Association of diurnal patterns in salivary cortisol with type 2 diabetes in the Whitehall II study

Depression and type 2 diabetes: A causal relationship and mechanistic pathway

Depression is a mood disorder that may increase risk for the development of insulin resistance (IR) and type 2 diabetes (T2D), and vice versa. However, the mechanistic pathway linking depression and T2D is not fully elucidated. The aim of this narrative review, therefore, was to discuss the possible link between depression and T2D. The coexistence of T2D and depression is twice as great compared to the occurrence of either condition independently. Hyperglycaemia and dyslipidaemia promote the incidence of depression by enhancing inflammation and reducing brain serotonin (5-hydroxytryptamine [5HT]). Dysregulation of insulin signalling in T2D impairs brain 5HT signalling, leading to the development of depression. Furthermore, depression is associated with the development of hyperglycaemia and poor glycaemic control. Psychological stress and depression promote the development of T2D. In conclusion, T2D could be a potential risk factor for the development of depression through the induction of inflammatory reactions and oxidative stress that affect brain neurotransmission. In addition, chronic stress in depression may induce the development of T2D through dysregulation of the hypothalamic-pituitary-adrenal axis and increase circulating cortisol levels, which triggers IR and T2D.

Stress and the CRH System, Norepinephrine, Depression, and Type 2 Diabetes

Major depressive disorder (MDD) increases the risk of type 2 diabetes (T2D) by 60% in untreated patients, and hypercortisolism is common in MDD as well as in some patients with T2D. Patients with MDD, despite hypercortisolism, show inappropriately normal levels of corticotropin-releasing hormone (CRH) and plasma adrenocorticotropin (ACTH) in the cerebrospinal fluid, which might implicate impaired negative feedback. Also, a positive feedback loop of the CRH-norepinephrine (NE)-CRH system may be involved in the hypercortisolism of MDD and T2D. Dysfunctional CRH receptor 1 (CRHR1) and CRH receptor 2 (CRHR2), both of which are involved in glucose regulation, may explain hypercortisolism in MDD and T2D, at least in a subgroup of patients. CRHR1 increases glucose-stimulated insulin secretion. Dysfunctional CRHR1 variants can cause hypercortisolism, leading to serotonin dysfunction and depression, which can contribute to hyperglycemia, insulin resistance, and increased visceral fat, all of which are characteristics of T2D. CRHR2 is implicated in glucose homeostasis through the regulation of insulin secretion and gastrointestinal functions, and it stimulates insulin sensitivity at the muscular level. A few studies show a correlation of the CRHR2 gene with depressive disorders. Based on our own research, we have found a linkage and association (i.e., linkage disequilibrium [LD]) of the genes CRHR1 and CRHR2 with MDD and T2D in families with T2D. The correlation of CRHR1 and CRHR2 with MDD appears stronger than that with T2D, and per our hypothesis, MDD may precede the onset of T2D. According to the findings of our analysis, CRHR1 and CRHR2 variants could modify the response to prolonged chronic stress and contribute to high levels of cortisol, increasing the risk of developing MDD, T2D, and the comorbidity MDD-T2D. We report here the potential links of the CRH system, NE, and their roles in MDD and T2D.

Type 2 diabetes mellitus related sarcopenia: a type of muscle loss distinct from sarcopenia and disuse muscle atrophy

Muscle loss is a significant health concern, particularly with the increasing trend of population aging, and sarcopenia has emerged as a common pathological process of muscle loss in the elderly. Currently, there has been significant progress in the research on sarcopenia, including in-depth analysis of the mechanisms underlying sarcopenia caused by aging and the development of corresponding diagnostic criteria, forming a relatively complete system. However, as research on sarcopenia progresses, the concept of secondary sarcopenia has also been proposed. Due to the incomplete understanding of muscle loss caused by chronic diseases, there are various limitations in epidemiological, basic, and clinical research. As a result, a comprehensive concept and diagnostic system have not yet been established, which greatly hinders the prevention and treatment of the disease. This review focuses on Type 2 Diabetes Mellitus (T2DM)-related sarcopenia, comparing its similarities and differences with sarcopenia and disuse muscle atrophy. The review show significant differences between the three muscle-related issues in terms of pathological changes, epidemiology and clinical manifestations, etiology, and preventive and therapeutic strategies. Unlike sarcopenia, T2DM-related sarcopenia is characterized by a reduction in type I fibers, and it differs from disuse muscle atrophy as well. The mechanism involving insulin resistance, inflammatory status, and oxidative stress remains unclear. Therefore, future research should further explore the etiology, disease progression, and prognosis of T2DM-related sarcopenia, and develop targeted diagnostic criteria and effective preventive and therapeutic strategies to better address the muscle-related issues faced by T2DM patients and improve their quality of life and overall health.

Cortisol secretion and abnormalities of glucose metabolism in nondiabetic patients with hypertension

OBJECTIVE

Glycometabolic changes are associated with hypercortisolism in Cushing's syndrome. Because impaired glucose tolerance (IGT) and insulin resistance are frequently detected in patients with essential hypertension, we hypothesized that in these patients, early glycometabolic abnormalities might be related to differences in regulation of cortisol secretion.

METHODS

In a cross-sectional study, we included 155 nondiabetic, essential hypertensive patients who were free of organ complications. The homeostasis model assessment (HOMA) index and the area under the curve of plasma glucose (AUC-glucose) and insulin (AUC-insulin) concentration following an oral glucose tolerance test were measured, together with daily plasma cortisol (8 a.m., 3 p.m. and 12 a.m.; AUC-cortisol) and 8 a.m. cortisol after 1 mg overnight dexamethasone suppression test (DST).

RESULTS

IGT was present in 27% of patients who were older and had higher BMI, plasma triglycerides and uric acid, AUC-cortisol and DST-cortisol, and lower HDL-cholesterol. Frequency of IGT increased progressively across tertiles of DST-cortisol, together with levels of glycated hemoglobin, fasting insulin and C-peptide, HOMA-index, AUC-glucose, and AUC-insulin. AUC-cortisol and DST-cortisol were directly correlated with insulin, C-peptide, HOMA-index, AUC-glucose, and AUC-insulin. Multivariate regression analysis showed that DST-cortisol was directly and independently correlated with HOMA index, AUC-glucose, and AUC-insulin. In a logistic regression model, both AUC-cortisol and DST-cortisol independently predicted IGT.

CONCLUSION

Daily cortisol and cortisol response to DST are independent determinants of IGT and insulin resistance in nondiabetic patients with hypertension, suggesting that even subtle differences in regulation of cortisol secretion might increase the risk of these patients to develop diabetes.

Tissue Glucocorticoid Metabolism in Adrenal Insufficiency: A Prospective Study of Dual-release Hydrocortisone Therapy

BACKGROUND

Patients with adrenal insufficiency (AI) require life-long glucocorticoid (GC) replacement therapy. Within tissues, cortisol (F) availability is under the control of the isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD). We hypothesize that corticosteroid metabolism is altered in patients with AI because of the nonphysiological pattern of current immediate release hydrocortisone (IR-HC) replacement therapy. The use of a once-daily dual-release hydrocortisone (DR-HC) preparation, (Plenadren®), offers a more physiological cortisol profile and may alter corticosteroid metabolism in vivo.

STUDY DESIGN AND METHODS

Prospective crossover study assessing the impact of 12 weeks of DR-HC on systemic GC metabolism (urinary steroid metabolome profiling), cortisol activation in the liver (cortisone acetate challenge test), and subcutaneous adipose tissue (microdialysis, biopsy for gene expression analysis) in 51 patients with AI (primary and secondary) in comparison to IR-HC treatment and age- and BMI-matched controls.

RESULTS

Patients with AI receiving IR-HC had a higher median 24-hour urinary excretion of cortisol compared with healthy controls (72.1 µg/24 hours [IQR 43.6-124.2] vs 51.9 µg/24 hours [35.5-72.3], P = .02), with lower global activity of 11β-HSD2 and higher 5-alpha reductase activity. Following the switch from IR-HC to DR-HC therapy, there was a significant reduction in urinary cortisol and total GC metabolite excretion, which was most significant in the evening. There was an increase in 11β-HSD2 activity. Hepatic 11β-HSD1 activity was not significantly altered after switching to DR-HC, but there was a significant reduction in the expression and activity of 11β-HSD1 in subcutaneous adipose tissue.

CONCLUSION

Using comprehensive in vivo techniques, we have demonstrated abnormalities in corticosteroid metabolism in patients with primary and secondary AI receiving IR-HC. This dysregulation of pre-receptor glucocorticoid metabolism results in enhanced glucocorticoid activation in adipose tissue, which was ameliorated by treatment with DR-HC.

Effects of Sleep Fragmentation and Estradiol Decline on Cortisol in a Human Experimental Model of Menopause

CONTEXT

Perturbations to the hypothalamic-pituitary-adrenal (HPA) axis have been hypothesized to increase postmenopausal cardiometabolic risk. Although sleep disturbance, a known risk factor for cardiometabolic disease, is prevalent during the menopause transition, it is unknown whether menopause-related sleep disturbance and estradiol decline disturb the HPA axis.

OBJECTIVE

We examined the effect of experimental fragmentation of sleep and suppression of estradiol as a model of menopause on cortisol levels in healthy young women.

METHODS

Twenty-two women completed a 5-night inpatient study during the mid-to-late follicular phase (estrogenized). A subset (n = 14) repeated the protocol after gonadotropin-releasing hormone agonist-induced estradiol suppression. Each inpatient study included 2 unfragmented sleep nights followed by 3 experimental sleep fragmentation nights. This study took place with premenopausal women at an academic medical center. Interventions included sleep fragmentation and pharmacological hypoestrogenism, and main outcome measures were serum bedtime cortisol levels and cortisol awakening response (CAR).

RESULTS

Bedtime cortisol increased 27% (P = .03) and CAR decreased 57% (P = .01) following sleep fragmentation compared to unfragmented sleep. Polysomnographic-derived wake after sleep-onset (WASO) was positively associated with bedtime cortisol levels (P = .047) and negatively associated with CAR (P < .01). Bedtime cortisol levels were 22% lower in the hypoestrogenized state compared to the estrogenized state (P = .02), while CAR was similar in both estradiol conditions (P = .38).

CONCLUSION

Estradiol suppression and modifiable menopause-related sleep fragmentation both independently perturb HPA axis activity. Sleep fragmentation, commonly seen in menopausal women, may disrupt the HPA axis, which in turn may lead to adverse health effects as women age.

The role of stress and health behaviour in linking weight discrimination and health: a secondary data analysis in England

OBJECTIVE

To examine the role of stress and health-risk behaviours in relationships between weight discrimination and health and well-being.

DESIGN

Secondary data analysis of an observational cohort study.

SETTING

The English Longitudinal Study of Ageing.

PARTICIPANTS

Data were from 4341 adults (≥50 years) with overweight/obesity.

PRIMARY OUTCOME MEASURES

We tested associations between perceived weight discrimination at baseline (2010/2011) and self-rated health, limiting long-standing illness, depressive symptoms, quality of life and life satisfaction over 4-year follow-up (2010/2011; 2014/2015). Potential mediation by stress exposure (hair cortisol) and health-risk behaviours (smoking, physical inactivity, alcohol consumption) was assessed.

RESULTS

Cross-sectionally, perceived weight discrimination was associated with higher odds of fair/poor self-rated health (OR=2.05 (95% CI 1.49 to 2.82)), limiting long-standing illness (OR=1.76 (95% CI 1.29 to 2.41)) and depressive symptoms (OR=2.01 (95% CI 1.41 to 2.85)) and lower quality of life (B=-5.82 (95% CI -7.01 to -4.62)) and life satisfaction (B=-2.36 (95% CI -3.25 to -1.47)). Prospectively, weight discrimination was associated with higher odds of fair/poor self-rated health (OR=1.63 (95% CI 1.10 to 2.40)) and depressive symptoms (OR=2.37 (95% CI 1.57 to 3.60)) adjusting for baseline status. Those who reported discrimination had higher hair cortisol concentrations (B=0.14 (95% CI 0.03 to 0.25)) and higher odds of physical inactivity (OR=1.90 (95% CI 1.18 to 3.05)). These variables did not significantly mediate associations between discrimination and health outcomes.

CONCLUSIONS

Weight discrimination is associated with poor health and well-being. While this discrimination is associated with stress exposure and physical inactivity, these variables explain little of the association between discrimination and poorer outcomes.

Diurnal Cortisol Features and Type 2 Diabetes Risk in Patients With Hypertension and Obstructive Sleep Apnea: A Cohort Study

CONTEXT

The hypothalamic-pituitary-adrenal (HPA) axis may be associated with type 2 diabetes (T2D); however, whether HPA axis dysfunction is associated with incident T2D remains unclear in patients with hypertension and obstructive sleep apnea (OSA).

OBJECTIVE

To investigate the relationship between the diurnal cortisol features and the risk of incident T2D in patients with hypertension and OSA.

METHODS

Participants with cortisol rhythm test at baseline in the Urumqi Research on Sleep Apnea and Hypertension cohort were enrolled. The Cox regression model was used to evaluate the relationship between ln-transformed diurnal cortisol features and T2D risk. Stratified and sensitivity analyses were also performed.

RESULTS

A total of 1478 patients with hypertension and OSA were enrolled in this study. During a median follow-up of 7.0 years, 196 participants developed T2D. Overall, a steep diurnal cortisol slope (DCS) was significantly associated with decreased T2D risk (per SD increase, HR 0.88, 95% CI 0.79-0.97, P = .014). Midnight cortisol was positively associated with increased T2D risk (per SD increase, HR 1.25, 95% CI 1.08-1.45, P = .003). Sensitivity analyses showed similar results. Neither DCS nor midnight cortisol was associated with incident T2D in the women's subgroup or participants with mild OSA.

CONCLUSION

Steeper DCS and higher midnight cortisol levels are associated with lower and higher T2D risks in patients with hypertension and OSA, respectively, at least in men or participants with moderate to severe OSA. Diurnal cortisol features may represent an early prevention target for diabetes in this population.

Dysregulated responses to stress and weight in people with type 2 diabetes

OBJECTIVE

Dysregulated stress responsivity has been linked with weight gain in healthy samples. However, the relationship between disturbances in stress-related biology and changes in weight in people with type 2 diabetes (T2D) is unclear.

METHOD

A total of 66 participants with T2D underwent laboratory stress-testing in 2011-2012. Cardiovascular, neuroendocrine and inflammatory responses to standardised mental stress were assessed, and Body Mass Index (BMI) was measured. Participants self-reported information on BMI in 2019. Associations between stress-related biological responses and BMI at follow-up were modelled using linear regression adjusting for age, sex, resting biological levels and baseline BMI.

RESULTS

Blunted diastolic blood pressure reactivity (B = -0.092, 95% CI -0.177; -0.007, p = 0.034) as well as poorer systolic blood pressure (B = -0.050, 95% CI -0.084; - 0.017, p = 0.004), diastolic blood pressure (B = -0.068, 95% CI -0.132; -0.004, p = 0.034) and heart rate (B = -0.122, 95% CI -0.015;-0.230, p = 0.027) recovery post-stress were associated with higher BMI 7.5 years later. Greater interleukin-1 receptor antagonist (B = 16.93, 95% CI 6.20; 27.67, p = 0.003) and monocyte chemoattractant protein-1 reactivity (B = 0.04, 95% CI 0.002; 0.084, p = 0.041) were associated with weight gain. No significant associations were detected for interleukin-6 or laboratory cortisol measures.

CONCLUSION

Disturbances in stress-related biology may promote weight gain in people with T2D. Research with a larger sample size is required to explore associations between stress responsivity and BMI in people with T2D.

Morning Serum Cortisol Is Uniquely Associated with Cardiometabolic Risk Independent of Body Composition in Latino Adolescents

Background: Alterations in morning serum cortisol (MSC) have been associated with higher cardiometabolic risk. This finding has been documented primarily in populations with overweight or obesity; however, it has not been clearly established if obesity plays a requisite role in this relationship. This study seeks to extend earlier findings by examining whether body composition measures alter the relationship between MSC with glucose and insulin markers, blood pressure, and lipid parameters in Latino youth in middle adolescence. Methods: This cross-sectional study included 196 healthy adolescents (130F/66M; mean age: 16.4 ± 0.6 years; 95% Latino; mean body mass index, BMI: 24.3 ± 5.7) from Los Angeles, California. Morning cortisol, glucose, insulin, glycated hemoglobin, and lipids (triglycerides and high-density lipoprotein cholesterol) were assessed from a fasting blood sample. Sitting systolic and diastolic blood pressure was averaged from duplicate measures. Body composition measures included BMI and waist circumference, which were used as proxies for total body and abdominal adiposity, respectively. Triplicate measurements of weight and height were averaged for calculation of BMI; age- and sex-specific BMI z-score was used to classify into normal BMI or overweight/obese BMI status. Waist circumference was measured in duplicate and the average was used to classify participants into two strata: normal/healthy waist circumference (<90th percentile for age, sex, and ethnicity) and high waist circumference (≥90th percentile). Results: The primary findings were that higher MSC was associated with higher fasting glucose and systolic blood pressure after adjusting for age, sex, and BMI z-score (and/or waist circumference). BMI status or waist circumference status did not alter these relationships. Main Conclusion: Our results suggest that the relationships between hypothalamic-pituitary-adrenal axis function and certain cardiometabolic risk factors may be independent of adiposity. Future research is warranted to discover the contributors and underlying mechanisms of these relationships in adolescent populations. ClinicalTrials.gov identifier: NCT02088294.

The association between type 2 diabetes and attention- deficit/hyperactivity disorder: A systematic review, meta-analysis, and population-based sibling study

We conducted a systematic review and a meta-analysis to quantitatively summarize evidence on the association between attention-deficit/hyperactivity disorder (ADHD) and type 2 diabetes (T2D). Moreover, a register-based sibling study was conducted to simultaneously control for confounding factors. A systematic search identified four eligible observational studies (N = 5738,287). The meta-analysis showed that individuals with ADHD have a more than doubled risk of T2D when considering adjusted estimates (OR=2.29 [1.48-3.55], d=0.46). Results from the register-based Swedish data showed a significant association between ADHD and T2D (HR=2.35 [2.14-2.58]), with substance use disorder, depression, and anxiety being the main drivers of the association, and cardiovascular and familiar risk playing a smaller role. While results from the meta-analysis provide evidence for an increased risk of T2D in individuals with ADHD, the register-based analyses show that the association between ADHD and T2D is largely explained by psychiatric comorbidities. Pending further evidence of causal association, our findings suggest that early identification and treatment of ADHD comorbidities might greatly reduce the risk of developing T2D in individuals with ADHD.

Using LC-MS/MS to Determine Salivary Steroid Reference Intervals in a European Older Adult Population

A number of steroids, including glucocorticoids and sex hormones, have been associated with neurodegenerative and cardiovascular conditions common in aging populations. The application of liquid chromatography tandem mass spectrometry (LC-MS/MS) steroid analysis offers an opportunity to conduct simultaneous multiplex steroid analysis within a given sample. In this paper, we describe the application of an LC-MS/MS steroid analysis method for the assessment of reference ranges of steroids in human saliva samples (200 µL) collected from older adults (age 50 years and above) enrolled in a European cohort investigating the risk for Alzheimer's dementia. Saliva samples were prepared using supported liquid extraction (SLE) along with a calibration curve and analysed using a Waters I-Class UPLC (Ultra Performance Liquid Chromatography) and a Sciex QTrap 6500+ mass spectrometer. Mass spectrometry parameters of steroids were optimised for each steroid and a method for the chromatographic separation of 19 steroids was developed. Lower limits of quantitation (LLOQs), linearity and other method criteria were assessed. In total, data from 125 participants (500 samples) were analysed and assessed for reference ranges (64 male, 61 female). A total of 19 steroids were detected in saliva within the range of the method. There were clear diurnal patterns in most of the steroid hormones detected. Sex differences were observed for androstenedione (A4), testosterone (T), cortisone (E) and aldosterone (Aldo). In the first sample of the day, dehydroepiandrosterone (DHEA) was significantly higher in healthy volunteers compared to those with Alzheimer's disease biomarkers. This LC-MS/MS method is suitable for the analysis of 19 steroids in saliva in adults.

Imagine HEALTH: Changes in diurnal salivary cortisol patterns following a 12-week guided imagery RCT lifestyle intervention in predominantly Latino adolescents

OBJECTIVE

Alterations in diurnal salivary cortisol patterns have been linked to adverse metabolic health outcomes. We have previously shown that stress-reduction guided imagery (GI) can reduce salivary cortisol levels acutely. We now ask whether addition of GI into a 12-week lifestyle intervention designed to improve eating and physical activity behaviors can alter diurnal salivary cortisol patterns and perceived stress.

METHODS

232 adolescent participants (ages 14-17 years) were cluster randomized by school into one of four intervention arms: non-intervention Control (C; n = 51), Lifestyle (LS; n=61), Stress-Reduction GI (SRGI; n = 55), and Lifestyle Behavior GI (LBGI; n = 65). LS group received one nutrition and one physical activity class per week after-school for 12 weeks. SRGI and LBGI groups received same LS classes plus an additional weekly GI session. Salivary cortisol was assessed pre- and post-intervention on 3 days, 3 times daily, at awakening, 30-minutes post-awakening, and in the evening to determine Cortisol Awakening Response (CAR) and Diurnal Cortisol Slope (DCS). Perceived Stress Scale (PSS) was administered pre- and post-intervention. Mixed effects modeling was used for intent-to-treat analysis and sensitivity analysis was used for those participants adherent to intervention protocol.

RESULTS

Analysis of 208 subjects with complete data showed a small between-group increase in CAR in LBGI vs C (p = 0.045, d=0.24), with no significant group differences among other intervention arms. There were no between group differences in change in DCS or change in PSS after 12-weeks. Amongst adherent participants, LBGI showed a small-moderate increase in CAR (p = 0.03, d=0.37), and moderate-large reduction in PSS (p = 0.02, d=-0.66) compared to C. There were no other between group differences in CAR, DCS, or PSS.

CONCLUSION

LBGI led to an increase in CAR, and in adherent subjects, a decrease in PSS, suggesting GI may be a mind-body intervention that can affect both objective and subjective measures of the stress response. Whether changes in cortisol patterns in this population affect measures of mental or physical health remains to be determined.

Severe psychiatric disorders and general medical comorbidities: inflammation-related mechanisms and therapeutic opportunities

Individuals with severe psychiatric disorders, such as mood disorders and schizophrenia, are at increased risk of developing other medical conditions, especially cardiovascular and metabolic diseases. These medical conditions are underdiagnosed and undertreated in these patients contributing to their increased morbidity and mortality. The basis for this increased comorbidity is not well understood, possibly reflecting shared risks factors (e.g. lifestyle risk factors), shared biological mechanisms and/or reciprocal interactions. Among overlapping pathophysiological mechanisms, inflammation and related factors, such as dysbiosis and insulin resistance, stand out. Besides underlying the association between psychiatric disorders and cardiometabolic diseases, these mechanisms provide several potential therapeutic targets.

Real-time racial discrimination, affective states, salivary cortisol and alpha-amylase in Black adults

Perceived racial discrimination has been associated with the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activities-two major stress response systems. To date, most studies have used cross-sectional data that captured retrospective measures of the racial discrimination associated with current physiological stress responses. The purpose of this study was to examine the relationship between racial discrimination measured in real-time and physiological stress responses. Twelve healthy Black adults completed baseline surveys and self-collected saliva samples 4x/day for 4 days to measure cortisol and alpha amylase (AA) as a proxy of HPA and ANS systems, respectively. Real-time racial discrimination was measured using ecological momentary assessments (EMA) sent to participants 5x/day for 7 days. Multilevel models were conducted to examine the relationship between racial discrimination and stress responses. In multilevel models, the previous day's racial discrimination was significantly associated with the next day's cortisol level at wakening (β = 0.81, partial r = 0.74, p<0.01) and diurnal slope (β = -0.85, partial r = -0.73, p<0.01). Also, microaggressions were significantly associated with the diurnal cortisol slope in the same day, indicating that on the day when people reported more microaggressions than usual, a flatter diurnal slope of cortisol was observed (β = -0.50, partial r = -0.64, p<0.01). The concurrent use of salivary biomarkers and EMA was feasible methods to examine the temporal relationship between racial discrimination and physiological stress responses. The within-person approach may help us understand the concurrent or lagged effects of racial discrimination on the stress responses. Further studies are needed to confirm the observed findings with a large sample size and to improve stress related health outcomes in racial/ethnic minorities.

Circadian rhythms and pancreas physiology: A review

Type 2 diabetes mellitus, obesity and metabolic syndrome are becoming more prevalent worldwide and will present an increasingly challenging burden on healthcare systems. These interlinked metabolic abnormalities predispose affected individuals to a plethora of complications and comorbidities. Furthermore, diabetes is estimated by the World Health Organization to have caused 1.5 million deaths in 2019, with this figure projected to rise in coming years. This highlights the need for further research into the management of metabolic diseases and their complications. Studies on circadian rhythms, referring to physiological and behavioral changes which repeat approximately every 24 hours, may provide important insight into managing metabolic disease. Epidemiological studies show that populations who are at risk of circadian disruption such as night shift workers and regular long-haul flyers are also at an elevated risk of metabolic abnormalities such as insulin resistance and obesity. Aberrant expression of circadian genes appears to contribute to the dysregulation of metabolic functions such as insulin secretion, glucose homeostasis and energy expenditure. The potential clinical implications of these findings have been highlighted in animal studies and pilot studies in humans giving rise to the development of circadian interventions strategies including chronotherapy (time-specific therapy), time-restricted feeding, and circadian molecule stabilizers/analogues. Research into these areas will provide insights into the future of circadian medicine in metabolic diseases. In this review, we discuss the physiology of metabolism and the role of circadian timing in regulating these metabolic functions. Also, we review the clinical aspects of circadian physiology and the impact that ongoing and future research may have on the management of metabolic disease.

Utilization of Mind–Body Intervention for Integrative Health Care of COVID-19 Patients and Survivors

Recent findings suggest a correlation between COVID-19 and diabetes, although the underlying causes are still little understood. COVID-19 infection tends to induce severe symptoms in patients with underlying diabetes, increasing their mortality rate. Moreover, COVID-19 itself appears to be a diabetogenic factor. In addition, mental health conditions, such as depression due to lockdown and anxiety about infection, were found to affect glycemic control and immunity, highlighting the importance of mental health care during the pandemic. Mind–Body Intervention (MBI), which includes meditation, yoga, and qigong, has emerged as a tool for mental health management due to its effects on stress reduction and the promotion of mental and physical well-being. Here, we review the latest randomized controlled trials to determine the effects of MBI on glycemic control and the immune system and discuss the underlying mechanisms by which MBI facilitates the virtuous cycle of stress management, glycemic control, and immune modulation. Furthermore, we examine the actual utilization of MBI during the COVID-19 pandemic era through recent studies. With proper online education, non-pharmacological MBI may be more widely used as an important tool for self-health care that complements the usual treatment of COVID-19 patients and survivors.

Ipriflavone as a non-steroidal glucocorticoid receptor antagonist ameliorates diabetic cognitive impairment in mice

Diabetic cognitive impairment (DCI) is a common diabetic complication with hallmarks of loss of learning ability and disorders of memory and behavior. Glucocorticoid receptor (GR) dysfunction is a main reason for neuronal impairment in brain of diabetic patients. Here, we determined that ipriflavone (IP) a clinical anti-osteoporosis drug functioned as a non-steroidal GR antagonist and efficiently ameliorated learning and memory dysfunction in both type 1 and 2 diabetic mice. The underlying mechanism has been intensively investigated by assay against the diabetic mice with GR-specific knockdown in the brain by injection of adeno-associated virus (AAV)-ePHP-si-GR. IP suppressed tau hyperphosphorylation through GR/PI3K/AKT/GSK3β pathway, alleviated neuronal inflammation through GR/NF-κB/NLRP3/ASC/Caspase-1 pathway, and protected against synaptic impairment through GR/CREB/BDNF pathway. To our knowledge, our work might be the first to expound the detailed mechanism underlying the amelioration of non-steroidal GR antagonist on DCI-like pathology in mice and report the potential of IP in treatment of DCI.

Cortisol awakening response in bipolar patients with comorbid type 2 diabetes mellitus

OBJECTIVES

Bipolar disorder (BD) is frequently associated with type 2 diabetes mellitus (T2DM). The functioning of the hypothalamic-pituitary-adrenal (HPA) axis has been never investigated in BD with respect to the glucose metabolic status. Therefore, we assessed the cortisol awakening response (CAR) in bipolar patients with or without comorbid T2DM.

METHODS

Twenty euglycemic bipolar patients [12 males and eight females; mean age (±SD): 47.4 ± 14.4 years; mean (±SD) duration of illness: 18.3 ± 12.1 years], 16 BD patients with T2DM [11 males and five females; mean age (±SD): 63.6 ± 12.8 years; mean (±SD) duration of bipolar illness: 17.1 ± 10.8 years; mean (±SD) duration of T2DM: 5.2 ± 5.3 years], 18 healthy subjects [seven males and 11 females; mean age (±SD): 45.0 ± 12.1 years] and 12 non-psychiatric subjects with T2DM [eight males and four females; mean age (±SD): 56.7 ± 11.2 years; mean (±SD) duration of T2DM: 5.2 ± 3.5 years] were recruited. Saliva cortisol was measured at awakening and after 15, 30, and 60 min.

RESULTS

With respect to both healthy controls and controls with T2DM, euglycemic and diabetic BD patients exhibited a CAR occurring at significantly lower levels. No significant difference emerged in the CAR between the two groups of bipolar patients. Controls with T2DM had an overall post-awakening cortisol production significantly higher than healthy controls.

CONCLUSIONS

Our results show that the CAR of patients with BD is reduced in terms of overall cortisol production but normal in terms of cortisol reactivity independently from the occurrence of comorbid T2DM. The dampened CAR points to a tuning down of the functioning of the HPA axis. in both euglycemic and diabetic BD patients, which may be a factor of vulnerability, since a preserved HPA axis functioning is essential to deal with stressors, which may precipitate affective episodes.

Glucocorticoid-Mediated Developmental Programming of Vertebrate Stress Responsivity

Glucocorticoids, vertebrate steroid hormones produced by cells of the adrenal cortex or interrenal tissue, function dynamically to maintain homeostasis under constantly changing and occasionally stressful environmental conditions. They do so by binding and thereby activating nuclear receptor transcription factors, the Glucocorticoid and Mineralocorticoid Receptors (MR and GR, respectively). The GR, by virtue of its lower affinity for endogenous glucocorticoids (cortisol or corticosterone), is primarily responsible for transducing the dynamic signals conveyed by circadian and ultradian glucocorticoid oscillations as well as transient pulses produced in response to acute stress. These dynamics are important determinants of stress responsivity, and at the systemic level are produced by feedforward and feedback signaling along the hypothalamus-pituitary-adrenal/interrenal axis. Within receiving cells, GR signaling dynamics are controlled by the GR target gene and negative feedback regulator fkpb5. Chronic stress can alter signaling dynamics via imperfect physiological adaptation that changes systemic and/or cellular set points, resulting in chronically elevated cortisol levels and increased allostatic load, which undermines health and promotes development of disease. When this occurs during early development it can "program" the responsivity of the stress system, with persistent effects on allostatic load and disease susceptibility. An important question concerns the glucocorticoid-responsive gene regulatory network that contributes to such programming. Recent studies show that klf9, a ubiquitously expressed GR target gene that encodes a Krüppel-like transcription factor important for metabolic plasticity and neuronal differentiation, is a feedforward regulator of GR signaling impacting cellular glucocorticoid responsivity, suggesting that it may be a critical node in that regulatory network.

Glucocorticoid Receptor Signaling in Diabetes

Stress and depression increase the risk of Type 2 Diabetes (T2D) development. Evidence demonstrates that the Glucocorticoid (GC) negative feedback is impaired (GC resistance) in T2D patients resulting in Hypothalamic-Pituitary-Adrenal (HPA) axis hyperactivity and hypercortisolism. High GCs, in turn, activate multiple aspects of glucose homeostasis in peripheral tissues leading to hyperglycemia. Elucidation of the underlying molecular mechanisms revealed that Glucocorticoid Receptor (GR) mediates the GC-induced dysregulation of glucose production, uptake and insulin signaling in GC-sensitive peripheral tissues, such as liver, skeletal muscle, adipose tissue, and pancreas. In contrast to increased GR peripheral sensitivity, an impaired GR signaling in Peripheral Blood Mononuclear Cells (PBMCs) of T2D patients, associated with hyperglycemia, hyperlipidemia, and increased inflammation, has been shown. Given that GR changes in immune cells parallel those in brain, the above data implicate that a reduced brain GR function may be the biological link among stress, HPA hyperactivity, hypercortisolism and hyperglycemia. GR polymorphisms have also been associated with metabolic disturbances in T2D while dysregulation of micro-RNAs—known to target GR mRNA—has been described. Collectively, GR has a crucial role in T2D, acting in a cell-type and context-specific manner, leading to either GC sensitivity or GC resistance. Selective modulation of GR signaling in T2D therapy warrants further investigation.

The health consequences of stress in couples: A review and new integrated Dyadic Biobehavioral Stress Model

Despite marriage's health benefits, all couples experience stress that can increase morbidity and mortality risks. Marital stress can alter endocrine, cardiovascular, and immune function-key pathways from troubled relationships to poor health. This review discusses how partners "get under each other's skin" to influence psychological, behavioral, and biological health. Then, I offer a comprehensive Dyadic Biobehavioral Stress Model to build on this foundational work and inspire transdisciplinary research integrating psychoneuroimmunological and relational lenses. This conceptual and empirically driven model provides promising new directions to investigate mechanisms linking individuals' relationships behaviors to their own and their partners' health, with particular emphasis on biological pathways. These mechanisms may impact each partner's physical health outcomes, such as disease development, illness severity, and accelerated biological aging. Risk and protective factors across developmental stages and diverse contexts are also discussed to help explain how, and under what conditions, partners influence each other's health. Research applying this model can push the boundaries of our current understanding on dyadic stress its far-reaching health effects on self-report and biological markers across the lifespan.

Chronic Inflammation Mediates the Association between Cortisol and Hyperglycemia: Findings from the Cross-Sectional Population-Based KORA Age Study

(1) Background: The study aimed to investigate the role of subclinical inflammation on the association between diurnal cortisol patterns and glycaemia in an aged population. (2) Methods: Salivary cortisol, interleukin-6 (IL-6) and glycated haemoglobin (HbA1c) were analysed in a sample of 394 men and 364 women (mean age = 5 ± 6.3, 65–90 years). The ratio of morning after awakening and late-night cortisol was calculated as an indication of diurnal cortisol slope (DCS). Multivariable regression models were run to examine whether IL-6 mediates the relationship between the DCS and glycaemia. The Sobel test and bootstrapping methods were used to quantify the mediation analyses. (3) Results: In comparison to normoglycaemic counterparts (n = 676, 89.2%), an increase in IL-6 concentrations, in individuals with hyperglycaemia (HbA1c ≥ 6.5%) (n = 82, 10.8%) (p = 0.04), was significantly associated with a flatter DCS. The link between flatter DCS and elevated HbA1c level was significant mediated by a heightened IL-6 level. Our results do not suggest reverse-directionality, whereby cortisol did not mediate the association of IL-6 with HbA1c. (4) Conclusions: In our sample, the relation between flatter DCS and hyperglycaemia was partly explained by IL-6 levels. The paradigm of subclinical inflammation-mediated cortisol response on glucose metabolism could have widespread implications for improving our understanding of the pathophysiology of type 2 diabetes mellitus.

Disruption of the Diurnal Cortisol Hormone Pattern by Pesticide Use in a Longitudinal Study of Farmers in Thailand

Alteration of the hypothalamic-pituitary-adrenal (HPA) axis hormones has been associated with a range of chronic metabolic and cardiovascular health conditions. This study evaluated whether type of farming (organic versus conventional) or the number of self-reported days of spraying pesticides in the past 8 months was associated with diurnal cortisol levels. Salivary cortisol levels were measured four times a day (waking, 30 min after waking, 6 h after waking and bedtime) longitudinally, 8 months apart during three rounds of data collection. Pesticide using (conventional) and organic farmers were recruited to participate. Pesticide use in the previous 8 months was determined as the number of spray days for each type of pesticide used (herbicide, insecticide, fungicide) from self-reported questionnaires. Estimates of cortisol levels at four time points, the cortisol awakening response (CAR), and the diurnal cortisol slope (DCS) were estimated with a longitudinal mixed model that accounted for the non-linearity of cortisol levels across the day. Conventional farmers had significantly lower cortisol levels at waking than organic farmers (3.39 versus 3.86 ng ml-1), 30 min after waking (5.87 versus 6.96 ng ml-1), 6 h after waking (1.62 versus 1.88 ng ml-1), and lower diurnal cortisol slope (-2.26 versus -2.51 ng ml-1). Farmers who frequently applied herbicides (90th percentile of the number of spray days in the past 8 months) had significantly lower waking, 30 min after waking, 6 h after waking, bedtime and diurnal cortisol slopes compared with those with no spray days of herbicide in the past 8 months (organic and some of the conventional farmers). Those who frequently applied insecticides in the past 8 months had significantly lower bedtime levels and diurnal cortisol slopes, compared with those with no spray days of insecticide in the past 8 months. There were no significant differences in cortisol hormones between those who frequently applied fungicides and those who did not spray fungicides. Repeated pesticide use appears to be disrupting the HPA axis and depressing the normal diurnal cortisol rhythm among conventional Thai farmers.

Identification of human glucocorticoid response markers using integrated multi-omic analysis from a randomized crossover trial

Background:

Glucocorticoids are among the most commonly prescribed drugs, but there is no biomarker that can quantify their action. The aim of the study was to identify and validate circulating biomarkers of glucocorticoid action.

Methods:

In a randomized, crossover, single-blind, discovery study, 10 subjects with primary adrenal insufficiency (and no other endocrinopathies) were admitted at the in-patient clinic and studied during physiological glucocorticoid exposure and withdrawal. A randomization plan before the first intervention was used. Besides mild physical and/or mental fatigue and salt craving, no serious adverse events were observed. The transcriptome in peripheral blood mononuclear cells and adipose tissue, plasma miRNAomic, and serum metabolomics were compared between the interventions using integrated multi-omic analysis.

Results:

We identified a transcriptomic profile derived from two tissues and a multi-omic cluster, both predictive of glucocorticoid exposure. A microRNA (miR-122-5p) that was correlated with genes and metabolites regulated by glucocorticoid exposure was identified (p=0.009) and replicated in independent studies with varying glucocorticoid exposure (0.01 ≤ p≤0.05).

Conclusions:

We have generated results that construct the basis for successful discovery of biomarker(s) to measure effects of glucocorticoids, allowing strategies to individualize and optimize glucocorticoid therapy, and shedding light on disease etiology related to unphysiological glucocorticoid exposure, such as in cardiovascular disease and obesity.

Funding:

The Swedish Research Council (Grant 2015-02561 and 2019-01112); The Swedish federal government under the LUA/ALF agreement (Grant ALFGBG-719531); The Swedish Endocrinology Association; The Gothenburg Medical Society; Wellcome Trust; The Medical Research Council, UK; The Chief Scientist Office, UK; The Eva Madura’s Foundation; The Research Foundation of Copenhagen University Hospital; and The Danish Rheumatism Association.

Clinical trial number:

NCT02152553.

Several diseases, including asthma, arthritis, some skin conditions, and cancer, are treated with medications called glucocorticoids, which are synthetic versions of human hormones. These drugs are also used to treat people with a condition call adrenal insufficiency who do not produce enough of an important hormone called cortisol. Use of glucocorticoids is very common, the proportion of people in a given country taking them can range from 0.5% to 21% of the population depending on the duration of the treatment. But, like any medication, glucocorticoids have both benefits and risks: people who take glucocorticoids for a long time have an increased risk of diabetes, obesity, cardiovascular disease, and death.

Because of the risks associated with taking glucocorticoids, it is very important for physicians to tailor the dose to each patient’s needs. Doing this can be tricky, because the levels of glucocorticoids in a patient’s blood are not a good indicator of the medication’s activity in the body. A test that can accurately measure the glucocorticoid activity could help physicians personalize treatment and reduce harmful side effects.

As a first step towards developing such a test, Chantzichristos et al. identified a potential way to measure glucocorticoid activity in patient’s blood. In the experiments, blood samples were collected from ten patients with adrenal insufficiency both when they were on no medication, and when they were taking a glucocorticoid to replace their missing hormones. Next, the blood samples were analyzed to determine which genes were turned on and off in each patient with and without the medication. They also compared small molecules in the blood called metabolites and tiny pieces of genetic material called microRNAs that turn genes on and off.

The experiments revealed networks of genes, metabolites, and microRNAs that are associated with glucocorticoid activity, and one microRNA called miR-122-5p stood out as a potential way to measure glucocorticoid activity. To verify this microRNA’s usefulness, Chantzichristos et al. looked at levels of miR-122-5p in people participating in three other studies and confirmed that it was a good indicator of the glucocorticoid activity.

More research is needed to confirm Chantzichristos et al.’s findings and to develop a test that can be used by physicians to measure glucocorticoid activity. The microRNA identified, miR-122-5p, has been previously linked to diabetes, so studying it further may also help scientists understand how taking glucocorticoids may increase the risk of developing diabetes and related diseases.

Cortisol level dysregulation and its prevalence-Is it nature's alarm clock?

This review examines the stress hormone cortisol which plays an important role in regulating and supporting different bodily functions. Disruption in cortisol production has an impact on health and this review looks at a wide range of papers where cortisol has been indicated as a factor in numerous chronic conditions—especially those which are classed as “noncommunicable diseases” (NCDs). Timely detection, screening, and treatment for NCDs are vital to address the growing problem of NCDs worldwide—this would have health and socioeconomic benefits. Interestingly, many of the papers highlight the pro‐inflammatory consequences of cortisol dysregulation and its deleterious effects on the body. This is particularly relevant given the recent findings concerning COVID‐19 where pro‐inflammatory cytokines have been implicated in severe inflammation.

Insufficient glucocorticoid receptor signaling and flattened salivary cortisol profile are associated with metabolic and inflammatory indices in type 2 diabetes

PURPOSE

Impaired negative feedback and hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis characterizes type 2 diabetes mellitus (T2DM). The glucocorticoid receptor (GR) is a key mediator of HPA axis negative feedback; however, its role in linking hypercortisolemia and T2DM-associated hyperglycemia, hyperlipidemia and inflammation is not yet known.

METHODS

In peripheral mononuclear cells (PBMC) from 31 T2DM patients and 24 healthy controls, we measured various GR-signaling parameters such as phosphorylated GR (pGR-S211), GRα/GRβ gene expression and GC-sensitivity [using the basal and dexamethasone (DEX)-induced leucine zipper (GILZ) and FK506 binding-protein (FKBP5) mRNA levels as well as the basal interleukin (IL)-1β protein levels]. Diurnal salivary cortisol curve parameters such as the cortisol awaking response (CAR) and area under the curve (AUC_total and AUCi) as well as inflammatory and metabolic indices were also determined.

RESULTS

T2DM patients exhibited diminished pGR-S211 protein content, increased GRβ, decreased basal GILZ and FKBP5 mRNA levels and increased IL-1β levels. Flattened DEX-induced GILZ and FKBP5 response curves and a flattened salivary cortisol profile characterized T2DM patients. Significant associations of GR measures and saliva cortisol curve parameters with biochemical and clinical characteristics were found.

CONCLUSION

Our novel data implicate an insufficient GR signaling in PBMCs in T2DM patients and HPA axis dysfunction. The significant associations of GR-signaling parameters with inflammatory and metabolic indices implicate that GR may be the critical link between HPA axis dysfunction, hypercortisolemia and diabetes-associated metabolic disturbances. Our findings provide significant insights into the contribution of GR-mediated mechanisms in T2DM aetiopathology and therapy.

The Mechanisms Underlying Autonomous Adrenocorticotropic Hormone Secretion in Cushing's Disease

Cushing’s disease caused due to adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (ACTHomas) leads to hypercortisolemia, resulting in increased morbidity and mortality. Autonomous ACTH secretion is attributed to the impaired glucocorticoid negative feedback (glucocorticoid resistance) response. Interestingly, other conditions, such as ectopic ACTH syndrome (EAS) and non-neoplastic hypercortisolemia (NNH, also known as pseudo-Cushing’s syndrome) also exhibit glucocorticoid resistance. Therefore, to differentiate between these conditions, several dynamic tests, including those with desmopressin (DDAVP), corticotrophin-releasing hormone (CRH), and Dex/CRH have been developed. In normal pituitary corticotrophs, ACTH synthesis and secretion are regulated mainly by CRH and glucocorticoids, which are the ACTH secretion-stimulating and -suppressing factors, respectively. These factors regulate ACTH synthesis and secretion through genomic and non-genomic mechanisms. Conversely, glucocorticoid negative feedback is impaired in ACTHomas, which could be due to the overexpression of 11β-HSD2, HSP90, or TR4, or loss of expression of CABLES1 or nuclear BRG1 proteins. Genetic analysis has indicated the involvement of several genes in the etiology of ACTHomas, including USP8, USP48, BRAF, and TP53. However, the association between glucocorticoid resistance and these genes remains unclear. Here, we review the clinical aspects and molecular mechanisms of ACTHomas and compare them to those of other related conditions.

Diabetes-related distress and daily cortisol output in people with Type 2 diabetes

AIMS

Diabetes-related distress is common in Type 2 Diabetes and is linked with poor diabetes control. However, mechanisms underlying this association are unclear. One pathway that could be involved is neuroendocrine dysfunction, as Type 2 Diabetes is associated with altered diurnal cortisol output. This study investigated the link between diabetes-related distress and diurnal cortisol output.

METHODS

134 people with Type 2 Diabetes provided 5 cortisol samples over the course of a day. Multivariate linear regression models were used to assess whether overall and sub-domains of diabetes-related distress measured by the Diabetes Distress Scale, predicted cortisol parameters (waking cortisol, cortisol awakening response, cortisol slope and evening cortisol).

RESULTS

Physician-related distress was associated with greater waking (B = 2.747, p = .015) and evening cortisol (B = 1.375, p = .014), and a blunted cortisol awakening response (B = -3.472, p = .038) adjusting for age, sex, income, body mass index, smoking and time of awakening. No associations were detected for overall distress, emotional, interpersonal or regimen distress.

CONCLUSION

Physician-related distress was associated with alterations in daily cortisol output. Longitudinal research is required to understand how physician-related distress is associated with diurnal cortisol patterning over time.

The longitudinal association of changes in diurnal cortisol features with fasting glucose: MESA

Little is known about the longitudinal association between fasting glucose (FG) and the diurnal cortisol profile among those with normal fasting glucose (NFG), impaired fasting glucose (IFG) and diabetes. To assess the temporality of the relationship between cortisol and glucose, we examined the association of: A) change (Δ) in diurnal cortisol curve features with ΔFG; B) prior annual percent change in FG with diurnal cortisol curve features; and C) baseline cortisol curve features with ΔFG over 6 years among participants with NFG, IFG and diabetes in the Multi-Ethnic Study of Atherosclerosis. The main outcome measures were: A) 6-year ΔFG (n = 512); B) diurnal cortisol curve features (wake-up cortisol levels, cortisol awakening response, total area under the curve, overall decline slope and bedtime cortisol) (n = 1275); and C) 6-year ΔFG (n = 700). After full multivariable adjustment among participants with diabetes, each annual percent change increase in wake-up cortisol, total area under the curve (AUC), and overall decline slope was associated with a significant increase in FG over 6 years in all models (all p < 0.05). A 1% prior annual increase in FG was associated with a 2.8 % lower (-2.8 %; 95 % CI: -5.3 % to -0.4 %) bedtime cortisol among participants with NFG at baseline. A 1 % flatter overall decline slope was associated with a 0.19 % increase in subsequent annual % change in FG over 6 years among participants with diabetes. Among participants with diabetes there was a positive association of change in wake-up cortisol, total AUC and overall decline slope with change in FG. Baseline overall decline slope was positively associated with change in FG among the baseline diabetes group. These results suggest a detrimental role of cortisol contributing to glycemia among individuals with diabetes.

The relationship between sleep problems and cortisol in people with type 2 diabetes

BACKGROUND

Sleep problems are linked with negative health outcomes, including coronary heart disease. Neuroendocrine dysfunction has been associated with sleep problems and may be a pathway linking sleep and ill health. Dysregulated cortisol output has observed in people with type 2 diabetes (T2D), though little is known about the links between sleep and cortisol in this population at high risk of coronary disease.

METHOD

This study investigated the association between sleep problems and cortisol over the course of an ordinary day and in response to acute laboratory stress in a sample of 129 individuals with T2D. Sleep problems were assessed using the Jenkins sleep problems questionnaire. Mental stress was induced using two five-minute laboratory stress tasks: a mirror-tracing task and the Stroop color-word interference task.

RESULTS

Sleep problems were positively associated with daily cortisol area under the curve (B = 17.051, C.I. = 6.547 to 27.554, p = 0.002) adjusting for age, sex, marital status, education, household income, body mass index and smoking; suggesting that those with greater sleep problems had greater cortisol concentrations over the course of an ordinary day. Participants reporting greater sleep problems also had raised evening cortisol levels (B = 0.96, C.I. = 0.176 to 1.746, p = 0.017) in adjusted models. In the laboratory sleep problems were negatively associated with cortisol immediately post-task (B = -0.030, C.I. = -0.059 to 0.000, p = 0.048) and 45 minutes post-task (B = -0.037, C.I. = -0.072 to -0.002, p = 0.039) in fully adjusted models; indicating that those who experienced greater sleep problems had lower cortisol concentrations after stress.

CONCLUSIONS

Sleep problems were associated with disturbances in cortisol responses to stress, as well as changes diurnal cortisol output in people with T2D. Further research is needed to assess if neuroendocrine disturbance increases the risk of cardiovascular disease in this population.

11β-hydroxysteroid dehydrogenase type 1 inhibitor use in human disease-a systematic review and narrative synthesis

INTRODUCTION

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an intracellular enzyme that catalyses conversion of cortisone into cortisol; correspondingly, 11β-HSD1 inhibitors inhibit this conversion. This systematic review focuses on the use of 11β-HSD1 inhibitors in diseases known to be associated with abnormalities in hypothalamic pituitary adrenal (HPA) axis function.

METHODS

The databases screened for suitable papers were: MedLine, EMBASE, Web of Science, ClinicalTrials.gov, and Cochrane Central.

RESULTS

1925 papers were identified, of which 29 were included in the final narrative synthesis. 11β-HSD1 and its inhibitors have been studied in diabetes, obesity, metabolic syndrome (MetS), and Alzheimer's disease (AD). Higher expression of 11β-HSD1 is seen in obesity and MetS, but has not yet been described in obesity or AD. Genetic studies identify 11β-HSD1 SNPs of interest in populations with diabetes, MetS, and AD. One phase II trial successfully reduced HbA1c in a diabetic population, however trials in MetS, obesity, and AD have not met primary endpoints.

CONCLUSIONS

Translation of this research from preclinical studies has proved challenging so far, however this is a growing area of research and more studies should focus on understanding the complex relationships between 11β-HSD1 and disease pathology, especially given the therapeutic potential of 11β-HSD1 inhibitors in development.

Emotional Pathways to the Biological Embodiment of Racial Discrimination Experiences

OBJECTIVE

Racial discrimination experiences are common among youth with an ethnic minority background, and such experiences affect health. Stress-sensitive systems like the hypothalamic-pituitary-adrenal (HPA) axis have been proposed as one mechanism. HPA-axis activity, measured through daily patterns of salivary cortisol, is altered among individuals who experience discrimination. We know little about the day-to-day processes by which discrimination experiences become embodied in stress biology. The HPA axis is responsive to negative social-evaluative (NSE) emotion. The present study investigated whether NSE emotions are a pathway by which discrimination dysregulates HPA-axis functioning as measured by cortisol levels.

METHODS

Perceived discrimination, diurnal cortisol, and changes in NSE emotion were assessed in a sample of 102 young adults. Emotions and cortisol were measured across the day for seven consecutive days in naturalistic settings. Multilevel modeling and regression analyses were used to examine average and day-to-day associations between discrimination, NSE emotion, and cortisol. Mediation and specificity analyses were conducted.

RESULTS

Discrimination was associated with NSE emotion (β = 0.34, p = .001). Day-to-day changes (β = 0.10, p = .002) and average levels (β = 0.03, p = .013) of NSE emotion were associated with dysregulated cortisol. NSE emotion mediated the association between discrimination and diurnal cortisol slopes (β = 0.10 [95% confidence interval = 0.01-0.21]). Findings were robust for covariates including stressful life events, more pronounced for NSE emotion compared with negative affect at the day level, similar for NSE emotion and general negative affect at the person level, and specific to cortisol slopes.

CONCLUSIONS

Findings suggest that daily NSE and average negative emotions are important pathways by which racial discrimination gets under the skin, or is embodied, in stress biology.

The Effect of a Maternal Mediterranean Diet in Pregnancy on Insulin Resistance is Moderated by Maternal Negative Affect

There is inconsistent evidence that healthy dietary interventions can effectively mitigate the risk of adverse outcomes associated with elevated insulin resistance in pregnancy, suggesting that other moderating factors may be at play. Maternal psychological state is an important factor to consider in this regard, because stress/mood state can directly influence glycemia and a bidirectional relationship may exist between nutrition and psychological state. The objective of this study was to examine the interaction between maternal negative affect and diet quality on third trimester insulin resistance. We conducted a prospective longitudinal study of N = 203 women with assessments in early and mid-pregnancy, which included an ecological momentary assessment of maternal psychological state, from which a negative affect score (NAS) was derived, and 24-h dietary recalls, from which the Mediterranean Diet Score (MDS) was computed. The homeostasis model assessment of insulin resistance (HOMA-IR) was computed from third trimester fasting plasma glucose and insulin values. Early pregnancy MDS was inversely associated with the HOMA-IR, but this did not maintain significance after adjusting for covariates. There was a significant effect of the mid-pregnancy MDS*NAS interaction term with the HOMA-IR in the adjusted model, such that a higher negative affect was found to override the beneficial effects of a Mediterranean diet on insulin resistance. These results highlight the need to consider nutrition and affective state concurrently in the context of gestational insulin resistance.

The effects of stress on cardiovascular disease and Alzheimer's disease: Physical exercise as a counteract measure

AD is a complicated multi-systemic neurological disorder that involves different biological pathways. Several risk factors have been identified, including chronic stress. Chronic stress produces an alteration in the activity of the hypothalamic pituitary adrenal (HPA) system, and the autonomic nervous system (ANS), which over time increase the risk of AD and also the incidence of cardiovascular disease (CVD) and risk factors, such as hypertension, obesity and type 2 diabetes, associated with cognitive impairment and AD. Considering the multi-factorial etiology of AD, understanding the complex interrelationships between different risk factors is of potential interest for designing adequate strategies for preventing, delaying the onset or slowing down the progression of this devastating disease. Thus, in this review we will explore the general mechanisms and evidence linking stress, cardiovascular disease and AD, and discuss the potential benefits of physical activity for AD by counteracting the negative effects of chronic stress, CVD and risk factors.

Adipogenesis and metabolic health

Obesity is characterized by increased adipose tissue mass and has been associated with a strong predisposition towards metabolic diseases and cancer. Thus, it constitutes a public health issue of major proportion. The expansion of adipose depots can be driven either by the increase in adipocyte size (hypertrophy) or by the formation of new adipocytes from precursor differentiation in the process of adipogenesis (hyperplasia). Notably, adipocyte expansion through adipogenesis can offset the negative metabolic effects of obesity, and the mechanisms and regulators of this adaptive process are now emerging. Over the past several years, we have learned a considerable amount about how adipocyte fate is determined and how adipogenesis is regulated by signalling and systemic factors. We have also gained appreciation that the adipogenic niche can influence tissue adipogenic capability. Approaches aimed at increasing adipogenesis over adipocyte hypertrophy can now be explored as a means to treat metabolic diseases.

Urinary Metabolomics Study of the Intervention Effect of Hypoglycemic Decoction on Type 2 Diabetes Mellitus Rats Model

The hypoglycemic decoction (HD) is a traditional Chinese medicine (TCM) preparation for the treatment of diabetes mellitus (DM), with a remarkable therapeutic effect. However, its mechanism of action is still unclear at the metabolic level. In this study, the biochemical markers from type 2 DM (T2DM) rats, induced by a high-sugar and high-fat diet combined with streptozotocin (STZ), were detected. The metabolomics-based analysis using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was conducted to evaluate urine samples from control, model, metformin, and HD groups. After oral administration of HD for 28 days, the general state, weight, fasting blood glucose (FBG), blood lipid level, oral glucose tolerance test (OGTT), fasting insulin (FINS), insulin sensitivity index (ISI), and homeostasis model assessment of insulin resistance (HOMA-IR) were significantly improved (P < 0.01). The western blotting showed that HD can enhance the protein expression of glucose transporter 4 (GLUT4) and adenosine monophosphate-activated protein kinase (AMPK). The metabolomics results revealed that after treatment with HD, the levels of L-carnitine, 1-methyladenosine, 1-methylhistamine, and 3-indoleacrylic acid were upregulated and the levels of riboflavin, phenylalanine, atrolactic acid, 2-oxoglutarate, citrate, isocitrate, cortisol, and glucose were downregulated. The main mechanism may be closely related to the regulation of the tricarboxylic acid (TCA) cycle, phenylalanine metabolism, glyoxylate metabolism, and dicarboxylate metabolism. Additionally, it was also found that HD can regulate the protein expression of GLUT4 and AMPK to interfere with TCA cycle and carbohydrate metabolism to treat T2DM.

Cardiovascular Disease and Hair Cortisol: a Novel Biomarker of Chronic Stress

PURPOSE OF REVIEW

This review focuses on the concentration of cortisol in human hair as a biomarker of chronic stress in cardiovascular disease (CVD). We outline the cardiovascular consequences of cortisol excess and provide a comprehensive overview of recent studies investigating the relationship of hair cortisol with CVD. In addition, clinical implications and limitations of the evidence are discussed, together with directions for future research.

RECENT FINDINGS

Hair cortisol may be a reliable biomarker of chronic stress since it provides quantification of total cortisol secreted into hair over several weeks. A growing body of evidence suggests that elevated hair cortisol levels are associated with both the incidence of CVD and poorer recovery and treatment outcomes. Moreover, increased hair cortisol concentration has been linked with established cardiometabolic risk factors for CVD including high blood pressure, diabetes, and adiposity. Hair cortisol is a promising biomarker of chronic cortisol excess which may contribute to both the pathogenesis and prognosis of CVD. However, the current evidence relies on small-scale cross-sectional studies. Further research adopting longitudinal designs across larger samples of CVD patients and healthy participants is required to inform the development of novel evidence-based interventions.

Comparison of Salivary Cortisol Level in Type 2 Diabetic Patients and Pre-Diabetics with Healthy People

BACKGROUND:

Cortisol is one of the important enzymes of saliva. Control of this hormone is an effective way to adjust the glucose level in diabetic patients.

AIM:

The aim of this research is to compare the salivary cortisol level in type 2 diabetic patients and pre-diabetics with healthy people.

METHODS:

In this case-control study (2018), the unstimulated salivary samples were collected from 44 patients with type 2 diabetes, 44 pre-diabetic people (case group), and 44 healthy subjects (control group), matched for age and gender. The samples were transferred to the laboratory, and salivary cortisol level was measured using ELISA. Data were analysed using SPSS 22 and Chi 2 tests.

RESULTS:

The mean salivary cortisol level in type 2 diabetic patients was 3.14 ± 1.17, in pre-diabetic cases was 1.83 ± 0.68, and in healthy controls was 0.86 ± 0.43 (P < 0.001). The mean DMFT in type 2 diabetic patients was 19.6 ± 6.5, in the pre-diabetic group was 13.43 ± 4.5, and in healthy controls was 9.38 ± 3.72 (P < 0.001).

CONCLUSION:

With regards to the results, salivary cortisol level in type 2 diabetic patients is more than pre-diabetic people, and in pre-diabetic people is more than healthy people. Also, there was a significant relation between salivary cortisol level and DMFT index.

Salivary cortisol is not associated with incident insulin resistance or type 2 diabetes mellitus

BACKGROUND

Excessive glucocorticoid secretion has been associated with type 2 diabetes mellitus (T2DM) and other features of the metabolic syndrome. We aimed to evaluate whether basal or evening salivary cortisol may predict the occurrence of incident insulin resistance (IR) or T2DM.

METHOD

This was a prospective, population-based study derived from the CoLaus/PsyCoLaus study including 1525 participants (aged 57.7 ± 10.3 years; 725 women). A total of 1149 individuals were free from T2DM at baseline. Fasting plasma glucose and insulin were measured after a follow-up of 5.3 years. Basal and evening salivary cortisol were measured at baseline. The association between basal or evening salivary cortisol level and incidence of IR or T2DM were analyzed by logistic regression, and the results were expressed for each independent variable as ORs and 95% CI.

RESULTS

After a median follow-up of 5.3 years, a total of 376 subjects (24.7%) developed IR and 32 subjects (2.1%) developed T2DM. Basal and evening salivary cortisol divided in quartiles were not associated with incidence of IR or T2DM. Multivariable analysis for age, gender, body mass index, physical activity and smoking status showed no association between basal or evening salivary cortisol and incidence of IR or T2DM.

CONCLUSION

In the CoLaus/PsyCoLaus study of healthy adults, neither basal nor evening salivary cortisol was associated with incident IR or T2DM.

Mitochondrial Dysfunction in Adipocytes as a Primary Cause of Adipose Tissue Inflammation

Adipose tissue inflammation is considered a major contributing factor in the development of obesity-associated insulin resistance and cardiovascular diseases. However, the cause of adipose tissue inflammation is presently unclear. The role of mitochondria in white adipocytes has long been neglected because of their low abundance. However, recent evidence suggests that mitochondria are essential for maintaining metabolic homeostasis in white adipocytes. In a series of recent studies, we found that mitochondrial function in white adipocytes is essential to the synthesis of adiponectin, which is the most abundant adipokine synthesized from adipocytes, with many favorable effects on metabolism, including improvement of insulin sensitivity and reduction of atherosclerotic processes and systemic inflammation. From these results, we propose a new hypothesis that mitochondrial dysfunction in adipocytes is a primary cause of adipose tissue inflammation and compared this hypothesis with a prevailing concept that "adipose tissue hypoxia" may underlie adipose tissue dysfunction in obesity. Recent studies have emphasized the role of the mitochondrial quality control mechanism in maintaining mitochondrial function. Future studies are warranted to test whether an inadequate mitochondrial quality control mechanism is responsible for mitochondrial dysfunction in adipocytes and adipose tissue inflammation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Loneliness and biological responses to acute stress in people with Type 2 diabetes

Loneliness is linked with all-cause mortality and coronary heart disease. Altered neuroendocrine and inflammatory responses to stress constitute potential pathways linking loneliness and ill-health. Stress responsivity is modified in people with Type 2 diabetes, but it is unclear whether loneliness influences biological stress responses in this population. We assessed interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1RA), monocyte chemoattractant protein-1 (MCP-1), and cortisol responses to acute stress in 135 people with Type 2 diabetes. Loneliness was measured used the Revised UCLA Loneliness Scale. Loneliness was inversely associated with cortisol output poststress (B = -4.429, p = 0.019) independent of age, sex, education, marital status, body mass index, and smoking. Lonelier individuals had raised MCP-1 concentrations 75 min poststress independent of covariates (B = 0.713, p = 0.022). No associations between loneliness and IL-6 or IL-1RA concentrations were detected. These results suggest that loneliness is associated with disturbances in stress responsivity in people with diabetes, and the impact of loneliness on health in people with diabetes may be mediated in part through dysregulation of inflammatory and neuroendocrine systems. Future research is required to understand if such changes increase the risk of poorer outcomes in this population.

Adrenal Aging and Its Implications on Stress Responsiveness in Humans

Normal aging results in subtle changes both in ACTH and cortisol secretion. Most notable is the general increase in mean daily serum cortisol levels in the elderly, without a noteworthy alteration in the normal circadian rhythm pattern. Glucocorticoid excess seen in the elderly population can have serious consequences in both the structural and functional integrity of various key areas in the brain, including the hippocampus, amygdala, prefrontal cortex, with consequent impairment in normal memory, cognitive function, and sleep cycles. The chronically elevated glucocorticoid levels also impinge on the normal stress response in the elderly, leading to an impaired ability to recover from stressful stimuli. In addition to the effects on the brain, glucocorticoid excess is associated with other age-related changes, including loss of muscle mass, hypertension, osteopenia, visceral obesity, and diabetes, among others. In contrast to the increase in glucocorticoid levels, other adrenocortical hormones, particularly serum aldosterone and DHEA (the precursor to androgens and estrogens) show significant decreases in the elderly. The underlying mechanisms for their decrease remain unclear. While the adrenomedullary hormone, norephinephrine, shows an increase in plasma levels, associated with a decrease in clearance, no notable changes observed in plasma epinephrine levels in the elderly. The multiplicity and complexity of the adrenal hormone changes observed throughout the normal aging process, suggests that age-related alterations in cellular growth, differentiation, and senescence specific to the adrenal gland must also be considered.

Do workplace-based mindfulness meditation programs improve physiological indices of stress? A systematic review and meta-analysis

OBJECTIVE

Mindfulness-based interventions (MBI) have been related with improved job satisfaction, wellbeing, health, and reduced workplace stress with employees. However, until now, synthesis of the evidence of the effect of MBIs on physiological indices associated with stress and ill-health has been lacking. Therefore the current systematic review aimed to synthesise the literature from employee samples to provide guidance for future investigations in terms of which physiological indicators and biological systems may be most impacted by MBIs.

METHODS

Electronic databases were searched. Studies that conducted a mindfulness-based program with an employee sample, which targeted workplace stress or work engagement, and measured a physiological outcome were selected for inclusion. Studies using either a between-group or within-group design were included. Nine papers were found to meet the inclusion criteria for our systematic review and meta-analysis of the literature.

RESULTS

MBIs were found to be effective in reducing cortisol production, as indicated by lowered high and low diurnal cortisol slopes. However, no changes were found for cortisol awakening response or concentrations for single a.m. and p.m. time-points. MBIs also improved autonomic balance, assessed by heart rate variability coherence measures, but not blood pressure. Sympathetic nervous system reactivity as measured by salivary alpha amylase was also reduced following MBI. While aspects of immune function were also improved following MBIs, specifically, increased antibody response to a viral vaccine and reduced C-reactive protein concentrations, each of these outcomes were only assessed in a single study.

CONCLUSION

Taken together, the findings suggest that MBIs are a promising avenue for intervention for improving physiological indices of stress. Our findings suggest that changes in daytime cortisol secretion and HRV coherence may be particularly influenced by MBIs. Future studies should aim to assess multiple physiological indices to confirm the current findings and further improve current understanding of which biological systems (and indices within these systems) show responses indicative of reduced stress due to MBI.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Neural, Hormonal, and Cognitive Correlates of Metabolic Dysfunction and Emotional Reactivity

OBJECTIVE

Prediabetes and type 2 diabetes (i.e., hyperglycemia) are characterized by insulin resistance. These problems with energy metabolism may exacerbate emotional reactivity to negatively valenced stimuli and related phenomena such as predisposition toward negative affect, as well as cognitive deficits. Higher emotional reactivity is seen with hyperglycemia and insulin resistance. However, it is largely unknown how metabolic dysfunction correlates with related neural, hormonal, and cognitive outcomes.

METHODS

Among 331 adults from the Midlife in the United States study, eye-blink response (EBR) we cross sectionally examined to gauge reactivity to negative, positive, or neutrally valenced pictures from international affect picture system stimuli proximal to an acoustic startle probe. Increased EBR to negative stimuli was considered an index of stress reactivity. Frontal alpha asymmetry, a biomarker of negative affect predisposition, was determined using resting electroencephalography. Baseline urinary cortisol output was collected. Cognitive performance was gauged using the Brief Test of Adult Cognition by telephone. Fasting glucose and insulin characterized hyperglycemia or the homeostatic model assessment of insulin resistance.

RESULTS

Higher homeostatic model assessment of insulin resistance corresponded to an increased startle response, measured by EBR magnitude, for negative versus positive stimuli (R = 0.218, F(1,457) = 5.48, p = .020, euglycemia: M(SD) = .092(.776), hyperglycemia: M(SD) = .120(.881)). Participants with hyperglycemia versus euglycemia showed greater right frontal alpha asymmetry (F(1,307) = 6.62, p = .011, euglycemia: M(SD) = .018(.167), hyperglycemia: M(SD) = -.029(.160)), and worse Brief Test of Adult Cognition by telephone arithmetic performance (F(1,284) = 4.25, p = .040, euglycemia: M(SD) = 2.390(1.526), hyperglycemia: M(SD) = 1.920(1.462)). Baseline urinary cortisol (log10 μg/12 hours) was also dysregulated in individuals with hyperglycemia (F(1,324) = 5.09, p = .025, euglycemia: M(SD) = 1.052 ± .332, hyperglycemia: M(SD) = .961 (.362)).

CONCLUSIONS

These results suggest that dysmetabolism is associated with increased emotional reactivity, predisposition toward negative affect, and specific cognitive deficits.

The biological impact of listening to music in clinical and nonclinical settings: A systematic review

This systematic review explored the evidence base on the impact of listening to music on biological response in both clinical and nonclinical settings. Human studies exploring the effects of listening to recorded music on biological markers were included. Studies had to involve a non-music control condition. Keyword searches were carried out of five major databases (Cochrane/Wiley, PsycINFO, PubMed, Sage, and Science Direct) and bias was assessed using the Cochrane Risk of Bias Tool for Randomized Studies (RoB 2.0). Forty-four studies assessing the biological impact of music listening were identified: 27 in clinical settings and 17 in nonclinical settings. Eighty-two percent had examined the effects of short-term listening interventions, while the remainder had looked at longitudinal interventions. Thirteen of 33 biomarkers tested were reported to change in response to listening to music. The most commonly analyzed biomarker was the stress hormone cortisol, with half of clinical studies demonstrating a stress-reducing effect of music listening. Blood glucose was also found repeatedly to reduce in response to music listening. Many of the other biomarkers analyzed are also part of biological stress pathways, which suggests that the primary way by which music listening affects us biologically is via modulations of stress response. Effects were shown irrespective of genre, self-selection of the music, or duration of listening, although a majority did use classical music. The evidence base for understanding biological responses to music is still developing, but there is support for the application of listening to music, especially within clinical settings for stress reduction.

The difficulties of pseudo-Cushing's syndrome (or "non-neoplastic hypercortisolism")

Pseudo-Cushing's syndrome covers different pathological conditions responsible for mild-to-moderate ACTH-dependent hypercortisolism, related not to an ACTH-secreting tumor but rather to CRH and/or AVP hypothalamic secretion through activation of various neural pathways, in patients generally displaying excess central adiposity. It is better termed "non-neoplastic hypercortisolism" (NNH). The main conditions implicated in NNH comprise: neuropsychiatric disorder, alcohol abuse, insulin-resistant obesity, polycystic ovary syndrome, and end-stage kidney disease. Glucocorticoid resistance is one differential diagnosis, as are some cases of primary adrenal disease with incompletely suppressed ACTH. Differentiating between NNH and mild-to-moderate Cushing's disease can be a real challenge. Clinical analysis, based on thorough history taking and screening for catabolic signs is essential; useful explorations include midnight serum or salivary cortisol and Dex/CRH and ddAVP stimulation response. Pituitary MRI suffers from limitations regarding both sensitivity and specificity, while bilateral inferior petrosal sinus sampling cannot distinguish between pituitary ACTH secretion by a tumor or by normal cells stimulated by endogenous CRH. Definitive diagnosis of functional etiology requires demonstrating that treatment of the underlying condition restores normal secretion of ACTH and cortisol, but this is not always possible. Lingering diagnostic uncertainty has to be accepted in certain patients, who will have to be followed up for some time before diagnosis can be considered more or less definitive.