64 research outputs found

    Diabetes mellitus tipo 1: multifatores que conferem suscetibilidade à patogenia auto-imune = Type 1 diabetes mellitus: multifactors that confer susceptibility to the autoimmune pathogenesis

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    Objetivos: revisar dados de literatura concernentes aos fatores que conferem suscetibilidade à patogenia auto-imune do diabetes mellitus tipo 1. Fonte de dados: revisão de artigos especializados no assunto publicados em bancos de dados nacionais e internacionais (SCIELO, LILACS e PUBMED). Síntese de dados: a etiopatogenia do diabetes mellitus tipo 1 está associada a fatores inflamatórios, genéticos e ambientais. Nesta revisão, abordamos o papel da auto-imunidade humoral e celular que culmina com a disfunção das células-beta produtoras de insulina. A precocidade da presença de alguns autoanticorpos como anti-ilhotas pancreáticas, antiinsulina e anti-ácido glutâmico descarboxilase é uma característica importante nesta patologia. Os diversos fatores genéticos associados ao deflagramento do diabetes mellitus tipo 1, sobretudo os associados ao sistema de antígenos leucocitários humanos, acabam por potencializar a apresentação de antígenos das ilhotas para o sistema imune. Por fim, fatores ambientais como exposição viral também contribuem para a quebra de tolerância imunológica observada nesses pacientes. Conclusões: o diabetes mellitus tipo 1 é uma entidade de etiopatogenia altamente complexa. Diversos fatores genéticos e ambientais potencializam os mecanismos de auto-imunidade humoral e celular que levam à insulite. O risco de hipoglicemia severa observada com o tratamento insulínico e as complicações crônicas do diabetes mellitus tipo 1 justificam pesquisas contínuas em relação à etiopatogenia desta entidade, o que contribuirá para abordagens terapêuticas mais eficazes. <br> Aims: To review the literature data concerning the factors which confer susceptibilitiy to the autoimmune pathogenesis of type I diabetes mellitus. Source of data: Review of specific articles on the issue published in national and in-ternational databases (SCIELO, LILACS, PUBMED). Summary of the findings: The etiopathogenesis of type I diabetes mellitus is associated to immunoinflammatory, genetic, and environmental factors. In this review, we approach the role of humoral (autoantibodies) and cellular autoimmunity which culminate with the disfunction of insulin-producers beta-cells. The precocity of the presence of some autoantibodies such as anti-islet cell antibodies, anti-insulin and anti-GAD65 are important characteristics of this pathology. The diverse genetic factors related to development of type 1 diabetes mellitus, mostly those linked to the human leucocyte antigen system, surely increment the apresentation of islet antigens to the immune system. Lastly, environmental factors, such as viral exposure, also contribute to the break of immunological tolerance observed in these patients. Conclusions: Type 1 diabetes mellitus has a highly complex etiopathogenesis. A variety of genetic and environmental factors potentialize the mechanisms of humoral and cellular autoimmunity which generate insulitis. The risk of severe hypoglicemia usually seen with insulin therapy and the chronic complications related to type 1 diabetes mellitus justify continuous research on the etiopathogenesis of this entity, so providing new therapeutic strategies

    A brief history of antiphospholipid antibodies and antiphospholipid syndrome = Uma breve história dos anticorpos antifosfolípides e da síndrome antifosfolípide

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    OBJETIVOS: Revisar os relatos históricos sobre anticorpos antifosfolípides (aAF) dos primeiros anos do século XX; delinear as características cardinais da síndrome antifosfolípide (SAF) a partir de 1983, incluindo critérios clínicos, etiopatogênese e terapia atual. MÉTODOS: Revisão de literatura utilizando o PubMed. Foram selecionados artigos com foco na história dos aAF e da SAF. RESULTADOS: Os aAF foram originalmente descritos em pacientes com sífilis ainda em 1906 por Wassermann. Uma primeira definição do anticoagulante lúpico foi proposta em 1963, enquanto o anticorpo anticardiolipina (aCL) foi descrito 20 anos mais tarde. A SAF, inicialmente reportada por Hughes em 1985 como "síndrome do aCL" é uma das mais prevalentes trombofilias adquiridas. Tromboses arteriais e venosas, associadas ou não à morbidade gestacional, compreendem os achados principais. É uma nova entidade, tendo sido primeiramente associada ao lupus eritematoso sistêmico. Uma forma primária de SAF foi reconhecida em1989, e muitas variantes de SAF são modernamente conhecidas. A terapia-padrão para a SAF trombótica é a anticoagulação plena e ininterrupta. Na SAF obstétrica, a combinação de ácido acetil-salicílico com enoxaparina tem-se mostrado altamente efetiva. CONCLUSÕES: A caracterização sequencial dos aAF desde Wasserman em 1906, e mais tarde da SAF nos anos 1980, é um interessante exemplo de como uma nova entidade é concebida passo a passo. A SAF é uma nova e intrigante causa de trombofilia autoimune, com uma complexa patogênese e uma pletora de manifestações clínicas e laboratoriais. O tratamento é baseado em anticoagulação contínu

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

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    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI &lt;18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school&#x2;aged children and adolescents, we report thinness (BMI &lt;2 SD below the median of the WHO growth reference) and obesity (BMI &gt;2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit
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