Deciphering the Association Between Hypothalamus-Pituitary-Adrenal Axis Activity and Obesity: A Meta-Analysis.

OBJECTIVE: Both the cortisol awakening response (CAR; corresponding to the state measurement) and hair cortisol concentration (HCC; corresponding to the trait measurement) are considered reliable markers of hypothalamus-pituitary-adrenal axis activity. Because cortisol has long been associated with adiposity, this systematic review and meta-analysis aims to summarize and compare the literature around CAR and HCC and their association with obesity or fat distribution indices. METHODS: The PubMed, Web of Science (Web of Science Core Collection and Medline), EBSCO Information Services, Embase, and PsycNET databases were searched, and full-text articles investigating the association between CAR or HCC and markers of adiposity in humans were included. Meta-analyses were then performed to compare studies associating CAR or HCC with BMI (a marker of general adiposity) and waist circumference (a marker of fat distribution). RESULTS: The results of this review highlight inconsistencies in cortisol sampling and CAR computation, which makes comparisons between studies difficult. It was found that adiposity indices are not associated with CAR but that they correlate significantly and positively with HCC. The subgroup analysis hinted to possible age differences in the magnitude of the association between HCC and BMI. CONCLUSIONS: Trait rather than state measurement of the hypothalamus-pituitary-adrenal axis activity is associated with increased general and abdominal adiposity in humans.

Establishing a food addiction diagnosis using the Yale Food Addiction Scale: A closer look at the clinically significant distress/functional impairment criterion.

The concept of food addiction (FA) represents a set of problematic eating behaviors related to overeating. According to the Yale Food Addiction Scale (YFAS), which was based on the DSM-IV-TR substance dependence diagnostic criteria, a FA diagnosis is assigned when at least three criteria and the criterion evaluating clinically significant distress and/or functional impairment are endorsed. Considering the decisive role of this last criterion, the present study aimed to investigate its endorsement among individuals suffering from severe obesity and awaiting bariatric surgery. A total of 146 individuals were recruited at the Quebec Heart and Lung Institute and were invited to complete various questionnaires. Differences between individuals who endorsed at least three FA criteria and reported distress/impairment (FA+D/I; N = 24) and individuals who endorsed at least three FA criteria but did not report distress/impairment (FA-D/I; N = 27) were examined. Results revealed that 16% of the total sample fulfilled a FA diagnosis when considering the clinically significant distress/functional impairment criterion; however, this prevalence rate climbed to 35% when removing the inclusion of distress/impairment. Furthermore, individuals from the FA+D/I group showed more FA symptomatology and hedonic hunger, but did not statistically differ from the FA-D/I group on expected markers of psychological distress (depressive symptoms and quality of life). Lastly, the experience of withdrawal symptoms and hedonic hunger were found to be the best predictors of the endorsement of the distress/impairment criterion. This study underlines the impact of this criterion in establishing a FA diagnosis and highlights the importance of considering alternative ways to interpret findings from the YFAS when dealing with clinical samples.

Executive functioning and psychological symptoms in food addiction: a study among individuals with severe obesity.

Food addiction (FA) has recently emerged as a new field in the study of obesity. Previous studies have contributed to identifying psychological correlates of FA. However, few researchers have examined the cognitive profile related to this condition; up until now, attentional biases related to food cues and a poorer performance monitoring have been observed. The present study aimed to examine the psychological profile and executive functioning related to FA in individuals with severe obesity and awaiting bariatric surgery. Participants (N = 86) were split into two groups, according to their level of FA symptoms (low FA vs high FA). Groups were compared on questionnaires measuring binge eating, depression and anxiety symptoms, and impulsivity as well as on measures reflecting executive functioning (D-KEFS and BRIEF-A). The relationship between FA groups and patterns of errors during the D-KEFS' Color-Word Interference Test was further analyzed. Individuals within the high FA group reported significantly more binge eating, depressive and anxiety symptoms, and more metacognitive difficulties. They also tended to show a poorer inhibition/cognitive flexibility score and a typical pattern of errors, characterized by an increased number of errors as the tasks' difficulty rose as opposed to a decreased number of errors, which characterizes an atypical pattern of errors. The present results show that the inability to learn from errors or past experiences is related to the severity of FA and overall impairments.Level of evidence Level V, descriptive study.

An examination of the mechanisms and personality traits underlying food addiction among individuals with severe obesity awaiting bariatric surgery.

PURPOSE: The aetiology underlying addiction has often been investigated to shed more light on the factors contributing to the development and maintenance of various disorders. In the field of addictive eating behaviours, data on the aetiological factors related to food addiction (FA) in the bariatric context remain scarce. The present study aimed to explore mechanisms and variables underlying FA among individuals suffering from severe obesity and awaiting bariatric surgery. METHODS: Participants (N = 146) were recruited at the Quebec Heart and Lung Institute during their pre-operative visit and were invited to complete questionnaires. Participants with and without FA were compared on reward sensitivity, impulsivity, emotion dysregulation, and personality traits. RESULTS: Findings showed that bariatric candidates with FA (16%) presented more emotion dysregulation, more harm avoidance, and less self-directedness. Further exploration showed that the association between harm avoidance and the number of FA criteria endorsed was mediated by emotion dysregulation, while the association between self-directedness and the number of FA criteria endorsed was mediated by reward sensitivity. CONCLUSIONS: These results indicate that an inability to regulate affect by strategies other than eating highly palatable food, in a context where negative affect and long-term goals can hardly be sustained, underlies a diagnostic of FA among bariatric candidates. From a clinical standpoint, the presence of a double vulnerability leading to FA symptomatology could help design better-targeted interventions to maximise weight loss maintenance in the bariatric context. LEVEL OF EVIDENCE: Level V, descriptive study.

n-back task performance and corresponding brain-activation patterns in women with restrictive and bulimic eating-disorder variants: preliminary findings.

Eating disorder (ED) variants characterized by "binge-eating/purging" symptoms differ from "restricting-only" variants along diverse clinical dimensions, but few studies have compared people with these different eating-disorder phenotypes on measures of neurocognitive function and brain activation. We tested the performances of 19 women with "restricting-only" eating syndromes and 27 with "binge-eating/purging" variants on a modified n-back task, and used functional magnetic resonance imaging (fMRI) to examine task-induced brain activations in frontal regions of interest. When compared with "binge-eating/purging" participants, "restricting-only" participants showed superior performance. Furthermore, in an intermediate-demand condition, "binge-eating/purging" participants showed significantly less event-related activation than did "restricting-only" participants in a right posterior prefrontal region spanning Brodmann areas 6-8-a region that has been linked to planning of motor responses, working memory for sequential information, and management of uncertainty. Our findings suggest that working memory is poorer in eating-disordered individuals with binge-eating/purging behaviors than in those who solely restrict food intake, and that observed performance differences coincide with interpretable group-based activation differences in a frontal region thought to subserve planning and decision making.

Cortisol responses on the dexamethasone suppression test among women with Bulimia-spectrum eating disorders: associations with clinical symptoms.

INTRODUCTION: Evidence associates Bulimia Nervosa (BN) with altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis, but the clinical implications of such alterations need to be better understood. We contrasted cortisol responses to the dexamethasone suppression test (DST) in bulimic and non-eating disordered women and examined relationships among DST cortisol responses, eating symptoms and co-morbid disturbances. METHOD: Sixty women with Bulimia Spectrum (BS) Disorders (either BN or normal weight Eating Disorder NOS with regular binge eating or purging) and 54 non-eating disordered women of similar age and body mass index participated in a 0.5 mg DST, and completed interviews and questionnaires assessing eating symptoms and co-morbid psychopathology. RESULTS: Compared with the normal-eater group, the BS women demonstrated significantly less DST suppression. Among BS women, DST non-suppression was associated with more severe depression, anxiety and eating preoccupations. CONCLUSIONS: Our findings show BS women to show less DST suppression compared to normal eater women, and results link extent of non-suppression, in BS individuals, to severity of depression, anxiety and eating preoccupations.

Childhood emotional abuse and eating symptoms in bulimic disorders: an examination of possible mediating variables.

OBJECTIVE: We sought to estimate prevalences of childhood emotional abuse (CEA) in bulimic and normal-eater control groups, and to replicate previous findings linking CEA to severity of eating symptoms in BN. We also examined potential mediators of the link between CEA and disordered eating. METHOD: Women diagnosed with a bulimic disorder (n = 176) and normal-eater women (n = 139) were assessed for childhood traumata, eating-disorder (ED) symptoms and psychopathological characteristics (ineffectiveness, perfectionism, depression, and affective instability) thought to be potential mediators of interest. RESULTS: CEA was more prevalent in the bulimic than in the nonbulimic group, and predicted severity of some eating-symptom indices. Ineffectiveness and affective instability both mediated relationships between CEA and selected ED symptoms. DISCUSSION: We found CEA to predict eating pathology through mediating effects of ineffectiveness and affective instability. CEA might influence severity of ED symptoms by impacting an individual's self-esteem and capacity for affect regulation.