Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas

Detalhes bibliográficos
Autor(a) principal: Sumita, Nairo Massakazu
Data de Publicação: 2008
Outros Autores: Andriolo, Adagmar [UNIFESP]
Tipo de documento: Artigo
Idioma: por
Título da fonte: Repositório Institucional da UNIFESP
Texto Completo: http://dx.doi.org/10.1590/S1676-24442008000300003
http://repositorio.unifesp.br/handle/11600/4453
Resumo: Diabetes mellitus remains a subject of study due to the fact that clinical trials and new laboratory resources have increasingly added updated information to medical practice. High glycemic levels are harmful and their persistence results in complications such as tissue damage, loss of normal function and failure of several organs. Glycated hemoglobin control has been a useful tool to monitor diabetic patients, and this analyte was validated by two major clinical studies about the impact assessment of rigid glycemic control on the incidence and progression of diabetes complications: Diabetes Control and Complications Trial (DCCT, 1993) and United Kingdom Prospective Diabetes Study (UKPDS, 1998). These studies showed that glycated hemoglobin level below 7% reduces the risk of complications in diabetes. In 2004, the Interdisciplinary Group of Standardization of Glycated Haemoglobin-A1C, a group of specialists from scientific societies and pharmaceutical companies in Brazil, published an official statement about the importance of glycated hemoglobin for the assessment of glycemic control. It discusses the clinical and laboratory aspects, which includes pre-analytical and analytical variations. The recommendations for the use of the test and the ideal control levels for adults, children and elderly people were established. According to this document, A1C tests should be performed at least twice a year by all patients with diabetes mellitus. However, when the results are not appropriate and/or changes are made in the therapeutic scheme, the test should be performed after three months. It is recommended for individuals with diabetes types 1 and 2 and the goal to be achieved is below 7% for effective control in both adults and youngsters. For children during the prepubertal stage the acceptable level of A1C is up to 8% and in pubertal stage, up to 8.5%. In elderly patients, A1C up to 8% is considered appropriate insofar as the attempt to a rigid glycemic level in this age group as well as in prepubertal and pubertal stages may cause side effects such as hypoglycemia. Glycated hemoglobin control is not recommended for pregnant women. The fasting blood glucose test, the glucose level after meals and the fructosamine determination, which corresponds to the group of glycated serum proteins, are more efficient in this case. The main difference between A1C and fasting blood glucose is that the levels of A1C vary more slowly, depending on the half-life of red blood cells. Therefore, they do not return to normality immediately after the normalization of glucose in the blood. The time to reach appropriate levels of A1C after a period of hyperglycemia is approximately 10 weeks. Consequently, A1C exams should be repeated only two to three months after the beginning or the modification of the therapeutic scheme in order to assess its effectiveness. Diseases that affect the survival of red blood cells, such as hemolytic anemia and hemorrhage, may result in false low A1C values due to the reductions of their half-life. On the other hand, anemia caused by iron, vitamin B12 or folate deficiencies, which increase the half-life of red blood cells, may result in false elevated A1C values. Depending on the methodology applied, other medical conditions, such as hypertriglyceridemia, hyperbilirubinemia, uremia, chronic alcoholism and chronic use of opiates or salicylates, may interfere in the results of A1C. Not only is the Brazilian official recommendation the use of DCCT traceable methods, certified by the National Glycohemoglobin Standardization Program (NGSP), but it also encourages participation in specific proficiency testing programs of glycated hemoglobin.
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spelling Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicasGlycohemoglobin importance in the diabetes mellitus control and in the risk evaluation of chronic complicationsDiabetes mellitusGlycated hemoglobinA1CGlycemic controlDiabetes mellitusHemoglobina glicadaA1CControle glicêmicoDiabetes mellitus remains a subject of study due to the fact that clinical trials and new laboratory resources have increasingly added updated information to medical practice. High glycemic levels are harmful and their persistence results in complications such as tissue damage, loss of normal function and failure of several organs. Glycated hemoglobin control has been a useful tool to monitor diabetic patients, and this analyte was validated by two major clinical studies about the impact assessment of rigid glycemic control on the incidence and progression of diabetes complications: Diabetes Control and Complications Trial (DCCT, 1993) and United Kingdom Prospective Diabetes Study (UKPDS, 1998). These studies showed that glycated hemoglobin level below 7% reduces the risk of complications in diabetes. In 2004, the Interdisciplinary Group of Standardization of Glycated Haemoglobin-A1C, a group of specialists from scientific societies and pharmaceutical companies in Brazil, published an official statement about the importance of glycated hemoglobin for the assessment of glycemic control. It discusses the clinical and laboratory aspects, which includes pre-analytical and analytical variations. The recommendations for the use of the test and the ideal control levels for adults, children and elderly people were established. According to this document, A1C tests should be performed at least twice a year by all patients with diabetes mellitus. However, when the results are not appropriate and/or changes are made in the therapeutic scheme, the test should be performed after three months. It is recommended for individuals with diabetes types 1 and 2 and the goal to be achieved is below 7% for effective control in both adults and youngsters. For children during the prepubertal stage the acceptable level of A1C is up to 8% and in pubertal stage, up to 8.5%. In elderly patients, A1C up to 8% is considered appropriate insofar as the attempt to a rigid glycemic level in this age group as well as in prepubertal and pubertal stages may cause side effects such as hypoglycemia. Glycated hemoglobin control is not recommended for pregnant women. The fasting blood glucose test, the glucose level after meals and the fructosamine determination, which corresponds to the group of glycated serum proteins, are more efficient in this case. The main difference between A1C and fasting blood glucose is that the levels of A1C vary more slowly, depending on the half-life of red blood cells. Therefore, they do not return to normality immediately after the normalization of glucose in the blood. The time to reach appropriate levels of A1C after a period of hyperglycemia is approximately 10 weeks. Consequently, A1C exams should be repeated only two to three months after the beginning or the modification of the therapeutic scheme in order to assess its effectiveness. Diseases that affect the survival of red blood cells, such as hemolytic anemia and hemorrhage, may result in false low A1C values due to the reductions of their half-life. On the other hand, anemia caused by iron, vitamin B12 or folate deficiencies, which increase the half-life of red blood cells, may result in false elevated A1C values. Depending on the methodology applied, other medical conditions, such as hypertriglyceridemia, hyperbilirubinemia, uremia, chronic alcoholism and chronic use of opiates or salicylates, may interfere in the results of A1C. Not only is the Brazilian official recommendation the use of DCCT traceable methods, certified by the National Glycohemoglobin Standardization Program (NGSP), but it also encourages participation in specific proficiency testing programs of glycated hemoglobin.O diabetes mellitus (DM) continua sendo objeto de pesquisa, dadas as constantes informações que os estudos clínicos e os novos recursos laboratoriais incorporam à prática médica a cada dia e com maiores rapidez e eficiência. Níveis glicêmicos persistentemente elevados são danosos ao organismo e o descontrole prolongado resulta em complicações, incluindo danos em diversos tecidos, perda da função normal e falência de vários órgãos. Para o acompanhamento do portador de DM, a hemoglobina glicada (A1C) tem se firmado como ferramenta útil depois de ter sido validada pelos dois estudos clínicos mais importantes sobre a avaliação do impacto do rígido controle glicêmico sobre a incidência e a progressão das complicações do diabetes: o Diabetes Control and Complications Trial (DCCT, 1993) e o United Kingdom Prospective Diabetes Study (UKPDS, 1998). Essas pesquisas demonstraram que manter o nível de A1C abaixo de 7% reduz o risco de desenvolvimento das complicações dessa doença. O Grupo Interdisciplinar de Padronização da Hemoglobina Glicada - A1C, criado pela associação de diversas sociedades científicas e farmacêuticas do Brasil, publicou, em 2004, um documento de posicionamento oficial acerca da importância da A1C para a avaliação do controle glicêmico, abordando os principais aspectos clínicos e laboratoriais, incluindo as condições de variação pré-analítica e analítica. Foram estabelecidas as recomendações a respeito das indicações do teste e dos valores ideais de controle para adultos, crianças e idosos. Segundo este posicionamento, os testes de A1C devem ser realizados pelo menos duas vezes ao ano por todos os portadores de DM. Quando os resultados não forem adequados e/ou forem realizadas alterações no esquema terapêutico, a dosagem deve ser feita depois de três meses. A dosagem está indicada tanto para os portadores de diabetes mellitus tipo 1 (DM1) quanto tipo 2 (DM2), sendo que a meta a ser atingida, representando efetivo controle, em ambas as condições é abaixo de 7%, tanto no adulto como no adulto jovem. Para as crianças durante a fase pré-puberal, o nível aceitável de A1C é de até 8% e, na fase puberal, até 8,5%. Nos pacientes idosos, a A1C de até 8% é considerada apropriada, uma vez que a tentativa de um controle muito rígido da glicemia nesta faixa etária, assim como nas fases pré-puberal e puberal, pode induzir a efeitos colaterais indesejados, como, por exemplo, hipoglicemia. Para a paciente gestante não está indicado o acompanhamento do controle glicêmico pela dosagem de A1C, sendo mais eficiente o controle dos níveis das glicemias de jejum e duas horas após as refeições e a dosagem de frutosamina, que corresponde ao conjunto das proteínas plasmáticas glicosadas. O grande diferencial da A1C em relação à glicemia de jejum é que os níveis daquela variam mais lentamente, dependendo da meia-vida das hemácias, portanto não retornam ao normal imediatamente depois da normalização da glicose no sangue. O tempo para que a A1C atinja os níveis adequados após um período de hiperglicemia é de aproximadamente dez semanas. Assim, a repetição do exame de A1C para avaliar a eficácia de um tratamento deve ser realizada somente dois a três meses depois do início ou da modificação do esquema terapêutico. Doenças que alteram a sobrevida das hemácias, como anemia hemolítica e hemorragia, por reduzirem sua vida média, podem resultar em valores falsamente baixos de Hb A1C, enquanto as anemias por carência de ferro, de vitamina B12 ou de folato, que aumentam a vida média das hemácias, resultam em valores falsamente elevados. Na dependência da metodologia utilizada, outras condições clínicas podem interferir no resultado de A1C, como hipertrigliceridemia, hiperbilirrubinemia, uremia, alcoolismo crônico, uso prolongado de opiáceos ou de salicilatos. O posicionamento oficial brasileiro recomenda a utilização de métodos rastreáveis do Diabetes Control and Complications Trial (DCCT), conforme certificado pelo National Glycohemoglobin Standardization Program (NGSP), e estimula a participação em programas de ensaios de proficiência específicos para A1C.Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP, EPM, Depto. de MedicinaSciELOSociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de CitopatologiaUniversidade de São Paulo (USP)Universidade Federal de São Paulo (UNIFESP)Sumita, Nairo MassakazuAndriolo, Adagmar [UNIFESP]2015-06-14T13:38:37Z2015-06-14T13:38:37Z2008-06-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersion169-174application/pdfhttp://dx.doi.org/10.1590/S1676-24442008000300003Jornal Brasileiro de Patologia e Medicina Laboratorial. Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, v. 44, n. 3, p. 169-174, 2008.10.1590/S1676-24442008000300003S1676-24442008000300003.pdf1676-2444S1676-24442008000300003http://repositorio.unifesp.br/handle/11600/4453porJornal Brasileiro de Patologia e Medicina Laboratorialinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UNIFESPinstname:Universidade Federal de São Paulo (UNIFESP)instacron:UNIFESP2024-07-28T15:38:11Zoai:repositorio.unifesp.br/:11600/4453Repositório InstitucionalPUBhttp://www.repositorio.unifesp.br/oai/requestbiblioteca.csp@unifesp.bropendoar:34652024-07-28T15:38:11Repositório Institucional da UNIFESP - Universidade Federal de São Paulo (UNIFESP)false
dc.title.none.fl_str_mv Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
Glycohemoglobin importance in the diabetes mellitus control and in the risk evaluation of chronic complications
title Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
spellingShingle Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
Sumita, Nairo Massakazu
Diabetes mellitus
Glycated hemoglobin
A1C
Glycemic control
Diabetes mellitus
Hemoglobina glicada
A1C
Controle glicêmico
title_short Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
title_full Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
title_fullStr Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
title_full_unstemmed Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
title_sort Importância da hemoglobina glicada no controle do diabetes mellitus e na avaliação de risco das complicações crônicas
author Sumita, Nairo Massakazu
author_facet Sumita, Nairo Massakazu
Andriolo, Adagmar [UNIFESP]
author_role author
author2 Andriolo, Adagmar [UNIFESP]
author2_role author
dc.contributor.none.fl_str_mv Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
dc.contributor.author.fl_str_mv Sumita, Nairo Massakazu
Andriolo, Adagmar [UNIFESP]
dc.subject.por.fl_str_mv Diabetes mellitus
Glycated hemoglobin
A1C
Glycemic control
Diabetes mellitus
Hemoglobina glicada
A1C
Controle glicêmico
topic Diabetes mellitus
Glycated hemoglobin
A1C
Glycemic control
Diabetes mellitus
Hemoglobina glicada
A1C
Controle glicêmico
description Diabetes mellitus remains a subject of study due to the fact that clinical trials and new laboratory resources have increasingly added updated information to medical practice. High glycemic levels are harmful and their persistence results in complications such as tissue damage, loss of normal function and failure of several organs. Glycated hemoglobin control has been a useful tool to monitor diabetic patients, and this analyte was validated by two major clinical studies about the impact assessment of rigid glycemic control on the incidence and progression of diabetes complications: Diabetes Control and Complications Trial (DCCT, 1993) and United Kingdom Prospective Diabetes Study (UKPDS, 1998). These studies showed that glycated hemoglobin level below 7% reduces the risk of complications in diabetes. In 2004, the Interdisciplinary Group of Standardization of Glycated Haemoglobin-A1C, a group of specialists from scientific societies and pharmaceutical companies in Brazil, published an official statement about the importance of glycated hemoglobin for the assessment of glycemic control. It discusses the clinical and laboratory aspects, which includes pre-analytical and analytical variations. The recommendations for the use of the test and the ideal control levels for adults, children and elderly people were established. According to this document, A1C tests should be performed at least twice a year by all patients with diabetes mellitus. However, when the results are not appropriate and/or changes are made in the therapeutic scheme, the test should be performed after three months. It is recommended for individuals with diabetes types 1 and 2 and the goal to be achieved is below 7% for effective control in both adults and youngsters. For children during the prepubertal stage the acceptable level of A1C is up to 8% and in pubertal stage, up to 8.5%. In elderly patients, A1C up to 8% is considered appropriate insofar as the attempt to a rigid glycemic level in this age group as well as in prepubertal and pubertal stages may cause side effects such as hypoglycemia. Glycated hemoglobin control is not recommended for pregnant women. The fasting blood glucose test, the glucose level after meals and the fructosamine determination, which corresponds to the group of glycated serum proteins, are more efficient in this case. The main difference between A1C and fasting blood glucose is that the levels of A1C vary more slowly, depending on the half-life of red blood cells. Therefore, they do not return to normality immediately after the normalization of glucose in the blood. The time to reach appropriate levels of A1C after a period of hyperglycemia is approximately 10 weeks. Consequently, A1C exams should be repeated only two to three months after the beginning or the modification of the therapeutic scheme in order to assess its effectiveness. Diseases that affect the survival of red blood cells, such as hemolytic anemia and hemorrhage, may result in false low A1C values due to the reductions of their half-life. On the other hand, anemia caused by iron, vitamin B12 or folate deficiencies, which increase the half-life of red blood cells, may result in false elevated A1C values. Depending on the methodology applied, other medical conditions, such as hypertriglyceridemia, hyperbilirubinemia, uremia, chronic alcoholism and chronic use of opiates or salicylates, may interfere in the results of A1C. Not only is the Brazilian official recommendation the use of DCCT traceable methods, certified by the National Glycohemoglobin Standardization Program (NGSP), but it also encourages participation in specific proficiency testing programs of glycated hemoglobin.
publishDate 2008
dc.date.none.fl_str_mv 2008-06-01
2015-06-14T13:38:37Z
2015-06-14T13:38:37Z
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format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://dx.doi.org/10.1590/S1676-24442008000300003
Jornal Brasileiro de Patologia e Medicina Laboratorial. Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, v. 44, n. 3, p. 169-174, 2008.
10.1590/S1676-24442008000300003
S1676-24442008000300003.pdf
1676-2444
S1676-24442008000300003
http://repositorio.unifesp.br/handle/11600/4453
url http://dx.doi.org/10.1590/S1676-24442008000300003
http://repositorio.unifesp.br/handle/11600/4453
identifier_str_mv Jornal Brasileiro de Patologia e Medicina Laboratorial. Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, v. 44, n. 3, p. 169-174, 2008.
10.1590/S1676-24442008000300003
S1676-24442008000300003.pdf
1676-2444
S1676-24442008000300003
dc.language.iso.fl_str_mv por
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dc.relation.none.fl_str_mv Jornal Brasileiro de Patologia e Medicina Laboratorial
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dc.format.none.fl_str_mv 169-174
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dc.publisher.none.fl_str_mv Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia
publisher.none.fl_str_mv Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia
dc.source.none.fl_str_mv reponame:Repositório Institucional da UNIFESP
instname:Universidade Federal de São Paulo (UNIFESP)
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