International projects source: SICRIS

The role of social, genetic and environmental factors in healthy eating: a multicentre analysis of eating disorders and obesity

Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  1620  University Psyhiatric Hospital  Ljubljana - Polje  1191004000  3,485 
This project aims to identify psychosocial and genetic risk factors for anorexia, bulimia and obesity, and correlate these with neuroimaging and neuropsychological. We will create an aetiological model, for use as tool for improving prevention and treatment of these disorders. We will examine environment by measuring psychosocial and endogenous risk factors such as childhood obesity, sexual abuse, personality and psychopathology. We will examine the human genome for genetic risk factors in large, well-characterised European samples. We will examine the brain by performing firm and PET neuroimaging to explore neuroanatomical and neurochemical correlates, and neuropsychological to reveal cognitive factors which trigger and prolong these disorders. Finally we will model interactions between psychopathology, genes, culture, gender and psychosocial risk.We have created an aetiological model of anorexia nervosa (AN) and bulimia nervosa (BN), based on genes, environment and function of the brain. Patients who develop eating disorder have a set of identified environmental risk factors together with genetic vulnerability which together lead to the illness. In addition, there are characteristic traits such as childhood perfectionism, cognitive inflexibility, and dieting behaviour which result from the actions of both genes and environment. We identified genetic risk factors, including BDNF which appears common to both disorders, and MCR4, which is a risk factor for BN. Thus, AN and BN appear to differ for some factors (BN for example having genetic risk factors in common with obesity) and have common risks for others (such as cognitive inflexibility and many environmental risk factors). These risks manifest themselves though specific abnormalities in neural process which can be viewed by neuroimaging. Specific results: Twin population analysis: Dieting is associated with many unhealthy behaviours at the age 14, but at this early risk age mood problems are a better predictor of future eating disorder symptoms than dieting. Predictors of obesity at age 14 were early puberty, daily TV watching, self-reported unpopularity among peers, sleeping disturbances (boys) and reduced daily outdoor activities.Many ED related traits are heritable. Functional magnetic resonance imaging: We found that medial prefrontal cortex response to symptom provoking stimuli is a common feature of anorexia and bulimia nervosa and common with obsessive-compulsive and addictive disorders; it is present even after long-term recovery from anorexia nervosa and may a trait vulnerability; prefrontal reaction is specifically associated with food; Decreased response to food in the anterior and lateral prefrontal cortex is specific to bulimia nervosa; Lateral and apical prefrontal involvement differentiates recovered people from chronic patients and is associated with a good outcome. Neuropsychology: A battery of neuropsychological tests of mental flexibility was used, and uncovered four factors: simple alteration, mental flexibility, preservation and semantic shifting. The AN group showed global impairment on three of four factors, compared to healthy controls, while BN had impairment in selected areas that present a cognitive set shifting dysfunction. Our findings suggest that cognitive inflexibility may present an important manifestation of biological substrate of AN and BN and may add to the broader phenotypic definition for future genetic studies. Risk factors: Nearly all risk factors previously found were replicated in this study using a within-family design corroborating that these risk factors are non-shared in nature. The occurrence of major depressive episodes was significantly more common in the pre-onset period of AN patients. Temperament and character has also been investigated and patients were high in harm avoidance, persistence, and self-transcendence, and low in novelty seeking, self-directedness and cooperativeness. They did not differ in reward dependence.
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