Modelo homeostático para evaluar la resistencia a la insulina (HOMA-IR) y síndrome metabólico en la línea de base de una cohorte brasileña multicéntrica : estudio ELSA-Brasil

Homeostasis model assessment of insulin resistance (HOMA-IR) is a method to measure insulin resistance. HOMA-IR cut-offs for identifying metabolic syndrome might vary across populations and body mass index (BMI) levels. We aimed to investigate HOMA-insulin resistance cut-offs that best discriminate individuals with insulin resistance and with metabolic syndrome for each BMI category in a large sample of adults without diabetes in the baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Among the 12,313 participants with mean age of 51.2 (SD 8.9) years, the prevalence of metabolic syndrome was 34.6%, and 60.1% had overweight or obesity. The prevalence of metabolic syndrome among normal weight, overweight and obesity categories were, respectively, 13%, 43.2% and 60.7%. The point of maximum combined sensitivity and specificity of HOMA-IR to discriminate the metabolic syndrome was 2.35 in the whole sample, with increasing values at higher BMI categories. This investigation contributes to better understanding HOMA-IR values associated with insulin resistance and metabolic syndrome in a large Brazilian adult sample, and that use of cut-off points according to ROC curve may be the better strategy. It also suggests that different values might be appropriate across BMI categories

Avaliação dos níveis plasmáticos de peptídeo natriurético tipo B e relação com obesidade mórbida e comorbidades associadas

Exportado OPUSMade available in DSpace on 2019-08-13T04:19:23Z (GMT). No. of bitstreams: 1 alline_maria_rezende_beleigoli.pdf: 1082462 bytes, checksum: 53dd48217a2a827e98540497532f7609 (MD5) Previous issue date: 8A obesidade mórbida (OM) apresenta níveis de crescimento mais importantes que qualquer outra forma da doença e está fortemente associada a comorbidades cardiovasculares. A insuficiência cardíaca (IC) é causa de elevadas morbidade e mortalidade e seu diagnóstico constitui verdadeiro desafio nessa população, devido à inespecificidade do quadro clínico e às limitações dos métodos diagnósticos existentes. Nesse contexto, o peptídeo natriurético tipo B (BNP) é potencialmente útil no diagnóstico de IC na OM. De acordo com as regras do Programa de Pós-Graduação em Saúde do Adulto, o presente estudo resultou em dois artigos. O primeiro é revisão publicada no periódico Obesity Reviews, em novembro de 2009. O segundo artigo descreve os resultados de estudo transversal, realizado de julho de 2008 a julho de 2009, com recrutamento consecutivo dos participantes no Grupo Multidisciplinar para Tratamento Cirúrgico da OM, no Hospital das Clínicas da UFMG e no ambulatório de obesidade do Centro de Especialidades Médicas da Santa Casa de Belo Horizonte. Revisão da literatura de língua inglesa mostrou que, além de ações hemodinâmicas, os peptídeos natriuréticos (PN) apresentam efeito lipolítico. Entre os 75 estudos selecionados, os que descreveram o comportamento dos PN em obesos, revelam, em sua maioria, níveis plasmáticos reduzidos em relação a indivíduos magros. Esse achado, aparentemente paradoxal, aponta para o papel dos PN na fisiopatologia da obesidade e de comorbidades, como hipertensão arterial e síndrome metabólica. Verificou-se grande heterogeneidade entre os estudos revisados, com diferenças importantes em relação à metodologia, seleção de pacientes e avaliação de obesidade e IC. Tais achados impossibilitam conclusões definitivas sobre o tema e indicam a necessidade de mais estudos na área. No estudo transversal, oitenta e nove obesos classe III foram submetidos à avaliação clínica, laboratorial, eletro e ecocardiográfica e dosagem de BNP, conforme protocolos padronizados, com os objetivos de descrever o comportamento do BNP e investigar sua utilidade na predição de disfunção ventricular. O BNP apresentou desde níveis inferiores ao limite de detecção do método (< 5,0 pg/mL) até 151,0 pg/mL. O BNP mostrou distribuição não-normal, com média de 19,5 ± 27,4 pg / mL e mediana de 9,5 pg / mL. Trinta porcento dos participantes apresentaram BNP abaixo do limite de detecção do método e seis por cento, níveis considerados diagnósticos de IC sistólica (= 100 pg/mL). Apenas quatro porcento tiveram diagnóstico de IC sistólica por avaliação clínica e ecocardiográfica. Análise de regressão logística ordinal, mostrou que, entre todas as variáveis clinica e/ou estatisticamente relevantes para entrada no modelo, apenas o volume do átrio esquerdo, marcador de disfunção diastólica, foi determinante dos valores de BNP (p=0,002). A partir dos resultados da revisão, conclui-se que os PN são agentes lipolíticos e seus níveis são diminuídos em obesos em relação a magros, refletindo a provável participação deles na fisiopatologia da obesidade. O estudo transversal mostra que obesos classe III apresentam níveis baixos de BNP, porém o peptídeo é útil na identificação de disfunção diastólica. Não foi possível estabelecer conclusões a respeito do comportamento do BNP em obesos mórbidos com disfunção sistólica.Following obesity epidemics, severe obesity has been increasing more importantly than any other form of obesity. Hence, morbid conditions associated to severe obesity, such as heart failure (HF), have had an impressive increase, as well. Diagnosing HF may be challenging, due to unspecific symptoms and signs, and limitations of diagnostic methods. In this context, brain natriuretic peptide (BNP) is a potential tool for identifying HF in the morbid obese population. Following the rules of the Adult Health Sciences Post-Graduation Program of the Medicine School of the Federal University of Minas Gerais, this study was composed by two phases. Each one resulted in a scientific article. The first one is a systematic review, published in Obesity Reviews, in November 2009. The second one is an original article, which displays the results of a cross- sectional study. The systematic review included seventy-five and revealed that natriuretic peptides (NP) have metabolic effects as potent lipolytic agents, in addition to cardiovascular actions. Most of the reviewed articles showed lower NP levels among obese subjects in relation to lean ones. This apparently paradoxical finding points to the potential role of NP in the physiopathological mechanisms of obesity, and obesity associated hypertension and metabolic syndrome. A critical analysis of the selected studies was performed as well. It revealed important heterogeinity among the studies in relation to methodology, participant´s selection criteria and criteria for diagnosing obesity and HF. Hence, definitive conclusions on NP behavior in obesity are not possible and we noticed the necessity for more studies on the subject. The cross-sectional study recruited participants from two obesity clinics in Hospital das Clínicas da UFMG and Centro de Especialidades Médicas da Santa Casa in Belo Horizonte, from July 2008 to July 2009. Its aim was to describe BNP behavior and investigate its utility in predicting ventricular dysfunction in class III obese patients. Clinical, laboratorial, electro and echocardiographic evaluation and BNP measures were performed in eighty-nine participants. BNP values varied from indetectable by the test (< 5.0 pg/mL) to 151.0 pg/mL. Thirty percent of the patients had values below 5.0 pg/mL and only six percent had values on the habitual range considered to diagnose heart failure (= 100 pg/mL). Multivariate ordinal logistic regression analysis verified that left atrial volume (LAV) was the only determinant of BNP levels among all the clinical, laboratorial and echocardiographic data considered relevant to enter the model (p=0.002). LAV is a marker of sustained left ventricular filling pressures and chronic diastolic dysfunction. Based on the systematic review results, it is possible to conclude that NP have important metabolic action as potent lipolytic agents. BNP levels are reduced in the obese subjects in relation to the lean ones. It probably has a role in obesity physiopathology. The second article showed low BNP levels, but the peptide was still able to identify diastolic dysfunction in severe obesity. It was not possible to determine the role of BNP in predicting systolic disfunction in class III obese patients

Factors associated with metabolically healthy status in obesity, overweight, and normal weight at baseline of ELSA-Brasil

The primary aim of this study was to evaluate metabolically healthy status (MHS) among participants in obesity, overweight, and normal weight groups and characteristics associated with this phenotype using baseline data of Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The secondary aim was to investigate agreement among 4 different MHS criteria. This cross-sectional study included 14,545 participants aged 35 to 74 years with a small majority (54.1%) being women. Of all participants, 22.7% (n=3298) were obese, 40.8% (n=5934) were overweight, and 37.5% (n=5313) were of normal weight. Socio-demographic, behavioral, and anthropometric factors related to MHS were ascertained. Logistic regression models estimated the odds of associations. We used 4 different criteria separately and in combination to define MHS: the National Health and Nutrition Examination Survey (NHANES), the National Cholesterol Education Program (NCEP-ATPIII), the International Diabetes Federation (IDF) and comorbidities, and the agreement between them were evaluated by Cohen-kappa coefficient. MHS was present among 12.0% (n=396) of obese, 25.5% (n=1514) of overweight, and 48.6% (n=2582) of normal weight participants according to the combination of the 4 criteria. The agreement between all the 4 MHS criteria was strong (kappa 0.73 P< 0.001). In final logistic models, MHS was associated with lower age, female sex, lower body mass index (BMI), and weight change from age 20 within all BMI categories. This study showed that, despite differences in prevalence among the 4 criteria, MHS was associated with common characteristics at every BMI category

Factors associated with metabolically healthy status in obesity, overweight, and normal weight at baseline of ELSA-Brasil

The primary aim of this study was to evaluate metabolically healthy status (MHS) among participants in obesity, overweight, and normal weight groups and characteristics associated with this phenotype using baseline data of Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The secondary aim was to investigate agreement among 4 different MHS criteria. This cross-sectional study included 14,545 participants aged 35 to 74 years with a small majority (54.1%) being women. Of all participants, 22.7% (n=3298) were obese, 40.8% (n=5934) were overweight, and 37.5% (n=5313) were of normal weight. Socio-demographic, behavioral, and anthropometric factors related to MHS were ascertained. Logistic regression models estimated the odds of associations. We used 4 different criteria separately and in combination to define MHS: the National Health and Nutrition Examination Survey (NHANES), the National Cholesterol Education Program (NCEP-ATPIII), the International Diabetes Federation (IDF) and comorbidities, and the agreement between them were evaluated by Cohen-kappa coefficient. MHS was present among 12.0% (n=396) of obese, 25.5% (n=1514) of overweight, and 48.6% (n=2582) of normal weight participants according to the combination of the 4 criteria. The agreement between all the 4 MHS criteria was strong (kappa 0.73 P< 0.001). In final logistic models, MHS was associated with lower age, female sex, lower body mass index (BMI), and weight change from age 20 within all BMI categories. This study showed that, despite differences in prevalence among the 4 criteria, MHS was associated with common characteristics at every BMI category