose regulation was mainly observed in heart failure and diabetes trials, while a neutral or positive effect was detected in diseases characterized by hyperandrogenism, and inconclusive for hypertension. Interpretation of data from heart failure trials was limited by the small number of studies. From a meta-analysis of 12 randomized controlled studies evaluating spironolactone's impact on HbA1c in diabetic patients, spironolactone had a nonsignificant effect in parallel-group studies (mean difference 0.03 [-0.20;0.26]), but significantly increased HbA1c in crossover studies (mean difference 0.24 [0.18;0.31]). Finally, eplerenone did not seem to influence glycemia, while limited data indicated that canrenone may exert a neutral or beneficial effect.The studies had important limitations regarding study design, sample size, duration of follow-up, and choice of glycemic markers.

CONCLUSION

Spironolactone may induce disease-specific and modest alterations on glycemia. It is uncertain whether these effects are transient or not. Data from the most extensively studied population, individuals with diabetes, do not support a long-term glycemic impact in these patients. Further prospective studies are necessary to establish spironolactone's true biological effects and their clinical implications.

Determination of the phytochemical composition of Jingning fang and the in vivo pharmacokinetics of its metabolites in rat plasma by UPLC-MS/MS

Jingning fang (JNF) is an effective Traditional Chinese Medicine (TCM) which is used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). To clarify the bioactive constituents of JNF, a Thermo Q Exactive™ Plus Orbitrap™ mass spectrometer was used in this study. More than 127 chemical compounds were isolated and identified tentatively in the JNF extract, while 42 prototype constituents with 4 potential metabolites were identified tentatively in rat plasma. A method for simultaneous determination of polygalaxanthone III (PAIII), sibiricose A5 (A5), sibiricose A6 (A6), 3, 6'-disinapoyl sucrose (3,6'-DISS), tenuifoliside C (TEC), tenuifolin B (TNB), verbascoside (VCE), heterophyllin B (HEB) and schisandrin (SCH) in rat was developed and validated using polydatin (PLN) and psoralen (PSN) as internal standards. All calibration curves proved favorable linearity (R2≥0.9923) in linear ranges. The lower limit of quantification (LLOQ) was 2.5ng/mL for PAIII, A5, 3, 6'-DISS, TNB, VCE, HEB and SCH, 1.0ng/mL for A6 and TEC, respectively. Intra-day and inter-day precisions didn't exceed 14.0% for all the analytes. Extraction recoveries and matrix effects of analytes and IS were acceptable. The validated method has been successfully applied to the pharmacokinetics (PK) studies of the nine compounds in JNF. These findings are useful for predicting the bioactive components of JNF, and will aid in optimizing dose regimens of the drug.

Autonomous cortisol secretion in adrenal incidentalomas and increased visceral fat accumulation during follow-up

OBJECTIVE

Autonomous cortisol secretion of adrenal incidentalomas (AIs) is associated with poor cardiovascular outcome. Because centripetal obesity is a cardiovascular risk factor, we aimed to investigate whether autonomous cortisol secretion is associated with increased visceral fat accumulation.

DESIGN

Retrospective cohort study.

PATIENTS

Patients with AIs who attended for follow-up between January 2014 and December 2016 were evaluated. Autonomous cortisol secretion was diagnosed when 1 mg overnight dexamethasone (post-DST) cortisol was >50 nmol/L at baseline and follow-up. Follow-up duration was 34 (12-105) months. Thirty patients with nonfunctioning AIs and 44 patients with autonomous cortisol secretion were included. Adrenalectomy was performed in five patients. Six patients with Cushing's syndrome were also recruited.

MEASUREMENTS

Hormonal evaluation and assessment of total (T), visceral (V) and subcutaneous (S) fat area by computed tomography and calculation of V:S and V:T ratios at baseline and follow-up.

RESULTS

V, V:S and V:T increased (P<.001 for each comparison, Wilcoxon signed rank test for repeated measures) in patients with autonomous cortisol secretion while did not change significantly in patients with nonfunctioning adenomas. Linear regression models including post-DST cortisol, gender, concomitant treatments and follow-up duration showed that both baseline and follow-up DST significantly predicted Δ(V:S) and Δ(V:T) (P<.01 for all models).

CONCLUSIONS

In patients with AIs, a post-DST cortisol >50 nmol/L at both baseline and follow-up, was associated with a significant increase in visceral fat after a follow-up duration of ~3 years. This may be of importance to explain the link between autonomous cortisol secretion and poor cardiovascular outcome.

High-fat diet and chronic stress aggravate adrenal function abnormality induced by prenatal caffeine exposure in male offspring rats

We previously demonstrated thatprenatal caffeine exposure (PCE) suppressed fetal adrenal steroidogenesis and resulted in developmental programming changes in offspring rats. However, whether these changes play a role in adrenal corticosterone synthesis under high-fat diet (HFD) and unpredictable chronic stress (UCS) remains unknown. In present study, rat model was established by PCE (120 mg/kg.d), and male offspring were provided normal diet or HFD after weaning. At postnatal week 21, several rats fed HFD were exposed to UCS for 3 weeks and sacrificed. The results showed that compared with the corresponding control group, the serum corticosterone levels and adrenal steroid synthetase expression of the PCE offspring without UCS were reduced. Moreover, the glucocorticoid (GC)-activation system was inhibited, and insulin-like growth factor 1 (IGF1) signaling pathway expression was increased. With UCS exposure in the PCE offspring, serum corticosterone levels and adrenal steroid synthetase expression were increased, the activity of GC-activation system was enhanced, and adrenal IGF1 signaling pathway expression was decreased. Based on these findings, PCE induced adrenal hypersensitivity in adult male offspring rats, as shown by the reduced corticosterone levels under HFD conditions but significantly enhanced corticosterone levels with UCS, in which GC-IGF1 axis programming alteration may play an important role.

Effects of subchronic exposure to waterborne cadmium on H-P-I axis hormones and related genes in rare minnows (Gobiocypris rarus)

The H (hypothalamic)-P (pituitary)-I (interrenal) axis is critical in the stress response and other activities of fish. To further investigate cadmium (Cd) toxicity on the H-P-I axis and to identify its potential regulatory genes in fish, the adult female rare minnows (Gobiocypris rarus) were exposed to subchronic (5weeks) levels of waterborne Cd in the present study. This kind of treatment caused dose-dependent decline in fish growth, with significance in the high dose group (100μg/L). Correspondingly, low dose (5-50μg/L) waterborne Cd disrupted the endocrine system of H-P-I axis just at the secretion level, while high dose Cd disrupted both the secretion and synthesis of cortisol and its downstream signals in rare minnows, revealed by the significantly upregulation and positive correlation of corticosteroidogenic genes including MC2R, StAR, CYP11A1, and CYP11B1 in the kidney (including the interrenal tissue) (P<0.05), and the significant alteration of Glcci1, Hsp90AA and Hsp90AB in the hepatopancreas, gill and intestine as well (P<0.05). The expression of Glcci1 was significantly decreased in hepatopancreas, gill and intestine of tested fish following treatment, and its positive correlation with GR (Glucocorticoid receptor) suggested its potential regulation on the cortisol and/or H-P-I axis in fish. The expression of FKBP5 in the intestine was positively and significantly correlated with that of Hsp90AA (P<0.05), and the Hsp90AB transcript in the hepatopancreas was positively correlated with that of Hsp90AA (P<0.05), which indicated that Hsp90AA and Hsp90AB were more likely to serve as cofactors of GR and FKBP5 in response to Cd exposure.

Assessing the test–retest repeatability of insulin resistance measures: Homeostasis model assessment 2 and oral glucose insulin sensitivity

Background: Insulin resistance is commonly assessed using the homeostasis model assessment (HOMA) variants. HOMA is potentially insensitive to change because of its high coefficient of variation. The repeatability coefficient is an alternative means of assessing test repeatability. To be confident of clinical change, rather than biological variation, a subsequent test needs to differ from the former by more than the repeatability coefficient using the equation.Test 1 = Test 2 ± repeatability coefficient.The repeatability coefficients for measures of insulin resistance are unknown.Aim: To compare the repeatability coefficient of HOMA2 variants (Beta-cell function [%B], insulin sensitivity [%S], insulin resistance [IR]) to a dynamic measure of insulin resistance, and the oral glucose insulin sensitivity (OGIS) test.Setting: The raw data from a previously used data set were reanalysed.Methods: Glycaemic and insulinaemic tests were performed on 32 men and women both with (n = 10) and without type 2 diabetes (n = 22). From these data, eight fasting tests and three 50-g oral glucose tolerance tests were used to calculate HOMA2 and OGIS. The methods of Bland and Altman assessed repeatability.Results: Repeatability coefficients for all participants for the HOMA2 %B, %S and IR variants were 72.91, 189.75 and 0.9, which equates to 89%, 135% and 89% of their respective grand means. By contrast, OGIS had a repeatability coefficient of 87.13, which equates to 21% of the grand mean.Conclusion: Because of the high repeatability coefficient relative to the grand mean, use of HOMA2 measures for assessing insulin resistance in small population studies should be reconsidered.

Developmental origins of the human hypothalamic-pituitary-adrenal axis

INTRODUCTION

The developmental origins of disease or fetal programming model predicts that intrauterine exposures have life long consequences for physical and psychological health. Prenatal programming of the fetal hypothalamic-pituitary-adrenal (HPA) axis is proposed as a primary mechanism by which early experiences are linked to later disease risk. Areas covered: This review describes the development of the fetal HPA axis, which is determined by an intricately timed cascade of endocrine events during gestation and is regulated by an integrated maternal-placental-fetal steroidogenic unit. Mechanisms by which stress-induced elevations in hormones of maternal, fetal, or placental origin influence the structure and function of the emerging fetal HPA axis are discussed. Recent prospective studies documenting persisting associations between prenatal stress exposures and altered postnatal HPA axis function are summarized, with effects observed beginning in infancy into adulthood. Expert commentary: The results of these studies are synthesized, and potential moderating factors are discussed. Promising areas of further research highlighted include epigenetic mechanisms and interactions between pre and postnatal influences.

Effects of high-intensity interval versus mild-intensity endurance training on metabolic phenotype and corticosterone response in rats fed a high-fat or control diet

The aim of the present study was to compare the effects of high-intensity interval training (HI) to mild-intensity endurance training (ME), combined with a high-fat diet (HFD) or control diet (CD) on metabolic phenotype and corticosterone levels in rats. Fifty-three rats were randomized to 6 groups according to diet and training regimen as follows: CD and sedentary (CS, n = 11), CD and ME (CME, n = 8), CD and HI (CHI, n = 8), HFD and sedentary (HS, n = 10), HFD and ME (HME, n = 8), and HFD and HI (HHI, n = 8). All exercise groups were trained for 10 weeks and had matched running distances. Dietary intake, body composition, blood metabolites, and corticosterone levels were measured. Histological lipid droplets were observed in the livers. The HFD led to hyperglycemia, hyperlipidemia and higher body fat (all, P < 0.01, η² > 0.06), as well as higher corticosterone levels (P < 0.01, η² = 0.09) compared with the CD groups. Exercise training improved fat weight, glucose, and lipid profiles, and reduced corticosterone levels (P < 0.01, η² = 0.123). Furthermore, body and fat weight, serum glucose and triglycerides, lipid content in the liver, and corticosterone levels (P < 0.05) were lower with HI training compared to ME training. Reductions in HFD-induced body weight gain, blood glucose and lipid profiles, and corticosterone levels, as well as improvements in QUICKI were better with HHI compared to HME. Correlation analyses revealed that corticosterone levels were significantly associated with phenotype variables (P < 0.01). Corticosterone level was inversely correlated with QUICKI (r = −0.38, P < 0.01). Altogether, these results indicate that HFD may elicit an exacerbated basal serum corticosterone level and thus producing a metabolic imbalance. Compared with ME training, HI training contributes to greater improvements in metabolic and corticosterone responses, leading to a greater reduction in susceptibility to HFD-induced disorders.

Combining field work and laboratory work in the study of financial risk-taking

A contribution to a special issue on Hormones and Human Competition. Financial markets are periodically destabilized by bubbles and crashes during which investors display respectively what has been called "irrational exuberance" and "irrational pessimism". How can we best study these pathologies in competitive and risk-taking behaviours? In this article, we argue that a science of risk-taking and of the financial markets needs to draw heavily on physiology and especially endocrinology, due to their central roles in moderating human behaviour. Importantly, this science of competition and risk requires the same spectrum of research protocols as is found in mature biological and medical sciences, a spectrum running from field work conducted within financial institutions themselves to more controlled laboratory studies, which permit cause to be distinguished from effect. Such a spectrum of studies is especially important for translational behavioural science.

Interleukin-1 Antagonism Decreases Cortisol Levels in Obese Individuals

CONTEXT

Increased cortisol levels in obesity may contribute to the associated metabolic syndrome. In obesity, the activated innate immune system leads to increased interleukin (IL)-1β, which is known to stimulate the release of adrenocorticotropin hormone (ACTH).

OBJECTIVES

We hypothesized that in obesity IL-1 antagonism would result in downregulation of the hypothalamo-pituitary-adrenal axis, leading to decreased cortisol levels.

DESIGN AND PARTICIPANTS

In this prospective intervention study, we included 73 patients with obesity (body mass index [BMI] ≥30 kg/m2) and at least one additional feature of the metabolic syndrome.

OUTCOME MEASURES

The primary end point was change in morning cortisol from baseline to after the administration of the IL-1 receptor antagonist (anakinra/Kineret®, total dose 3 × 100 mg). Secondary end points were effects on salivary cortisol and ACTH.

RESULTS

Median age was 56 years, 50.7% of patients were female, and median BMI was 36.3 kg/m2. Median morning serum cortisol levels (nmol/L) decreased significantly after IL-1 antagonism [from baseline, 452 to 423; absolute difference, -38.7; 95% confidence interval (CI), -64 to -13.4; P = 0.0019]. Similar effects were found for salivary cortisol levels (-2.8; 95% CI, -4.4 to -1.3; P = 0.0007), ACTH levels (-2.2; 95% CI; -4.2 to -0.1; P = 0.038), systolic blood pressure (-5.2, 95% CI, -8.5 to -1.8; P = 0.0006), and heart rate (-2.9; 95% CI, -4.7 to -1.0; P = 0.0029).

CONCLUSION

IL-1 antagonism in obese individuals with features of the metabolic syndrome leads to a decrease in serum cortisol, salivary cortisol, and ACTH levels along with a reduction in systolic blood pressure and heart rate.

Post-dexamethasone serum copeptin corresponds to HPA axis responsiveness in human obesity

CONTEXT

Increased activities of the arginine-vasopressin (AVP) system and the hypothalamic-pituitary-adrenal (HPA) axis were shown to be associated with human obesity, but relationships between these systems in obesity remain unclear.

OBJECTIVES

To assess HPA axis responsiveness and its relation to serum concentrations of the AVP-surrogate copeptin in subjects with obesity (OB) in comparison to non-obesity controls (NOC).

METHODS

In a cross-sectional monocentric study, thirty-nine OB (f/m 25/14; age 36.5±10.0years; body mass index, BMI, 41.5±4.7kg/m²) were compared to twenty-two NOC (f/m 12/10; age 35.3±8.5years; BMI 23.1±2.4kg/m²), matched for age and sex. All individuals underwent the combined dexamethasone/CRH test.

MAIN OUTCOME MEASURES

Plasma ACTH and cortisol curve indicators derived from the dex/CRH test (post-CRH concentrations 30min after 100μg CRH; maximum concentration, MAX; area-under-the-curve, AUC; ACTH/cortisol ratios). Copeptin was assessed in 1500h samples of the dex/CRH test (after 1.5mg of oral dexamethasone, prior to CRH administration).

RESULTS

Copeptin serum concentrations were higher in OB (median [IQR]: OB 4.62 [2.60-5.88] vs. NOC 3.04 [2.52-4.29] pmol/l, P=0.04). Correspondingly, OB showed higher post-CRH cortisol concentrations (OB: 51.5 [25.9-159.3] vs. NOC: 28.6 [20.0-41.6] nmol/l, P=0.01) and a lower post-CRH ACTH/cortisol ratio (OB: 0.028 [0.016-0.053] vs. NOC: 0.048 [0.034-0.070] pmol/nmol, P<0.01). Serum copeptin was significantly associated with HPA responsiveness in OB (post-CRH ACTH: R=0.42, P<0.01), driven by OB men (post-CRH ACTH: R=0.76, P<0.01, post-CRH cortisol: R=0.64, P=0.02). All associations withstand adjustments for BMI and age.

CONCLUSIONS

The association between increased copeptin with ACTH and cortisol release suggests a potential mechanistic interaction of the AVP system with HPA activation in human obesity. The relation of copeptin and HPA responsiveness should be further validated in situations with pronounced HPA activation, such as depression or multiple sclerosis.

Marital status as a predictor of diurnal salivary cortisol levels and slopes in a community sample of healthy adults

Married people tend to be healthier than both the previously (bereaved, divorced, and separated) and never married, but the mechanisms through which this occurs remain unclear. To this end, research has increasingly focused on how psychological stress experienced by unmarried versus married individuals may differentially impact physiological systems related to health. One key system that is modulated by stress is the hypothalamic-pituitary-adrenal (HPA) axis, of which cortisol is a key hormonal product. Increased cortisol production and disruption of cortisol's daily rhythm have been linked to poorer health outcomes. This study examined the association between current marital status and these two indices of cortisol in a community sample of 572 healthy men and women aged 21-55. It also tested whether marriage buffers against the effect of stress (perceived stress by marital status interaction) on cortisol production. Participants provided salivary cortisol samples during waking hours on three nonconsecutive separate days to calculate diurnal cortisol levels and slopes. Married individuals had lower cortisol levels than either their never married or previously married counterparts. Differences in cortisol levels were due at least in part to currently married individuals having a more rapid decline in cortisol through the afternoon hours compared to individuals who were never married (but not those who were previously married). Furthermore, there was an interaction between perceived stress and marital status in predicting cortisol levels. Specifically, higher stress was associated with higher cortisol levels for previously married individuals but not for the married or never married. The results of this study support cortisol as one candidate mechanism accounting for the association of marital status and health.