Gut hormones, adipokines, and pro- and anti-inflammatory cytokines/markers in loss of control eating: A scoping review

Association between endocrine and neuropsychological endophenotypes and gambling disorder severity

BACKGROUND

Neurobiological characteristics have been identified regarding the severity of gambling disorder (GD). The aims of this study were: (1) to examine, through a path analysis, whether there was a relationship between neuroendocrine features, potentially mediational GD variables, and GD severity, and (2) to associate neuroendocrine variables, with GD severity-related variables according to gambling preferences.

METHODS

The sample included 297 outpatients with GD. We analyzed endocrine concentrations of different appetite-related hormones (ghrelin, liver antimicrobial peptide 2 [LEAP-2], leptin, adiponectin), and neuropsychological performance (working memory, cognitive flexibility, inhibition, decision making, premorbid intelligence). Path analysis assessed mechanisms between neuroendocrine features and GD severity, including mediational GD variables (impulsivity traits and gambling-related cognitive distortions). Partial correlations evaluated the associations between neuroendocrine variables, including impulsivity traits, and variables related to GD severity (DSM-5, South Oaks Gambling Screen, illness duration, and gambling-related cognitive distortions).

RESULTS

Lower adiponectin concentrations predicted greater GD severity, while higher LEAP-2 concentrations predicted more gambling-related cognitive distortions. Likewise, better neuropsychological performance directly predicted GD severity, but worse neuropsychological performance was associated with GD severity through the mediational variables of impulsivity traits and gambling-related cognitive distortions. Also, in non-strategic individuals with GD, poor working memory was associated with gambling expectancies and predictive control. In strategic individuals with GD, poor cognitive flexibility was associated with illusion of control, predictive control, and inability to stop gambling.

CONCLUSIONS

These results provide updated information about the comprehension of the interaction between neuroendocrine features, clinical variables, and severity of GD. Thus, neurobiological functions seem to be strongly related to GD severity.

The interplay between leptin, glucocorticoids, and GLP1 regulates food intake and feeding behaviour

Nutritional, endocrine, and neurological signals converge in multiple brain centres to control feeding behaviour and food intake as part of the allostatic regulation of energy balance. Among the several neuroendocrine systems involved, the leptin, glucocorticoid, and glucagon-like peptide 1 (GLP1) systems have been extensively researched. Leptin is at the top hierarchical level since its complete absence is sufficient to trigger severe hyperphagia. Glucocorticoids are key regulators of the energy balance adaptation to stress and their sustained excess leads to excessive adiposity and metabolic perturbations. GLP1 participates in metabolic adaptation to food intake, regulating insulin secretion and satiety by parallel central and peripheral signalling systems. Herein, we review the brain and peripheral targets of these three hormone systems that integrate to regulate food intake, feeding behaviour, and metabolic homeostasis. We examine the functional relationships between leptin, glucocorticoids, and GLP1 at the central and peripheral levels, including the cross-regulation of their circulating levels and their cooperative or antagonistic actions at different brain centres. The pathophysiological roles of these neuroendocrine systems in dysregulated intake are explored in the two extremes of body adiposity - obesity and lipodystrophy - and eating behaviour disorders.

Cluster analysis in gambling disorder based on sociodemographic, neuropsychological, and neuroendocrine features regulating energy homeostasis

BACKGROUND

The heterogeneity of gambling disorder (GD) has led to the identification of different subtypes, mostly including phenotypic features, with distinctive implications on the GD severity and treatment outcome. However, clustering analyses based on potential endophenotypic features, such as neuropsychological and neuroendocrine factors, are scarce so far.

AIMS

This study firstly aimed to identify empirical clusters in individuals with GD based on sociodemographic (i.e., age and sex), neuropsychological (i.e., cognitive flexibility, inhibitory control, decision making, working memory, attention, and set-shifting), and neuroendocrine factors regulating energy homeostasis (i.e., leptin, ghrelin, adiponectin, and liver-expressed antimicrobial peptide 2, LEAP-2). The second objective was to compare the profiles between clusters, considering the variables used for the clustering procedure and other different sociodemographic, clinical, and psychological features.

METHODS

297 seeking-treatment adult outpatients with GD (93.6% males, mean age of 39.58 years old) were evaluated through a semi-structured clinical interview, self-reported psychometric assessments, and a protocolized neuropsychological battery. Plasma concentrations of neuroendocrine factors were assessed in peripheral blood after an overnight fast. Agglomerative hierarchical clustering was applied using sociodemographic, neuropsychological, and neuroendocrine variables as indicators for the grouping procedure. Comparisons between the empirical groups were performed using Chi-square tests (χ2) for categorical variables, and analysis of variance (ANOVA) for quantitative measures.

RESULTS

Three-mutually-exclusive groups were obtained, being neuropsychological features those with the greatest weight in differentiating groups. The largest cluster (Cluster 1, 65.3%) was composed by younger males with strategic and online gambling preferences, scoring higher on self-reported impulsivity traits, but with a lower cognitive impairment. Cluster 2 (18.2%) and 3 (16.5%) were characterized by a significantly higher proportion of females and older patients with non-strategic gambling preferences and a worse neuropsychological performance. Particularly, Cluster 3 had the poorest neuropsychological performance, especially in cognitive flexibility, while Cluster 2 reported the poorest inhibitory control. This latter cluster was also distinguished by a poorer self-reported emotion regulation, the highest prevalence of food addiction, as well as a metabolic profile characterized by the highest mean concentrations of leptin, adiponectin, and LEAP-2.

CONCLUSIONS

To the best of our knowledge, this is the first study to identify well-differentiated GD clusters using neuropsychological and neuroendocrine features. Our findings reinforce the heterogeneous nature of the disorder and emphasize a role of potential endophenotypic features in GD subtyping. This more comprehensive characterization of GD profiles could contribute to optimize therapeutic interventions based on a medicine of precision.

Plasma concentration of leptin is related to food addiction in gambling disorder: Clinical and neuropsychological implications

Background

Data implicate overlaps in neurobiological pathways involved in appetite regulation and addictive disorders. Despite different neuroendocrine measures having been associated with both gambling disorder (GD) and food addiction (FA), how appetite-regulating hormones may relate to the co-occurrence of both entities remain incompletely understood.

Aims

To compare plasma concentrations of ghrelin, leptin, adiponectin, and liver-expressed antimicrobial peptide 2 (LEAP-2) between patients with GD, with and without FA, and to explore the association between circulating hormonal concentrations and neuropsychological and clinical features in individuals with GD and FA.

Methods

The sample included 297 patients diagnosed with GD (93.6% males). None of the patients with GD had lifetime diagnosis of an eating disorder. FA was evaluated with the Yale Food Addiction Scale 2.0. All patients were assessed through a semi-structured clinical interview and a psychometric battery including neuropsychological tasks. Blood samples to measure hormonal variables and anthropometric variables were also collected.

Results

From the total sample, FA was observed in 23 participants (FA+) (7.7% of the sample, 87% males). When compared participants with and without FA, those with FA+ presented both higher body mass index (BMI) (p < 0.001) and leptin concentrations, after adjusting for BMI (p = 0.013). In patients with FA, leptin concentrations positively correlated with impulsivity, poorer cognitive flexibility, and poorer inhibitory control. Other endocrine measures did not differ between groups.

Discussion and conclusions

The present study implicates leptin in co-occurring GD and FA. Among these patients, leptin concentration has been associated with clinical and neuropsychological features, such as impulsivity and cognitive performance in certain domains.

Sleep deprivation in development of obesity, effects on appetite regulation, energy metabolism, and dietary choices

Sleep deprivation, which is a decrease in duration and quality of sleep, is a common problem in today's life. Epidemiological and interventional investigations have suggested a link between sleep deprivation and overweight/obesity. Sleep deprivation affects homeostatic and non-homoeostatic regulation of appetite, with the food reward system playing a dominant role. Factors such as sex and weight status affect this regulation; men and individuals with excess weight seem to be more sensitive to reward-driven and hedonistic regulation of food intake. Sleep deprivation may also affect weight through affecting physical activity and energy expenditure. In addition, sleep deprivation influences food selection and eating behaviours, which are mainly managed by the food reward system. Sleep-deprived individuals mostly crave for palatable energy-dense foods and have low desire for fruit and vegetables. Consumption of meals may not change but energy intake from snacks increases. The individuals have more desire for snacks with high sugar and saturated fat content. The relationship between sleep and the diet is mutual, implying that diet and eating behaviours also affect sleep duration and quality. Consuming healthy diets containing fruit and vegetables and food sources of protein and unsaturated fats and low quantities of saturated fat and sugar may be used as a diet strategy to improve sleep. Since the effects of sleep deficiency differ between animals and humans, only evidence from human subject studies has been included, controversies are discussed and the need for future investigations is highlighted.

Reactive hypoglycemia in binge eating disorder, food addiction, and the comorbid phenotype: unravelling the metabolic drive to disordered eating behaviours

BACKGROUND

Impaired metabolic response such as blood glucose fast fluctuations may be hypothesized in binge eating disorder (BED) and food addiction (FA) by virtue of the repetitive consumption of highly processed food. Conversely, rapid changes in plasma glucose (i.e., hypoglycemia) may trigger craving for the same food products. The investigation of early glycemic disturbances in BED and FA could enhance the understanding of the metabolic mechanisms involved in the maintenance of the disorders. Present study investigated hypoglycemia events during a 5-h-long oral glucose tolerance test (OGTT) in people with BED, FA, and the comorbid phenotype. Further, the association between the severity of eating psychopathology and the variability in hypoglycaemia events was explored.

METHODS

Two-hundred participants with high weight and no diabetes completed the extended OGTT and were screened for BED, FA, BED-FA, or no-BED/FA. The four groups were compared in hypoglycemia events, OGTT-derived measures, and eating psychopathology. The association between predictors (eating psychopathology), confounders (demographics, metabolic features), and the outcomes (hypoglycemia, early/late hypoglycemia, severe hypoglycemia, reactive hypoglycemia) was examined through logistic regression.

RESULTS

Hypoglycemia in general, and reactive hypoglycemia were highly frequent (79% and 28% of the sample, respectively). Hypoglycemia events (< 70 mg/dL) were equally experienced among groups, whilst severe hypoglycemia (< 54 mg/dL) was more frequent in BED at the late stage of OGTT (5 h; χ2 = 1.120, p = .011). The FA and BED groups exhibited significantly higher number of reactive hypoglycemia (χ2 = 13.898, p = .003), in different times by diagnosis (FA: 210'-240'; BED: at the 270'). FA severity was the only predictor of early and reactive hypoglycemia.

CONCLUSIONS

People with BED or FA are prone to experiencing reactive hypoglycemia; FA severity may predict early and symptomatic hypoglycemia events. This can further reinforce disordered eating behaviours by promoting addictive responses, both biologically and behaviourally. These results inform professionals dealing with eating disorders about the need to refer patients for metabolic evaluation. On the other hand, clinicians dealing with obesity should screen for and address BED and FA in patients seeking care for weight loss.

Leptin, but not ghrelin, is associated with food addiction scores in a population-based subject sample

BACKGROUND

Ghrelin and leptin are both peptide hormones and act as opposing players in the regulation of hunger, satiety and energy expenditure. Leptin reduces appetite and feelings of hunger and is secreted mainly by adipocytes, while ghrelin increases appetite and food intake and reduces metabolic rate. Both hormones have been implicated in addictive disorders. Ghrelin was shown to have pro-addictive effects while leptin's role in addiction yields more conflicting results. Their involvement in the regulation of both food intake and addictive behaviors make them interesting candidates when investigating the regulation of food addiction. However, only few human studies have been performed and large-scale studies are lacking to date. We aimed to investigate the association between total ghrelin and leptin serum levels with scores in the Yale Food Addiction Scale (YFAS).

METHODS

Subjects were recruited in the LIFE Adult cohort. 909 subjects were included in the analysis and we performed univariate multiple linear regression models, adjusted for age, sex (in total group analyses only), alcohol consumption, smoking status, BMI scores, cortisol concentrations, Center for Epidemiological Studies Depression Scale (CES-D) and the 7-item Generalized Anxiety Disorder Scale (GAD-7) sum scores. The dependent variable was the YFAS score.

RESULTS

In men, leptin serum levels showed a significant positive association (standardized β = 0.146; p = 0.012) with the YFAS score. This finding was confirmed in an extreme-group comparison: men in the highest quartile of leptin levels had significantly higher YFAS sum scores than men in the lowest quartile (1.55 vs. 1.18; p = 0.00014). There was no association with YFAS sum score in the total group (standardized β = -0.002; p = 0.974) or in women (standardized β = -0.034; p = 0.674). Total serum ghrelin showed no association with YFAS sum score neither in the total group (standardized β = -0.043; p = 0.196) nor in men (n = 530; standardized β = -0.063; p = 0.135) or women (n = 379; standardized β = -0.035; p = 0.494).

CONCLUSION

Our findings are in line with previous literature and suggest that total ghrelin serum levels are not associated with food addiction scores. Leptin had been previously shown to be associated with food addiction and we confirmed this finding for men in a large, population-based approach.

The Role of Adipokines in Health and Disease

Adipokines are cell-signaling proteins secreted by adipose tissue that has been related to a low-grade state of inflammation and different pathologies. The present review aims to analyze the role of adipokines in health and disease in order to understand the important functions and effects of these cytokines. For this aim, the present review delves into the type of adipocytes and the cytokines produced, as well as their functions; the relations of adipokines in inflammation and different diseases such as cardiovascular, atherosclerosis, mental diseases, metabolic disorders, cancer, and eating behaviors; and finally, the role of microbiota, nutrition, and physical activity in adipokines is discussed. This information would allow for a better understanding of these important cytokines and their effects on body organisms.

Neuroendocrinological factors in binge eating disorder: A narrative review

Neuroendocrine mechanisms play a key role in the regulation of eating behavior. In individuals with binge eating disorder (BED), alterations in these mechanisms signaling hunger and satiety have been observed. It has been investigated that these alterations may underlie the development and maintenance of compulsive overeating in BED. The present narrative review examined the current literature related to the neurobiological processes involved in feeding dysregulation in BED with the aim of updating the most relevant aspects with special attention to neuroendocrine signaling. Studies have shown both central and peripheral endocrine dysfunctions in hormones participating in homeostatic and hedonic pathways in BED. Most studies have been especially focused on orexigenic signals, pointing out the existence of a hyperactivated mechanism promoting hunger. Fewer studies have explored anorexigenic pathways, but the findings so far seem to suggest an abnormal satiety threshold. Despite this, to date, it is unable to identify whether these alterations are typical of the BED pathophysiology or are related to an obesogenic pattern due to most studies included patients with BED and obesity. The identification of endophenotypes in BED may provide a new approach to aberrant eating behavior, favoring the implementation of biological therapeutic targets.

Weight cycling based on altered immune microenvironment as a result of metaflammation

As a result of the obesity epidemic, more people are concerned about losing weight; however, weight regain is common, leading to repeated weight loss and weight cycling. The health benefits of early weight loss are nullified by weight regain after weight cycling, which has much more severe metabolic consequences. Weight cycling alters body composition, resulting in faster fat recovery and slower muscle reconstruction. This evident fat accumulation, muscle loss, and ectopic fat deposition destroy the intestinal barrier, increase the permeability of the small intestinal epithelium, and cause the lipotoxicity of lipid metabolites and toxins to leak into extraintestinal tissues and circulation. It causes oxidative stress and hypoxia in local tissues and immune cell infiltration in various tissues, all contributing to the adaptation to this metabolic change. Immune cells transmit inflammatory responses in adipose and skeletal muscle tissue by secreting cytokines and adipokines, which mediate immune cell pathways and cause metaflammation and inefficient metabolic degradation. In this review, we focus on the regulatory function of the immunological microenvironment in the final metabolic outcome, with a particular emphasis on the cellular and molecular processes of local and systemic metaflammation induced by weight cycling-induced changes in body composition. Metaflammation in adipose and muscle tissues that is difficult to relieve may cause weight cycling. As this chronic low-grade inflammation spreads throughout the body, metabolic complications associated with weight cycling are triggered. Inhibiting the onset and progression of metabolic inflammation and enhancing the immune microenvironment of adipose and muscle tissues may be the first step in addressing weight cycling.

Are Signals Regulating Energy Homeostasis Related to Neuropsychological and Clinical Features of Gambling Disorder? A Case-Control Study

Gambling disorder (GD) is a modestly prevalent and severe condition for which neurobiology is not yet fully understood. Although alterations in signals involved in energy homeostasis have been studied in substance use disorders, they have yet to be examined in detail in GD. The aims of the present study were to compare different endocrine and neuropsychological factors between individuals with GD and healthy controls (HC) and to explore endocrine interactions with neuropsychological and clinical variables. A case−control design was performed in 297 individuals with GD and 41 individuals without (healthy controls; HCs), assessed through a semi-structured clinical interview and a psychometric battery. For the evaluation of endocrine and anthropometric variables, 38 HCs were added to the 41 HCs initially evaluated. Individuals with GD presented higher fasting plasma ghrelin (p < 0.001) and lower LEAP2 and adiponectin concentrations (p < 0.001) than HCs, after adjusting for body mass index (BMI). The GD group reported higher cognitive impairment regarding cognitive flexibility and decision-making strategies, a worse psychological state, higher impulsivity levels, and a more dysfunctional personality profile. Despite failing to find significant associations between endocrine factors and either neuropsychological or clinical aspects in the GD group, some impaired cognitive dimensions (i.e., WAIS Vocabulary test and WCST Perseverative errors) and lower LEAP2 concentrations statistically predicted GD presence. The findings from the present study suggest that distinctive neuropsychological and endocrine dysfunctions may operate in individuals with GD and predict GD presence. Further exploration of endophenotypic vulnerability pathways in GD appear warranted, especially with respect to etiological and therapeutic potentials.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Loss-of-Control Eating and Cardiometabolic Health in Relation to Overweight and Obesity

PURPOSE OF REVIEW

Loss-of-control (LOC) eating, the subjective feeling of being unable to control what or how much is being consumed, is common. The purpose of this review was to examine the relationships among LOC eating, cardiometabolic health, and weight management intervention outcomes.

RECENT FINDINGS

In youth and adults, LOC eating is associated with and predictive of psychological symptoms, high weight, and worsened cardiometabolic health. While LOC eating pre-intervention does not appear to impact outcomes, LOC eating during or following is associated with worsened outcomes from behavioral and surgical weight management interventions. When individuals are undergoing weight management interventions, it may be important to regularly assess for LOC eating. There is limited research on the examined relationships in diverse populations (e.g., males, individuals of a lower socio-economic status, racial/ethnic minority groups). Future research should examine these relationships across the lifespan in diverse populations, with a focus on how these relationships can be impacted through targeted interventions.

Perivascular Adipose Tissue Inflammation: The Anti-Inflammatory Role of Ghrelin in Atherosclerosis Progression

Perivascular adipose tissue (PVAT) and its adipokines engage in bidirectional crosstalk with the vascular wall. Atherosclerosis disrupts this interaction through inflammation, rupture-prone plaques, and subsequent thrombosis. The cardioprotective effects of ghrelin are in contradiction to its adipogenic properties. The concurrent research of anti-/pro-atherogenic mechanisms of ghrelin and PVAT-derived adipokines provides a better understanding of atherosclerosis progression in metabolic disorders. In-depth coverage of the characteristic features of PVAT concerning vascular dysfunction, with a survey of ghrelin-induced anti-inflammatory effects on adipose tissue macrophage infiltration and the inhibitory activity of ghrelin on the proinflammatory adipokine secretion, show that the impact of ghrelin on the endothelial function should be studied in relation to PVAT.

Binge eating disorder

Binge eating disorder (BED) is characterized by regular binge eating episodes during which individuals ingest comparably large amounts of food and experience loss of control over their eating behaviour. The worldwide prevalence of BED for the years 2018-2020 is estimated to be 0.6-1.8% in adult women and 0.3-0.7% in adult men. BED is commonly associated with obesity and with somatic and mental health comorbidities. People with BED experience considerable burden and impairments in quality of life, and, at the same time, BED often goes undetected and untreated. The aetiology of BED is complex, including genetic and environmental factors as well as neuroendocrinological and neurobiological contributions. Neurobiological findings highlight impairments in reward processing, inhibitory control and emotion regulation in people with BED, and these neurobiological domains are targets for emerging treatment approaches. Psychotherapy is the first-line treatment for BED. Recognition and research on BED has increased since its inclusion into DSM-5; however, continuing efforts are needed to understand underlying mechanisms of BED and to improve prevention and treatment outcomes for this disorder. These efforts should also include screening, identification and implementation of evidence-based interventions in routine clinical practice settings such as primary care and mental health outpatient clinics.

Free fatty acid receptors in the endocrine regulation of glucose metabolism: Insight from gastrointestinal-pancreatic-adipose interactions

Glucose metabolism is primarily controlled by pancreatic hormones, with the coordinated assistance of the hormones from gastrointestine and adipose tissue. Studies have unfolded a sophisticated hormonal gastrointestinal-pancreatic-adipose interaction network, which essentially maintains glucose homeostasis in response to the changes in substrates and nutrients. Free fatty acids (FFAs) are the important substrates that are involved in glucose metabolism. FFAs are able to activate the G-protein coupled membrane receptors including GPR40, GPR120, GPR41 and GPR43, which are specifically expressed in pancreatic islet cells, enteroendocrine cells as well as adipocytes. The activation of FFA receptors regulates the secretion of hormones from pancreas, gastrointestine and adipose tissue to influence glucose metabolism. This review presents the effects of the FFA receptors on glucose metabolism via the hormonal gastrointestinal-pancreatic-adipose interactions and the underlying intracellular mechanisms. Furthermore, the development of therapeutic drugs targeting FFA receptors for the treatment of abnormal glucose metabolism such as type 2 diabetes mellitus is summarized.