Stress-related cortisol secretion in men: relationships with abdominal obesity and endocrine, metabolic and hemodynamic abnormalities

Glucocorticoids and type 2 diabetes: from physiology to pathology

Type 2 diabetes mellitus is the result of interaction between genetic and environmental factors, leading to heterogeneous and progressive pancreatic β-cell dysfunction. Overweight and obesity are major contributors to the development of insulin resistance and impaired glucose tolerance. The inability of β cells to secrete enough insulin produces type 2 diabetes. Abnormalities in other hormones such as reduced secretion of the incretin glucagon-like peptide 1 (GLP-1), hyperglucagonemia, and raised concentrations of other counterregulatory hormones also contribute to insulin resistance, reduced insulin secretion, and hyperglycaemia in type 2 diabetes. Clinical-overt and experimental cortisol excess is associated with profound metabolic disturbances of intermediate metabolism resulting in abdominal obesity, insulin resistance, and low HDL-cholesterol levels, which can lead to diabetes. It was therefore suggested that subtle abnormalities in cortisol secretion and action are one of the missing links between insulin resistance and other features of the metabolic syndrome. The aim of this paper is to address the role of glucocorticoids on glucose homeostasis and to explain the relationship between hypercortisolism and type 2 diabetes.

Translational applications of evaluating physiologic variability in human endotoxemia

Dysregulation of the inflammatory response is a critical component of many clinically challenging disorders such as sepsis. Inflammation is a biological process designed to lead to healing and recovery, ultimately restoring homeostasis; however, the failure to fully achieve those beneficial results can leave a patient in a dangerous persistent inflammatory state. One of the primary challenges in developing novel therapies in this area is that inflammation is comprised of a complex network of interacting pathways. Here, we discuss our approaches towards addressing this problem through computational systems biology, with a particular focus on how the presence of biological rhythms and the disruption of these rhythms in inflammation may be applied in a translational context. By leveraging the information content embedded in physiologic variability, ranging in scale from oscillations in autonomic activity driving short-term heart rate variability to circadian rhythms in immunomodulatory hormones, there is significant potential to gain insight into the underlying physiology.

Low-calorie diet induced weight loss may alter regulatory hormones and contribute to rebound visceral adiposity in obese persons with a family history of type-2 diabetes

PURPOSE

To examine potential detrimental long-term effects of acute diet-induced weight loss on visceral adiposity, insulin resistance, cortisol, and adipokines in obese individuals at risk for type-2 diabetes.

DATA SOURCES

Anthropometric measures (height, weight, waist circumference), self-report instruments, abdominal computed tomography (CT) scan, and blood samples (glucose, insulin, interleukin-6, leptin, adiponectin) were obtained from a convenience sample of 20 participants at baseline, after a 28-day low-calorie diet (800 kcal/day) intervention, and again 6 months later.

CONCLUSIONS

Fifteen of 20 participants completed the 28-day diet intervention and had a mean weight loss of 15 pounds. Comparison between baseline, postdiet, and 6-month data, demonstrated that although participants had significant improvements after the diet, they regained fat mass, particularly in the visceral area.

IMPLICATIONS FOR PRACTICE

Clinicians may need to revise recommendations for using low-calorie diets to achieve weight loss. Diet-induced weight cycling may contribute to dysregulation of metabolism and have long-term detrimental consequences for accumulation of visceral adipose tissue. The likelihood of success is low, with high dropout rates, and those patients who achieve weight loss are very likely to regain it. Thus, the perceived short-term benefits of calorie-restricted diets in this population likely do not outweigh the potential long-term detrimental effects.

The expression of serotonin transporter protein correlates with the severity of psoriasis and chronic stress

Psoriasis may be worsened by stress and mood disorders. There is an increased expression of the serotonin transporter protein (SERT) in involved psoriatic skin as compared to non-involved psoriatic skin and normal skin. The aim of this study was to investigate if the increased expression of SERT in psoriasis correlates with the severity of disease, chronic stress, and depression. Biopsies from involved and non-involved skin from the back of 20 patients with chronic plaque psoriasis were immunohistochemically analysed, using a monoclonal antibody to SERT. The severity of psoriasis was assessed for each patient using the Psoriasis area and severity index (PASI). Levels of depression and chronic stress were measured using Beck's Depression Inventory (BDI) and the salivary cortisol test, respectively. A positive correlation (r = 0.53; p < 0.05) between PASI and the numbers of SERT-positive dendritic cells in the epidermis of involved psoriatic skin was determined. We also observed a negative correlation (r = -0.46; p < 0.05) between salivary cortisol ratio levels and the numbers of SERT-positive cells in the epidermis of involved psoriatic skin, indicating a correlation between SERT expression and chronic stress. The serotonergic system may be involved in the chronic inflammation evident in psoriatic skin. Through modulating the levels of SERT, there might be a therapeutic possibility for reducing chronic inflammation in psoriasis.

Contrasting effects of type 2 and type 1 diabetes on plasma RBP4 levels: the significance of transthyretin

Retinol-binding protein 4 (RBP4) is the principle carrier of retinol in the human plasma, which circulates as a complex with transthyretin (TTR), a homotetrameric thyroxine transport protein. Although this complex formation is thought to prevent glomerular filtration of RBP4, it also stabilizes the quaternary structure of TTR. Recent studies indicate elevated plasma levels of RBP4 in type 2 diabetes (T2D). In contrast, reduced RBP4 levels were observed in type 1 diabetes (T1D). Herein, we critically examine the probable mechanisms involved in the regulation of RBP4 and TTR levels during T2D and T1D. The available evidences point to the involvement of pancreatic factors in regulating the expression of both RBP4 and TTR. It appears that during T1D, TTR levels are reduced and it exists predominantly as a monomer that may interfere its interaction with RBP4 resulting in its loss through glomerular filtration. However, plasma TTR levels remain high under T2D conditions and thus reducing glomerular filtration of RBP4. Therefore, the plasma TTR levels appear to be an important determinant of plasma RBP4 levels in these two diabetic conditions.

Excessive zinc in diet induces leptin resistance in Wistar rat through increased uptake of nutrients at intestinal level

PROJECT

The ob gene has either been found to be mutant defective resulting in a deficiency of its product leptin or leptin has been found to be resistant to its receptors in obese human and rodents. The factors inducing leptin resistance have not been identified. Since excessive bioavailability of Zn has been implicated in obesity, we investigated if its excess in diet induces leptin resistance.

PROCEDURE

For the investigations, three groups of Wistar rats were included in this study and they were fed on equicalories semi synthetic basal diet containing 20 mg, 40 mg or 80 mg Zn/kg diet for 120 days. There after they were sacrificed for hormonal status and intestinal investigations.

RESULTS

The data of this study revealed that the food intake, gain in body weight, serum leptin, glucose, insulin, cortisol increased with increased Zn concentration in diet. TEM study showed a positive correlation between Zn concentration in diet and number of microvilli/unit surface area of the mucosal epithelial cells of the intestine.

CONCLUSION

The results of this study suggest that excessive bioavailability of Zn induces leptin resistance through increased uptake of nutrients at intestinal level, leading to the growth of the fat cells which aggravated the leptin synthesis and its release in the blood stream. In spite of its higher circulating level, it was unable to reduce the food intake and gain in body weight in Zn treated rats equivalent to the control group.

Attenuation of Zn-induced hyperleptinemia/leptin resistance in Wistar rat after feeding modified poultry egg

BACKGROUND

The prevalence of obesity is increasing exponentially world over. Leptin resistance/hyperleptinemia is attributed to its cause in majority of the obese humans where mutation in genetic component or ob gene has not been found operative. The generation of oxidative stress was suggested as its cause. In our previous study, we have reported that the inclusion of antioxidant enriched modified poultry egg (ME) in diet reversed the ionic imbalance and ameliorated the oxidative stress caused by excessive Zn in diet. In the present study, the efficacy of ME verses conventional egg (CE) was tested on Zn-induced leptin resistance in rat model to ascertain if the supplementation of antioxidants in the form of egg can reverse Zn-induced leptin resistance to leptin sensitive state.

METHODS

Hyperleptinemia was induced in rats by feeding them Zn-supplemented hyperleptinemic diets-I and II (Zn-HL-Diet) for 2 months. Thereafter, half of them were fed either on CE or ME mixed Zn-HL-diets I and II for another two months. The data was analyzed applying one way Anova and Tukey's HSD post hoc test.

RESULTS

The results revealed that food intake, gain in body weight, height and number/unit surface area of intestinal microvillus and serum leptin, glucose, insulin and cortisol were higher in CE and Zn-HL-Diet treated groups; serum Zn, Cu, Mg were higher and Cu and Mg in tissues were lower in them than the control group. In ME treated groups, these parameters were lower and were close to the control group. These changes resulted from the restoration of ionic balance of Zn, Cu and Mg in the blood serum and tissues including liver and hair in ME treated rats.

CONCLUSION

The data suggest that Zn-induced leptin resistance can be attenuated through restoring the ionic balance of Zn, Cu and Mg through inclusion of antioxidants in diet such as these modified eggs. But further clinical studies are required before they are put to use for human consumption.

The hypothalamic-pituitary-adrenal axis and sex hormones in chronic stress and obesity: pathophysiological and clinical aspects

Obesity, particularly the abdominal phenotype, has been ascribed to an individual maladaptation to chronic environmental stress exposure mediated by a dysregulation of related neuroendocrine axes. Alterations in the control and action of the hypothalamic-pituitary-adrenal axis play a major role in this context, with the participation of the sympathetic nervous system. The ability to adapt to chronic stress may differ according to sex, with specific pathophysiological events leading to the development of stress-related chronic diseases. This seems to be influenced by the regulatory effects of sex hormones, particularly androgens. Stress may also disrupt the control of feeding, with some differences according to sex. Finally, the amount of experimental data in both animals and humans may help to shed more light on specific phenotypes of obesity, strictly related to the chronic exposure to stress. This challenge may potentially imply a different pathophysiological perspective and, possibly, a specific treatment.

Obesity, obstructive sleep apnoea and metabolic syndrome

OSA is increasingly recognized as a major health problem in developed countries. Obesity is the most common risk factor in OSA and hence, the prevalence of OSA is undoubtedly rising given the epidemic of obesity. Recent data also suggest that OSA is highly associated with the metabolic syndrome, and it is postulated that OSA contributes to cardiometabolic dysfunction, and subsequently vasculopathy. Current evidence regarding the magnitude of impact on ultimate cardiovascular morbidity or mortality attributable to OSA-induced metabolic dysregulation is scarce. Given the known pathophysiological triggers of intermittent hypoxia and sleep fragmentation in OSA, the potential mechanisms of OSA-obesity-metabolic syndrome interaction involve sympathetic activation, oxidative stress, inflammation and neurohumoral changes. There is accumulating evidence from human and animal/cell models of intermittent hypoxia to map out these mechanistic pathways. In spite of support for an independent role of OSA in the contribution towards metabolic dysfunction, a healthy diet and appropriate lifestyle modifications towards better control of metabolic function are equally important as CPAP treatment in the holistic management of OSA.

The skin-blanching assay

The skin-blanching assay is used for the determination and bioequivalence of dermatologic glucocorticoids (GCs). The exact mechanism of the production of blanching is not fully understood, but it is considered that local vasoconstriction of the skin microvasculature and the consequent blood-flow reduction cause this phenomenon. Several factors influence skin blanching, including drug concentration, duration of application, nature of vehicle, occlusion, posture and location. The intensity of vasoconstriction can be measured in several ways: visual or quantitative methods, such as reflectance spectroscopy, thermography, laser Doppler velocimetry and chromametry. In literature, contradicting results in the correlation of the skin-blanching assay with different tests to determine GC sensitivity have been reported, limiting its clinical usefulness.

Stress and obesity/metabolic syndrome in childhood and adolescence

Chronic distress contributes to the development of obesity and comorbid states. Stress is the disturbance of the complex dynamic equilibrium that all organisms must maintain, and is associated with activation of the Stress system comprising of the hypothalamic-pituitary-adrenal axis and the arousal/sympathetic nervous systems. The stress system functions in a baseline circadian fashion and interacts with other systems of the organism to regulate a variety of behavioral, endocrine, metabolic, immune and cardiovascular functions. The experience of perceived or real uncontrollable intense and/or chronic stress (distress) may lead to several psychopathologic conditions, including anxiety, depressive and psychosomatic disorders, substance abuse, obesity and the metabolic syndrome, and osteoporosis, as well as impaired reproductive and immune functions. Developing children and adolescents are particularly vulnerable to the effects of chronic stress. Both behavioral and biological pathways are involved in the connection between chronic stress and obesity in adults and children. Emotional "comfort" eating, lack of sleep, impulsive behaviours and selection of specific foods often characterize stressed individuals. In addition to specific behaviours, dysregulation of the stress system through increased secretion of cortisol and catecholamines, especially in the evening hours, and in concert with concurrently elevated insulin concentrations, leads to development of central obesity, insulin resistance and the metabolic syndrome. In children, chronic alterations in cortisol secretion may have additional effects on cognitive and emotional development, timing of puberty and final stature. Obese children and adolescents are frequently entangled in a vicious cycle between distress, impairing self-image and distorted self-image, maintaining and worsening distress.

Childbearing, stress and obesity disparities in women: a public health perspective

The perinatal period, from early in the first trimester to 1 year postpartum, provides opportunities for novel public health interventions to reduce obesity disparities. We present a unifying socio-biological framework to suggest opportunities for multidisciplinary research and public health approaches to elucidate and target the mechanisms for the development of maternal obesity and related disparities. The framework illustrates the interplay of the social, cultural and physical environment; stress appraisal and response; and coping behaviors on short-term outcomes (e.g. allostatic load and gestational weight gain), the intermediate outcomes of persistent insulin resistance and post-partum weight retention, and longer term outcomes of obesity and its disease consequences. Testing the proposed relationships may provide insights into how childbearing risk factors such as gestational weight gain, postpartum weight retention and parity contribute to obesity, which are needed to inform public health policies and clinical care guidelines aimed at reducing obesity and improving the health of women.

Discrimination makes me sick! An examination of the discrimination-health relationship

The attitudes of the general British population towards Muslims changed post 2001, and this change led to a significant increase in Anti-Muslim discrimination. We use this exogenous attitude change to estimate the causal impact of increased discrimination on a range of objective and subjective health outcomes. The difference-in-differences estimates indicate that discrimination worsens blood pressure, cholesterol, BMI and self-assessed general health. Thus, discrimination is a potentially important determinant of the large racial and ethnic health gaps observed in many countries. We also investigate the pathways through which discrimination impacts upon health, and find that discrimination has a negative effect on employment, perceived social support, and health-producing behaviours. Crucially, our results hold for different control groups and model specifications.

Waist circumference, abdominal obesity, and depression among overweight and obese U.S. adults: National Health and Nutrition Examination Survey 2005-2006

BACKGROUND

Obesity is associated with an increased risk of mental illness; however, evidence linking body mass index (BMI)-a measure of overall obesity, to mental illness is inconsistent. The objective of this study was to examine the association of depressive symptoms with waist circumference or abdominal obesity among overweight and obese U.S. adults.

METHODS

A cross-sectional, nationally representative sample from the 2005-2006 National Health and Nutrition Examination Survey was used. We analyzed the data from 2,439 U.S. adults (1,325 men and 1,114 nonpregnant women) aged ≥ 20 years who were either overweight or obese with BMI of ≥ 25.0 kg/m2. Abdominal obesity was defined as waist circumference of > 102 cm for men and > 88 cm for women. Depressive symptoms (defined as having major depressive symptoms or moderate-to-severe depressive symptoms) were assessed by the Patient Health Questionnaire-9 diagnostic algorithm. The prevalence and the odds ratios (ORs) with 95% confidence intervals (CIs) for having major depressive symptoms and moderate-to-severe depressive symptoms were estimated using logistic regression analysis.

RESULTS

After multivariate adjustment for demographics and lifestyle factors, waist circumference was significantly associated with both major depressive symptoms (OR: 1.03, 95% CI: 1.01-1.05) and moderate-to-severe depressive symptoms (OR: 1.02, 95% CI: 1.01-1.04), and adults with abdominal obesity were significantly more likely to have major depressive symptoms (OR: 2.18, 95% CI: 1.35-3.59) or have moderate-to-severe depressive symptoms (OR: 2.56, 95% CI: 1.34-4.90) than those without. These relationships persisted after further adjusting for coexistence of multiple chronic conditions and persisted in participants who were overweight (BMI: 25.0-< 30.0 kg/m2) when stratified analyses were conducted by BMI status.

CONCLUSION

Among overweight and obese U.S. adults, waist circumference or abdominal obesity was significantly associated with increased likelihoods of having major depressive symptoms or moderate-to-severe depressive symptoms. Thus, mental health status should be monitored and evaluated in adults with abdominal obesity, particularly in those who are overweight.

Expression of tachykinins and their receptors in plaque psoriasis with pruritus

BACKGROUND Various mediators of pruritus have been suggested that might be responsible for the mechanism of pruritus in psoriasis.

OBJECTIVES

To study the expression levels of members of the tachykinin family, substance P and neurokinin (NK) A and their receptors, NK-1 and NK-2, in psoriasis and to correlate their expression with the intensity of pruritus. A possible correlation with chronic stress and depression was also evaluated.

METHODS

Biopsies were obtained from 28 patients with chronic plaque psoriasis; the majority had pruritus. The samples were taken from lesional and nonlesional areas on the back and also from 10 healthy controls, for immunohistochemistry staining, and from lesional skin for radioimmunoassay. Prior to biopsy, the clinical severity of the psoriasis of each patient was assessed by the Psoriasis Area and Severity Index (PASI) and the intensity of pruritus was measured by using a visual analogue scale (VAS). Levels of depression and stress were measured using Beck's Depression Inventory (BDI) and the salivary cortisol test, respectively.

RESULTS

Substance P-, NKA- and NK-2 receptor-immunoreactive nerves, and non-neuronal inflammatory cells positive for substance P and NKA and their respective receptors, NK-1 and NK-2, were numerous in psoriasis compared with healthy controls. The numbers of substance P-positive nerves and NK-2 receptor-positive cells in lesional skin were significantly correlated to pruritus intensity. The cortisol ratio was inversely correlated with the number of NK-1 receptor-immunoreactive inflammatory cells in lesional and nonlesional psoriasis skin. There was also a positive correlation between the BDI score and the number of substance P-positive cells in nonlesional skin and with NK-1 receptor-positive cells in lesional and nonlesional skin.

CONCLUSIONS

Tachykinins may play a role in psoriasis per se, in addition to pruritus in this disease. Targeting the combined NK-1 and NK-2 receptors might be a possible treatment.

Association between perceived interpersonal everyday discrimination and waist circumference over a 9-year period in the Midlife Development in the United States cohort study

The relation between perceived interpersonal experiences of discrimination and measures of obesity is of great interest to many. This study examined the relation between changes in waist circumference and changes in perceived interpersonal everyday discrimination using the 1995-2004 Midlife Development in the United States cohort study (N = 1,452). After controlling for potential confounding variables that assessed behavioral and sociodemographic characteristics, sex-stratified ordinary least squares regression analyses suggested that the waist circumference of adult males who reported consistently high levels of interpersonal everyday discrimination increased 2.39 cm more than that of adult males who consistently reported low levels of interpersonal everyday discrimination (P < 0.05). Similarly, the waist circumference of adult females who reported an increase in interpersonal everyday discrimination increased 1.88 cm more than that of adult females who reported consistently low levels of interpersonal everyday discrimination (P < 0.05). These findings suggest that perceived interpersonal everyday discrimination may be associated with an increase in waist circumference over time among adults in the United States.

Reducing psychological distress and obesity in Australian farmers by promoting physical activity

BACKGROUND

Studies have confirmed that the rate of mental illness is no higher in rural Australians than that of urban Australians. However, the rate of poor mental health outcomes, and in particular suicide, is significantly raised in rural populations. This is thought to be due to lack of early diagnosis, health service access, the distance-decay effect, poor physical health determinants and access to firearms. Research conducted by the National Centre for Farmer Health between 2004 and 2009 reveals that there is a correlation between obesity and psychological distress among the farming community where suicide rates are recognised as high. Chronic stress overstimulates the regulation of the hypothalamic-pituitary-adrenal (HPA) axis that is associated with abdominal obesity. Increasing physical activity may block negative thoughts, increase social contact, positively influence brain chemistry and improve both physical and mental health. This paper describes the design of the Farming Fit study that aims to identify the effect of physical activity on psychological distress, obesity and health behaviours such as diet patterns and smoking in farm men and women.

METHODS/DESIGN

For this quasi-experimental (convenience sample) control-intervention study, overweight (Body Mass Index ≥25 kg/m(2)) farm men and women will be recruited from Sustainable Farm Families™ (SFF) programs held across Victoria, Australia. Baseline demographic data, health data, depression anxiety stress scale (DASS) scores, dietary information, physical activity data, anthropometric data, blood pressure and biochemical analysis of plasma and salivary cortisol levels will be collected. The intervention group will receive an exercise program and regular phone coaching in order to increase their physical activity. Analysis will evaluate the impact of the intervention by longitudinal data (baseline and post intervention) comparison of intervention and control groups.

DISCUSSION

This study is designed to examine the effect of physical activity on psychological health and other co-morbidities such as obesity, impaired glucose tolerance, hypertension and dyslipidaemia within a high-risk cohort. The outcomes of this research will be relevant to further research and service delivery programs, in particular those tailored to rural communities.

TRIAL REGISTRATION

ACTRN12610000827033.

Prevalence of comorbid obstructive sleep apnea and metabolic syndrome: syndrome Z and maxillofacial surgery implications

PURPOSE

To determine the prevalence of the recently identified syndrome Z (SZ), which is the co-occurrence of obstructive sleep apnea (OSA; hypoxia, systemic and pulmonary hypertension, nocturnal arrhythmias) and metabolic syndrome (MetS; increased abdominal girth, hypertriglyceridemia, decreased high-density lipoprotein, hypertension, increased fasting glucose), which places the surgical patient at heightened risk of perioperative complications (myocardial infarction, stroke, pneumonia, wound infection).

MATERIALS AND METHODS

Electronic medical records of 296 male veterans were assessed for the presence of SZ using the American Academy of Sleep Medicine definition of OSA and a modified Adult Treatment Panel III definition of MetS, where obesity was defined by a body mass index of at least 30 kg/m(2) rather than by waist circumference.

RESULTS

SZ was diagnosed in 59% of patients. These individuals commonly exhibited severe OSA and least commonly mild OSA. The more severe the OSA, the more likely (60%) that patients manifested moderate (4 risk markers) or severe (5 risk markers) MetS. Furthermore, with increasing apnea-hypopnea index values, the more severe were the MetS elements.

CONCLUSIONS

The results of this study demonstrate the high prevalence rate of MetS in patients with OSA seeking treatment. Given the risk of perioperative complications, it is suggested that all patients scheduled for maxillofacial surgical procedures to treat OSA be evaluated for SZ.

Globalization and modernization: an obesogenic combination

Animal research has well established that a link exists between variations in corticosteroids and the proneness to excess body fat accumulation. Accordingly, it is known that adrenalectomy is an efficient approach to counteract weight gain in most animal models of obesity. In humans, the association between variations in corticosteroids, its stress-related environmental effects and the predisposition to obesity is more difficult to demonstrate. In this paper, we propose that this relationship is accentuated by globalization and modernization which favour a labour context imposing additional stress and changes in life habits promoting a positive energy balance. Our main hypothesis is that the increase in knowledge-based work, and the decrease of quality and duration of sleep both induce an increase in cortisolaemia and glycaemia instability, which results in an increase in food intake, a reduction in energy expenditure and body fat gain. The authors of this paper believe that, from a socioeconomic perspective, globalization leads every nation of the world in conflict with itself and may consequently represent a real problem. On one hand, there are preoccupations related to productivity and money making. On the other hand, people have to adopt a daily lifestyle leading to hyperphagia and decreased energy expenditure in order to maintain their economic competitiveness.

Cortisol variability and self-reports in the measurement of work-related stress

We examined whether a high cortisol awakening response (CAR) and low cortisol decline over the day (CDD) are related to self-reported work stress and well-being, and whether there are gender differences in these relationships. Three hundred eighty-three working men and women responded to a survey measuring job stress factors, mastery at work, symptoms and well-being. Salivary cortisol was sampled at awakening, after 45 min and at 21:00, from which the variables CAR and CDD were defined. A high CAR was associated with lower perceived job control and work mastery, and poorer well-being. Low CDD was associated only with higher job demands, but the self-report scores showed a number of interactions between cortisol group and gender. Among women, those showing a low CDD, compared with those with a higher CDD, had more favourable scores on a number of job stress factors and symptom load. In contrast, among men, a similar comparison showed those with low CDD to have poorer scores on job stress factors and symptom load. We conclude that individuals displaying high CAR or low CDD differ from those not displaying these cortisol profiles in self-report of work stress and well-being, and that gender differences appear in these relationships.

Impaired glucose tolerance and metabolic syndrome in idiopathic polyneuropathy: the role of pain and depression

Chronic idiopathic axonal polyneuropathy (CIAP) is referred to as axonal neuropathy after an adequate workup fails to determine a cause. A subgroup of patients with CIAP has impaired glucose tolerance (IGT). These patients have been considered by some investigators to have a neuropathy as a result of IGT and/or metabolic syndrome (MetS). Patients with CIAP usually suffer from chronic pain and associated depression, both of which have been proposed to cause insulin resistance (IR) by such mechanisms as a sustained increase in the corticosteroids and catecholamines, and chronic low grade inflammation. In a pilot study of 14 patients with CIAP+IGT and eight normal controls, we found a correlation between the number of features of the MetS with scores of pain and depression. There was no increase in the frequency of retinopathy and nephropathy in these patients, contrary to what would have been expected if chronic hyperglycemia was the cause of the neuropathy. We hypothesize that neuropathy has an unclear cause in the majority of patients with CIAP+IGT/MetS--and IGT/MetS are a result of comorbidities of CIAP, including chronic pain and depression.

Mindfulness Intervention for Stress Eating to Reduce Cortisol and Abdominal Fat among Overweight and Obese Women: An Exploratory Randomized Controlled Study

Psychological distress and elevated cortisol secretion promote abdominal fat, a feature of the Metabolic Syndrome. Effects of stress reduction interventions on abdominal fat are unknown. Forty-seven overweight/obese women (mean BMI = 31.2) were randomly assigned to a 4-month intervention or waitlist group to explore effects of a mindfulness program for stress eating. We assessed mindfulness, psychological distress, eating behavior, weight, cortisol awakening response (CAR), and abdominal fat (by dual-energy X-ray absorptiometry) pre- and posttreatment. Treatment participants improved in mindfulness, anxiety, and external-based eating compared to control participants. Groups did not differ on average CAR, weight, or abdominal fat over time. However, obese treatment participants showed significant reductions in CAR and maintained body weight, while obese control participants had stable CAR and gained weight. Improvements in mindfulness, chronic stress, and CAR were associated with reductions in abdominal fat. This proof of concept study suggests that mindfulness training shows promise for improving eating patterns and the CAR, which may reduce abdominal fat over time.

A novel genetically-obese rat model with elevated 11 beta-hydroxysteroid dehydrogenase type 1 activity in subcutaneous adipose tissue

11 β-hydroxysteroid dehydrogenase type 1 (11 β-HSD1) catalyzes the conversion of inactive glucocorticoids to active glucocorticoids and plays an important role in the development of obesity and metabolic syndrome. 11 β-HSD1 activity is lower in liver and higher in omental adipose tissue of obese rodent models like obese zucker rats, Ob/Ob and db/db mice. Here, we report the 11 β-HSD1 activity in liver and adipose tissue of lean and obese rats of WNIN/Ob strain, a new genetic rat model of obesity. 11 β-HSD1 activity in liver, omental and subcutaneous adipose tissues of 3 month-old male WNIN/Ob lean and obese rats was assayed. As observed in other rodent models, 11 β-HSD1 activity was lower in liver and higher in omental adipose tissue. In contrast to other rodent obese models, WNIN/Ob obese rats had elevated 11 β-HSD1 activity in subcutaneous adipose tissue, which is in line with the observation in human obesity. Here, we conclude that dysregulation of 11 β-HSD1 in WNIN/Ob obese rat model is identical to human obesity, which makes it an excellent model for studying the effect of 11 β-HSD1 inhibitors in ameliorating obesity and metabolic syndrome.

Co-peptin: Role as a novel biomarker in clinical practice

BACKGROUND

Arginine vasopressin (AVP) is a key regulator of water balance, but its instability makes reliable measurement difficult and precludes its routine use. Co-peptin is the C-terminal part of the AVP precursor which plays an important role in the correct structural formation of the AVP precursor and its efficient proteolytic maturation. Because of its stoichiometric generation, co-peptin mirrors the release of AVP and measurement of more stable co-peptin may be an indicator of AVP levels.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

Recent and ongoing research indicates the diagnostic and prognostic roles of co-peptin in various clinical settings especially in critically ill patients.

CONCLUSION

Co-peptin levels are altered in various physiological and pathological conditions indicating its possible role as a biomarker. However, further research using co-peptin in various clinical settings will prove its cost-effectiveness and clinical usefulness.

Cortisol, energy intake, and food frequency in overweight/obese women

OBJECTIVE

This retrospective study investigated the relation between daily urinary free cortisol excretion rate, as a marker of cortisol production rate, to daily caloric intake, food choice, body mass index (BMI), and waist circumference.

METHODS

One hundred twenty-seven overweight/obese women and 21 normal-weight subjects were enrolled in the study. Fasting blood samples for metabolic parameters were taken from each subject, followed by an oral glucose tolerance test. Cortisol excretion rate was assessed on 24-h urine collection (UFC/24 h). In obese patients, the daily caloric intake was calculated, and a weekly food-frequency questionnaire was assessed. Analysis of variance was used to assess the differences between groups. The relations between parameters were investigated by simple and multiple regressions.

RESULTS

Obese women had significantly higher UFC/24 h than the normal-weight women (P < 0.001). The obese subjects had an unbalanced diet, particularly rich in saturated lipids, and weekly food choice showed a preference for highly caloric foods. UFC/24 h values and waist circumference were significantly correlated (P < 0.001), regardless of BMI. In the obese group, after adjustment for BMI, the UFC/24 h values were also significantly and positively correlated to daily carbohydrate and lipid intake and to weekly starchy food consumption.

CONCLUSION

We demonstrated a significant association between higher UFC/24 h and energy intake, fats, and consumption of starchy foods, and that these relations were independent of BMI.

Corticosteroid-mediated programming and the pathogenesis of obesity and diabetes

Epidemiological studies have shown that low birthweight is associated with increased risk of development of diabetes and obesity in later life. Over-exposure of the developing fetus to glucocorticoids is one of the major hypotheses that has been proposed to explain this association. In animal models, a range of manipulations that increase fetal glucocorticoid load, 'programme' permanent changes in glucose and insulin metabolism and adiposity. This may be mediated by alterations in regulation of the hypothalamic-pituitary-adrenal (HPA) axis. In humans, low birthweight is associated with increased circulating glucocorticoid levels, and an increased cortisol response to physiological and psychosocial stressors, in child- and adulthood. This activation of the HPA axis is also associated with increased risk of development of diabetes and obesity in later life.

Further exploration of the possible influence of polymorphisms in HTR2C and 5HTT on body weight

Receptors of the 5-HT2C subtype are of importance for the influence of serotonin on food intake, and 2 single nucleotide polymorphisms in this gene (HTR2C)--Cys23Ser (rs6318) and -759C>T (rs3813929)--have been reported to be associated with weight and/or antipsychotic-induced weight gain. The present study aimed to replicate these associations; in addition, the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene (SLC6A4) was assessed. The polymorphisms were genotyped in subjects recruited from the normal population (n = 510), and possible associations between genotype and body mass index (BMI) were assessed. The Ser23 allele was more common in underweight subjects (BMI <20) than in normal- and overweight (BMI > or =20) subjects (P = .006). The T allele of the -759C/T polymorphism was less common in the overweight group (BMI > or =25) (P = .007). Homozygosity for the short allele of 5-HTTLPR was more frequent in underweight subjects (P = .015). Our results are in agreement with previous studies, suggesting polymorphisms in HTR2C to be associated with body weight, particularly in women; and they also suggest that 5-HTTLPR may influence this phenotype. Further studies on the importance of the investigated genes for eating disorders and drug-induced weight gain are warranted.

Diet choice, cortisol reactivity, and emotional feeding in socially housed rhesus monkeys

Chronic psychosocial stress produces an array of adverse health consequences that are highly comorbid, including emotional eating, affective disorders, and metabolic syndrome. The consumption of high caloric diets (HCDs) is thought to provide comfort in the face of unrelenting psychosocial stress. Using social subordination in female rhesus monkeys as a model of continual exposure to daily stressors in women, we tested the hypothesis that subordinate females would consume significantly more calories from a HCD compared to dominant females, and this pattern of food intake would be associated with reduced cortisol release and reduced frequency of anxiety-like behaviors. Food intake, parameters of cortisol secretion, and socio-emotional behavior were assessed for 3 weeks during a no choice phase when only a low caloric diet (LCD) was available and during a choice condition when both a LCD and HCD were available. While all animals preferred the HCD, subordinate females consumed significantly more of the HCD than did dominant females. A flattening of the diurnal cortisol rhythm and a greater increase in serum cortisol to an acute social separation occurred during the diet choice condition in all females. Furthermore, the rate of anxiety-like behavior progressively declined during the 3-week choice condition in subordinate but not dominant females. These data provide support for the hypothesis that daily exposure to psychosocial stress increases consumption of calorically dense foods. Furthermore, consumption of HCDs may be a metabolic stressor that synergizes with the psychosocial stress of subordination to further increase the consumption of these diets.

Association between the catechol-O-methyltransferase Val158Met polymorphism and panic disorder: a replication

The association between the catechol-O-methyltransferase Val158Met polymorphism and panic disorder was studied in a Swedish sample of 211 patients and 452 controls. We found a significant excess of the Val allele in both male and female patients, the latter but not the former finding being in line with previous studies.

Stress and cardiovascular disease risk in female law enforcement officers

PURPOSE

To assess the levels of stress and the prevalence of cardiovascular disease (CVD) risk factors in female law enforcement officers (LEOs).

METHODS

Self-reported data including job-related stress and CVD risk factors were obtained from 65 female LEOs. Stress scores were compared with 429 males LEOs and CVD risk factors were compared with 1,213 demographically similar female respondents to the CDC BRFSS survey. All subjects resided in Iowa.

RESULTS

Female LEOs had more stress (perceived stress, p < 0.01), more job-related stress (job strain, vital exhaustion and effort-reward imbalance, p < 0.01 for all), but similar social support (social provision scale, p = 0.412) than male LEOs. Female LEOs had a significantly higher prevalence of hypercholesterolemia than the general Iowa female population (46.2 vs. 29.3%, p < 0.01). There was a trend towards a higher prevalence of diabetes in female LEOs (9.2 vs. 4.5%, p = 0.084). The most commonly cited contributor to their perceived CVD risk was stress (77%). Female LEOs who felt that being either a LEO (67.7%) or a female LEO (41.5%) contributed to their risk for chronic diseases had more stress and a higher prevalence of overweight and obesity than female LEOs who felt differently.

CONCLUSIONS

Female LEOs have higher stress than male LEOs. The prevalences of hypercholesterolemia and diabetes are higher in female LEOs than that of the general female population. Thus, female LEOs may be at a greater risk for CVD than their male counterparts.

Corticosteroid-binding globulin: the clinical significance of altered levels and heritable mutations

Corticosteroid-binding globulin (CBG) is the specific high-affinity plasma transport glycoprotein for cortisol. Stress-induced falls in CBG levels may heighten hypothalamic-pituitary-adrenal axis responses and CBG:tissue interactions may allow targeted cortisol delivery. Three genetic variants of CBG have been identified that reduce cortisol binding affinity and/or CBG levels. These include the Leuven and Lyon mutations which reduce CBG:cortisol binding affinity 3- and 4-fold, respectively, and the null mutation resulting in a 50% (heterozygote) or 100% (homozygote) reduction in CBG levels. The three reported null homozygotes demonstrate that complete CBG deficiency is not lethal, although it may be associated with hypotension and fatigue. The phenotype of a CBG null murine model included fatigue and immune defects. One community-based study revealed that severe CBG mutations are rare in idiopathic fatigue disorders. The mechanisms by which CBG mutations may cause fatigue are unknown. There are preliminary data of altered CBG levels in hypertension and in the metabolic syndrome; however, the nature of these associations is uncertain. Further studies may clarify the functions of CBG, and clinical observations may validate and/or extend the phenotypic features of various CBG mutations.

Neuroendocrine alterations in obese patients with sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a serious, prevalent condition that has significant morbidity and mortality when untreated. It is strongly associated with obesity and is characterized by changes in the serum levels or secretory patterns of several hormones. Obese patients with OSAS show a reduction of both spontaneous and stimulated growth hormone (GH) secretion coupled to reduced insulin-like growth factor-I (IGF-I) concentrations and impaired peripheral sensitivity to GH. Hypoxemia and chronic sleep fragmentation could affect the sleep-entrained prolactin (PRL) rhythm. A disrupted Hypothalamus-Pituitary-Adrenal (HPA) axis activity has been described in OSAS. Some derangement in Thyroid-Stimulating Hormone (TSH) secretion has been demonstrated by some authors, whereas a normal thyroid activity has been described by others. Changes of gonadal axis are common in patients with OSAS, who frequently show a hypogonadotropic hypogonadism. Altogether, hormonal abnormalities may be considered as adaptive changes which indicate how a local upper airway dysfunction induces systemic consequences. The understanding of the complex interactions between hormones and OSAS may allow a multi-disciplinary approach to obese patients with this disturbance and lead to an effective management that improves quality of life and prevents associated morbidity or death.

Cortisol patterns and brachial artery reactivity in a high stress environment

Chronic stress can result in frequent or persistent challenges of the hypothalamic-pituitary-adrenal (HPA) axis resulting in abnormal cortisol patterns and increased risk for cardiovascular disease (CVD). Police work is an environment replete with stress. The present article describes associations between cortisol, a biomarker of stress, and brachial artery flow mediated dilation (FMD) in police officers. A random sample stratified on gender (n=100, 33% women) was generated from officers in a mid-sized urban department. Four salivary cortisol parameters were derived: after awakening, following a standardized high protein meal challenge, during the entire day, and after a dexamethasone suppression test. Continuous scan B-Mode ultrasound was used to measure percent change in brachial artery FMD following occlusion and release. Elevated cortisol secretion after awakening was significantly associated with impaired FMD in women, reflected by an inverse trend. Adjustment for age, smoking, and alcohol consumption did not appreciably alter this trend. A similar result was not evident among male officers. Responses of other cortisol challenges to the HPA axis were not associated with FMD. In conclusion, increased cortisol secretion after awakening was independently associated with impaired FMD in female police officers only, indicating a possible link between HPA axis stress response and subclinical CVD. However, because associations were not found with other cortisol parameters and were not evident in male officers, replication of these findings with a prospective study design may be warranted.

Depressive symptoms and metabolic risk: effects of cortisol and gender

We examined gender effects and the role of cortisol in the association between depressive symptoms and metabolic risk in the Stress, Atherosclerosis, and ECG Study (STRATEGY). In 215 healthy adults from the general population (n=107 men, n=108 women, distributed equally across four age groups, 30-70 years), we assessed depressive symptoms by the Patient Health Questionnaire (PHQ score >10) and measured variables of the metabolic syndrome: high-density lipoprotein (HDL), triglycerides, systolic and diastolic blood pressure, fasting blood glucose and waist circumference. Salivary cortisol was assessed at 08:00, 12:00, 16:00 and 22:00 h. Depressive symptoms were not associated with the metabolic syndrome as entity in the total sample or in men and women separately. However, women with depressive symptoms had larger waist circumferences, higher fasting blood glucose, lower HDL-cholesterol, higher diastolic blood pressure, and higher 16:00 and 22:00 h salivary cortisol compared to women without depressive symptoms. These results persisted after adjusting for age, education, smoking, and physical activity. In adjusted regression analyses, inclusion of cortisol attenuated the association between depressive symptoms and waist, fasting glucose, HDL and diastolic blood pressure in women. In men, we did not find an association between depressive symptoms and variables of the metabolic syndrome. In women, depressive symptoms are associated with several variables of the metabolic syndrome. Elevated afternoon and evening cortisol appear to partially mediate this association.

Circulating plasma cortisol concentrations are not associated with coronary artery disease or peripheral vascular disease

BACKGROUND

Although the prevalence of cardiovascular disease is declining, the obesity epidemic with associated metabolic syndrome may reverse this trend. Hypothalamic-pituitary-adrenal (HPA) axis activation may underlie the metabolic syndrome, but whether circulating cortisol levels predict vascular disease is less clear. A recent study reported a positive correlation between cortisol levels measured prior to coronary angiography and disease severity, but others have not demonstrated such a relationship. This may be due to different sampling conditions, reflecting basal cortisol levels, vs. responsiveness of HPA axis activity, which may have diverse influences on the pathogenesis of atherosclerosis.

AIMS

To determine whether basal circulating cortisol levels predict coronary artery (CAD) or peripheral vascular disease.

METHODS

Basal plasma cortisol levels were measured in 278 subjects with suspected CAD, who had undergone elective coronary angiography and in 76 cases and 85 controls with and without peripheral vascular disease, respectively.

RESULTS

After adjustment for potential confounding factors, circulating cortisol levels tended to be lower in those with confirmed coronary vessel disease at angiography (P = 0.10), and in those requiring intervention following angiography (P = 0.07). Lower cortisol levels also predicted those with more symptoms of angina (P = 0.01). Cortisol levels were no different in those with or without peripheral vascular disease.

CONCLUSION

A single measurement of circulating cortisol is a poor predictor of vascular disease. More detailed characterization of the HPA axis is necessary to determine the role of circulating endogenous glucocorticoids and their responsiveness to stress in atherosclerosis.

Acute effects of stress-reduction Interactive Guided Imagery(SM) on salivary cortisol in overweight Latino adolescents

OBJECTIVES

Chronic stress with relative hypercortisolism has been associated with metabolic disease risk. Stress-reduction interventions may therefore hold promise for reducing such chronic disease risk in obese youth. The purpose of this study was to conduct a 4-week pilot intervention to determine whether stress-reduction Interactive Guided Imagery(SM) (IGI) could serve as an acceptable and effective stress-reduction modality in overweight Latino adolescents.

DESIGN

Subjects (6 male/6 female, ages 14-17, body-mass index >95th percentile) were randomly assigned to the experimental guided imagery group (IGI, n = 6), or the nonintervention control group (C, n = 6). IGI subjects received four weekly 45-minute stress-reduction IGI sessions. Salivary cortisol was assessed immediately before and after each session. Acceptability was assessed by compliance and qualitative interviews.

RESULTS

Subjects attended all sessions and expressed acceptance of the IGI intervention. There were significant within-group reductions in salivary cortisol in the IGI group in three of the four sessions, and no reductions in cortisol in the control group. For all four sessions combined, there was a significant between-group effect for the change in salivary cortisol in IGI versus C (p = 0.007). Effect sizes of cortisol change in IGI group were moderate to very high in the four sessions.

CONCLUSIONS

We conclude that IGI may be feasible and effective in acutely reducing salivary cortisol levels in overweight Latino adolescents. Future studies will need to determine whether stress-reduction IGI can result in longer-term reductions in chronic stress and measures of HPA activity.

Salivary cortisol, serum lipids, and adiposity in patients with depressive and anxiety disorders

Depressive and anxiety disorders are associated with an increased risk of cardiovascular disease. Chronic stress induces hypothalamus-pituitary-adrenal (HPA)-axis perturbations, which might subsequently induce atherogenic lipoprotein profiles and adiposity. The aim of the present study was to investigate the relationship between basal saliva cortisol levels and serum lipids and adiposity in psychiatric patients. Eight salivary cortisol samples (awakening; 30, 45, and 60 minutes after awakening; 11:00 AM, 3:00 PM, 7:00 PM, and 11:00 PM) on 2 consecutive days in medication-free outpatients with depressive and/or anxiety disorders (n = 72) and in healthy controls (n = 42) were used to derive 2 measures of HPA-axis function: basal cortisol concentrations (ie, area under the curve [AUC(cortisol)]) and circadian cortisol variability (variability(cortisol)). Index z scores were calculated for dyslipidemia (from serum triglycerides, inverse high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) and adiposity (from body mass index and waist-to-hip ratio). Regression analyses were conducted to determine the contribution of AUC(cortisol) and variability(cortisol) in explaining the variance of, respectively, the lipid and adiposity index. Patients showed a higher mean AUC(cortisol) compared with healthy controls (t = 2.7, P = .01). Both cortisol parameters were independently associated with dyslipidemia in patients after adjustment for age, alcohol use, and smoking habits (beta = .31, P = .02 and beta = -.29, P = .02, respectively), but not in controls. Cortisol measures were not associated with adiposity in either group. We conclude that elevated basal cortisol concentrations and lower circadian cortisol variability were independently associated with a less favorable lipoprotein profile in patients with depressive and/or anxiety disorders. These data lend support to the hypothesis that the relationship between affective disorders and cardiovascular disease is partly mediated by HPA-axis perturbations.

Possible association between the androgen receptor gene and autism spectrum disorder

Autism is a highly heritable disorder but the specific genes involved remain largely unknown. The higher prevalence of autism in men than in women, in conjunction with a number of other observations, has led to the suggestion that prenatal brain exposure to androgens may be of importance for the development of this condition. Prompted by this hypothesis, we investigated the potential influence of variation in the androgen receptor (AR) gene on the susceptibility for autism. To this end, 267 subjects with autism spectrum disorder and 617 controls were genotyped for three polymorphisms in exon 1 of the AR gene: the CAG repeat, the GGN repeat and the rs6152 SNP. In addition, parents and affected siblings were genotyped for 118 and 32 of the cases, respectively. Case-control comparisons revealed higher prevalence of short CAG alleles as well as of the A allele of the rs6152 SNP in female cases than in controls, but revealed no significant differences with respect to the GGN repeat. Analysis of the 118 families using transmission disequilibrium test, on the other hand, suggested an association with the GGN polymorphism, the rare 20-repeat allele being undertransmitted to male cases and the 23-repeat allele being overtransmitted to female cases. Sequencing of the AR gene in 46 patients revealed no mutations or rare variants. The results lend some support for an influence of the studied polymorphisms on the susceptibility for autism, but argue against the possibility that mutations in the AR gene are common in subjects with this condition.

Stress effects on declarative memory retrieval are blocked by a beta-adrenoceptor antagonist in humans

Previous evidence indicates that stress hormone effects on memory consolidation depend on concurrent emotional arousal-induced noradrenergic activity. Here, we asked whether this is also true for stress effects on memory retrieval and hypothesized that administration of the beta-adrenoceptor antagonist propranolol would block the effects of stress on declarative and procedural retrieval performance. In a double-blind, placebo-controlled, crossover study, 44 healthy young men learned a list of emotional and neutral words (declarative memory task) and completed a serial reaction time task (procedural memory task). On the following day, participants received either a placebo or 40 mg propranolol orally. One hour later, they were exposed to stress (socially evaluated cold pressor test (SECPT)) or a control condition 30 min prior to retention testing. Stress selectively enhanced the retrieval of emotionally arousing words. Pretreatment with propranolol had no effect on memory alone but blocked the stress-induced memory enhancement for emotional words, confirming the importance of noradrenergic activity in stress effects on memory retrieval. Memory for neutral words and the procedural task was neither affected by stress nor by propranolol. The present findings suggest that stress (hormone) effects on emotional memory retrieval require concurrent noradrenergic activation. Procedural memory retrieval and the retrieval of neutral verbal material appear to be less susceptible to stress.

Hypothalamic-pituitary-adrenal axis function: relative contributions of perceived stress and obesity in women

OBJECTIVE

A range of behavioral and psychosocial factors may contribute to a chronically stimulated hypothalamic-pituitary-adrenal (HPA) axis and subsequently altered diurnal patterns. The goal of this cross-sectional study was to examine associations among diurnal cortisol levels, perceived stress, and obesity patterns.

METHODS

Seventy-eight women (aged 24-72 years) employed in a rural public school system completed the perceived stress scale, collected diurnal saliva samples, and underwent anthropometric assessments. Reduced peak-to-nadir cortisol values across the day were considered a sign of impairment in HPA function. A series of linear regression models determined the best predictors of diurnal cortisol variation.

RESULTS

There was a marginal linear trend in stress levels across body mass index (BMI) categories, with obese women reporting the highest levels of stress (p = 0.07). Perceived stress was the only significant predictor of the degree of flattening of the diurnal cortisol curve in the sample as a whole (beta = -0.042, R(2) = 0.11, F = 8.6, p = 0.005), indicating reduction in the normal diurnal pattern. Among overweight women (BMI = 25-29.9 kg/m(2)), stress and waist circumference combined predicted 35% of the variability in diurnal cortisol. In contrast, among obese women (BMI > or = 30 kg/m(2)), BMI predicted 31% of the variability in diurnal cortisol (F = 13.8, p = 0.001), but stress was no longer significantly related to diurnal cortisol.

CONCLUSIONS

Psychological stress predicts a significant portion of HPA axis functioning. In overweight women, perceived stress and waist circumference were of approximately equal importance in predicting adrenal cortisol secretion. However, among obese women, a major portion of the diurnal cortisol variation was predicted by BMI alone, not stress or waist circumference. This may help elucidate the mechanisms linking obesity to increased risk of cardiovascular disease (CVD).

Stress and fatigue in sound engineers: the effect of broadcasting in a life show and shift work

The aim was to study the time-of-day variations of cortisol, fatigue and sleep disturbances in sound engineers in relation to job task and shift work. The concentration of saliva cortisol and feeling of stress, sleepiness and fatigue were followed at three hour intervals in 21 sound engineers: 13 sound engineers, aged 45.1 +/- 7.3 years, broadcasting in a life show during fast forward rotating shifts and 8 sound engineers, aged 47.1 +/- 9.8 years, making records in a studio during fast rotating day shifts. Cortisol concentration was assessed in saliva with radioimmunological kits. The participants reported for stress symptoms during the shifts and filled sleep diary. The data were analyzed by tests of between-subjects effects (SPSS). A trend for higher cortisol was found with the group broadcasting in a life show. The sound engineers broadcasting in a life show reported higher scores of stress, sleepiness and fatigue, but no significant differences concerning the sleep disturbances between the groups were found. In conclusion our data show moderate level of stress and fatigue with the studied sound engineers, higher with the subjects broadcasting in a life show. The quality of sleep showed no significant differences between the studied groups, an indication that the sound engineers were able to tolerate the fast forward rotating shifts.

Higher body mass index (BMI) is associated with reduced glucocorticoid inhibition of inflammatory cytokine production following acute psychosocial stress in men

BACKGROUND

Body mass index (BMI) and mental stress seem to exert part of their cardiovascular risk by eliciting inflammation. However, the adverse effects of stress on inflammatory activity with BMI are not fully understood. We investigated whether higher BMI is associated with reduced glucocorticoid inhibition of inflammatory cytokine production following stress in men while controlling for age and blood pressure. We measured glucocorticoid inhibition of lipopolysaccharide (LPS)-stimulated release of the proinflammatory cytokine tumor necrosis factor (TNF)-alpha.

METHODS

Forty-two men (age range 21-65 years; BMI range 21-34 kg/m(2)) underwent the Trier Social Stress Test (combination of mock job interview and mental arithmetic task). Whole blood samples were taken immediately before and after stress, and during recovery up to 60 min post-stress. Glucocorticoid sensitivity of LPS-stimulated TNF-alpha expression was assessed in vitro with and without coincubating increasing doses of dexamethasone. Moreover, salivary cortisol was measured during the experiment and on a normal day for assessment of baseline circadian cortisol.

RESULTS

Higher BMI was associated with lower glucocorticoid sensitivity of monocyte TNF-alpha production after stress (main effect of BMI: p<0.001) and with more pronounced decreases of glucocorticoid sensitivity following stress (interaction of stress-by-BMI: p=0.002). Neither LPS-stimulated TNF-alpha release nor baseline glucocorticoid sensitivity were associated with BMI. Similarly, BMI was not associated with salivary cortisol, either in reaction to stress or in circadian cortisol secretion.

CONCLUSIONS

Our data suggest that with increasing BMI, glucocorticoids are less able to inhibit TNF-alpha production following stress. This might suggest a new mechanism linking BMI with elevated risk for adverse cardiovascular outcomes following stress.