Chronic stress increases vulnerability to diet-related abdominal fat, oxidative stress, and metabolic risk

Perceived stress correlates with visceral obesity and lipid parameters of the metabolic syndrome: A systematic review and meta-analysis

BACKGROUND

Perceived stress has been proposed as a risk factor of metabolic syndrome. However, correlations between perceived stress and parameters of the metabolic syndrome have not been properly analyzed despite extensive research data on the topic. Our current meta-analysis aimed to examine the mutual association between perceived stress of patients and parameters of metabolic syndrome.

METHODS

This systematic review has been registered on the PROSPERO database (registration number CRD42017055293). Eligible studies divided participants based on their stress level or on the presence of metabolic syndrome. They reported at least one parameter of the metabolic syndrome or the stress level of the participants measured with some stress scale. Data from 17 articles met the eligibility criteria and were included. Random effects model with the DerSimonian and Laird weighting methods was applied. I-squared indicator and Q test were performed to assess heterogeneity.

RESULTS

Although the majority of individual studies failed to demonstrate correlations between stress and their analyzed parameters of metabolic syndrome, our meta-analysis showed a significant association between stress and BMI [average effect size (ES) with 95% confidence interval (95%CI), ES = 0.65, 95%CI 0.16, 1.14), waist circumference (ES = 1.84 cm, 95%CI 0.79, 2.89) and serum triglyceride level (ES = 7.52 mg/dl, 95%CI 0.07, 14.96). Additional analysis confirmed effects of stress on serum HDL (ES = - 1.699 mg/dl, 95%CI -2.966, -0.432) and diastolic blood pressure (ES = 1.04 mmHg, 95%CI 0.18, 1.89). No correlations were found for fasting glucose or systolic blood pressure. No association between metabolic syndrome and stress level of patients was detected either.

CONCLUSION

The potentially key role of visceral obesity in the association between perceived stress and dyslipidemia or diastolic blood pressure are discussed together with potential moderators (e.g. gender-differences, variations in stress assessment and metabolic syndrome criteria) that may explain the inconsistent, contradictory results of the individual studies.

Stress and Obesity

Many pathways connect stress and obesity, two highly prevalent problems facing society today. First, stress interferes with cognitive processes such as executive function and self-regulation. Second, stress can affect behavior by inducing overeating and consumption of foods that are high in calories, fat, or sugar; by decreasing physical activity; and by shortening sleep. Third, stress triggers physiological changes in the hypothalamic-pituitary-adrenal axis, reward processing in the brain, and possibly the gut microbiome. Finally, stress can stimulate production of biochemical hormones and peptides such as leptin, ghrelin, and neuropeptide Y. Obesity itself can be a stressful state due to the high prevalence of weight stigma. This article therefore traces the contribution of weight stigma to stress and obesogenic processes, ultimately describing a vicious cycle of stress to obesity to stigma to stress. Current obesity prevention efforts focus solely on eating and exercise; the evidence reviewed in this article points to stress as an important but currently overlooked public policy target.

Chronic Stress and Impulsive Risk-Taking Predict Increases in Visceral Fat over 18 Months

OBJECTIVE

The aim of this study was to examine whether baseline chronic stress and impulsive risk-taking synergistically predict changes in visceral fat among healthy mothers in an observational, longitudinal, 18-month study.

METHODS

A prospective cohort of 113 adult women (age, mean ± SD: 42.83 ± 4.70; BMI, mean ± SD: 24.86 ± 4.32; 74%, n = 84 white) completed assessments at baseline and 18-month follow-up. Chronically stressed mothers caring for a child with an autism spectrum disorder ("caregivers"; n = 72 participants) were compared with lower stress mothers caring for a neurotypical child ("controls"; n = 41). This study objectively assessed impulsive risk-taking by using the Behavioral Analog Risk Task at baseline and assessed visceral fat at baseline and 18-month follow-up by using bioelectrical impedance (ViScan; Tanita Corporation, Tokyo, Japan).

RESULTS

The interaction of baseline chronic caregiving stress and impulsive risk-taking predicted an 18-month change in visceral fat, such that greater impulsive risk-taking was associated with greater 18-month increases in visceral fat among caregivers (ß = 0.423; P = 0.005) but not among controls (ß = -0.030; P = 0.802), both in unadjusted models and after accounting for covariates. Neither chronic stress nor impulsive risk-taking independently predicted 18-month changes in visceral fat.

CONCLUSIONS

The combination of high chronic stress and high impulsive risk-taking may increase risk for visceral fat gain over time and therefore may be an important intervention target in obesity prevention.

Impact of a Specific Amino Acid Composition with Micronutrients on Well-Being in Subjects with Chronic Psychological Stress and Exhaustion Conditions: A Pilot Study

Chronic work-life stress leads to dysfunction of the hypothalamus–pituitary–adrenal axis, the autonomic nervous system, and the serotonergic system, with resultant impairment of overall well-being. Aim of the study was to improve perceived stress by a specific amino acid composition with micronutrients in the verum versus placebo group. A total of 59 participants (18–65 years) with self-reported perceived chronic stress and exhaustion conditions participated in this randomized, double-blind, placebo-controlled study. The Perceived Stress Questionnaire (PSQ₃₀), amino acid profile, anthropometric, clinical, blood, urine parameters, and dietary intake were assessed. After 12 weeks, the verum group achieved significantly greater improvements in the total PSQ₃₀ score compared with the placebo group. In the verum group, serum taurine concentration, folic acid concentration, urinary magnesium excretion, and the ratio of l-tryptophan to the sum of competing amino acids rose significantly. In the placebo group, serum concentrations of serotonin, protein, and magnesium decreased significantly, whereas the cardiometabolic risk parameters body weight, body mass index, waist circumference, and waist-to-height ratio increased significantly. Compared with placebo, the verum supplementation resulted in a higher improvement in perceived stress. Beneficial effects on the serotonergic system and preventive effects on magnesium homeostasis and some cardiometabolic risk factors were supposed. Additional effects might be caused by the optimized food intake.

Thyroid Dysfunction, Neurological Disorder and Immunosuppression as the Consequences of Long-term Combined Stress

Stress is a powerful modulator of neuroendocrine, behavioral, and immunological functions. So far, the molecular mechanisms of response to stressors still remain elusive. In the current study, after 10 days of repeated chronic stress (hot-dry environment and electric foot-shock), a murine model of combined-stress (CS) was created in the SPF Wistar rats. Meanwhile, we established an ulcerative-colitis (UC) rat model induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS)/ethanol enema according to previous studies. The blood, hypothalamus, and colon tissues of these rats from CS, normal control (NC), UC and sham (SH) groups, were collected for further investigations. Comparing to the NC group, the serum levels of T3, T4, fT3 and fT4 were obviously decreased in the CS group after chronic stress, indicating that thyroid dysfunction was induced by long-term combined stress. Moreover, the application of RNA-seq and subsequent analyses revealed that neurological disorder and immunosuppression were also caused in the hypothalamus and colon tissues, respectively. Comparing with SH group, besides the induced colon inflammation, thyroid dysfuntion and neurological disorder were also produced in the UC group, suggesting that hypothalamic-pituitary-thyroid (HPT) axis and gastrointestinal system might not function in isolation, but rather, have intricate crosstalks.

Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa?

Decades of research have reported only weak associations between the intakes of specific foods or drinks and weight gain and obesity. Randomized controlled dietary intervention trials have only shown very modest effects of changes in nutrient intake and diet composition on body weight in obese subjects. This review summarizes the scientific evidence on the role mental stress (either in or not in association with impaired sleep) may play in poor sleep, enhanced appetite, cravings and decreased motivation for physical activity. All these factors contribute to weight gain and obesity, possibly via decreasing the efficacy of weight loss interventions. We also review evidence for the role that lifestyle and stress management may play in achieving weight loss in stress-vulnerable individuals with overweight.

Snacking and Diet Quality Are Associated With the Coping Strategies Used By a Socioeconomically Diverse Urban Cohort of African-American and White Adults

BACKGROUND

Stress affects health-related quality of life through several pathways, including physiological processes and health behaviors. There is always a relationship between stress (the stimulus) and coping (the response). The relationship between snacking and snackers' diet quality and stress coping is a topic overlooked in research.

OBJECTIVE

The study was primarily designed to determine whether energy provided by snacks and diet quality were associated with coping behaviors to manage stress.

DESIGN

We analyzed a baseline cohort of the Healthy Aging in Neighborhoods of Diversity across the Life Span study (2004 to 2009).

PARTICIPANTS

The sample was composed of 2,177 socioeconomically diverse African-American and white adults who resided in Baltimore, MD.

MAIN OUTCOME MEASURES

Energy from snacks was calculated from 2 days of 24-hour dietary recalls collected using the US Department of Agriculture's Automated Multiple Pass Method. Snack occasions were self-reported as distinct eating occasions. Diet quality was evaluated by the Healthy Eating Index-2010.

STATISTICAL ANALYSES PERFORMED

Multiple regression analyses were used to determine whether coping factors were associated with either energy provided by snacks or Healthy Eating Index-2010, adjusting for age, sex, race, socioeconomic status, education, literacy, and perceived stress. Coping was measured by the Brief COPE Inventory with instrument variables categorized into three factors: problem-focused coping, emotion-focused coping, and use of support. Perceived stress was measured with the 4-item Perceived Stress Scale.

RESULTS

Adjusting for perceived stress and selected demographic characteristics, emotion-focused coping strategies were associated with greater energy intakes from snacks (P=0.020), and use of coping strategies involving support was positively associated with better diet quality (P=0.009).

CONCLUSIONS

Energy contributed by snacks and diet quality were affected by the strategy that an individual used to cope with stress. The findings suggest that health professionals working with individuals seeking guidance to modify their eating practices should assess a person's coping strategies to manage stress.

An association of health behaviors with depression and metabolic risks: Data from 2007 to 2014 U.S. National Health and Nutrition Examination Survey

BACKGROUND

Both depression and metabolic syndrome (MetS) confer an increased risk of developing type 2 diabetes (T2D) and cardiovascular disease. Accumulating evidence suggests healthy behaviors are crucial to maintain, improve and manage chronical disease and mental health; and unhealthy diet and sedentary behavior were found two major risk factors of MetS. The objective of this study was to investigate whether health behaviors (alcohol consumption, smoking, diet and recreational physical activity) are associated with depression and metabolic syndrome simultaneously.

METHODS

This study included 1300 participants aged 20 years and over who had answered mental health-depression screener questions (PHQ-9) and finished examinations and laboratory tests related to five risk factors of MetS during the U.S. National Health and Nutrition Examination Survey (NHANES) 2007-2014. A set of series of weighted logistic regression models were used to investigate the aforementioned relationship.

RESULTS

The prevalence of depression among U.S. adults is 15.08%. The two most often reported depression symptoms were "Trouble sleeping or sleeping too much" and "Feeling tired or having little energy", with rates of14.68% and 13.09%, respectively. Participants who engaged in only light physical activity were more likely to have been identified as experiencing depression and MetS than those who engaged in vigorous physical activity with odd ratios 3.18 (95% CI: 1.59, 6.37) and 3.50 (95%CI: 2.17, 5.63), respectively. Individuals in the study having poor diets were more likely to suffer from depression than those eating good diets (OR=2.17, 95%CI: 1.47, 3.22).

CONCLUSION

Physical activity is strongly and inversely associated with depression and MetS. Diet is significantly associated with depression rather than MetS in this study.

High-fat diet effects on metabolic responses to chronic stress

CONTEXT

High-fat diets and chronic stress are prevalent risk factors for various chronic diseases in modern societies.

OBJECTIVE

This study investigated the effect of high-fat diet on glucose-related metabolic responses to chronic foot-shock stress.

MATERIALS AND METHODS

Male rats were divided into high-fat diet (containing 54.21% saturated and 44.89% unsaturated fatty acids) and normal diet groups and then into stress and non-stress subgroups. The diets were applied for 5 weeks, and stress was induced during the last week of the diet course. Plasma levels of metabolic parameters, HOMA-IR index, intra-abdominal fat weight, and islets' insulin secretion were assessed.

RESULTS

High-fat diet increased abdominal fat weight and plasma leptin, and insulin levels in response to stress without affecting HOMA-IR index and islets' insulin secretion.

CONCLUSIONS

High proportion of unsaturated fat may not lead to deleterious metabolic responses; however combined with chronic stress has a synergistic and adverse effect on visceral adiposity and results in elevated plasma leptin.

Diabetes Knowledge, Management, and Prevention Among Haitian Immigrants in Philadelphia

Purpose Guided by the PEN-3 Cultural Model, the purpose of this study is to generate culturally framed insight into diabetes knowledge, management, and prevention among Haitians. Despite the disproportionate distribution of type II diabetes mellitus among US minorities, limited research explores outcomes within racial ethnic groups. It is particularly important to disaggregate the large racial-ethnic groups of black given the population growth among foreign-born blacks, such as Haitians, whose population has more than quadrupled in recent decades. Methods Focus group interviews were employed to understand diabetes knowledge, management, and prevention in the Haitian immigrant population in Philadelphia. Interviews were conducted in 2 groups: (1) people living with diabetes and (2) an at-risk sample for diabetes (defined as 30 and older with self-reported family history of diabetes). Interviews were recorded and transcribed verbatim in preparation for content analysis. Results Of the 10 participants, who were recruited through a Philadelphia church-based population, ages ranged from 41 to 91, with an average of 65. Content analysis revealed 3 emergent themes across: (1) cultural identity, including person, extended family, and neighborhood; (2) relationships and expectations, including perceptions, enablers, and nurturers; and (3) cultural empowerment, including positive, existential, and negative. Conclusions Results may inform culturally appropriate diabetes interventions for Haitians. Future research should explore compliance with food recommendations as well as the cultural competency of health care professional's information delivery.

Lovesick: How Couples' Relationships Influence Health

This review highlights recent advances in research addressing intimate partner relationships and health. Consideration of the strong mutual influences that the members of a couple have on each other's mental and physical health trajectories provides a new way to view the health implications of couples' convergence or interdependence; marital closeness can have a clear downside when one partner has mental or physical health problems. Couples' interconnectedness can also be leveraged to promote better treatment outcomes. Major themes include the pivotal role of depression and the importance of gender differences in the pathways from the marital relationship to physiological functioning and health. The health risks and benefits of support are weighed. Additionally, two prominent emerging paths from marital distress to poor health are emphasized: sleep problems and metabolic alterations that promote obesity and its comorbidities.

Lovesick: How Couples' Relationships Influence Health

This review highlights recent advances in research addressing intimate partner relationships and health. Consideration of the strong mutual influences that the members of a couple have on each other's mental and physical health trajectories provides a new way to view the health implications of couples' convergence or interdependence; marital closeness can have a clear downside when one partner has mental or physical health problems. Couples' interconnectedness can also be leveraged to promote better treatment outcomes. Major themes include the pivotal role of depression and the importance of gender differences in the pathways from the marital relationship to physiological functioning and health. The health risks and benefits of support are weighed. Additionally, two prominent emerging paths from marital distress to poor health are emphasized: sleep problems and metabolic alterations that promote obesity and its comorbidities.

The Relationship between Stress and Severe Obesity: A Case-Control Study

Background

Several etiological factors for obesity have been identified, whereas other factors related to obesity, such as stress, remain poorly understood. This study used psychiatric methods to examine the relationship between stress and obesity.

Methods

Matched study and control groups were established, and the female and male control subjects were selected separately by random sampling. The control subjects were matched with the case subjects with respect to place of residence, sex, age, date that a pension was granted, and occupation. Psychiatric and psychological methods were assessed using a questionnaire and statistical analyses.

Results

Psychiatric interviews indicated that stress was more prevalent in the study group than in the control group. Separation from parents was nearly significantly more frequently in the study group than in the control group. The questionnaire on coping mechanisms revealed that case subjects tended to resolve their problems in an active manner.

Conclusions

The aim of this case-control study was to examine the relationship between stress and obesity in individuals receiving a disability pension. We identified stress factors that affect the development of obesity. We believe our study is both necessary and important, as these findings provide valuable insight into the relationship between severe obesity and stress.

Dietary Factors and Cognitive Function in Poor Urban Settings

A significant body of evidence suggests that poor dietary intake is associated with reduced cognitive function. However, few studies have examined this relation in poor urban settings. Our brief review suggests that (a) higher overall diet quality may play a particularly important role in cognitive function among the poorest; and (b) greater vitamin E intake is related to better cognitive performance, at least in part, via fewer depressive symptoms. The broader recent literature strongly suggests the beneficial role of diet for learning and memory, and potentially synergistic influences on other cognitive domains. However, adherence to healthful diet among urban poor may be limited by factors such as cost and access. Here, we propose several potential moderators and mediators of diet-cognition relations among urban poor. Future studies should focus on the complex interplay among factors that influence the role of diet in cognitive function among poor, urban-dwelling persons.

The association between insulin resistance and depression in the Korean general population

BACKGROUND

Previous studies showed that the insulin resistance (IR) could be related to depression. However, this association is still equivocal in the general population. Herein, we aimed to investigate the association between IR and depressive symptoms in a large sample in South Korea.

METHODS

A cross-sectional study was carried out for 165,443 Korean men and women who received a health checkup including various clinical parameters and the Center for Epidemiologic Studies Depression scales (CES-D). Subjects were stratified into subgroups by CES-D score, sex, age, and presence of diabetes. The odd ratios (ORs) for homeostasis model assessment of insulin resistance (HOMA-IR) were compared between groups using multivariable logistic regression analyses.

RESULTS

After adjusting covariates (e.g. smoking, family income, marriage state, unemployment status, average alcohol use, BMI, physical activity, systolic blood pressure, diabetes), increased IR was weakly associated with greater depressive symptoms (adjusted OR=1.01 [95% CI 1.0001-1.03]). Subgroup analysis revealed this association was statistically significant in females (adjusted OR=1.03, [95% CI 1.001-1.06]), non-diabetic group (adjusted OR=1.04, [95% CI 1.02-1.06]), and young participants under the age of thirty (adjusted OR=1.17, [95% CI 1.07-1.27]). But we couldn't find significant association in diabetic and middle to elderly participants.

CONCLUSIONS

This study demonstrates that there is a relationship between IR and depressive symptoms in the Korean general population. Results from this epidemiological study revealed that young adults and non-diabetic individuals with increased IR may be related with depressive symptoms.

Chronic stress is associated with reduced circulating hematopoietic progenitor cell number: A maternal caregiving model

BACKGROUND

Chronic psychological stress is a risk factor for cardiovascular disease and mortality. Circulating hematopoietic progenitor cells (CPCs) maintain vascular homeostasis, correlate with preclinical atherosclerosis, and prospectively predict cardiovascular events. We hypothesize that (1) chronic caregiving stress is related to reduced CPC number, and (2) this may be explained in part by negative interactions within the family.

METHODS

We investigated levels of stress and CPCs in 68 healthy mothers - 31 of these had children with an autism spectrum disorder (M-ASD) and 37 had neurotypical children (M-NT). Participants provided fasting blood samples, and CD45⁺CD34⁺KDR⁺ and CD45⁺CD133⁺KDR⁺ CPCs were assayed by flow cytometry. We averaged the blom-transformed scores of both CPCs to create one index. Participants completed the perceived stress scale (PSS), the inventory for depressive symptoms (IDS), and reported on daily interactions with their children and partners, averaged over 7 nights.

RESULTS

M-ASD exhibited lower CPCs than M-NT (Cohen's d=0.83; p⩽0.01), controlling for age, BMI, and physical activity. Across the whole sample, positive interactions were related to higher CPCs, and negative interactions to lower CPCs (allp's<0.05). The adverse effects of group on CPCs were significantly mediated through negative interactions with the child (indirect β=-0.24, p⩽0.01). In the full model, greater age (β=-0.19, p=0.04), BMI (β=-0.18, p=0.04), and negative interactions with the child (β=-0.33, p<0.01) were independently associated with lower CPCs. M-ASD had a less healthy lipid profile (total cholesterol/HDL), which in turn, was associated with lower CPCs.

CONCLUSIONS

Chronic stress adversely impacts CPC number, an early-stage biomarker that predicts subclinical atherosclerosis and future CVD events, independent of traditional cardiovascular risk factors and inflammatory factors. Among maternal caregivers, child-related interpersonal stress appears to be a key psychological predictor of stress-related CVD risk.

Chronic psychological stress and high-fat high-fructose diet disrupt metabolic and inflammatory gene networks in the brain, liver, and gut and promote behavioral deficits in mice

The mechanisms underlying the association between chronic psychological stress, development of metabolic syndrome (MetS), and behavioral impairment in obesity are poorly understood. The aim of the present study was to assess the effects of mild chronic psychological stress on metabolic, inflammatory, and behavioral profiles in a mouse model of diet-induced obesity. We hypothesized that (1) high-fat high-fructose diet (HFHF) and psychological stress would synergize to mediate the impact of inflammation on the central nervous system in the presence of behavioral dysfunction, and that (2) HFHF and stress interactions would impact insulin and lipid metabolism. C57Bl/6 male mice underwent a combination of HFHF and two weeks of chronic psychological stress. MetS-related conditions were assessed using untargeted plasma metabolomics, and structural and immune changes in the gut and liver were evaluated. Inflammation was measured in plasma, liver, gut, and brain. Our results show a complex interplay of diet and stress on gut alterations, energetic homeostasis, lipid metabolism, and plasma insulin levels. Psychological stress and HFHF diet promoted changes in intestinal tight junctions proteins and increases in insulin resistance and plasma cholesterol, and impacted the RNA expression of inflammatory factors in the hippocampus. Stress promoted an adaptive anti-inflammatory profile in the hippocampus that was abolished by diet treatment. HFHF increased hippocampal and hepatic Lcn2 mRNA expression as well as LCN2 plasma levels. Behavioral changes were associated with HFHF and stress. Collectively, these results suggest that diet and stress as pervasive factors exacerbate MetS-related conditions through an inflammatory mechanism that ultimately can impact behavior. This rodent model may prove useful for identification of possible biomarkers and therapeutic targets to treat metabolic syndrome and mood disorders.

Early Stress History Alters Serum Insulin-Like Growth Factor-1 and Impairs Muscle Mitochondrial Function in Adult Male Rats

Early-life adversity is associated with an enhanced risk for adult psychopathology. Psychiatric disorders such as depression exhibit comorbidity for metabolic dysfunction, including obesity and diabetes. However, it is poorly understood whether, besides altering anxiety and depression-like behaviour, early stress also evokes dysregulation of metabolic pathways and enhances vulnerability for metabolic disorders. We used the rodent model of the early stress of maternal separation (ES) to examine the effects of early stress on serum metabolites, insulin-like growth factor (IGF)-1 signalling, and muscle mitochondrial content. Adult ES animals exhibited dyslipidaemia, decreased serum IGF1 levels, increased expression of liver IGF binding proteins, and a decline in the expression of specific metabolic genes in the liver and muscle, including Pck1, Lpl, Pdk4 and Hmox1. These changes occurred in the absence of alterations in body weight, food intake, glucose tolerance, insulin tolerance or insulin levels. ES animals also exhibited a decline in markers of muscle mitochondrial content, such as mitochondrial DNA levels and expression of TFAM (transcription factor A, mitochondrial). Furthermore, the expression of several genes involved in mitochondrial function, such as Ppargc1a, Nrf1, Tfam, Cat, Sesn3 and Ucp3, was reduced in skeletal muscle. Adult-onset chronic unpredictable stress resulted in overlapping and distinct consequences from ES, including increased circulating triglyceride levels, and a decline in the expression of specific metabolic genes in the liver and muscle, with no change in the expression of genes involved in muscle mitochondrial function. Taken together, our results indicate that a history of early adversity can evoke persistent changes in circulating IGF-1 and muscle mitochondrial function and content, which could serve to enhance predisposition for metabolic dysfunction in adulthood.

Understanding and effectively addressing breast cancer in African American women: Unpacking the social context

Black women have a higher incidence of breast cancer before the age of 40 years, more severe disease at all ages, and an elevated mortality risk in comparison with white women. There is limited understanding of the contribution of social factors to these patterns. Elucidating the role of the social determinants of health in breast cancer disparities requires greater attention to how risk factors for breast cancer unfold over the lifecourse and to the complex ways in which socioeconomic status and racism shape exposure to psychosocial, physical, chemical, and other individual and community-level assaults that increase the risk of breast cancer. Research that takes seriously the social context in which black women live is also needed to maximize the opportunities to prevent breast cancer in this underserved group. Cancer 2016;122:2138-49. © 2016 American Cancer Society.

Neuropeptide Y gene-by-psychosocial stress interaction effect is associated with obesity in a Korean population

BACKGROUND

Chronic psychosocial stress is a crucial risk factor in the development of many diseases including obesity. Neuropeptide Y (NPY), distributed throughout the peripheral and central nervous system, is believed to pay a role in the pathophysiologic relationship between stress and obesity. Although several animal studies have investigated the impact on obesity of interactions between NPY single nucleotide polymorphisms (SNPs) and stress, the same remains to be analyzed in humans.

METHODS

To identify NPY gene-by-stress interaction effects on human obesity, we analyzed the interaction between four NPY SNPs and stress with obesity-related traits, including visceral adipose tissue (VAT). A total of 1468 adult subjects were included for this analysis.

RESULTS

In a SNP-only model without interaction with stress, no significant SNPs were found (pSNP>0.05). However, NPY SNPs-by-stress interaction effects were significantly linked to body mass index (BMI), waist circumference, and VAT (pint<0.05), even though a significant interaction effect for rs16135 on BMI was not identified. These significant interaction effects were also detected in interaction results for the binary traits of obesity. Among the obesity traits, mean changes of VAT by increased stress levels in homozygous risk allele carriers were the greatest (range of mean increases for four SNPs (min-max)=12.57cm(2)-29.86cm(2)).

CONCLUSIONS

This study suggests that common polymorphisms for NPY were associated with human obesity by interacting with psychosocial stress, emphasizing the need for stress management in obesity prevention.

Glucocorticoid Regulation of Food-Choice Behavior in Humans: Evidence from Cushing's Syndrome

The mechanisms by which glucocorticoids regulate food intake and resulting body mass in humans are not well-understood. One potential mechanism could involve modulation of reward processing, but human stress models examining effects of glucocorticoids on behavior contain important confounds. Here, we studied individuals with Cushing's syndrome, a rare endocrine disorder characterized by chronic excess endogenous glucocorticoids. Twenty-three patients with Cushing's syndrome (13 with active disease; 10 with disease in remission) and 15 controls with a comparably high body mass index (BMI) completed two simulated food-choice tasks (one with “explicit” task contingencies and one with “probabilistic” task contingencies), during which they indicated their objective preference for viewing high calorie food images vs. standardized pleasant, unpleasant, and neutral images. All participants also completed measures of food craving, and approximately half of the participants provided 24-h urine samples for assessment of cortisol and cortisone concentrations. Results showed that on the explicit task (but not the probabilistic task), participants with active Cushing's syndrome made fewer food-related choices than participants with Cushing's syndrome in remission, who in turn made fewer food-related choices than overweight controls. Corroborating this group effect, higher urine cortisone was negatively correlated with food-related choice in the subsample of all participants for whom these data were available. On the probabilistic task, despite a lack of group differences, higher food-related choice correlated with higher state and trait food craving in active Cushing's patients. Taken together, relative to overweight controls, Cushing's patients, particularly those with active disease, displayed a reduced vigor of responding for food rewards that was presumably attributable to glucocorticoid abnormalities. Beyond Cushing's, these results may have relevance for elucidating glucocorticoid contributions to food-seeking behavior, enhancing mechanistic understanding of weight fluctuations associated with oral glucocorticoid therapy and/or chronic stress, and informing the neurobiology of neuropsychiatric conditions marked by abnormal cortisol dynamics (e.g., major depression, Alzheimer's disease).

Resilience training for healthcare providers: an Asian perspective

The level of burnout has been found to be high in medical students, alongside maladaptive coping behaviours such as heightened alcohol and drug intake and mental health issues in the US, Europe and other developed countries. While burnout and resilience in healthcare have been researched in the West, there is a paucity of data in Asia pertaining to these factors. In this article, we review stressors in medicine, specifically during medical school training, the consequences of burnout on physicians' health and patient care, and the interventions that might expound resilience among students. Finally, we present potential solutions within an Asian context.

Work Stress and Metabolic Syndrome in Police Officers. A Prospective Study

OBJECTIVE

The aim of this longitudinal study was to evaluate the association between occupational stress and metabolic syndrome (MetS) in a rapid response police unit.

METHOD

Work-related stress was continuously monitored during the 5-year period with both the Demand-Control-Support (DCS) and the Effort-Reward Imbalance (ERI) models. Blood pressure, body mass index (BMI), waist circumference, triglycerides, HDL-cholesterol, and fasting blood glucose were measured at baseline in January 2009, and in January 2014. 234 out of 290 police officers (81%) completed the follow-up.

RESULTS

The majority of police officers had high stress levels. At follow-up, police officers in the highest quartile of stress had significantly higher mean levels of triglycerides, and lower levels of HDL-cholesterol than their colleagues in the lowest quartile. Police officers with high stress had an increased adjusted risk of developing MetS (aOR = 2.68; CI95% = 1.08-6.70), and hypertriglyceridemia (aOR = 7.86; CI95 = 1.29-48.04). Demand and Effort were significant predictors of MetS.

CONCLUSION

Our study supports the hypothesis that work-related stress induces MetS, particularly through its effects on blood lipids. Future longitudinal studies with continuous monitoring of stress levels will definitively confirm this hypothesis.

Comparison of overweight and obese military-dependent and civilian adolescent girls with loss-of-control eating

OBJECTIVE

Limited data suggest that the children of U.S. service members may be at increased risk for disordered-eating. To date, no study has directly compared adolescent military-dependents to their civilian peers along measures of eating pathology and associated correlates. We, therefore, compared overweight and obese adolescent female military-dependents to their civilian counterparts along measures of eating-related pathology and psychosocial functioning.

METHOD

Adolescent females with a BMI between the 85th and 97th percentiles and who reported loss-of-control eating completed interview and questionnaire assessments of eating-related and general psychopathology.

RESULTS

Twenty-three military-dependents and 105 civilians participated. Controlling for age, race, and BMI-z, military-dependents reported significantly more binge episodes per month (p < 0.01), as well as greater eating-concern, shape-concern, and weight-concern (p's < 0.01) than civilians. Military-dependents also reported more severe depression (p < 0.05).

DISCUSSION

Adolescent female military-dependents may be particularly vulnerable to disordered-eating compared with civilian peers. This potential vulnerability should be considered when assessing military-dependents.

Marital discord, past depression, and metabolic responses to high-fat meals: Interpersonal pathways to obesity

BACKGROUND

Longitudinal studies have implicated both marital distress and depression in the development of the metabolic syndrome, a risk factor for diabetes and cardiovascular disease. This study addressed the impact of hostile marital interactions and a mood disorder history on obesity-related metabolic responses to high-fat meals.

METHODS

This double-blind, randomized crossover study included serial assessments of resting energy expenditure (REE), fat and carbohydrate oxidation, triglycerides, insulin, glucose, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) before and after two high-fat meals. During two separate 9.5h visits, 43 healthy married couples, ages 24-61 (mean=38.22), received either a high saturated fat meal or a high oleic sunflower oil meal, both 930kcal and 60g fat. The Structured Diagnostic Interview for DSM-IV assessed mood disorder history. Couples discussed a marital disagreement during both visits; behavioral coding of these interactions provided data on hostile marital behaviors.

RESULTS

Men and women who displayed more hostile behaviors and who also had a mood disorder history had significantly lower post-meal REE, higher insulin, and higher peak triglyceride responses than other participants, with nonsignificant effects for fat and carbohydrate oxidation. Participants with a mood disorder history had a steeper rise in postprandial IL-6 and glucose than those without a past history. Higher levels of hostile behaviors were associated with higher post-meal TNF-α. The two meals did not differ on any outcome assessed.

CONCLUSIONS

People spend about 18 of every 24h in a postprandial state, and dining with one's partner is a common daily event. Among subjects with a mood disorder history, the cumulative 6.75-h difference between high and low hostile behaviors translates into 128kcal, a difference that could add 7.6pounds/year. Our findings illustrate novel pathways through which chronic marital stress and a mood disorder history synergistically heighten the risk for obesity, metabolic syndrome, and cardiovascular disease.

Bilateral internal mammary artery grafting in obese: outcomes, concerns and controversies

Obese patients are generally considered unsuitable to receive bilateral internal mammary arteries (BIMA) during coronary artery bypass grafting (CABG) due to the perceived vulnerability to sternal wound infection and lack of evidence supporting long-term survival benefit. However, no consistent evidence currently discourages the use of BIMA in obese patients. The present review questions the common perception that obesity unacceptably increases the risk of sternal wound complications in patients receiving BIMA grafting. Moreover, the use of skeletonization harvesting technique is expected to further minimize such a risk. Our institutional experience confirmed that BIMA grafting is a safe strategy which does not increase operative mortality and does not significantly affect the incidence of sternal wound complications. On the other hand, a long term benefit in terms of overall survival and freedom from repeat revascularization from the use of BIMA was found.

The effect of early-life stress and chronic high-sucrose diet on metabolic outcomes in female rats

Early-life stress affects metabolic outcomes and choice of diet influences the development of metabolic disease. Here we tested the hypothesis that chronic sugar intake exacerbates metabolic deficits induced by early-life stress. Early-life stress was induced in Sprague-Dawley rats using limited nesting material in early lactation (LN, postnatal days 2-9), and siblings were given chow alone or with additional sucrose post weaning (n = 9-17 per group). Female control and LN siblings had unlimited access to either chow plus water, or chow and water plus 25% sucrose solution (Sucrose), from 3-15 weeks of age. Weekly body weight and food intake were measured. Glucose and insulin tolerance were tested at 13 and 14 weeks of age, respectively. Rats were killed at 15 weeks. Hepatic triglyceride and markers of lipid synthesis - fatty acid synthase, acetyl-CoA carboxylase alpha and oxidation - and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) were examined. Mediators of hepatic glucocorticoid metabolism, specifically 11-beta hydroxysteroid dehydrogenase-1 (11βHSD-1), 5-α reductase, and glucocorticoid and mineralocorticoid receptor mRNAs were also measured. Sucrose increased caloric intake in both groups, but overall energy intake was not altered by LN exposure. LN exposure had no further impact on sucrose-induced glucose intolerance and increased plasma and liver triglycerides. Hepatic markers of fat synthesis and oxidation were concomitantly activated and 11βHSD-1 mRNA expression was increased by 53% in LN-Sucrose versus Con-Sucrose rats. Adiposity was increased by 26% in LN-Sucrose versus Con-Sucrose rats. Thus, LN exposure had minimal adverse metabolic effects despite high-sugar diet postweaning.

The hypothalamic-pituitary-adrenal-leptin axis and metabolic health: a systems approach to resilience, robustness and control

Glucocorticoids contribute to obesity and metabolic syndrome; however, the mechanisms are unclear, and prognostic measures are unavailable. A systems level understanding of the hypothalamic-pituitary-adrenal (HPA)-leptin axis may reveal novel insights. Eighteen obese premenopausal women provided blood samples every 10 min over 24 h, which were assayed for cortisol, adrenocorticotropin releasing hormone (ACTH) and leptin. A published personalized HPA systems model was extended to incorporate leptin, yielding three parameters: (i) cortisol inhibitory feedback signalling, (ii) ACTH-adrenal signalling, and (iii) leptin-cortisol antagonism. We investigated associations between these parameters and metabolic risk profiles: fat and lean body mass (LBM; using dual-energy X-ray absorptiometry), and insulin resistance. Decreased cortisol inhibitory feedback signalling was significantly associated with greater fat (kg; p = 0.01) and insulin resistance (p = 0.03) but not LBM. Leptin significantly antagonized cortisol dynamics in eight women, who exhibited significantly lower 24 h mean leptin levels, LBM and higher ACTH-adrenal signalling nocturnally (all p < 0.05), compared with women without antagonism. Traditional neuroendocrine measures did not predict metabolic health, whereas a dynamic systems approach revealed that lower central inhibitory cortisol feedback signalling was significantly associated with greater metabolic risk. While exploratory, leptin-cortisol antagonism may reflect a 'neuroendocrine starvation' response.