Pedro Guatimosim Vidigal

The Bambuí health and ageing study (BHAS): methodological approach and preliminary results of a population-based cohort study of the elderly in Brazil

OBJECTIVE A cohort study has been designed to identify predictors of adverse health events in the elderly. The methodology of the study and preliminary descriptive results are presented. METHODS The study population comprises all residents of Bambuí (Minas Gerais, Brazil), aged 60 or more years (n=1.742). From these, 92.2% were interviewed and 85.9% underwent clinical examination, consisting of haematological and biochemical tests, serology for Trypanosoma cruzi, anthropometric and blood pressure measures and electrocardiogram. Aliquots of serum, plasma and DNA were stored for future investigations. The baseline interview included sociodemographic characteristics, self-referred health condition and history of selected diseases, medication use, health service use, source of medical care, physical activities, smoking, drinking and eating habits, reproductive history, physical functioning, life events, social support and mental health. Individuals are being followed up annually. RESULTS The following characteristics predominated among participants: women (60,0%), married (48.9%) or widowed (35.4%), people living in households with up to 2 residents (73.8%), heads of family (76.7%), people with monthly income between 1.00 and 2.99 Brazilian minimum wages (62.0%) and people with up to 4 years of schooling (89.1%). The median age was 68 years. Among the cohort members, only 1.7% were lost in the first follow-up. CONCLUSIONS In general, the characteristics of the study population were very similar to those from other epidemiological studies of the elderly based on large Brazilian cities. The small number of losses to follow-up indicates that the choice of Bambuí was adequate, assuring the feasibility of a long term cohort study.

The Bambuí Health and Aging Study (BHAS): private health plan and medical care utilization by older adults

The aim of this cross sectional study was to investigate whether holding a private health plan affects the consumption of medical services (hospitalization and visits to a doctor) and use of medications by older adults. All residents in Bambuí town (Minas Gerais, Brazil) aged >/= 60 years (n = 1,742) were selected. From these, 92.2% were interviewed and 85.9% were examined (blood tests and physical measurements). After adjustments for worse health status, reported less visits to a doctor, and used a small number of prescribed medications. The main explanation for the aged holding a private health plan was economic, not health. Even though those who had only public health coverage complained more in relation to medical care (70.9%), an important proportion of the aged with a private health care plan presented some kind of complaint (45.2%). Another worrying factor was the difficulty to acquire medication because of financial problems (47.2 and 25.2% reported, respectively). Further investigations are needed to verify whether our results can be generalized to other communities of the country.

Logistica de coleta e transporte de material biologico e organizacao do laboratorio central no ELSA-Brasil

The ELSA (Estudo Longitudinal de Saude do Adulto - Brazilian Longitudinal Study for Adult Health) is a multicenter cohort study which aims at the identification of risk factors associated with type 2 diabetes and cardiovascular diseases in the Brazilian population. The paper describes the strategies for the collection, processing, transportation, and quality control of blood and urine tests in the ELSA. The study decided to centralize the tests at one single laboratory. The processing of the samples was performed at the local laboratories, reducing the weight of the material to be transported, and diminishing the costs of transportation to the central laboratory at the Universidade de Sao Paulo Hospital. The study included tests for the evaluation of diabetes, insulin resistance, dyslipidemia, electrolyte abnormalities, thyroid hormones, uric acid, hepatic enzyme abnormalities, inflammation, and total blood cell count. In addition, leukocyte DNA, urine, plasma and serum samples were stored. The central laboratory performed approximately 375,000 tests.

The Bambuí Health and Aging study (BHAS): prevalence of risk factors and use of preventive health care services

OBJECTIVE To describe, for the first time in Brazil, the prevalence of risk factors and the use of preventive health care services among adults 60 years and older. METHODS This population-based study was conducted during 1996-1997 in the state of Minas Gerais, in the town of Bambuí, which is located in the municipality of the same name. In 1996 the town had 14,950 inhabitants. For the study, all the towns residents aged > or = 60 years were selected, along with a comparison sample of persons aged 18-59 years. Data were gathered using interviews and physical examinations. RESULTS Of the 1,742 inhabitants of the town of Bambuí aged > or = 60 years, 1,606 (92.2%) participated in the interview and 1,495 (85.8%) were examined (blood pressure, anthropometric measurements, and blood tests). Among the 1,020 younger adults selected for the survey, 909 of them (89.1%) participated in the interview, and 820 of them (80.4%) underwent the physical examination. The prevalence of the following risk factors was higher among older adults than among younger adults: physical inactivity (47.7% vs. 28.0%); blood pressure 140-159 mmHg (systolic) or 90-99 mmHg (diastolic) (25.8% vs. 8.7%); blood pressure > or = 160 mmHg (systolic) or > or = 100 mmHg (diastolic) (19.1% vs. 4.1%); total cholesterol > or = 240 mg/dL (40.6% vs. 9.8%); and blood glucose > or = 126 mg/dL (12.4% vs. 2.2%). The daily consumption of fruits and vegetables was similar among the older adults and the younger ones (51.9% and 51.7%), as was also body mass index > or = 25 kg/m2 (51.6% and 56.2%). Smoking was lower among the older adults (18.7%) than among the younger ones (31.1%). The proportion of participants whose blood pressure had been checked in the preceding year was high (86.8% among the older adults and 61.2% among the younger ones), suggesting that the high prevalence of uncontrolled hypertension was not due to limited access to health care. CONCLUSIONS For a long time it was believed that the kinds of risk factors that we found in the urban section of the municipality of Bambuí were public health problems only in large Brazilian cities. Around 72% of the municipalities in Brazil have < or = 20,000 inhabitants, and these smaller municipalities contain some 19% of the countrys entire population. The high prevalence of various risk factors among the older and younger adults in Bambuí indicates a great need for health promotion and disease prevention actions. More research is needed to find out whether our results in Bambuí reflect the reality of other small towns in Brazil.

Prevalence of sleep complaints and associated factors in community-dwelling older people in Brazil: the Bambuı́ Health and Ageing Study (BHAS)

BACKGROUND Population-based studies of insomnia among older people residing in communities in developing countries are rare. The objectives of this population-based study were to determine the prevalence and factors associated with insomnia among older adults (60 years and over) living in a Brazilian town with 15,000 inhabitants (Bambuí MG). METHODS All 1742 residents in this age group were selected for a structured interview and blood tests. From these, 1516 (87.0%) participated in the study. RESULTS The prevalence of insomnia was 38.9%, being higher among women (45.3%) than among men (28.8%). The use of sleeping pills was reported by 380/1513 (25.1%) of the participants; 186 (49.0%) of these complained of insomnia, suggesting that their treatment should be reassessed. Factors independently associated with insomnia were: female sex (OR=1.78, 95% CI=1.41-2.24), dissatisfaction with free time arrangements (OR=1.88, 95% CI=1.28-2.77), self-rated health as reasonable or bad/very bad (OR=2.02, 95% CI=1.50-2.72 and OR=3.12, 95% CI=2.21-4.39, respectively), history of previous medical diagnosis of some chronic conditions (OR=1.38, 95% CI=1.10-1.73), inability to perform routine activities due to a health problem in the previous 2 weeks (OR=1.54, 95% CI=1.10-2.15), and staying in bed in the previous 2 weeks (OR=1.61, 95% CI=1.04-2.48). CONCLUSIONS The prevalence of insomnia was high, indicating that this was a public health problem for older adults living in the study community. Our results emphasize the necessity for further investigations about insomnia among older people living in small communities in Brazil and other developing countries.

Chronic kidney disease among adult participants of the ELSA-Brasil cohort: association with race and socioeconomic position

Background There is increased interest in understanding why chronic kidney disease (CKD) rates vary across races and socioeconomic groups. We investigated the distribution of estimated glomerular filtration rate (eGFR), urinary albumin–creatinine ratio (ACR) and CKD according to these factors in Brazilian adults. Methods Using baseline data (2008–2010) of 14 636 public sector employees (35–74 years) enrolled in the Brazilian Longitudinal Study of Adult Health (ELSA)-Brasil multicentre cohort, we estimated the prevalence of CKD by sex, age, race and socioeconomic factors. CKD was defined as ACR≥30 mg/g and/or eGFR<60 mL/min/1.73 m2. GFR was estimated by CKD epidemiology collaboration without correction for race. We used logistic regression to estimate the association of race and socioeconomic position (education, income, social class and occupational nature) with CKD after adjusting for sex, age and several health-related factors. Results The prevalence of high ACR or low eGFR, in isolation and combined, increased with age, and was higher in individuals with lower socioeconomic position and among black individuals and indigenous individuals. The overall prevalence of CKD was 8.9%. After full adjustments, it was similar in men and women (OR=0.90; 95% CI 0.79 to 1.02) and increased with age (OR=1.07; 95% CI 1.06 to 1.08). Compared to white individuals, black individuals (OR=1.23; 95% CI 1.03 to 1.47), ‘pardos’ (OR=1.16; 95% CI 1.00 to 1.35) and Indigenous (OR=1.72; 95% CI 1.07 to 2.76) people had higher odds for CKD. Having high school (OR=1.15; 95% CI 1.00 to 1.34) or elementary education (OR=1.23; 95% CI 1.03 to 1.47) increased the odds for CKD compared to those having a university degree. Conclusions There were marked discrepancies in the increases in reduced eGFR and high ACR with age and race. The higher prevalences of CKD in individuals with lower educational status and in non-whites were not explained by differences in health-related factors.

C-Reactive Protein and B-Type Natriuretic Peptide Yield Either a Non-Significant or a Modest Incremental Value to Traditional Risk Factors in Predicting Long-Term Overall Mortality in Older Adults

Background New biomarkers may aid in preventive and end-of-life decisions in older adults if they enhance the prognostic ability of traditional risk factors. We investigated whether C-reactive protein (CRP) and/or B-type natriuretic peptide (BNP) improve the ability to predict overall mortality among the elderly of the Bambuí, Brazil Study of Aging when added to traditional risk factors. Methods From 1997 to 2007, 1,470 community-dwelling individuals (≥60 years) were followed-up. Death was ascertained by continuous verification of death certificates. We calculated hazard ratios per 1 standard deviation change (HR) of death for traditional risk factors only (old model), and traditional risk factors plus CRP and/or BNP (new models) and assessed calibration of the models. Subsequently, we compared c-statistic of each of the new models to the old one, and calculated integrated discriminative improvement (IDI) and net reclassification improvement (NRI). Results 544 (37.0%) participants died in a mean follow-up time of 9.0 years. CRP (HR 1.28, 95% CI 1.17-1.40), BNP (HR 1.31 95% CI 1.19-1.45), and CRP plus BNP (HR 1.26, 95% CI 1.15-1.38, and HR 1.29, 95% CI 1.16-1.42, respectively) were independent determinants of mortality. All models were well-calibrated. Discrimination was similar among the old (c-statistic 0.78 [0.78-0.81]) and new models (p=0.43 for CRP; p=0.57 for BNP; and p=0.31 for CRP plus BNP). Compared to the old model, CRP, BNP, and CRP plus BNP models led to an IDI of 0.009 (p<0.001), -0.005 (p<0.001) and -0.003 (p=0.84), and a NRI of 0.04 (p=0.24), 0.07 (p=0.08) and 0.06 (p=0.10), respectively. Conclusions Despite being independent predictors of long-term risk of death, compared to traditional risk factors CRP and/or BNP led to either a modest or non-significant improvement in the ability of predicting all-cause mortality in older adults.

Life Course Socioeconomic Position and C-Reactive Protein: Mediating Role of Health-Risk Behaviors and Metabolic Alterations. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background Chronic inflammation has been postulated to be one mediating mechanism explaining the association between low socioeconomic position (SEP) and cardiovascular disease (CVD). We sought to examine the association between life course SEP and C-reactive protein (CRP) levels in adulthood, and to evaluate the extent to which health-risk behaviors and metabolic alterations mediate this association. Additionally, we explored the possible modifying influence of gender. Methods and Findings Our analytical sample comprised 13,371 participants from ELSA-Brasil baseline, a multicenter prospective cohort study of civil servants. SEP during childhood, young adulthood, and adulthood were considered. The potential mediators between life course SEP and CRP included clusters of health-risk behaviors (smoking, low leisure time physical activity, excessive alcohol consumption), and metabolic alterations (obesity, hypertension, low HDL, hypertriglyceridemia, and diabetes). Linear regression models were performed and structural equation modeling was used to evaluate mediation. Although lower childhood SEP was associated with higher levels of CRP in adult life, this association was not independent of adulthood SEP. However, CRP increased linearly with increasing number of unfavorable social circumstances during the life course (p trend <0.001). The metabolic alterations were the most important mediator between cumulative SEP and CRP. This mediation path accounted for 49.5% of the total effect of cumulative SEP on CRP among women, but only 20.2% among men. In consequence, the portion of the total effect of cumulative SEP on CRP that was mediated by risk behaviors and metabolic alterations was higher among women (55.4%) than among men (36.8%). Conclusions Cumulative SEP across life span was associated with elevated systemic inflammation in adulthood. Although health-risk behaviors and metabolic alterations were important mediators of this association, a sizable fraction of this association was not mediated by these factors, suggesting that other pathways might play a role, especially among men.

The Bambuí health and aging study (BHAS). Prevalence of intermittent claudication in the aged population of the community of Bambuí and its associated factors

OBJECTIVE To assess the prevalence of intermittent claudication in the aged population of Bambuí, Brazil, and to identify the factors associated with this disease. METHODS Population-based cross-sectional study of the aged population (>/= 60 years of age) of Bambuí. Participants were interviewed and examined, after written consent. Intermittent claudication was defined based on a standardized questionnaire. Analysis was performed using multiple logistic regression. RESULTS Of the 1,742 elderly living in Bambuí, 1,485 (85.2%) were enrolled in the study. Thirty-seven individuals (2.5%) with intermittent claudication were identified: 28 (1.9%) males and 9 (0.6%) females. Their age brackets were: 16 (1.08%) individuals between 60 and 69 years of age, 17 (1.15%) between 70 and 79 years, and 4 (0.27%) >/= 80 years. A significant association between intermittent claudication and the following characteristics was found: male sex (OR=5.1; CI 2.4-11.0), smokers (OR=3.1; CI 1.2-8.5), ex-smokers (OR=3.4; CI 1.3-8.7), and more than 2 hospital admissions in the last 12 months (OR=2.8; CI 1.1-7.2). CONCLUSION Disease prevalence was similar to that of other countries. The association between intermittent claudication and smoking strengthens the significance of tobacco in peripheral artery disease pathogenesis. The association of intermittent claudication and a higher number of hospital admissions suggests greater morbidity in the elderly affected.

Delineamento e implementacao do biobanco do ELSA-Brasil: estudo prospectivo na populacao brasileira

The Brazilian Longitudinal Study for Adult Health (ELSA-Brasil) is a multicenter prospective cohort of civil servants designed to assess the determinants of chronic diseases, especially cardiovascular diseases and type 2 diabetes. The present article describes the main design and implementation points of the ELSA-Brasil biobank project. Economic, political, logistical and technological aspects of this study are characterized. Additionally, it discusses the final biorepository protocol and the facilities implemented to achieve this objective. The design and implementation process of the ELSA-Brasil biobank took three years to be performed. Both the central and local biobanks were built according to the best biorepository techniques, using different technological solutions for the distinct needs expected in this study.