The executive functions in overweight and obesity: a systematic review of neuropsychological cross-sectional and longitudinal studies

Background: The increasing incidence of people affected by overweight or obesity is a significant health problem. The knowledge of the factors which influences the inappropriate eating behaviors causing excessive body fat is an essential goal for the research. Overweight and obesity are significant risk factors for many health diseases, such as cardiovascular problems, diabetes. Recently, many studies have focused on the relationship between body weight and cognitive processes. Objectives: This systematic review is aimed to investigate the existence and the nature of the relationship between excessive body weight (overweight/obesity) and executive functions, analyzing cross-sectional, and longitudinal studies in order to verify the evidence of a possible causality between these variables. Methods: The review was carried out according to the PRISMA-Statement, through systematic searches in the scientific databases PubMed, Medline, PsychInfo, and PsycArticles. The studies selected examined performance on executive tasks by participants with overweight or obesity, aged between 5 and 70 years. Studies examining eating disorders or obesity resulting from other medical problems were excluded. Furthermore, the results of studies using a cross-sectional design and those using a longitudinal one were separately investigated. Results: Sixty-three cross-sectional studies and twenty-eight longitudinal studies that met our inclusion and exclusion criteria were analyzed. The results confirmed the presence of a relation between executive functions and overweight/obesity, although the directionality of this relation was not clear; nor did any single executive function emerge as being more involved than others in this relation. Despite this, there was evidence of a reciprocal influence between executive functions and overweight/obesity. Conclusions: This systematic review underlines the presence of a relationship between executive functions and overweight/obesity. Moreover, it seems to suggest a bidirectional trend in this relationship that could be the cause of the failure of interventions for weight reduction. The results of this review highlight the importance of a theoretical model able to consider all the main variables of interest, with the aim to structuring integrated approaches to solve the overweight/obesity problems

The complex interactions between obesity, metabolism and the brain

Obesity is increasing at unprecedented levels globally, and the overall impact ofobesity on the various organ systems of the body is only beginning to be fullyappreciated. Because of the myriad of direct and indirect effects of obesity causingdysfunction of multiple tissues and organs, it is likely that there will be heterogeneityin the presentation of obesity effects in any given population. Taken together, theserealities make it increasingly difficult to understand the complex interplay betweenobesity effects on different organs, including the brain. The focus of this review isto provide a comprehensive view of metabolic disturbances present in obesity, theirdirect and indirect effects on the different organ systems of the body, and to discussthe interaction of these effects in the context of brain aging and the development ofneurodegenerative diseases.Fil: Uranga, Romina Maria. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Keller, Jeffrey Neil. Louisiana State University System; Estados Unido

Sleep Dysfunction in Fibromyalgia and Therapeutic Approach Options

Fibromyalgia, characterised by persistent pain, sleep disturbance, fatigue and cognitive dysfunction, is a central sensitivity syndrome that also involves abnormality in peripheral generators and in the hypothalamic pituitary adrenal axis. Heterogeneity of clinical expression of fibromyalgia with a multifactorial aetiology has made the development of effective therapeutic strategies challenging. Non-restorative sleep associated with poor sleep quality is a characteristic of fibromyalgia which is linked to symptom severity. A relationship between sleep disorder and central sensitization could be a possible factor involved in development, exacerbation and/or maintenance of fibromyalgia. Association between disordered sleep and the risk of fibromyalgia suggests that limiting sleep problems would reduce the incidence of the condition. Therapeutic approaches with treatments that consolidate or deepen sleep may be preferential to improve sleep in patients with fibromyalgia. Thus, disordered sleep appears fundamental to the pathophysiology of fibromyalgia and as such the risk of sleep disturbances needs to be proactively assessed and when identified in this patient group be actively managed to improve health outcomes for patients with fibromyalgia

Central adiposity and brain vulnerability in mid-life : evidence for early risk

This set of projects focused on visceral fat, measured using proximal and direct methods. Specifically, I was interested in the effects of visceral fat on brain structure and integrity in middle age. Study 1 looked at waist to hip ratio (WHR) as a proximal measure of visceral fat and used statistical mediation to directly examine a possible mechanism behind the relationship between visceral fat and cognitive decline. Reductions in executive function seen in middle-aged adults with high visceral fat were found to occur in the context of lowered serum brain derived neurotrophic factor (BDNF) a key neurotrophin involved in synaptic plasticity as well as neuronal regeneration. Study 2 utilized Dual Energy X Ray Absorptiometry (DXA) to directly estimate visceral fat mass and volume as well as thickness of the cortical mantle in middle age. High-resolution Magnetization Prepared Rapid Acquisition Gradient Echo (MPRAGE) images were used. High visceral fat was found to predict increased thickness in the posterior cingulate cortex independently of age and cardiovascular risk in a cognitively intact middle-aged sample. Study 3 examined changes in concentrations of crucial cerebral metabolites in the posterior cingulate cortex among individuals with high visceral fat. Results indicated that visceral fat predicted reduced concentrations of N Acetyl Asparate, a marker of neuronal viability and increased concentrations of myo-inositol, a glial marker that is implicated in a number of disease states including prodromal Alzheimer’s Disease and Multiple Sclerosis. Collectively, the 3 studies highlight important evidence for early brain vulnerability even in cognitively intact middle- aged adults with high levels of cognitive reserve. An important next step would be to examine modifiable mediators of these relationships, such as inflammation and BDNF so that targeted interventions may be developed.Psycholog

Insulin in the nervous system and the mind: Functions in metabolism, memory, and mood

Background: Insulin, a pleotrophic hormone, has diverse effects in the body. Recent work has highlighted the important role of insulin's action in the nervous system on glucose and energy homeostasis, memory, and mood. Scope of review: Here we review experimental and clinical work that has broadened the understanding of insulin's diverse functions in the central and peripheral nervous systems, including glucose and body weight homeostasis, memory and mood, with particular emphasis on intranasal insulin. Major conclusions: Implications for the treatment of obesity, type 2 diabetes, dementia, and mood disorders are discussed in the context of brain insulin action. Intranasal insulin may have potential in the treatment of central nervous system-related metabolic disorders. Keywords: Insulin, Intranasal insulin, Memory, Metabolism, Moo

Excess body weight as a risk factor to well-being and performance of flight personnel : potential strategies of prevention

Flight personnel is at risk of excessive weight and obesity. This is due to, for instance, irregular work schedules, irregular nutritional habits, excessive workload, and an inability to plan regular physical exercise or recreation. These factors lead to excessive body weight gains, and hence to obesity. Obesity directly infl uences quality of life as well as readiness to fulfi ll duties by the aircraft maintenance personnel. Obesity is an independent risk factor for various diseases such as hypertension, type 2 diabetes, coronary artery disease, atherosclerosis, each of which can lead to a loss of medical licence. Obesity is associated with extensive caloric consumption that cannot be controlled by the aff ected person. State of the art research has demonstrated not only hormonal and neuronal changes associated with obesity, but also points to deterioration of cognitive functions; these changes are likely induced by suboptimal diets. Furthermore, we will review prevention strategies, as well as treatments aimed at losing weight in fl ight personnel already aff ected by obesity. Implementation of these programs may prolong the time a pilot is fi t to fl y and improve his/her performance

Dietary Approaches and Supplements in the Prevention of Cognitive Decline and Alzheimer's Disease

Age-associated cognitive decline and dementia are conditions in which there is deterioration in memory, thinking, and behavior, with profound effects on the ability to perform everyday activities and well-being. Even if dementia mainly affects older persons, it is not a normal part of aging. Alzheimer's disease accounts for 60-75% of dementia cases. The number of persons affected will increase in the next decades in parallel with aging of the world population. Hence, unless some approach is found to reduce age-related deterioration of cognitive functions, health care costs will continue to rise exponentially. There is a wealth of epidemiological evidence supporting a relationship between diet and Alzheimer's disease, and suggesting that the risk of cognitive decline may be reduced by dietary interventions. It has been proposed that adopting a healthy diet and lifestyle that improves cardiovascular function may help delaying the onset of Alzheimer's disease due to its potential association with vascular disease. Several nutrients, dietary components, supplements and dietary patterns have been reported in relation to their association with cognition and with the development of cognitive decline and Alzheimer's disease. The possible effect of diet on the prevention of dementia is of tremendous scientific and general interest, because hitherto there is no definitive evidence of any effective pharmacological treatment for dementia. The aim of this review is to evaluate the evidence for the effects of some dietary components, supplements, and dietary patterns as neuroprotective, with potential to delay cognitive decline and the onset of dementia

The Relation of Impulsivity and Obesity: A Neuroimaging Analysis

The current study examined the relation of impulsivity and obesity in three neuroimaging studies using MRI techniques to test the hypothesis that deficits in brain regions responsible for inhibitory control are associated with obesity. The first study used voxel-based morphometry (VBM) to explore volumetric differences in lean, overweight, and obese women (N=83) and found that BMI was negatively correlated with grey matter (GM) in the insula, frontal operculum, and inferior frontal gyrus. BMI was positively correlated with white matter (WM) in the fusiform gyrus, parahippocampal gyrus, Rolandic operculum, and dorsal striatum. Genetic alleles for dopamine expression moderated these relations. Additionally, less GM in the superior frontal gyrus predicted future increases in BMI. The second study used VBM to examine differences between lean adolescents at risk versus not at risk for obesity (N=54). There were no regional GM or WM differences based on risk status. There were also no regional differences that predicted weight gain over 1-year follow-up. Additionally, genetic alleles for dopamine expression did not moderate any of these regions. These findings suggest that volumetric differences may emerge after excessive weight gain. Finally, the third study used a psychophysiological interaction analysis to test functional connectivity between prefrontal and limbic regions as a function of BMI in lean, overweight, and obese women (N=37) during a go/no-go task. There was no functional connectivity found in seed regions in relation to BMI. Implications for intervention and future research are discussed

Functional magnetic resonance imaging study of working memory in obstructive sleep apnea patients before and after treatment with continuous positive airway pressure

Tese de doutoramento, Medicina (Neurologia), Universidade de Lisboa, Faculdade de Medicina, 201