Year: 2016
Type: dissertation
Abstract: There is an increasing worldwide prevalence of obesity and anorexia nervosa. These conditions are having important health consequences. Among the numerous factors linked to these extreme weight conditions, deviations in physical activity and sleep patterns have been identified. However, the underlying mechanisms are not yet clear. Compared to healthy-weight individuals, those with obesity and anorexia nervosa present a distinctive temperament and cognitive profile as well as specific alterations in plasma endocannabinoid and endocrine hormone levels. Separately, these psychobiological processes are being associated with sleep-wake behaviour. This thesis gathers six studies to examine sleep and physical activity patterns in extreme weight conditions and the modulating role of several neuroendocrine factors, temperament, psychopathological indexes and cognitive functioning. A further aim, exclusive to anorexia nervosa, was to evaluate the effects of these mechanisms on the outcome of a partial, day hospital treatment. An inverse association was found between moderate-to-vigorous physical activity (MVPA) and body mass index, in part mediated via the actions of exercise on endocannabinoid system functioning. A temperament profile of low novelty seeking and high harm avoidance, as was in the participants with obesity, may be implicated in the adversity of these individuals towards exercise. Additionally, individuals with obesity were found to have difficulties in decision-making (selecting choices that provided immediate reward despite long-term loss), which was linked to both elevated plasma concentrations of irisin and less MVPA. Contrarily, a large variation was identified in the physical activity patterns of patients with anorexia nervosa; the majority presented daytime physical activity and MVPA habits that are similar to those of individuals without an eating disorder, except for a group who were particularly active. Furthermore, regulated and supervised MVPA may be a useful strategy for reducing the symptoms of depression identified in these patients and to promote treatment success. Regarding sleep, both individuals with obesity and anorexia nervosa reported several sleep difficulties, suggesting a u-shaped relationship between sleep and body mass index. Poor sleep quality was associated with increased plasma orexin-A in both conditions. In obesity the interaction between poor sleep and raised plasma orexin-A was associated with elevated body mass index. The interplay between sleep and orexin-A may have an adverse effect on treatment outcome. In conclusion, the present thesis demonstrates that both physical activity and sleep are highly relevant components in the psychopathology of obesity and anorexia nervosa, contributing to the development and maintenance of these conditions via their interaction with other altered psychobiological processes.
Author: Sarah Sauchelli Toran
Language: English
Subfield: Clinical Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
Funders: Universitat Pompeu Fabra, Generalitat de Catalunya, Universitat de València, Universidad de Navarra, Ministerio de Ciencia e Innovación, Universitat de Barcelona, Centro de Investigación Biomédica en Red de Salud Mental, Universitat Rovira i Virgili, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red-Fisiopatología de la Obesidad y Nutrición, Agència de Gestió d'Ajuts Universitaris i de Recerca, Instituto de Salud Carlos III, European Regional Development Fund, Servicio Gallego de Salud
OpenAlex ID: W2617270906