The effect of bariatric surgery on the expression of gastrointestinal taste receptors: A systematic review.

Gastrointestinal nutrient sensing via taste receptors may contribute to weight loss, metabolic improvements, and a reduced preference for sweet and fatty foods following bariatric surgery. This review aimed to investigate the effect of bariatric surgery on the expression of oral and post-oral gastrointestinal taste receptors and associations between taste receptor alterations and clinical outcomes of bariatric surgery. A systematic review was conducted to capture data from both human and animal studies on changes in the expression of taste receptors in oral or post-oral gastrointestinal tissue following any type of bariatric surgery. Databases searched included Medline, Embase, Emcare, APA PsychInfo, Cochrane Library, and CINAHL. Two human and 21 animal studies were included. Bariatric surgery alters the quantity of many sweet, umami, and fatty acid taste receptors in the gastrointestinal tract. Changes to the expression of sweet and amino acid receptors occur most often in intestinal segments surgically repositioned more proximally, such as the alimentary limb after gastric bypass. Conversely, changes to fatty acid receptors were observed more frequently in the colon than in the small intestine. Significant heterogeneity in the methodology of included studies limited conclusions regarding the direction of change in taste receptor expression induced by bariatric surgeries. Few studies have investigated associations between taste receptor expression and clinical outcomes of bariatric surgery. As such, future studies should look to investigate the relationship between bariatric surgery-induced changes to gut taste receptor expression and function and the impact of surgery on taste preferences, food palatability, and eating behaviour.Registration code in PROSPERO: CRD42022313992.

A paraventricular thalamus to insular cortex glutamatergic projection gates "emotional" stress-induced binge eating in females.

It is well-established that stress and negative affect trigger eating disorder symptoms and that the brains of men and women respond to stress in different ways. Indeed, women suffer disproportionately from emotional or stress-related eating, as well as associated eating disorders such as binge eating disorder. Nevertheless, our understanding of the precise neural circuits driving this maladaptive eating behavior, particularly in women, remains limited. We recently established a clinically relevant model of 'emotional' stress-induced binge eating whereby only female mice display binge eating in response to an acute "emotional" stressor. Here, we combined neuroanatomic, transgenic, immunohistochemical and pathway-specific chemogenetic approaches to investigate whole brain functional architecture associated with stress-induced binge eating in females, focusing on the role of Vglut2 projections from the paraventricular thalamus (PVTVglut2+) to the medial insular cortex in this behavior. Whole brain activation mapping and hierarchical clustering of Euclidean distances revealed distinct patterns of coactivation unique to stress-induced binge eating. At a pathway-specific level, PVTVglut2+ cells projecting to the medial insular cortex were specifically activated in response to stress-induced binge eating. Subsequent chemogenetic inhibition of this pathway suppressed stress-induced binge eating. We have identified a distinct PVTVglut2+ to insular cortex projection as a key driver of "emotional" stress-induced binge eating in female mice, highlighting a novel circuit underpinning this sex-specific behavior.

Incidence of adverse mental health outcomes after sleeve gastrectomy compared with gastric bypass and restrictive bariatric procedures: a retrospective cohort study.

OBJECTIVE: This study examined rates of suicide and hospitalization with psychiatric diagnoses after sleeve gastrectomy compared with gastric bypass and restrictive procedures (gastric banding/gastroplasty). METHODS: This was a longitudinal retrospective cohort study comprising all patients who underwent primary bariatric surgery in New South Wales or Queensland, Australia, between July 2001 and December 2020. Hospital admission records, death registration, and cause of death records (if applicable) within these dates were extracted and linked. Primary outcome was death by suicide. Secondary outcomes were admissions with self-harm; substance-use disorder, schizophrenia, mood, anxiety, behavioral, and personality disorders; any of these; and psychiatric inpatient admission. RESULTS: A total of 121,203 patients were included, with median follow-up of 4.5 years per patient. There were 77 suicides, with no evidence of difference in rates by surgery type (rates [95% CI] per 100,000 person years: 9.6 [5.0-18.4] restrictive, 10.8 [8.4-13.9] sleeve gastrectomy, 20.4 [9.7-42.8] gastric bypass; p = 0.18). Rates of admission with self-harm declined after restrictive and sleeve procedures. Admission with anxiety disorders, any psychiatric diagnosis, and as a psychiatric inpatient increased after sleeve gastrectomy and gastric bypass, but not restrictive procedures. Admissions with substance-use disorder increased after all surgery types. CONCLUSIONS: Variable associations between bariatric surgeries and hospitalization with psychiatric diagnoses might indicate distinct vulnerabilities among patient cohorts or that differing anatomical and/or functional changes may contribute to effects on mental health.

Binge eating, overeating and food addiction: Approaches for examining food overconsumption in laboratory rodents.

Overeating ranges in severity from casual overindulgence to an overwhelming drive to consume certain foods. At its most extreme, overeating can manifest as clinical diagnoses such as binge eating disorder or bulimia nervosa, yet subclinical forms of overeating such as emotional eating or uncontrolled eating can still have a profoundly negative impact on health and wellbeing. Although rodent models cannot possibly capture the full spectrum of disordered overeating, studies in laboratory rodents have substantially progressed our understanding of the neurobiology of overconsumption. These experimental approaches range from simple food-exposure protocols that promote binge-like eating and the development of obesity, to more complex operant procedures designed to examine distinct 'addiction-like' endophenotypes for food. This review provides an overview of these experimental approaches, with the view to providing a comprehensive resource for preclinical investigators seeking to utilize behavioural models for studying the neural systems involved in food overconsumption.

Opioid use-related stigma and health care decision-making.

OBJECTIVE: Stigma is described as highly relevant to the treatment context for opioid use disorder (OUD) partly because it is known to influence providers' treatment decisions and care provision. However, further study is needed to directly test the salience of stigmatizing views for healthcare decision-making among providers, and particularly those including medication for opioid use disorder (MOUD). This study assessed whether stigma toward illicit opioid use was associated with a willingness to provide or refer patients for MOUD treatment among a sample of healthcare providers. It also evaluated variation in stigmatizing views as a function of familiarity with OUD and MOUD and provider type. METHOD: Structural equation modeling was utilized to evaluate the antecedents and healthcare decision-making consequences associated with stigma based on survey data from a sample of 144 clinicians participating in a buprenorphine waiver training program (30% female). RESULTS: Providers who have less familiarity with OUD and MOUD and those who are medical students or residents are significantly more likely to endorse stigmatizing views of illicit opioid use. In turn, greater stigma is significantly associated with a lesser willingness to provide treatment or refer patients to MOUD treatment. CONCLUSIONS: Further consideration of stigma is recommended in future research to improve clinical practice and increase the implementation of MOUD treatment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Addiction-like behaviour towards high-fat high-sugar food predicts relapse propensity in both obesity prone and obesity resistant C57BL/6 J mice.

Compulsive overeating of palatable food is thought to underlie some forms of obesity. Similarities are often observed in the behavioural symptomology and the neuropathophysiology underlying substance use disorder and compulsive overeating. As such, preclinical animal models which assess addiction-like behaviour towards food may assist the understanding of the neurobiology underlying overeating behaviour. Further, the relationship between these behaviours and the propensity for diet-induced obesity warrants examination. In this study we investigated the relationship between the propensity for diet-induced obesity (DIO) and addiction-like behaviour towards highly palatable food in C57BL/6 J mice as measured by a 3-criteria model. We also examined the extent to which performance on this 3-criteria model predicted two key hallmark features of addiction - resistance to extinction and relapse propensity (as measured by reinstatement of lever pressing). C57BL/6 J mice were allowed free access to a palatable diet for 8 weeks then separated by weight gain into DIO-prone and DIO-resistant subgroups. Access to palatable food was then restricted to daily operant self-administration sessions whereby addiction-like behaviour towards a high-fat high-sugar food reward was assessed using a 3-criteria model similar to that used to assess addiction-like behaviour towards drugs of abuse. In contrast to findings in rats, no difference in addiction-like behaviour towards food was observed between obesity prone (OP) and obesity resistant (OR) mice. Similarly, principal components analysis found no distinct patterns in the relationship between addiction-like behaviours across treatment groups. This suggests that the strain and species of rodent may be critical for studying the mechanisms underlying pathological overconsumption. Further analysis revealed that the extent of performance on the 3-criteria model correlated with the propensity for C57BL/6 J mice to both extinguish food seeking behaviour and "relapse" after a period of withdrawal. This finding was evident across all groups, regardless of DIO. Collectively, these data validate the 3-criteria model as a robust model to comprehensively assess food addiction-like behaviour in mice, regardless of prior food intake history.

A Comparison of Emotional Triggers for Eating in Men and Women with Obesity.

OBJECTIVE: Emotional eating (EE) is prevalent in people seeking obesity treatment and is a contributor to poor weight loss outcomes. We aimed to delineate the emotions most associated with this type of eating, and whether they differ by sex in people undergoing obesity treatment. METHODS: A cross-sectional study recruiting 387 adults from a hospital obesity management service. Emotional eating was measured using the Emotional Eating Scale (EES). Separate analyses included all participants, and those undergoing lifestyle interventions alone or in combination with obesity medication and/or bariatric surgery. RESULTS: A total of 387 people (71% women) participated in the study (n = 187 receiving lifestyle modification alone; n = 200 in combination with additional treatments). Feeling 'bored' was most commonly and most strongly associated with the urge to eat, regardless of sex or treatment. Women had higher scores for total EES, for subscales of depression and anger, and individual feelings of 'blue', 'sad' and 'upset' compared to men. CONCLUSIONS: Understanding why certain emotions differentially trigger an urge to eat in men and women, and finding strategies to break the link between boredom and eating may enable better personalisation of lifestyle interventions for people with obesity.

Compulsive-like eating of high-fat high-sugar food is associated with 'addiction-like' glutamatergic dysfunction in obesity prone rats.

Chronic overeating is a core feature of diet-induced obesity. There is increasing evidence that in vulnerable individuals, such overeating could become compulsive, resembling an addictive disorder. The transition to compulsive substance use has been linked with changes at glutamatergic synapses in the nucleus accumbens. In this study, we investigated a potential link between such glutamatergic dysregulation and compulsive-like eating using a rat model of diet-induced obesity. A conditioned suppression task demonstrated that diet-induced obese rats display eating despite negative consequences, as their consumption was insensitive to an aversive cue. Moreover, nucleus accumbens expression of GluA1 and xCT proteins was upregulated in diet-induced obese animals. Lastly, both a computed 'addiction score' (based on performance across three criteria) and weight gain were positively correlated with changes in GluA1 and xCT expression in the nucleus accumbens. These data demonstrate that the propensity for diet-induced obesity is associated with compulsive-like eating of highly palatable food and is accompanied by 'addiction-like' glutamatergic dysregulation in the nucleus accumbens, thus providing neurobiological evidence of addiction-like pathology in this model of obesity.

Influence of Jamaican Cultural and Religious Beliefs on Adherence to Pharmacotherapy for Non-Communicable Diseases: A Pharmacovigilance Perspective.

Worldwide, socio-cultural determinants have been shown to influence the beliefs of patients about their health and decision making for treatment. This is consistent with the evidence that cultural and religious beliefs affect illness conceptualization and behaviors of Jamaican patients living with non-communicable diseases, such as diabetes mellitus and hypertension. Despite these known socio-cultural influences, an acknowledgment of relevance of adherence to pharmacotherapy has been grossly understudied. Furthermore, while poor adherence to pharmacotherapy, especially in the management of patients living with non-communicable diseases is associated with adverse drug reactions; reporting of such information in the pharmacovigilance process is inadequate. We review previous studies on the cultural and religious beliefs within the Jamaican context that may contribute to poor adherence to pharmacotherapy, especially among those patients living with non-communicable diseases. We support the ongoing perspective that current pharmacovigilance processes need retooling with the inclusion of socio-cultural influences on adherence to pharmacotherapy.

Psychometric evaluation of two indices assessing stigma toward opioid misuse and treatment among health care providers.

Background: Stigma is described as highly relevant to the treatment context for opioid use disorder (OUD) partly because it is known to influence clinicians' treatment decisions and care provision. However, appropriate measures are needed to test the salience of stigmatizing views held by clinicians directly.Objective: This study assessed dimensionality, reliability, and validity evidence for two measures - of public stigma toward opioid misuse and clinician stigma associated with medication for opioid use disorder (MOUD), respectively.Methods: Psychometric tests were conducted based on survey data collected from a sample of 144 clinicians participating in a buprenorphine waiver training program (30% female).Results: Factor analysis indicated that the indices of stigma associated with opioid misuse and MOUD stigma are best represented as separate measures. Spearman-Brown Prophesy estimates (opioid misuse stigma = .88; MOUD stigma = .93) and Cronbach's alpha coefficients (opioid misuse stigma = .93; MOUD stigma = .91) supported the reliability of both measures. Construct validity evidence was additionally found in correlation tests based on provider background characteristics, and discriminant validity evidence is supported by the between-factor correlation coefficient (r = .44, p = .04) for the opioid misuse stigma and MOUD stigma indices.Conclusions: Both indices examined in this report are psychometrically acceptable measures for assessing general bias among health care providers toward persons who misuse opioids and toward those seeking MOUD treatment. Further consideration of these forms of bias are recommended in future research to improve clinical practice and increase the implementation of MOUD treatment.

Metabolic sensing in AgRP neurons integrates homeostatic state with dopamine signalling in the striatum.

Agouti-related peptide (AgRP) neurons increase motivation for food, however, whether metabolic sensing of homeostatic state in AgRP neurons potentiates motivation by interacting with dopamine reward systems is unexplored. As a model of impaired metabolic-sensing, we used the AgRP-specific deletion of carnitine acetyltransferase (Crat) in mice. We hypothesised that metabolic sensing in AgRP neurons is required to increase motivation for food reward by modulating accumbal or striatal dopamine release. Studies confirmed that Crat deletion in AgRP neurons (KO) impaired ex vivo glucose-sensing, as well as in vivo responses to peripheral glucose injection or repeated palatable food presentation and consumption. Impaired metabolic-sensing in AgPP neurons reduced acute dopamine release (seconds) to palatable food consumption and during operant responding, as assessed by GRAB-DA photometry in the nucleus accumbens, but not the dorsal striatum. Impaired metabolic-sensing in AgRP neurons suppressed radiolabelled 18F-fDOPA accumulation after ~30 min in the dorsal striatum but not the nucleus accumbens. Impaired metabolic sensing in AgRP neurons suppressed motivated operant responding for sucrose rewards during fasting. Thus, metabolic-sensing in AgRP neurons is required for the appropriate temporal integration and transmission of homeostatic hunger-sensing to dopamine signalling in the striatum.

Quality of fracture reduction is associated with patient survival at one year, but not 30 days, following trochanteric hip fracture fixation. A retrospective cohort study.

INTRODUCTION: Few studies have been performed to evaluate the association between technical surgical factors and patient outcomes following hip fracture surgery. We performed a retrospective cohort study of elderly patients who had undergone fixation of trochanteric hip fractures using a sliding hip screw (SHS), with the aim of establishing whether there was a correlation between quality of fracture reduction and mortality at 30 days and one year. PATIENTS AND METHODS: A retrospective cohort study was designed. Inclusion criteria were trochanteric (AO 31A1 or 31A2) fractures in patients aged ≥ 65 years, presenting <3 days after injury and fixed using an SHS. Fracture reduction was classified using the Baumgaertner Reduction Quality Criteria (BRQC). A validated predictor of mortality following hip fracture was used to stratify for confounding variables that might affect mortality. Multivariate logistic regression was used to explore the association between fracture reduction and mortality. RESULTS: 329 patients were identified (mean age 86, 27% male). 57% had a good reduction, 39% had a fair reduction and 4% had a poor reduction. As reduction grade deteriorated, predicted mortality increased (good reduction: 7.3%; fair reduction: 8.4%; poor reduction: 15.5%). Without adjustment for predicted mortality, there was a significant correlation between decreasing reduction grade and mortality at both time points (30-day: odds ratio 1.95, p = 0.049; one year: odds ratio 1.86, p = 0.003). When adjusted for predicted mortality, only one year mortality remained significant (30 day: odds ratio 1.61, p = 0.173; one year: odds ratio 1.62, p = 0.037). CONCLUSION: Some, but not all, of the association between fracture reduction and mortality can be explained by predetermined predictors of a poor outcome. There remains, however, a correlation between poor fracture reduction and mortality at one year. Every effort must be made to achieve an anatomical reduction for these injuries, and trainees must be instructed in methods to achieve this.

Gut-brain mechanisms underlying changes in disordered eating behaviour after bariatric surgery: a review.

Bariatric surgery results in long-term weight loss and an improved metabolic phenotype due to changes in the gut-brain axis regulating appetite and glycaemia. Neuroendocrine alterations associated with bariatric surgery may also influence hedonic aspects of eating by inducing changes in taste preferences and central reward reactivity towards palatable food. However, the impact of bariatric surgery on disordered eating behaviours (e.g.: binge eating, loss-of-control eating, emotional eating and 'addictive eating'), which are commonly present in people with obesity are not well understood. Increasing evidence suggests gut-derived signals, such as appetitive hormones, bile acid profiles, microbiota concentrations and associated neuromodulatory metabolites, can influence pathways in the brain implicated in food intake, including brain areas involved in sensorimotor, reward-motivational, emotional-arousal and executive control components of food intake. As disordered eating prevalence is a key mediator of weight-loss success and patient well-being after bariatric surgery, understanding how changes in the gut-brain axis contribute to disordered eating incidence and severity after bariatric surgery is crucial to better improve treatment outcomes in people with obesity.

Stressors associated with the COVID-19 pandemic, disability, and mental health: Considerations from the Intermountain West.

The deleterious mental health effects associated with the COVID-19 pandemic are increasingly apparent, however, questions remain about the extent to which pandemic-related stressor exposure has contributed to increased psychological distress among an already disadvantaged group, individuals with disabilities. The first aim of the study was to examine the distribution of pandemic-related stressors across multiple dimensions-employment, personal and family finances, personal relationships, and quality of social life-among individuals with and without disabilities. The second aim of the study was to examine the association between a composite COVID-19 stressor score and two mental health outcomes-depressive and anxiety symptoms-among the two subsamples. The study used quota-based online survey data (N = 2043) collected in the summer of 2020 from adults (18 and older) residing in the Intermountain West, half of whom had a self-reported disability. Study results demonstrated that individuals with disabilities experienced pandemic-related stressors at significantly higher rates relative to their non-disabled counterparts. Further, pandemic stressor exposure was associated with greater negative effects on their psychological well-being. We argue that the COVID-19 pandemic is generating a secondary mental illness pandemic, and that individuals with disabilities are affected by it at significantly higher proportions.

The link between food insecurity and psychological distress: The role of stress exposure and coping resources.

This study examines the association between food insecurity and mental health over a 3-year period. It also assesses the salience of life stressors and psychosocial coping resources for this association. We utilize data from a two-wave community survey of Miami-Dade County, Florida residents (N = 1488). Findings from SEM analysis reveal that greater food insecurity at W1 is associated with greater depressive symptoms at W2, lending credence to characterizations of food insecurity as a chronic stressor. This association is partly mediated by variation over the study period in social support and mastery. However, no significant mediating effects are observed for the social stress indicators assessed. Food insecurity is associated with diminished psychosocial coping resources, which leads to greater psychological distress. We discuss how these findings extend a stress and coping model of food insecurity, and implications for research and practice.

New directions in modelling dysregulated reward seeking for food and drugs.

Behavioral models are central to behavioral neuroscience. To study the neural mechanisms of maladaptive behaviors (including binge eating and drug addiction), it is essential to develop and utilize appropriate animal models that specifically focus on dysregulated reward seeking. Both food and cocaine are typically consumed in a regulated manner by rodents, motivated by reward and homeostatic mechanisms. However, both food and cocaine seeking can become dysregulated, resulting in binge-like consumption and compulsive patterns of intake. The speakers in this symposium for the 2021 International Behavioral Neuroscience Meeting utilize behavioral models of dysregulated reward-seeking to investigate the neural mechanisms of binge-like consumption, enhanced cue-driven reward seeking, excessive motivation, and continued use despite negative consequences. In this review, we outline examples of maladaptive patterns of intake and explore recent animal models that drive behavior to become dysregulated, including stress exposure and intermittent access to rewards. Lastly, we explore select behavioral and neural mechanisms underlying dysregulated reward-seeking for both food and drugs.

Disability, Discrimination, and Mental Health during the COVID-19 Pandemic: A Stress Process Model.

Drawing on data from a community survey with a sizeable subsample of people with physical, intellectual, and psychological disabilities in the Intermountain West region of the United States (N = 2,043), this investigation examined the association of social stressors stemming from the COVID-19 pandemic with ableism or disability-related discrimination. We further assessed the significance of these associations for variation by disability status in psychological well-being with a moderated mediation analysis. Study findings provide clear evidence that greater pandemic-related stressor exposure was associated with greater discrimination, which in turn increased the psychologically distressing aspects of the pandemic for people with disabilities relative to people without disabilities. This set of findings challenges us to think about how we engage in research concerning ableism and the proliferation of macro-level stressors such as those associated with the COVID-19 pandemic. The findings also support the application of a minority stress model in addressing mental health contingencies among people with disabilities-in this case, in examining the pandemic's psychological impact.

Potential gut-brain mechanisms behind adverse mental health outcomes of bariatric surgery.

Bariatric surgery induces sustained weight loss and metabolic benefits via notable effects on the gut-brain axis that lead to alterations in the neuroendocrine regulation of appetite and glycaemia. However, in a subset of patients, bariatric surgery is associated with adverse effects on mental health, including increased risk of suicide or self-harm as well as the emergence of depression and substance use disorders. The contributing factors behind these adverse effects are not well understood. Accumulating evidence indicates that there are important links between gut-derived hormones, microbial and bile acid profiles, and disorders of mood and substance use, which warrant further exploration in the context of changes in gut-brain signalling after bariatric surgery. Understanding the basis of these adverse effects is essential in order to optimize the health and well-being of people undergoing treatment for obesity.