Food-induced cortisol secretion in relation to anthropometric, metabolic and haemodynamic variables in men

Neurocognitive effects of stress: a metaparadigm perspective

Stressful experiences, both physical and psychological, that are overwhelming (i.e., inescapable and unpredictable), can measurably affect subsequent neuronal properties and cognitive functioning of the hippocampus. At the cellular level, stress has been shown to alter hippocampal synaptic plasticity, spike and local field potential activity, dendritic morphology, neurogenesis, and neurodegeneration. At the behavioral level, stress has been found to impair learning and memory for declarative (or explicit) tasks that are based on cognition, such as verbal recall memory in humans and spatial memory in rodents, while facilitating those that are based on emotion, such as differential fear conditioning in humans and contextual fear conditioning in rodents. These vertically related alterations in the hippocampus, procedurally observed after subjects have undergone stress, are generally believed to be mediated by recurrently elevated circulating hypothalamic-pituitary-adrenal (HPA) axis effector hormones, glucocorticoids, directly acting on hippocampal neurons densely populated with corticosteroid receptors. The main purposes of this review are to (i) provide a synopsis of the neurocognitive effects of stress in a historical context that led to the contemporary HPA axis dogma of basic and translational stress research, (ii) critically reappraise the necessity and sufficiency of the glucocorticoid hypothesis of stress, and (iii) suggest an alternative metaparadigm approach to monitor and manipulate the progression of stress effects at the neural coding level. Real-time analyses can reveal neural activity markers of stress in the hippocampus that can be used to extrapolate neurocognitive effects across a range of stress paradigms (i.e., resolve scaling and dichotomous memory effects issues) and understand individual differences, thereby providing a novel neurophysiological scaffold for advancing future stress research.

Cortisol/DHEA ratio in morbidly obese patients before and after bariatric surgery: Relation to metabolic parameters and cardiovascular performance

INTRODUCTION

Bariatric surgery (BS) is the most effective therapy for morbid obesity. Cortisol and DHEA are steroid hormones with opposing effects, thus using Cortisol/DHEA ratio (C/D) rather than the use of either hormone alone has been found to predict health outcomes more reliably. It was interesting to study C/D as an indicator of favorable metabolic and cardiovascular outcomes after BS.

OBJECTIVE

To assess C/D in morbidly obese patients before and after BS in relation to metabolic parameters and cardiovascular performance.

PATIENTS AND METHODS

Forty morbidly obese patients were followed prospectively for 1 year after BS. Fasting blood glucose (FBG), fasting insulin (FI), C/D, lipid profile, high-sensitive CRP (hs-CRP), and echocardiography were done before BS and at 3 months and 1 year post BS.

RESULTS

A total of 40 morbidly obese patients undergone sleeve gastrectomy. Blood pressure, FBG, FI, hs-CRP, C/D were significantly decreased after BS (p < 0.001). At 1 year post BS; significant reduction in left ventricular posterior wall thickness (LVPW) (p < 0.001), left ventricular mass (LVM) (p = 0.003), relative wall thickness (RWT) (p < 0.001) with a significant improvement in early diastolic velocity (E) (p < 0.001), early diastolic velocity/late diastolic velocity (E/A) (p = 0.01). After BS; C/D significantly positively correlated with FBG (p = 0.019), hs-CRP (p = 0.008), interventricular septum thickness (IVS) (p = 0.028), LVPW (p = 0.028), relative wall thickness (RWT) (p = 0.022), early diastolic velocity /early diastolic velocity (E') measured by pulsed tissue Doppler imaging (E/E') (p = 0.001), and significantly negatively correlated with E' (p = 0.032). C/D was the single significant independent variable affecting E' and E/E' post BS.

CONCLUSION

C/D can be used as a surrogate marker of the improved FBG and the resolution of inflammation post BS. C/D is an independent predictor of diastolic function improvement post BS.

Negative associations of morning serum cortisol levels with obesity: the Henan rural cohort study

AIMS

To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations.

MATERIALS AND METHODS

A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography-tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively.

RESULTS

After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers.

CONCLUSION

Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.

Acute psychosocial stress increases third-party helping but not punishing behavior

Despite extensive research on the effects of stress on the brain and behaviors, there is a debate whether stress promotes prosocial behaviors, especially acute stress due to intricate costly punishment in the ultimatum game. Therefore, the present study introduced an irrelevant third party to examine how acute stress and the triggered cortisol influence third parties' punishing and helping behaviors as more convincing altruistic behaviors. The 65 participants were exposed to a psychosocial stressor (n = 33) or a control condition (n = 32). Afterwards, two third-party intervention tasks (a token allocation task and criminal scenario judgment task) were completed, during which the participants, as an "irrelevant" third party, could choose whether to sacrifice their own interests to help the victim or punish the transgressor. Participants' affective states, heart rate, and salivary cortisol were repeatedly measured throughout the experiment. Results showed that acute stress can lead to more third-party helping behaviors but not more punishing behaviors. Specifically, participants under stress tended to transfer more monetary units to the victim in the token allocation task than the control-group participants, and they tended to help the victim in the scenario task. In contrast, there was no significant difference in punishing behavior between the stressed and control participants. These findings reveal that acute psychosocial stress triggers the "tend and befriend" response, which might reflect the prosocial intuition under acute stress.

Effects of glucose intake on stress reactivity in young, healthy men

The psychobiological stress response has a broad impact on energy metabolism, while the availability of energy may, in turn, affect the stress response. Specifically, a reduced cortisol response has been found after 8-11 hours of fasting, while glucose intake has led to an increase in cortisol reactivity. We compared the effects of standardized glucose or artificial sweetener drinks, as well as water, ingested prior to a physical (cold pressor test, CPT) or a psychosocial stressor (Trier Social Stress Test, TSST) after four hours of fasting. Healthy male subjects (N = 151) were randomized to one of six groups (either glucose, sweetener or water group and stress induction with the CPT or TSST). Thirty minutes after ingestion, participants were exposed to the stressor. Repeated measures of the subjective stress response, salivary cortisol and alpha amylase as well as continuous heart rate recordings were taken to capture the psychobiological stress response. Capillary blood glucose levels were measured four times. We found significant psychobiological stress responses for all variables and both stressors, but significantly stronger responses for the TSST. Moreover, we found a significant but small effect for a slightly stronger cortisol response to stress after glucose ingestion, which is presumably driven by a more pronounced effect in the TSST compared to the CPT condition. Responder rates did not differ for the three conditions in either the TSST or in the CPT. Our results demonstrate that even after a short fasting timeframe of four hours, higher glucose availability results in slightly higher cortisol stress responses in men.

The 'Jekyll and Hyde' of Gluconeogenesis: Early Life Adversity, Later Life Stress, and Metabolic Disturbances

The physiological response to a psychological stressor broadly impacts energy metabolism. Inversely, changes in energy availability affect the physiological response to the stressor in terms of hypothalamus, pituitary adrenal axis (HPA), and sympathetic nervous system activation. Glucocorticoids, the endpoint of the HPA axis, are critical checkpoints in endocrine control of energy homeostasis and have been linked to metabolic diseases including obesity, insulin resistance, and type 2 diabetes. Glucocorticoids, through the glucocorticoid receptor, activate transcription of genes associated with glucose and lipid regulatory pathways and thereby control both physiological and pathophysiological systemic energy homeostasis. Here, we summarize the current knowledge of glucocorticoid functions in energy metabolism and systemic metabolic dysfunction, particularly focusing on glucose and lipid metabolism. There are elements in the external environment that induce lifelong changes in the HPA axis stress response and glucocorticoid levels, and the most prominent are early life adversity, or exposure to traumatic stress. We hypothesise that when the HPA axis is so disturbed after early life adversity, it will fundamentally alter hepatic gluconeogenesis, inducing hyperglycaemia, and hence crystalise the significant lifelong risk of developing either the metabolic syndrome, or type 2 diabetes. This gives a “Jekyll and Hyde” role to gluconeogenesis, providing the necessary energy in situations of acute stress, but driving towards pathophysiological consequences when the HPA axis has been altered.

Cortisol levels before and after cognitive behavioural therapy in patients with eating disorders reporting childhood abuse: A follow-up study

The etiopathogenesis of eating disorders (EDs) is complex and still not well understood. Biological, psychological and environmental factors (e.g. childhood abuse) have all been considered to be involved in the onset and the persistence of EDs. The hypothalamic-pituitary-adrenal (HPA) axis is a relevant biological factor capable of influencing the onset and the course of EDs and not many information are available about the impact of a Cognitive Behavioral Therapy (CBT) on cortisol changes in EDs. The HPA-axis functioning has been evaluated before and after CBT in a group of patients with Anorexia Nervosa (n = 34) and Bulimia Nervosa (n = 35) according to the presence/absence of a history of sexual/physical abuse. At baseline, only patients reporting childhood abuse showed lower morning cortisol levels as compared with other patients of the same diagnostic group and Healthy Controls. After CBT, a variation of cortisol levels has been found only in patients without abuse, suggesting a role of childhood adversities in the persistence of HPA-axis alterations in Eating Disorders.

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.

Evidence for disruption of normal circadian cortisol rhythm in women with obesity

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis may play a role in the pathogenesis of comorbidities encountered in obesity, including the relative hypogonadotropic hypogonadism that we and others have observed. We sought to examine serum cortisol profiles throughout the day and evening in a sample of normal weight women and women with obesity. In this cross-sectional study, regularly cycling obese (n = 12) and normal weight (n = 10) women were recruited. Mean serum cortisol was measured by frequent blood sampling for 16 h (8am-midnight) in the luteal phase of the menstrual cycle. Women with obesity had significantly higher overall cortisol levels when compared to normal weight women (6.2 [4.3, 6.6] vs. 4.7 [3.7, 5.5] ug/dl, p = .04). Over the two-hour postprandial period, obese women displayed an almost two-fold greater (7.2 [6.5, 8.6] ug/dl) rise in cortisol than normal weight controls (4.4 [3.7, 6.2] ug/dl, p < .01). In addition, obese women demonstrated a sustained evening cortisol elevation compared to normal weight women, who displayed the typical decline in cortisol (3.2 [2.3, 4] vs. 2 [1.5, 3.2] ug/dl, p < .05). Changes in the HPA axis in the setting of obesity may be related to risks of obesity-associated metabolic comorbidities and reproductive dysfunction often seen in these women.

Muscle-specific downregulation of GR levels inhibits adipogenesis in porcine intramuscular adipocyte tissue

Intramuscular adipose is conducive to good pork quality, whereas subcutaneous adipose is considered as waste in pig production. So uncovering the regulation differences between these two adiposes is helpful to tissue-specific control of fat deposition. In this study, we found the sensitivity to glucocorticoids (GCs) was lower in intramuscular adipocytes (IMA) compared with subcutaneous adipocytes (SA). Comparison of glucocorticoid receptor (GR) revealed that IMA had lower GR level which contributed to its reduced GCs sensitivity. Higher methylation levels of GR promotor 1-C and 1-H were detected in IMA compared with SA. GR expression decrease was also found in adipocytes when treated with muscle conditioned medium (MCM) in vitro, which resulted in significant inhibition of adipocytes proliferation and differentiation. Since abundant myostatin (MSTN) was detected in MCM by ELISA assay, we further investigated the effect of this myokine on adipocytes. MSTN treatment suppressed adipocytes GR expression, cell proliferation and differentiation, which mimicked the effects of MCM. The methylation levels of GR promotor 1-C and 1-H were also elevated after MSTN treatment. Our study reveals the role of GR in muscle fiber inhibition on intramuscular adipocytes, and identifies myostatin as a muscle-derived modulator for adipose GR level.

Energetic stress: The reciprocal relationship between energy availability and the stress response

The worldwide epidemic of metabolic syndromes and the recognized burden of mental health disorders have driven increased research into the relationship between the two. A maladaptive stress response is implicated in both mental health disorders and metabolic disorders, implicating the hypothalamic-pituitary-adrenal (HPA) axis as a key mediator of this relationship. This review explores how an altered energetic state, such as hyper- or hypoglycemia, as may be manifested in obesity or diabetes, affects the stress response and the HPA axis in particular. We propose that changes in energetic state or energetic demands can result in "energetic stress" that can, if prolonged, lead to a dysfunctional stress response. In this review, we summarize the role of the hypothalamus in modulating energy homeostasis and then briefly discuss the relationship between metabolism and stress-induced activation of the HPA axis. Next, we examine seven mechanisms whereby energetic stress interacts with neuroendocrine stress response systems, including by glucocorticoid signaling both within and beyond the HPA axis; by nutrient-induced changes in glucocorticoid signaling; by impacting the sympathetic nervous system; through changes in other neuroendocrine factors; by inducing inflammatory changes; and by altering the gut-brain axis. Recognizing these effects of energetic stress can drive novel therapies and prevention strategies for mental health disorders, including dietary intervention, probiotics, and even fecal transplant.

Sex-related differences in the association of salivary cortisol levels and type 2 diabetes. Findings from the cross-sectional population based KORA-age study

BACKGROUND

Dysregulation in the cortisol secretion may have a role in the development of type 2 diabetes although conflicting evidence on the particular cortisol secretion patterns and type 2 diabetes demands further investigations. We aim to examine the association of cortisol levels and diurnal secretion patterns with prevalence of type 2 diabetes and HbA1c levels as well as the potential impact of sex and adiposity on this association.

METHODS

A cross-sectional analysis was conducted among 757 participants (aged 65-90 years) of the population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study. Multivariate regression analyses were employed to examine the association between salivary cortisol (measured upon waking (M1), 30min after awakening (M2), and in the late night (LNSC)) and type 2 diabetes as well as glycated hemoglobin (HbA1c) with adjustments for potential confounders.

RESULTS

In the total sample population, an elevated LNSC level was observed in type 2 diabetes patients compared to non-patients (P=0.04). In sex-stratified analyses, diabetic men showed a greater Cortisol Awakening Response (CAR) (P=0.02). Diabetic women had significantly elevated LNSC levels (P=0.04). HbA1c was positively associated with both CAR and LNSC levels but was negatively associated with M1 to LNSC ratio.

CONCLUSION

In this aged population, type 2 diabetes is associated with dysregulated cortisol secretion characterized by distinct sex specific diurnal patterns.

Dietary fat and corticosterone levels are contributing factors to meal anticipation

Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content.

Assessment of the cortisol awakening response: Expert consensus guidelines

The cortisol awakening response (CAR), the marked increase in cortisol secretion over the first 30-45 min after morning awakening, has been related to a wide range of psychosocial, physical and mental health parameters, making it a key variable for psychoneuroendocrinological research. The CAR is typically assessed from self-collection of saliva samples within the domestic setting. While this confers ecological validity, it lacks direct researcher oversight which can be problematic as the validity of CAR measurement critically relies on participants closely following a timed sampling schedule, beginning with the moment of awakening. Researchers assessing the CAR thus need to take important steps to maximize and monitor saliva sampling accuracy as well as consider a range of other relevant methodological factors. To promote best practice of future research in this field, the International Society of Psychoneuroendocrinology initiated an expert panel charged with (i) summarizing relevant evidence and collective experience on methodological factors affecting CAR assessment and (ii) formulating clear consensus guidelines for future research. The present report summarizes the results of this undertaking. Consensus guidelines are presented on central aspects of CAR assessment, including objective control of sampling accuracy/adherence, participant instructions, covariate accounting, sampling protocols, quantification strategies as well as reporting and interpreting of CAR data. Meeting these methodological standards in future research will create more powerful research designs, thus yielding more reliable and reproducible results and helping to further advance understanding in this evolving field of research.

Hypothalamic-pituitary-adrenal axis dysregulation and cortisol activity in obesity: A systematic review

BACKGROUND

Although there is substantial evidence of differential hypothalamic-pituitary-adrenal (HPA) axis activity in both generalized and abdominal obesity, consistent trends in obesity-related HPA axis perturbations have yet to be identified.

OBJECTIVES

To systematically review the existing literature on HPA activity in obesity, identify possible explanations for inconsistencies in the literature, and suggest methodological improvements for future study.

DATA SOURCES

Included papers used Pubmed, Google Scholar, and the University of California Library search engines with search terms body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, sagittal diameter, abdominal versus peripheral body fat distribution, body fat percentage, DEXA, abdominal obesity, and cortisol with terms awakening response, slope, total daily output, reactivity, feedback sensitivity, long-term output, and 11β-HSD expression.

STUDY ELIGIBILITY CRITERIA

Empirical research papers were eligible provided that they included at least one type of obesity (general or abdominal), measured at least one relevant cortisol parameter, and a priori tested for a relationship between obesity and cortisol.

RESULTS

A general pattern of findings emerged where greater abdominal fat is associated with greater responsivity of the HPA axis, reflected in morning awakening and acute stress reactivity, but some studies did show underresponsiveness. When examined in adipocytes, there is a clear upregulation of cortisol output (due to greater expression of 11β-HSD1), but in hepatic tissue this cortisol is downregulated. Overall obesity (BMI) appears to also be related to a hyperresponsive HPA axis in many but not all studies, such as when acute reactivity is examined.

LIMITATIONS

The reviewed literature contains numerous inconsistencies and contradictions in research methodologies, sample characteristics, and results, which partially precluded the development of clear and reliable patterns of dysregulation in each investigated cortisol parameter.

CONCLUSIONS AND IMPLICATIONS

The literature to date is inconclusive, which may well arise from differential effects of generalized obesity vs. abdominal obesity or from modulators such as sex, sex hormones, and chronic stress. While the relationship between obesity and adipocyte cortisol seems to be clear, further research is warranted to understand how adipocyte cortisol metabolism influences circulating cortisol levels and to establish consistent patterns of perturbations in adrenal cortisol activity in both generalized and abdominal obesity.

Effects of caloric restriction and low glycemic index diets associated with metformin on glucose metabolism and cortisol response in overweight/obese subjects: a case series study

BACKGROUND

To determine whether cortisol secretion and glucocorticoid receptors in lymphocytes and monocytes are altered in patients with impaired glucose tolerance, and whether treatment with a hypocaloric diet and metformin could interfere with these aspects.

METHODS

This is an analytical, interventional, case series study. Patients with impaired glucose tolerance were included. They received 500 mg of metformin twice daily and followed a low glycemic index diet for 16 weeks. Cortisol levels were assessed at 8:00 A.M. before and after use of 0.25 mg of dexamethasone at 11:00 P.M. the day before.

RESULTS

Sixteen subjects (9 men) were included. Normal basal levels of cortisol and adequate responses to the low dose of dexamethasone were observed before and after treatment. There was no significant correlation between the parameters evaluated and cortisol levels. Nevertheless, there was a strong correlation between the number of glucocorticoid receptors, BMI (r = 0.88; p = 0.02), and insulin AUC (r = 0.94; p = 0.005) before treatment; after treatment, all these associations ceased to exist.

CONCLUSION

The cortisol secretion remained normal in the group of patients with impaired glucose tolerance. Treatment with metformin and diet did not change this condition. However, glucocorticoid receptor number had a strong correlation with insulin, due to insulin resistance, but this characteristic was lost after treatment.

The influence of foetal prednisone exposure on the cortisol levels in the offspring

OBJECTIVE

Pregnant women suffering from autoimmune disease use glucocorticoids. Glucocorticoids can partly diffuse to the foetus and may influence the development of the foetal hypothalamic-pituitary-adrenal axis, especially in early stage of pregnancy. The objective was to investigate whether prednisone exposure in utero influences the cortisol levels of the prepubertal children.

DESIGN

Mothers participated in a prospective cohort study on rheumatoid arthritis (RA) and pregnancy. Children were exposed (n = 44) or nonexposed (n = 65) to prednisone in utero. Salivary cortisol levels were taken from all children during 1 day: at awakening, 30 min after awakening, 1 p.m. and bedtime. Cortisol levels between groups were also analysed using area under the curve (AUC), cortisol awakening response (CAR) and slope.

RESULTS

The mean age (SD) of the children was 6·98 (1·23). The difference in mean (SD) cortisol level at '1 p.m.' was 5·42 nm (4·08) in the prednisone-exposed and 3·97 nm (4·00) in the nonexposed (P = 0·03). Prednisone-exposed children had a higher AUC (β = 13·28; P = 0·02), even after correction for RA disease activity. No differences were found on CAR, slope or blood pressure. The cortisol levels of the nonexposed were more similar to the age-specific references than the prednisone-exposed.

CONCLUSION

Prednisone use during pregnancy is associated with a higher daytime cortisol level, in the prepubertal offspring, not yet accompanied with clinical outcomes. This conclusion will have no consequences at this moment, but it does raise questions concerning prednisone exposure in utero and the long-term consequences for the offspring.

No effect of caloric restriction on salivary cortisol levels in overweight men and women

OBJECTIVE

The effect of weight loss by diet or diet and exercise on salivary cortisol levels, a measure of hypothalamic pituitary adrenal activity, in overweight individuals is not known. The objective was to test the hypothesis that 24 weeks of moderate caloric restriction (CR) (25%) by diet or diet and aerobic exercise would alter morning and diurnal salivary cortisol levels.

DESIGN AND SETTING

Randomized control trial in an institutional research center.

PARTICIPANTS

Thirty-five overweight (BMI: 27.8±0.7 kg/m(2)) but otherwise healthy participants (16 M/19 F).

INTERVENTION

Participants were randomized to either calorie restriction (CR: 25% reduction in energy intake, n=12), calorie restriction+exercise (CR+EX: 12.5% reduction in energy intake+12.5% increase in exercise energy expenditure, n=12) or control (healthy weight-maintenance diet, n=11) for 6 months.

MAIN OUTCOME MEASURE

Salivary cortisol measured at 8:00, 8:30, 11:00, 11:30, 12:30, 13:00, 16:00 and 16:30. Morning cortisol was defined as the mean cortisol concentration at 08:00 and 08:30. Diurnal cortisol was calculated as the mean of the 8 cortisol measures across the day.

RESULTS

In the whole cohort, higher morning and diurnal cortisol levels were associated with impaired insulin sensitivity (morning: P=0.004, r(2)=0.24; diurnal: P=0.02, r(2)=0.15). Using mixed model analysis, there was no significant effect of group, time or sex on morning or diurnal cortisol levels.

CONCLUSION

A 10% weight loss with a 25% CR diet alone or with exercise did not impact morning or diurnal salivary cortisol levels.

The postprandial rise in plasma cortisol in men is mediated by macronutrient-specific stimulation of adrenal and extra-adrenal cortisol production

CONTEXT

Circadian variation is a fundamental characteristic of plasma glucocorticoids, with a postprandial rise in cortisol an important feature. The diurnal rhythm is presumed to reflect alterations in hypothalamic-pituitary-adrenal axis activity; however, cortisol is produced not only by the adrenal glands but also by regeneration from cortisone by the enzyme 11β-hydroxysteroid dehydrogenase type 1, mainly in liver and adipose tissue.

OBJECTIVE

We tested the contribution of peripheral cortisol regeneration to macronutrient-induced circadian variation of plasma cortisol in humans.

DESIGN

This was a randomized, single-blinded, crossover study.

SETTING

The study was conducted at a hospital research facility.

PARTICIPANTS

Eight normal-weight healthy men participated in the study.

INTERVENTIONS

Subjects were given isocaloric energy isodense flavor-matched liquid meals composed of carbohydrate, protein, fat, or low-calorie placebo during infusion of the stable isotope tracer 9,11,12,12-[2H]4-cortisol.

OUTCOME MEASURES AND RESULTS

Plasma cortisol increased similarly after all macronutrient meals (by ∼90 nmol/L) compared with placebo. Carbohydrate stimulated adrenal secretion and extra-adrenal regeneration of cortisol to a similar degree. Protein and fat meals stimulated adrenal cortisol secretion to a greater degree than extra-adrenal cortisol regeneration. The increase in cortisol production by 11β-hydroxysteroid dehydrogenase type 1 was in proportion to the increase in insulin. The postprandial cortisol rise was not accounted for by decreased cortisol clearance.

CONCLUSIONS

Food-induced circadian variation in plasma cortisol is mediated by adrenal secretion and extra-adrenal regeneration of cortisol. Given that the latter has the more potent effect on tissue cortisol concentrations and that effects on adrenal and extra-adrenal cortisol production are macronutrient specific, this novel mechanism may contribute to the physiological interplay between insulin and glucocorticoids and the contrasting effects of certain diets on postprandial metabolism.

Correlates of cortisol in human hair: implications for epidemiologic studies on health effects of chronic stress

Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis, and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, "cortisol," "hair," "confounders," "chronic," "stress," and "correlates." Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., post-traumatic stress disorder), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing's syndrome), and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear not to be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies.

Biobehavioral measures as outcomes: a cautionary tale

This article discusses the use of biobehavioral measures as outcomes for health care intervention studies. Effect size (ES) values for salivary cortisol and observation-based measures of pain and agitation were examined. Effects pre to post treatment were assessed separately for nursing home residents with and without acute psychotic symptoms. This study revealed large positive effects on both pain and agitation measures in the group with acute psychotic symptoms and small-to-medium positive effects on these same measures in the group without acute psychotic symptoms. In both of these groups, the ES values were not consistently positive on the cortisol measures. Prior to determining whether a measure can be used to estimate minimum clinically important differences, it is essential to consider if the biomarker will be responsive to therapy in the populations and contexts being studied.

Deconstructing the roles of glucocorticoids in adipose tissue biology and the development of central obesity

Central obesity is associated with insulin resistance and dyslipidemia. Thus, the mechanisms that control fat distribution and its impact on systemic metabolism have importance for understanding the risk for diabetes and cardiovascular disease. Hypercortisolemia at the systemic (Cushing's syndrome) or local levels (due to adipose-specific overproduction via 11β-hydroxysteroid dehydrogenase 1) results in the preferential expansion of central, especially visceral fat depots. At the same time, peripheral subcutaneous depots can become depleted. The biochemical and molecular mechanisms underlying the depot-specific actions of glucocorticoids (GCs) on adipose tissue function remain poorly understood. GCs exert pleiotropic effects on adipocyte metabolic, endocrine and immune functions, and dampen adipose tissue inflammation. GCs also regulate multiple steps in the process of adipogenesis. Acting synergistically with insulin, GCs increase the expression of numerous genes involved in fat deposition. Variable effects of GC on lipolysis are reported, and GC can improve or impair insulin action depending on the experimental conditions. Thus, the net effect of GC on fat storage appears to depend on the physiologic context. The preferential effects of GC on visceral adipose tissue have been linked to higher cortisol production and glucocorticoid receptor expression, but the molecular details of the depot-dependent actions of GCs are only beginning to be understood. In addition, increasing evidence underlines the importance of circadian variations in GCs in relationship to the timing of meals for determining their anabolic actions on the adipocyte. In summary, although the molecular mechanisms remain to be fully elucidated, there is increasing evidence that GCs have multiple, depot-dependent effects on adipocyte gene expression and metabolism that promote central fat deposition. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.

Dairy food consumption and meal-induced cortisol response interacted to influence weight loss in overweight women undergoing a 12-week, meal-controlled, weight loss intervention

Dairy food enhances weight loss in animal models, possibly by modifying the metabolic effects of cortisol. This study determined in overweight women (ages 20.0-45.9 y; n = 51) whether including dairy food in an energy-restricted diet affects cortisol concentrations and whether differences in provoked cortisol explain the magnitude of weight loss. Women received either an adequate amount of dairy food (AD), the equivalent of ≥711 mL/d milk, or a low amount of dairy food (LD), the equivalent to ≤238 mL/d milk, in a 12-wk, energy-restricted dietary intervention. Participants were tested in a 12-h laboratory visit, which included 2 standard meals and a dinner buffet that was consumed ad libitum. Salivary cortisol was measured from waking to bedtime. Energy restriction increased (P ≤ 0.04) the minimum and decreased (P ≤ 0.02) the diurnal amplitude in the salivary cortisol concentration from baseline to postintervention. Energy restriction enhanced the dinner meal-stimulated salivary cortisol response (DMR) (P ≤ 0.02) but only in the LD group. Compared with the LD treatment, the AD treatment induced (P ≤ 0.04) greater reductions in body weight and fat, but only in women characterized as having a baseline DMR (responders) (n = 26); weight and fat lost in the AD and LD groups were similar in nonresponders (n = 25). Overall, energy restriction dampened diurnal salivary cortisol fluctuations [symptomatic of hypothalamic-pituitary-adrenal (HPA) axis dysfunction] and enhanced dinner meal-stimulated salivary cortisol concentrations. The AD treatment prevented the latter. Furthermore, certain phenotypic markers of HPA axis function may help to expose the weight-reducing effects of consuming dairy food.

Associations between suicide attempts and elevated bedtime salivary cortisol levels in bipolar disorder

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been reported in bipolar disorder and also in suicidal behavior, but few studies have examined the relationship between suicidal behaviors and the HPA axis function in bipolar disorder, attending to and minimizing confounding factors. We compare HPA axis activity in bipolar individuals with and without suicidal behavior and unaffected healthy controls through measurement of salivary cortisol.

METHOD

Salivary cortisol was collected for three consecutive days in 29 controls, 80 bipolar individuals without a history of suicide and 56 bipolar individuals with a past history of suicide. Clinical factors that affect salivary cortisol were also examined.

RESULTS

A past history of suicide was associated with a 7.4% higher bedtime salivary cortisol level in bipolar individuals. There was no statistical difference between non-suicidal bipolar individuals and controls in bedtime salivary cortisol and awakening salivary cortisol was not different between the three groups.

LIMITATIONS

The measure of salivary cortisol was a home based collection by the study subjects and the retrospective clinical data was primarily based on their historical account.

CONCLUSIONS

Bipolar individuals with a past history of suicidal behavior exhibit hyperactivity in the HPA axis. This biological marker remains significant regardless of demographic factors, mood state, severity and course of illness. This finding in bipolar disorder is consistent with the evidence for altered HPA axis functioning in suicide and mood disorders and is associated with a clinical subgroup of bipolar patients at elevated risk for suicide based on their history, and in need of further attention and study.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects and, conversely, that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife--a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated, that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common, mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of estrogen (E2). This review summarizes data supporting these contentions with the intent of placing depression and estrogen therapy in their proper physiologic context.

Carbohydrates for improving the cognitive performance of independent-living older adults with normal cognition or mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) is an intermediate state between normal cognition and dementia in which daily function is largely intact. This condition may present an opportunity for research into the prevention of dementia. Carbohydrate is an essential and easily accessible macronutrient which influences cognitive performance. A better understanding of carbohydrate-driven cognitive changes in normal cognition and mild cognitive impairment may suggest ways to prevent or reduce cognitive decline.

OBJECTIVES

To assess the effectiveness of carbohydrates in improving cognitive function in older adults.

SEARCH STRATEGY

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register on 22 June 2010 using the terms: carbohydrates OR carbohydrate OR monosaccharides OR disaccharides OR oligosaccharides OR polysaccharides OR CARBS. ALOIS contains records from all major healthcare databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trial databases and grey literature sources.

SELECTION CRITERIA

All randomised controlled trials (RCT) that have examined the efficacy of any form of carbohydrates in normal cognition and MCI.

DATA COLLECTION AND ANALYSIS

One review author selected and retrieved relevant articles for further assessment. The remaining authors independently assessed whether any of the retrieved trials should be included. Disagreements were resolved by discussion. 

MAIN RESULTS

There is no suitable RCT of any form of carbohydrates involving independent-living older adults with normal cognition or mild cognitive impairment.

AUTHORS' CONCLUSIONS

There are no suitable RCTs on which to base any recommendations about the use of any form of carbohydrate for enhancing cognitive performance in older adults with normal cognition or mild cognitive impairment. More studies of many different carbohydrates are needed to tease out complex nutritional issues and further evaluate memory improvement.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects, and conversely that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife-a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen (E2) deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common and mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of E2. This review summarizes data supporting this contention with the intent of placing depression and E2 therapy in their proper physiologic context.

Diurnal variation of cortisol in people with dementia: relationship to cognition and illness burden

Cortisol patterns in nursing home residents with dementia are described and examined in relation to cognition and comorbid illnesses. Saliva was sampled 4 times in a 24-hour period (week 1) and at the same times 1 week later (week 2). In general, cortisol levels decreased from morning to evening, with 50% exhibiting a negative slope. In contrast, 38% of the participants had a relatively flat cortisol diurnal rhythm, and 7% exhibited an afternoon increase. The cortisol pattern was consistent between weeks 1 and 2 for 39% with a negative slope, 13% with a flat profile, and for 2% with an afternoon increase pattern. Cortisol rhythm was not statistically significantly related to cognition or illness burden. While this study contributes to the understanding of differences in the diurnal pattern of cortisol for older adults with dementia, more research is needed to understand the etiology of the differences and the biological mechanisms involved.

A nonlinear relationship of generalized and central obesity with diurnal cortisol secretion in the Whitehall II study

CONTEXT

Evidence for an association of measures of generalized and central obesity with salivary cortisol secretion is equivocal.

OBJECTIVE

The objective of this study was to assess the relationship between body mass index (BMI), waist circumference, and salivary cortisol.

DESIGN

The design was a cross-sectional study of BMI, waist circumference, and salivary cortisol from phase 7 (2002-2004) of the Whitehall II study.

SETTING

The occupational cohort was originally recruited in 1985-1988.

PARTICIPANTS

Participants included 2915 men and 1041 women aged 50-74 yr with complete information on height, weight and waist circumference, and cortisol secretion.

OUTCOME MEASURES

Saliva samples were taken on waking, waking plus 0.5, 2.5, 8, and 12 h, and bedtime for the assessment of cortisol. The cortisol awakening response and slope in diurnal secretion were calculated.

RESULTS

After adjustment for age, sex, social position, waking time, and time since waking of sample collection, increasing central and generalized obesity was associated with lower waking cortisol (P = 0.001). U-shaped associations were apparent between diurnal slope in salivary cortisol and both BMI and waist circumference (P < 0.0001 for quadratic term). For example, the shallowest (most adverse) slopes in salivary cortisol were associated with highest (>31 kg/m(2)) and lowest (<21 kg/m(2)) levels of BMI, and the steepest slopes were apparent for those with BMI of 26 kg/m(2), independently of the 12 covariates examined. No associations were apparent for the cortisol awakening response (P > 0.05).

CONCLUSION

The associations of measures of generalized and central obesity with diurnal slope in salivary cortisol are not linear in older adults. These nonlinear associations may explain previously described mixed findings.

Salivary cortisol and binge eating disorder in obese women after surgery for morbid obesity

BACKGROUND

Binge eating episodes characterized by loss of control are hypothesized to be accompanied by changes in hypothalamic pituitary adrenal (HPA) axis functioning. Cortisol is an end product of this neuroendocrine stress system.

PURPOSE

The aim of this study was to examine the cortisol levels and the awakening cortisol response (ACR) in obese persons showing binge eating after surgery for morbid obesity.

METHOD

Sixteen obese women with binge eating disorder (BED) and 18 obese women without BED participated in the study. Means+/-SD: age 43 +/- 15, body mass index 40 +/- 8. Salivary cortisol, anthropometric assessments, and the eating disorder examination interview were taken.

RESULTS

Women with BED showed a significantly lower waist-to-hip ratio and cortisol levels during the day than women without BED, whereas the ACR did not differ.

CONCLUSION

Our cross-sectional study in a small sample generates the hypothesis that neuroendocrine regulation differs between obese women with and without BED after obesity surgery. This finding needs replication in future studies that should also examine the causal direction of the observed association.

Elevated maternal cortisol levels during pregnancy are associated with reduced childhood IQ

BACKGROUND

In animal models, there is evidence to suggest a causal link between maternal cortisol levels during pregnancy and offspring outcomes; however, evidence for this relationship in humans is inconclusive. We address important confounders of this association by estimating the relationship between maternal cortisol levels in late pregnancy and childhood IQ in a birth cohort and in a subsample of siblings.

METHODS

This study included 832 children who were members of the Collaborative Perinatal Project. Maternal serum collected between 1959 and 1966 during the third trimester of pregnancy was analysed for free cortisol. We investigated the relationship between maternal cortisol in quintiles and full, verbal and performance scale scores on the Wechsler Intelligence Scale for Children at age 7 years, adjusting for prenatal and family characteristics. We repeated this analysis among 74 discordant sibling pairs using a fixed effects approach, which adjusts for shared family characteristics.

RESULTS

Maternal cortisol levels were negatively related to full-scale IQ, an effect driven by verbal IQ scores. Compared with those in the lowest quintile of cortisol exposure, the verbal IQ of children in the highest quintile of exposure was 3.83 points lower [95% confidence interval (CI): -6.44 to -1.22]. Within sibling pairs, being in the highest quintile of exposure was associated with verbal IQ scores 5.5 points lower (95% CI: -11.24 to 0.31) compared with the other quintiles.

CONCLUSION

These findings are consistent with prior human and animal studies, and suggest that exposure to high levels of maternal cortisol during pregnancy may be negatively related to offspring cognitive skills independently of family attributes that characterize the postnatal environment.

Levels and confounders of morning cortisol collected from adolescents in a naturalistic (school) setting

Salivary cortisol is widely used in research but little is known about the typical, or expected, functioning of the HPA-axis in adolescents in naturalistic settings, nor whether the extensive array of confounders documented in the literature is applicable in this situation. In a school-based study, 2995 15-year-old pupils provided two saliva samples, 30 min apart, in morning sessions timed to capture peak cortisol decline. The collection protocol was a balance between the large sample size obtainable in a school situation and a limited number of samples, constrained by the school timetable. In addition, pupils completed a questionnaire containing items previously shown to be associated with cortisol levels (e.g. time since awakening and life events), and their height and weight were measured. Outcome measures were cortisol levels at Times 1 and 2, and change (per minute) in cortisol between the two time points. Median (IQR) cortisol levels for males and females were 10.5 (8.1) and 11.6 (9.3) nmol/L at Time 1, and 8.2 (6.0) and 8.1 (6.5) nmol/L at Time 2. 73% had a decline in cortisol level of more than 10% across the two time points, compatible with the expected diurnal pattern. In bivariate analyses, cortisol sampled on Monday, times of measurement and since awakening, prior smoking and several life events were associated with cortisol levels at Times 1 and 2 in both sexes. However, in multivariate analysis, few of these variables remained after controlling for times of measurement and since awakening and, in addition, the final models differed between the sexes. Two events (friend dying and splitting with a boy/girlfriend) predicted cortisol levels in both sexes while age, maturity, recent eating and smoking were predictors only in males. Several factors associated with cortisol change differed from those observed for absolute levels. Further adjustment for school clustering affected some associations, particularly time of measurement. This study managed many of the problems found in naturalistic research on cortisol and provides norms for morning cortisol levels in 15-year-old adolescents.

Ecological salivary cortisol analysis-- part 2: relative impact of trauma history, posttraumatic stress, comorbidity, chronic stress, and known confounds on hormone levels

BACKGROUND

Although bio-psycho-social health research is an ideal, samples adequate for complex modeling require biomarker specimens from hundreds of participants. Ecological sampling departs from laboratory study norms, with implications for analysis.

OBJECTIVE

To inform ecological study designs, this article compares salivary cortisol levels and effect sizes of "focal" psychiatric factors, such as trauma history, posttraumatic stress diagnosis, comorbidity, and chronic stress, and "nuisance" factors, including endocrine disorders and medications and physiological factors such as gestational age and smoking.

STUDY DESIGN

This is a descriptive analysis of ecologically collected cortisol specimens, assayed in an ongoing perinatal psychobiological study, addressing methodological considerations.

RESULTS

Focal and nuisance factors are often interdependent with similar effect sizes. Careful specimen deletion decisions and model specification are needed to achieve the hoped-for external validity while maintaining internal validity.

CONCLUSIONS

Results of multivariate models lend support to the validity and usefulness of an ecological approach to incorporating biomarkers in health research. J Am Psychiatr Nurses Assoc, 2008; 14(4), 285-296. DOI: 10.1177/1078390308321939.

Ecological salivary cortisol specimen collection--part 1: methodological consideration of yield, error, and effects of sampling decisions in a perinatal mental health study

BACKGROUND

Current health research strives to integrate biological, psychological, and social factors consistent with ecological models. Home-based biomarker specimens are consistent with an ecological approach, but deviations from laboratory norms could affect validity of results.

OBJECTIVE

This article uses salivary cortisol specimens collected early in a perinatal mental health study to describe (a) return rate and returner characteristics, (b) adherence to procedures, (c) sources of laboratory error, (d) effects of deleting specimens with "nuisance" factors, and (e) effects that selection bias could have on cortisol concentration distribution.

STUDY DESIGN

This includes methodological analysis of collection, assay, and preanalysis decision components.

RESULTS

Rates of return do not differ by participants' sociodemographic, perinatal, or psychiatric characteristics. Excluding smokers affects representativeness. Selection bias in favor of more or less disadvantaged participants affects cortisol distribution.

CONCLUSIONS

The large yield of useable specimens permits multivariate modeling of cortisol level in association with health outcomes, potentially enhancing ecological validity. J Am Psychiatr Nurses Assoc, 2008; 14(4), 273-284. DOI: 10.1177/1078390308322944.

Psychological underpinnings of metabolic syndrome

Metabolic syndrome (MS) is more common among socio-economically disadvantaged individuals and is associated with certain risky lifestyle practices. MS also appears to be triggered by adverse social circumstances and chronic stress. The present paper reviews accumulating evidence to imply that individuals who have certain personality and behaviour traits are particularly predisposed to develop MS, and brings together theories that relate to possible psychological mechanisms underlying MS. It considers how such factors might interact causally to encourage the development of MS. As part of the EU-funded LIPGENE Integrated Project, multi-level modelling will be undertaken to explore potential pathways to MS, taking into consideration the interplay between a range of psycho-social, demographic, cultural and lifestyle factors thought to contribute to the development of MS. Data will be gathered for this purpose from a representative sample of >50-year-olds living in Britain (n 1000) and Portugal (n 500). It is anticipated that this information will assist in the development and targetting of future intervention to prevent and treat MS in the normal population.

Associations of early growth and adult adiposity with patterns of salivary cortisol in adulthood

CONTEXT

Early growth and obesity are associated with adult chronic disease. A suspected mediator is the hypothalamic-pituitary-adrenal axis and cortisol regulation. Our prior hypothesis was that cortisol levels are affected by anthropometry at several life stages.

OBJECTIVE

The objective of the study was to assess whether prenatal and postnatal growth and adiposity are associated with adult cortisol levels, and whether early growth and adiposity are related to later cortisol through adult body size.

DESIGN

Weight, head circumference (birth), height, and body mass index (BMI) (7 yr); and height, BMI (33 yr), and waist-hip ratio (WHR) (45 yr) were measured in the 1958 British birth cohort.

SETTING

All study subjects were born in England, Scotland, and Wales in 1 wk in March 1958.

PARTICIPANTS

A total of 6,470 participants with salivary cortisol were gathered from 12,069 invitees (54%) at 45 yr.

MAIN OUTCOME MEASURES

Two saliva samples on 1 d were collected: 45 min postwaking (t1) and 3 h later (t2). Three cortisol outcomes were measured: t1 level, area-under-curve, and abnormal t1-t2 pattern.

RESULTS

WHR was associated with all cortisol measures: among men over the WHR range 0.81-1.05, t1 cortisol decreased by approximately 3 nmol/liter, and the risk of an abnormal t1-t2 pattern increased by 77%; for women, over the WHR range 0.69-0.93, the risk of an abnormal t1-t2 pattern increased by 74%. For childhood measures, among males, increasing 7-yr BMI was associated with decreased t1 cortisol and increased risk of an abnormal t1-t2 pattern. Poorer prenatal growth in women, and postnatal growth in both sexes, was associated with increasing area-under-curve.

CONCLUSIONS

Smaller head circumference, shorter stature, lower BMI, and WHR are associated with higher cortisol levels.

Stress response and binge eating disorder

In clinical practice, obese patients report stress as a primary trigger for binge eating. However, the biological mechanism underlying this relationship is poorly understood. This paper presents, a theoretical overview of how cortisol secretion, a major component of the stress response, could play a role in binge eating, given that exogenous glucocorticoids can lead to obesity by increasing food intake. I will discuss findings from recent studies demonstrating links between laboratory stress, cortisol, food intake and abdominal fat in humans. Cortisol is elevated following laboratory stressors in women with anorexia nervosa (AN), bulimia nervosa (BN), and obesity, but has not been widely studied in women with binge eating disorder (BED). Additionally, I will review recent findings demonstrating a greater cortisol response to stress in obese women with BED compared to non-BED.

Hormetic influence of glucocorticoids on human memory

In this paper, we discuss the effects of glucocorticoids on human learning and memory using the recent model of hormesis proposed by Calabrese and collaborators. Although acute increases in glucocorticoids have been shown to impair memory function in humans, other studies report no such impairments or, in contrast, beneficial effects of acute glucocorticoid increases on human memory function. We summarize these studies and assess whether the wealth of data obtained in humans with regard to the effects of acute increase of glucocorticoids on human cognition are in line with a hormetic function. We then discuss several factors that will have to be taken into account in order to confirm the presence of a hormetic function between glucocorticoids and human cognitive performance.

The influence of perceived control and locus of control on the cortisol and subjective responses to stress

Stress has been implicated in the etiology of numerous mental and physical illnesses. Thus, it is important to identify factors that buffer individuals against stress. The purpose of this study was to examine the influence of perceived control (PC) on the biological and subjective stress responses, and to investigate the potential moderating effect of locus of control (LOC) on this relationship. Stress was induced with a noise-cognitive paradigm, and PC was manipulated by offering the option of manual control over noise intensity. Saliva cortisol and subjective stress were measured. There was no main effect of control on cortisol. However, LOC moderated the relation between control and cortisol; participants with more internal LOC, who also perceived themselves to have control over the stressor, showed a reduced cortisol response in the PC condition. The results are discussed in light of their implications for elucidating the determinants of the effects of perceived control on stress.

Responses of lipolysis and salivary cortisol to food intake and physical activity in lean and obese children

This investigation was conducted to determine whether there were differences in lipolytic responses to feeding and physical activity between lean (LN) and obese (OB) children, and if these responses were related to cortisol. Fourteen LN and 11 OB children participated in this study of abdominal lipolysis and salivary cortisol response to breakfast and lunch with an intervening exercise session. Calculated fasting glycerol release was lower in OB than LN (0.645 +/- 0.06 vs. 0.942 +/- 0.11 micromol/ml; P < 0.05). Fasting adipose tissue nutritive flow was lower in OB than in LN subjects, but responses to feeding and exercise were not different. Breakfast elicited a decrease in interstitial glycerol concentration in LN (-33%; P < 0.05), but not in OB (-5%), children, although decreases in glycerol concentration in response to lunch were similar (LN, -41%; OB, -36%). An interaction was evident in the salivary cortisol response to breakfast (LN, no change; OB, increase) and exercise (LN, no change; OB, decrease), but there were no group differences in response to lunch. Alterations in salivary cortisol and lipolysis were not related. These data suggest that salivary cortisol and lipolytic responses are not necessarily linked, but are altered in obesity. Furthermore, prior exercise may improve the antilipolytic response to a meal in OB children.

Flattened cortisol rhythms in metastatic breast cancer patients

Allostatic load, the physiological accumulation of the effects of chronic stressors, has been associated with multiple adverse health outcomes. Flattened diurnal cortisol rhythmicity is one of the prototypes of allostatic load, and has been shown to predict shorter survival among women with metastatic breast cancer. The current study compared diurnal cortisol slope in 17 breast cancer patients and 31 controls, and tested associations with variables previously found to be related to cortisol regulation, i.e, abdominal adiposity, perceived stress, social support, and explicit memory. Women with metastatic breast cancer had significantly flatter diurnal cortisol rhythms than did healthy controls. Patients with greater disease severity showed higher mean cortisol levels, smaller waist circumference, and a tendency toward flatter diurnal cortisol rhythms. There were no relations between cortisol slope and psychological or cognitive functioning among patients. In contrast, controls with flatter rhythms showed the expected allostatic load profile of larger waist circumference, poorer performance on explicit memory tasks, lower perceived social support, and a tendency toward higher perceived stress. These findings suggest that the cortisol diurnal slope may have important but different correlates in healthy women versus those with breast cancer.

Aerobic exercise: a potential therapeutic intervention for patients with liver disease

Fatigue is a symptom of liver disease. Indirect evidence suggests that this type of fatigue is centrally mediated. Non-alcoholic steatohepatitis (NASH), which may lead to cirrhosis, is associated with insulin resistance. An activated hypothalamic pituitary adrenal axis results in increased secretion of cortisol releasing hormone, cortisol and catecholamines. Prolonged exposure to high levels of cortisol is associated with insulin resistance, as exemplified by the metabolic syndrome. Accumulation in visceral fat is an independent factor associated with insulin resistance. Central (visceral) fat is less sensitive to insulin than the rest of body fat and the central nervous system and not peripheral insulin, appears to regulate lipolysis in visceral fat by, at least in part, adrenergic mechanisms. Aerobic training has documented beneficial effects on mental health and fatigue secondary to chronic illness. In addition, aerobic training increases insulin sensitivity. Thus, aerobic training may decrease fatigue in liver disease and improve NASH.

Extinction deficits in male rhesus macaques with a history of self-injurious behavior

Self-injurious behavior (SIB) occurs in both human and nonhuman primate populations. Despite the potential for harm, SIB may persist in part because of an inability to inhibit behavior that results in wounding. A lever-pressing task was used to test the prediction that monkeys with SIB would show greater persistence in lever-pressing on extinction trials than monkeys without the disorder. The subjects were 15 individually-housed adult male rhesus macaques, 10 of which (the SIB group) had a veterinary record of self-inflicted wounding. All of the monkeys were trained to lever-press for food rewards to a criterion of 400 total responses. The test procedures consisted of five daily 30-min sessions divided into six 5-min intervals. On day 1, the subjects received continuous reinforcement. On days 2-4, testing consisted of alternating reinforced/unreinforced 5-min intervals, beginning with reinforcement. Reinforced intervals were cued with a buzzer. On day 5, the subjects received no reinforcement. The number of lever-presses and behavioral responses were recorded during each session. Saliva samples were collected for cortisol measurement before and after test sessions on days 1, 2, and 5. As predicted, monkeys with SIB lever-pressed more than controls during extinction intervals on days 2-4. There was no difference on day 1 or day 5. The frequency of scratching, yawning, and abnormal behavior increased when reinforcement was intermittent (days 2-4) or absent (day 5). Cortisol levels were highest with continuous reinforcement (day 1), and may reflect differential levels of food intake rather than stress. The presence of extinction deficits suggests that SIB may persist in some monkeys because they lack the ability to regulate the intensity of their biting behavior.

Emotion-induced amnesia in rats: working memory-specific impairment, corticosterone-memory correlation, and fear versus arousal effects on memory

We have shown previously that psychological stress (predator exposure) impairs spatial memory in rats. We have extended that finding here to show that predator stress selectively impaired recently acquired (hippocampal-dependent) spatial working memory without affecting long-term (hippocampal-independent) spatial reference memory. We also investigated why predator exposure impairs memory. Was spatial memory impaired because of the fear-provoking aspects of predator exposure or only because the cat was a novel and arousing stimulus? If the latter possibility was correct, then any novel and arousing stimulus, independent of its emotional valence (i.e., aversive or appetitive), would impair memory. We found that spatial working memory was not impaired when the male rats were exposed to a sexually receptive female rat, a stimulus that was novel and arousing to them, but not aversive. We also found that there was an equivalent increase in serum corticosterone levels in male rats exposed to either a cat or a female rat, but only the cat-exposed rats exhibited a significant correlation between corticosterone levels and impaired memory. Overall, this series of experiments demonstrates that (1). predator stress selectively impaired working (hippocampal-dependent), but not reference (hippocampal-independent), memory; (2). a fear-provoking stimulus, and not merely novelty and increased arousal, impaired spatial memory; and (3). increased corticosterone levels correlated with impaired spatial working memory only under predator exposure, that is, fear-provoking conditions.