neuropeptide-y and Bulimia-Nervosa

The biological research predominant in the last decades have not brought a solution in the discovery of risk factors contributing to the development of eating disorders, and elaborating a more effective therapy. The large amount of molecular genetic studies, however, by showing the various genetic vulnerability, contributed significantly to recognizing a more specific effect of the environmental factors. The authors evaluate the genetic studies of eating disorders and present environmental factors having a role in the development of eating disorders. They report about recently published data of gene-environment interaction and conclude from the data clinically applicable consequences.

Topics: Anorexia Nervosa; Brain-Derived Neurotrophic Factor; Bulimia Nervosa; Family; Feeding and Eating Disorders; Genetic Predisposition to Disease; Ghrelin; Humans; Leptin; Melanocortins; Neuropeptide Y; Receptor, Melanocortin, Type 4; Receptors, Dopamine D4; Receptors, Estrogen; Receptors, Serotonin; Serotonin Plasma Membrane Transport Proteins; Social Environment; Twin Studies as Topic

Peptides ghrelin, obestatin and neuropeptide Y (NPY) play an important role in regulation of energy homeostasis, the imbalance of which is associated with eating disorders anorexia (AN) and bulimia nervosa (BN). The changes in ghrelin, obestatin and NPY plasma levels were investigated in AN and BN patients after administration of a high-carbohydrate breakfast (1604 kJ). Eight AN women (aged 25.4+/-1.9, BMI: 15.8+/-0.5), thirteen BN women (aged 22.0+/-1.05, BMI: 20.1+/-0.41) and eleven healthy women (aged 25.1+/-1.16, BMI: 20.9+/-0.40) were recruited for the study. We demonstrated increased fasting ghrelin in AN, but not in BN patients, while fasting obestatin and NPY were increased in both AN and BN patients compared to the controls. Administration of high-carbohydrate breakfast induced a similar relative decrease in ghrelin and obestatin plasma levels in all groups, while NPY remained increased in postprandial period in both patient groups. Ghrelin/obestatin ratio was lower in AN and BN compared to the controls. In conclusions, increased plasma levels of fasting NPY and its unchanged levels after breakfast indicate that NPY is an important marker of eating disorders AN and BN. Different fasting ghrelin and obestatin levels in AN and BN could demonstrate their diverse functions in appetite and eating suppression.

Topics: Anorexia Nervosa; Body Composition; Body Mass Index; Bulimia Nervosa; Dietary Carbohydrates; Eating; Female; Ghrelin; Humans; Neuropeptide Y; Postprandial Period

Genetic factors likely contribute to the biological vulnerability of eating disorders.. Case-control association study on one neuropeptide Y gene (Leu7Pro) polymorphism and three ghrelin gene (Arg51Gln, Leu72Met and Gln90Leu) polymorphisms.. 114 eating disorder patients (46 with anorexia nervosa, 30 with bulimia nervosa, 38 with binge eating disorder) and 164 healthy controls were genotyped.. No differences were detected between patients and controls for any of the four polymorphisms in allele frequency and genotype distribution (P > 0.05). Allele frequencies and genotypes had no significant influence on body mass index (P > 0.05) in eating disorder patients.. Positive findings of former case-control studies of associations between ghrelin gene polymorphisms and eating disorders could not be replicated. Neuropeptide Y gene polymorphisms have not been investigated in eating disorders before.

Topics: Adolescent; Adult; Anorexia Nervosa; Binge-Eating Disorder; Body Mass Index; Bulimia Nervosa; Case-Control Studies; Feeding and Eating Disorders; Female; Gene Frequency; Genetic Association Studies; Genotype; Ghrelin; Humans; Male; Middle Aged; Neuropeptide Y; Polymorphism, Single Nucleotide; Young Adult

Ghrelin is predominantly produced by the stomach and the growth hormone (GH)-ghrelin feedback loop between the stomach and the pituitary gland has recently been suggested. The disruption of the gut-brain axis might be involved in bulimia nervosa (BN).. We investigated responses of plasma GH, ghrelin, and neuropeptide Y (NPY) concentrations to exercise or to exercise after the administration of the antilipolytic drug Acipimox (Aci) in seven BN patients and seven healthy women (C). Aci was administered 1h before exercise (45 min, 2 W/kg of lean body mass/LBM/). Ghrelin, GH, NPY, free fatty acids (FFA) and glycerol plasma levels were measured during the test using commercial kits.. The exercise induced an increase in plasma GH, NPY and FFA in both groups and a decrease in plasma ghrelin levels only in BN patients. Exercise after Aci administration resulted in an increase in plasma GH, and a decrease in plasma ghrelin in both groups; NPY increased more in BN patients. Exercise-induced FFA increase was depressed after Aci.. We conclude that the Aci-induced suppression in plasma ghrelin levels during exercise in both groups suggests a negative feedback of GH on ghrelin secretion. Observed changes in plasma FFA levels were not related to changes in GH and ghrelin levels.

Topics: Adult; Body Mass Index; Bulimia Nervosa; Case-Control Studies; Exercise; Fatty Acids, Nonesterified; Feedback, Physiological; Female; Gastric Mucosa; Ghrelin; Glycerol; Human Experimentation; Human Growth Hormone; Humans; Hypolipidemic Agents; Neuropeptide Y; Pituitary Gland; Pyrazines; Stomach

The aim of this study was to evaluate the role of orexigenic and anorexigenic factors in an interdisciplinary weight loss therapy for obese adolescents with symptoms of eating disorders.. Thirty-seven post-pubertal, obese adolescents (14 to 19 years old) with symptoms of eating disorders were submitted to long-term interdisciplinary therapy (1 year). Bulimic and binge eating symptoms were measured using the Bulimic Investigatory Test, Edinburgh, and the Binge Eating Scale respectively. Neuropeptide Y, melanin-concentrating hormone, total ghrelin, alpha-melanocyte stimulating hormone and leptin were measured using radioimmunoassay.. After long-term interdisciplinary therapy, the adolescents showed significantly improved body composition, visceral and subcutaneous fat and reduced symptoms of bulimia and binge eating. Intriguingly, orexigenic peptides were up-regulated after short-term therapy and down-regulated at the end of therapy, whereas the anorexigenic pathway was improved with therapy. Furthermore, after long-term therapy, a negative correlation was observed between leptin concentration and melanin-concentrating hormone.. We suggest that long-term therapy promotes an intrinsic association between weight loss, improvement of eating disorder symptoms and a decrease in orexigenic factors. Together, these results represent a more effective course by which patients can normalise behaviours related to eating disorders as well the actions of hormones involved in energy balance, and thus advance obesity control.. Long-term interdisciplinary therapy was effective to improve anorexigenic and orexigenic factors that influence energy balance and avoid the development of eating disorders in obese adolescents. However, the associations between eating disorders and neuroendocrine factors need to be confirmed in future studies.

Topics: Adolescent; Binge-Eating Disorder; Body Mass Index; Bulimia Nervosa; Energy Intake; Female; Ghrelin; Humans; Hypothalamic Hormones; Male; Melanins; Neuropeptide Y; Obesity; Patient Care Team; Physical Therapy Modalities; Pituitary Hormones; Weight Loss