Álvaro Vigo

Leptin and incident type 2 diabetes: risk or protection?

Aims/hypothesisThe aim of this study was to investigate the association of leptin levels with incident diabetes in middle-aged adults, taking into account factors purportedly related to leptin resistance.Subjects and methodsWe conducted a case–cohort study (570 incident diabetes cases and 530 non-cases) representing the 9-year experience of 10,275 participants of the Atherosclerosis Risk in Communities Study. Plasma leptin was measured by direct sandwich ELISA.ResultsIn proportional hazards models adjusting for age, study centre, ethnicity and sex, high leptin levels (defined by sex-specific cut-off points) predicted an increased risk of diabetes, with a hazard ratio (HR) comparing the upper with the lower quartile of 3.9 (95% CI 2.6–5.6). However, after further adjusting additionally for obesity indices, fasting insulin, inflammation score, hypertension, triglycerides and adiponectin, high leptin predicted a lower diabetes risk (HR=0.40, 95% CI 0.23–0.67). Additional inclusion of fasting glucose attenuated this protective association (HR=0.59, 95% CI 0.32–1.08, p<0.03 for linear trend across quartiles). In similar models, protective associations were generally seen across subgroups of sex, race, nutritional status and smoking, though not among those with lower inflammation scores or impaired fasting glucose (interaction p=0.03 for both).Conclusions/interpretationHigh leptin levels, probably reflecting leptin resistance, predict an increased risk of diabetes. Adjusting for factors purportedly related to leptin resistance unveils a protective association, independent of adiponectin and consistent with some of leptin’s described protective effects against diabetes.

Doenças crônicas não transmissíveis no Brasil: prioridade para enfrentamento e investigação

As Doencas Cronicas Nao Transmissiveis representam a maior carga de morbimortalidade no Brasil. Em 2011, o Ministerio da Saude lancou seu Plano de Acoes Estrategicas para o Enfrentamento das Doencas Cronicas Nao Transmissiveis, enfatizando acoes populacionais para controlar as doencas cardiovasculares, diabetes, câncer e doenca respiratoria cronica, predominantemente pelo controle do fumo, inatividade fisica, alimentacao inadequada e uso prejudicial de alcool. Apesar da producao cientifica significativa sobre essas doencas e seus fatores de risco no Brasil, poucos sao os estudos de coorte nessa tematica. Nesse contexto, o Estudo Longitudinal da Saude do Adulto (ELSA-Brasil) acompanha 15.105 servidores publicos do Pais. Seus dados espelham a realidade brasileira de altas prevalencias de diabetes e hipertensao e dos fatores de risco. A diversidade das informacoes produzidas permitira aprofundar o entendimento causal dessas doencas e subsidiar politicas publicas para seu enfrentamento.Chronic Non-Communicable Diseases are the main source of disease burden in Brazil. In 2011, the Brazilian Ministry of Health launched the Strategic Plan of Action for Management of Chronic Non-Communicable Diseases focusing on population-based interventions to manage cardiovascular diseases, diabetes, cancer, and chronic respiratory diseases mainly through fighting tobacco use, unhealthy diets, physical inactivity and the harmful use of alcohol. Although a significant number of scientific studies on chronic diseases and their risk factors have been undertaken in Brazil, few are of cohort design. In this context, the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a cohort study of 15,105 Brazilian public servants reflects the reality of high prevalences of diabetes, hypertension and the main chronic diseases risk factors. The diversity of information that the Study will produce can provide important input to better understand the causes of chronic diseases and to support public policies for fighting them.

Estratégias e desenvolvimento de garantia e controle de qualidade no ELSA-Brasil

The ELSA-Brasil (Estudo Longitudinal de Saude do Adulto - Brazilian Longitudinal Study for Adult Health) is a cohort study composed of 15,105 adults followed up in order to assess the development of chronic diseases, especially diabetes and cardiovascular disease. Its size, multicenter nature and the diversity of measurements required effective and efficient mechanisms of quality assurance and control. The main quality assurance activities (those developed before data collection) were: careful selection of research instruments, centralized training and certification, pretesting and pilot studies, and preparation of operation manuals for the procedures. Quality control activities (developed during data collection and processing) were performed more intensively at the beginning, when routines had not been established yet. The main quality control activities were: periodic observation of technicians, test-retest studies, data monitoring, network of supervisors, and cross visits. Data that estimate the reliability of the obtained information attest that the quality goals have been achieved.

Low birth weight and markers of inflammation and endothelial activation in adulthood: The ARIC study

BACKGROUND To investigate the hypothesis that intrauterine growth restriction might produce a longstanding pro-inflammatory tendency, we investigated the association of low birth weight with blood levels of markers of inflammation and endothelial activation in middle-aged adults. METHODS The ARIC Study enrolled subjects aged 45-64 years sampled from four U.S. communities. An inflammation/endothelial activation score from 0 to 6 was created, one point being given for each above-median value of white blood cell count, fibrinogen, von Willebrand factor and Factor VIII, and for each below-median value of albumin and activated partial thromboplastin time. RESULTS Of the 9809 individuals reporting birth weight and having all inflammation/endothelial markers and covariates, 349 (3.6%) reported low birth weight (LBW). The mean (standard deviation) score was 3.5 (1.5) for those with and 3.1 (1.6) for those without LBW (p<0.001). In robust poisson regression models adjusting for gender, ethnicity, age, study center, educational level, and current drinking and smoking status and amount, those with LBW were more likely to have a high score (> or =4 points) (RR=1.16, 95% CI: 1.05-1.29). CONCLUSION In the ARIC Study, LBW predicted greater inflammation and endothelial activation, as indicated by the higher score of blood markers, consistent with the hypothesis that early life events may result in a hyper-responsive innate immune system. Such a pro-inflammatory tendency could help explain the association of low birth weight with elements of the metabolic syndrome and ischemic heart disease.

Aborto e coerção sexual: o contexto de vulnerabilidade entre mulheres jovens

This study aims to investigate the relationship between abortion and experiences of sexual coercion. The data came from GRAVAD, a household survey with a stratified random sample of young women (18-24 years) in Rio de Janeiro, Porto Alegre, and Salvador, Brazil. The sample used in this article included 870 interviews of women who reported having become pregnant. Abortion was associated with: a reported experience of sexual coercion, more schooling, failure to obtain first information about sex from parents, and a history of more pregnancies and sexual partners. The association between abortion and sexual coercion reflects a situation of gender vulnerability and reveals young womens precariousness in sex negotiation and reproduction. A veil of silence in public agencies concerning sexual coercion helps perpetuate young womens vulnerability, as it blocks access to the appropriate educational, legal, and health services.

Impact of the International Association of Diabetes and Pregnancy Study Groups criteria for gestational diabetes

AIMS To evaluate the diagnostic criteria of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) and alternative criteria in terms of resultant prevalence of gestational diabetes mellitus (GDM) and measures of diagnostic impact. METHODS The Brazilian Gestational Diabetes Study (EBDG) is a cohort of pregnant women enrolled consecutively in prenatal care clinics of the Brazilian National Health Service from 1991 to 1995, a time and setting in which those with lesser than diabetes hyperglycemia rarely received drug treatment. Eligibility criteria were age ≥20 years, gestational age 20-28 weeks and no history of diabetes outside pregnancy. After interview and anthropometric measurements, a standardized 2h 75g OGTT was scheduled. Women were followed through early postpartum. RESULTS Prevalence of GDM defined by IADPSG criteria was 18.0% (95% CI 16.9-19.0), ranging from 2.7 to 17.0% with the alternative criteria. Relative risks for large for gestational age (LGA) and preeclampsia were generally small. The diagnostic impact assessed by pre- to post-test gain in the probability of an outcome was also small (3.6% for LGA and 0.5% for preeclampsia). Alternative criteria reached maximum gains of 9.7% and 5.3%, respectively. The fractions of LGA births and preeclampsia attributable to GDM by the IADPSG criteria were small, 6.7% and 3.5%, respectively. CONCLUSIONS The IADPSG criteria identify more women as having GDM but their diagnostic and population impacts with respect to adverse outcomes are small. Alternative definitions, although also presenting small diagnostic and population impacts, showed advantages which may be useful in specific settings.

Gestational diabetes and pre-eclampsia: common antecedents?

OBJECTIVE To evaluate commonality of risk factor profiles of women who develop gestational diabetes and pre-eclampsia. METHODS Prospective cohort study in prenatal clinics of the Brazilian Unified Health System in six state capitals. 4.766 pregnant women between 20 to 48 years old were consecutively enrolled between 20th and 28th gestational weeks. Smoking habits and traditional risk factors for pre-eclampsia and gestational diabetes were obtained by the interview at enrollment. Gestational diabetes was diagnosed using a 75-g oral glucose tolerance test and pre-eclampsia through chart review. RESULTS Both gestational diabetes and pre-eclampsia were associated with age (OR 2.07; 95% CI 1.65-2.23 and OR 1.55; 95% CI 1.08-2.23, respectively), pre-pregnancy body mass index (OR 1.62; 95% CI 1.40-3.53 and OR 1.83; 95% CI 1.52-4.80, respectively) and weight gain in early pregnancy (OR 1.28; 95% CI 1.12-1.47 and OR 1.27; 95% CI 1.06-1.52, respectively). Lower odds of gestational diabetes (OR 0.31; 95% CI 0.22-0.44) and pre-eclampsia (OR 0.36; 95% CI 0.20-0.51) were observed in nulliparous women who have smoked during pregnancy. CONCLUSIONS Gestational diabetes and pre-eclampsia share a pattern of risk factors, suggesting the possibility of common aetiology.

Prevalence, Correlates, and Description of Self-Reported Diabetes in Brazilian Capitals – Results from a Telephone Survey

Introduction The prevalence of diabetes is increasing worldwide. The objective of this study is to estimate the prevalence of self-reported diabetes in Brazilian adults and to describe its population correlates as well as the clinical characteristics of the reported cases. Methods We analyzed basic and supplementary data of 54.144 subjects participating in VIGITEL 2011 (Surveillance System for Risk and Protective Factors for Chronic Diseases), a telephone survey based on a probabilistic sample of subjects ≥18 years old residing in Brazilian state capitals and the Federal District. Estimates reported are weighted so as to represent the surveyed population. Results The prevalence of self-reported diabetes was 6.3% (95% CI 5.9–6.7), increasing markedly with age and nutritional status, and decreasing with level of education. Prevalence was higher among those self-declaring their race/color as black. Most cases (90%) reported the diagnosis being made at 35 years or older. The vast majority (99.8%) of self-reported cases informed having previously performed at least one glucose test, and 76% of those not reporting diabetes also informed having previously performed glucose testing. Most cases (92.6%) reported following some form of diabetes treatment, 79% taking medication. Conclusion The estimated prevalence of known diabetes found, 6.3%, is consistent with estimates given by international summaries. The additional data collected in VIGITEL 2011 regarding previous glucose testing and current treatment support the use of telephone-based information to monitor the prevalence of known diabetes in Brazilian capitals.

Chronic non-communicable diseases in Brazil: priorities for disease management and research

As Doencas Cronicas Nao Transmissiveis representam a maior carga de morbimortalidade no Brasil. Em 2011, o Ministerio da Saude lancou seu Plano de Acoes Estrategicas para o Enfrentamento das Doencas Cronicas Nao Transmissiveis, enfatizando acoes populacionais para controlar as doencas cardiovasculares, diabetes, câncer e doenca respiratoria cronica, predominantemente pelo controle do fumo, inatividade fisica, alimentacao inadequada e uso prejudicial de alcool. Apesar da producao cientifica significativa sobre essas doencas e seus fatores de risco no Brasil, poucos sao os estudos de coorte nessa tematica. Nesse contexto, o Estudo Longitudinal da Saude do Adulto (ELSA-Brasil) acompanha 15.105 servidores publicos do Pais. Seus dados espelham a realidade brasileira de altas prevalencias de diabetes e hipertensao e dos fatores de risco. A diversidade das informacoes produzidas permitira aprofundar o entendimento causal dessas doencas e subsidiar politicas publicas para seu enfrentamento.Chronic Non-Communicable Diseases are the main source of disease burden in Brazil. In 2011, the Brazilian Ministry of Health launched the Strategic Plan of Action for Management of Chronic Non-Communicable Diseases focusing on population-based interventions to manage cardiovascular diseases, diabetes, cancer, and chronic respiratory diseases mainly through fighting tobacco use, unhealthy diets, physical inactivity and the harmful use of alcohol. Although a significant number of scientific studies on chronic diseases and their risk factors have been undertaken in Brazil, few are of cohort design. In this context, the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a cohort study of 15,105 Brazilian public servants reflects the reality of high prevalences of diabetes, hypertension and the main chronic diseases risk factors. The diversity of information that the Study will produce can provide important input to better understand the causes of chronic diseases and to support public policies for fighting them.

Fasting plasma glucose to avoid a full OGTT in the diagnosis of gestational diabetes

AIMS To evaluate the performance of fasting plasma glucose (FPG) in determining the need for a full oral glucose tolerance test (OGTT) to diagnose gestational diabetes (GDM) by the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. METHODS A multicenter cohort study of 4926 pregnant women 20 years or older consecutively enrolled in prenatal care clinics of the Brazilian National Health Service from 1991 to 1995. All women underwent a single 2 h 75 g OGTT by weeks 24-28 of pregnancy and were followed to detect adverse pregnancy outcomes. RESULTS A FPG cut-off value of 80 mg/dl indicated that only 38.7% of all women needed to undergo a complete OGTT, while detecting 96.9% of all GDM cases. When the 85 mg/dl cut-off was used, the corresponding percentages were 18.7% and 92.5%, respectively. The fraction of women labeled with GDM who had adverse pregnancy outcomes was nearly identical when using FPG strategies and universal full testing. CONCLUSIONS Using a FPG cut-off to diagnose GDM and to determine the need for post-load OGTT measurements is a valid strategy to diagnose GDM by IADPSG criteria. This approach may improve feasibility of applying IADPSG diagnostic criteria by reducing costs and increasing convenience.