| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 374.06 KB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
A obesidade é considerada um problema de saúde pública pela OMS, existindo mundialmente cerca de 1,9 mil milhões de pessoas com excesso de peso e, destas, 600 milhões são obesas1. Esta patologia representa um risco elevado para doenças cardiovasculares, diabetes, hipertensão e cancro2. Na sua génese está um desequilíbrio entre a energia ingerida e a energia despendida. Este desequilíbrio pode resultar de fatores psicológicos, ambientais, genéticos e metabólicos, indutores de perturbações do comportamento alimentar, como o aumento de ingestão alimentar ou de um estilo de vida sedentário. A regulação do balanço energético resulta de uma variedade de estímulos aferentes que são processados no sistema nervoso central e respostas eferentes, reguladoras do apetite e saciedade. Os sinais aferentes podem ser transmitidos ao cérebro através do nervo vago ou pela via sistémica e envolver hormonas libertadas pelo tecido adiposo (leptina, adiponectina, resistina e visfatina) e pelo trato gastrointestinal (ghrelina, PYY, PP, GPL-1 e CCK). A resposta aos estímulos provoca ativação ou inibição de neurónios orexígenos (NPY, AgRP) e/ou anorexígenos (POMC, CART) localizados no hipotálamo. Enquanto a ativação dos neurónios que expressam NPY e AgRP aumenta o apetite, a ativação dos neurónios que expressam POMC ou CART origina saciedade3. Muitos são os estudos que procuraram compreender os mecanismos do balanço energético. Contudo, os resultados são ainda, em alguns casos, pouco esclarecedores ou mesmo contraditórios. Pretende-se, com este artigo, fazer uma revisão sobre os mecanismos de regulação hormonal envolvidos na patogénese da obesidade, dando especial relevo às hormonas produzidas no tecido adiposo, estômago e intestino. Considerada uma epidemia do século XXI pela sua elevada prevalência e complicações associadas, tornam-se cruciais mais estudos nesta área a fim de encontrar novas abordagens terapêuticas.
ABSTRACT - Obesity is considered by WHO a public health problem, as the number of overweight people worldwide is now 1.9 billion, out of which approximately 600 million are obese1. This condition is correlated with a high risk of cardiovascular disease, diabetes, hypertension and cancer2. This pathology arises as a consequence of an imbalance between energy intake and energy expended. This imbalance can result from psychological, environmental, genetic and metabolic factors, which are inducers of eating disorders such as increased food intake and a sedentary lifestyle. The regulation of energy balance, results from a variety of afferent stimuli that are processed in the central nervous system, and efferent responses regulating the appetite and satiety. Afferent stimuli may occur by stimulation of the vagus nerve or involving hormones released by adipose tissue (leptin, adiponectin, resistin and visfatin) and the gastrointestinal tract (ghrelin, PYY, PP, GPL-1 and CCK). The response to the stimulus causes activation or inhibition of orexigenic neurons (NPY, AgRP) and / or anorexigenic neurons (POMC, CART), primarily expressed in the hypothalamus. While the activation of neurons that express AgRP and NPY increases appetite, activation of neurons that express POMC provides satiety3. Many studies have sought to understand these regulatory mechanisms of energy balance. However the results are still not clear and arguably even contradictory. With this article, we intend to review the mechanisms of hormonal regulation involved in the pathogenesis of obesity, with particular emphasis on hormones produced in fat tissue, stomach and intestine. As an epidemic of the XXI century because of its high prevalence and associated complications, it is crucial that obesity becomes the topic of further studies in order to find new therapeutic approaches.
ABSTRACT - Obesity is considered by WHO a public health problem, as the number of overweight people worldwide is now 1.9 billion, out of which approximately 600 million are obese1. This condition is correlated with a high risk of cardiovascular disease, diabetes, hypertension and cancer2. This pathology arises as a consequence of an imbalance between energy intake and energy expended. This imbalance can result from psychological, environmental, genetic and metabolic factors, which are inducers of eating disorders such as increased food intake and a sedentary lifestyle. The regulation of energy balance, results from a variety of afferent stimuli that are processed in the central nervous system, and efferent responses regulating the appetite and satiety. Afferent stimuli may occur by stimulation of the vagus nerve or involving hormones released by adipose tissue (leptin, adiponectin, resistin and visfatin) and the gastrointestinal tract (ghrelin, PYY, PP, GPL-1 and CCK). The response to the stimulus causes activation or inhibition of orexigenic neurons (NPY, AgRP) and / or anorexigenic neurons (POMC, CART), primarily expressed in the hypothalamus. While the activation of neurons that express AgRP and NPY increases appetite, activation of neurons that express POMC provides satiety3. Many studies have sought to understand these regulatory mechanisms of energy balance. However the results are still not clear and arguably even contradictory. With this article, we intend to review the mechanisms of hormonal regulation involved in the pathogenesis of obesity, with particular emphasis on hormones produced in fat tissue, stomach and intestine. As an epidemic of the XXI century because of its high prevalence and associated complications, it is crucial that obesity becomes the topic of further studies in order to find new therapeutic approaches.
Description
Keywords
Obesidade Hormonas Tecido adiposo Trato gastrointestinal Abordagem terapêutica Obesity Hormones Adipose tissue Gastrointestinal tract Therapeutic approaches
Citation
Veiga L. Obesidade: regulação hormonal. Saúde & Tecnologia. 2016;(16):5-15.
Publisher
Instituto Politécnico de Lisboa, Escola Superior de Tecnologia da Saúde de Lisboa