Sérgio Viana Peixoto

Critical analysis of the estimated number of schistosomiasis mansoni carriers in Brazil

The number of carriers of Schistosoma mansoni infection in Brazil was estimated based on the results of parasitological examinations of feces carried out by the Fundação Nacional de Saúde (FNS - National Health Foundation) in 1996 and 1997, as well as population data from 18 states collected by the Instituto Brasileiro de Geografia e Estatística (IBGE - Brazilian Institute of Geography and Statistics). This information allowed the number of carriers of schistosomiasis mansoni to be estimated at 7.1 million in 1996 and 6. 3 million in 1997. These figures may not reflect the true situation since the population sample used was not originally selected for this purpose. The absence of precise data indicates the need for an adequate national survey of the prevalence of schistosomiasis, which continues to be an important endemic parasitic disease, justifying greater efforts for its control in Brazil.

Plasma β-Type Natriuretic Peptide As a Predictor of Mortality in Community-Dwelling Older Adults With Chagas Disease: 10-Year Follow-up of the Bambuí Cohort Study of Aging

In this study, the authors aimed to investigate the prognostic value of brain-type natriuretic peptide (BNP) for all-cause mortality among persons with Chagas disease, a parasitic disease caused by the protozoan Trypanosoma cruzi. The authors used data on 1,398 participants (37.5% infected with T. cruzi) aged 60 years and over from the Bambuí Cohort Study of Aging in Brazil. From 1997 to 2007, 512 participants died, leading to 12,406 person-years of observation. The hazard ratio for death was 1.27 for each unit of log-transformed BNP level (95% confidence interval (CI: 1.11, 1.45) among infected persons, independent of potentially confounding factors. Infected persons with baseline BNP levels in the top quartile had a risk of death twice that of persons in the bottom quartile (hazard ratio = 2.07, 95% CI: 1.29, 3.32). The discriminatory ability of BNP in predicting mortality (C = 0.69, 95% CI: 0.66, 0.71) was similar to that of an electrocardiogram (C = 0.68, 95% CI: 0.65, 0.71), with reasonably stable risk discrimination over time. BNP is a strong predictor of mortality in older adults with Chagas disease. Although the usefulness of BNP for risk stratification in this parasitic disease remains a topic of debate, this study found that BNP-based risk discrimination is at least comparable to that of an electrocardiogram.

Chagas disease and mortality in old age as an emerging issue: 10 year follow-up of the Bambuí population-based cohort study (Brazil)

Earlier studies of the natural history of Chagas disease (ChD), which is caused by the protozoan Trypanosoma cruzi, had suggested that the consequences of the disease in the elderly are negligible. The objective of this study was to estimate long-term mortality in ChD in old age using data from a large population-based cohort study. The study was conducted in Bambui City (~15,000 inhabitants), Brazil. Participants were 1479 residents aged 60 years and over (84.9% from total), who were followed from 1997 to 2007. During a mean follow-up of 8.72 years, 567 participants died, resulting in a total of 12,896 person-years observation. The baseline prevalence of T. cruzi infection was 38.1%. T. cruzi infection was a strong predictor of mortality among cohort members, and this association remained largely significant after adjustments for age, sex, and conventional cardiovascular risk factors (hazard ratio [HR] = 1.56; 95% CI 1.32-1.85). Increased risks for mortality associated with T. cruzi infection were consistently observed in those aged 60-69 (HR= 1.79; 95%CI 1.37-1.85), 70-79 (HR=1.35; 95% CI 1.04-1.76) and 80 years and over (HR= 1.59; 95% CI 1.09-2.33). Overall, population attributable risk for mortality due to T. cruzi infection was 13.2% (95% CI 9.8-16.4). Our results indicate that ChD is a relevant individual and population health issue in old age, supporting the need for measures to reduce the burden of ChD in this growing segment of the population.

Associação entre via de parto e complicações maternas em hospital público da Grande São Paulo, Brasil

The purpose of this study was to assess the relationship between mode of delivery and maternal complications, based on a retrospective cohort of all births at a public hospital in 2003. Complications included: infection, hemorrhage, hysterectomy, uterine rupture, lesions in adjacent organs, deep venous thrombosis, and pulmonary embolism. The analysis used odds ratio (OR), chi-squared test, and Fishers exact test, besides logistic regression. Fifteen complications were identified. Taking vaginal delivery as the reference, an association was found between cesarean section and overall complications. Analysis of confounding showed an association between hypertension, HIV, placenta previa, and abruptio placentae. After controlling for these variables, an association remained between overall complications and cesarean section (OR = 9.7; p = 0.04). Another analysis comparing elective cesareans and vaginal deliveries also showed an increased risk for cesarean (OR = 4.7; p = 0.02). Finally, comparing elective cesareans with trial of labor, we found an increased proportion of complications in elective cesareans, with borderline significance (OR = 3; p = 0.058). We concluded that cesarean section is associated with maternal morbidity, even after controlling for confounders.

Vagal impairment in elderly Chagas disease patients: a population-based study (the Bambuí study).

BACKGROUND Chagas disease (ChD) will become predominantly a disease of the elderly, as a consequence of the effectiveness of control measures in many Latin American countries. The effects of the disease in old age have received little attention. We investigated the effects of ageing in the association between cardiac vagal impairment, a typical feature of ChD, and chronic Trypanosoma cruzi infection. METHODS The study sample of this cross-sectional study consists of 1014 subjects ≥ 60 years old (mean age = 68.3; SD = 6.9) residing in Bambuí City (Southeast Brazil). ECG was recorded and one-breath sinus arrhythmia test was performed. Maximal expiratory over the minimal inspiratory (E:I) ratio and heart rate variability (HRV) measurements were calculated. Ordinal logistic regression was used to assess the relation between vagal indexes and chronic T. cruzi infection. RESULTS The prevalence of T. cruzi infection was 32.0% and of major ECG abnormalities, 43.4%. Among individuals aged 60-69 years, T. cruzi infection was significantly and independently associated with reduced SDNN (OR 0.38; 95% CI 0.27-0.53), RMSSD (OR 0.48; 0.34-0.67) and EI: ratio (OR 0.45; 95% CI 0.33-0.63). Among individuals aged >70 years, no significant odds ratios were found in either the unadjusted or the adjusted analysis. The presence of major ECG abnormalities did not affect the association between vagal indexes and T. cruzi infection. CONCLUSIONS Disease-specific vagal cardiac dysfunction was observed in ChD individuals below 70. However, further ageing interferes significantly with vagal heart modulation, attenuating the difference of HRV indexes between ChD and non-ChD subjects.

Genomic ancestry, Self-rated health and its association with mortality in an admixed population: 10 year follow-up of the Bambui-Epigen (Brazil) cohort study of ageing

Background Self-rated health (SRH) has strong predictive value for mortality in different contexts and cultures, but there is inconsistent evidence on ethnoracial disparities in SRH in Latin America, possibly due to the complexity surrounding ethnoracial self-classification. Materials/Methods We used 370,539 Single Nucleotide Polymorphisms (SNPs) to examine the association between individual genomic proportions of African, European and Native American ancestry, and ethnoracial self-classification, with baseline and 10-year SRH trajectories in 1,311 community dwelling older Brazilians. We also examined whether genomic ancestry and ethnoracial self-classification affect the predictive value of SRH for subsequent mortality. Results European ancestry predominated among participants, followed by African and Native American (median = 84.0%, 9.6% and 5.3%, respectively); the prevalence of Non-White (Mixed and Black) was 39.8%. Persons at higher levels of African and Native American genomic ancestry, and those self-identified as Non-White, were more likely to report poor health than other groups, even after controlling for socioeconomic conditions and an array of self-reported and objective physical health measures. Increased risks for mortality associated with worse SRH trajectories were strong and remarkably similar (hazard ratio ~3) across all genomic ancestry and ethno-racial groups. Conclusions Our results demonstrated for the first time that higher levels of African and Native American genomic ancestry—and the inverse for European ancestry—were strongly correlated with worse SRH in a Latin American admixed population. Both genomic ancestry and ethnoracial self-classification did not modify the strong association between baseline SRH or SRH trajectory, and subsequent mortality.

Physical activity and all-cause mortality among older Brazilian adults: 11-year follow-up of the Bambuí Health and Aging Study

Objective To investigate the association between physical activity (eg, energy expenditure) and survival over 11 years of follow-up in a large representative community sample of older Brazilian adults with a low level of education. Furthermore, we assessed sex as a potential effect modifier of this association. Materials and methods A population-based prospective cohort study was conducted on all the ≥60-year-old residents in Bambuí city (Brazil). A total of 1,606 subjects (92.2% of the population) enrolled, and 1,378 (85.8%) were included in this study. Type, frequency, and duration of physical activity were assessed in the baseline survey questionnaire, and the metabolic equivalent task tertiles were estimated. The follow-up time was 11 years (1997–2007), and the end point was mortality. Deaths were reported by next of kin during the annual follow-up interview and ascertained through the Brazilian System of Information on Mortality, Brazilian Ministry of Health. Hazard ratios (95% confidence intervals [CIs]) were estimated by Cox proportional-hazard models, and potential confounders were considered. Results A statistically significant interaction (P<0.03) was found between sex and energy expenditure. Among older men, increases in levels of physical activity were associated with reduced mortality risk. The hazard ratios were 0.59 (95% CI 0.43–0.81) and 0.47 (95% CI 0.34–0.66) for the second and third tertiles, respectively. Among older women, there was no significant association between physical activity and mortality. Conclusion It was possible to observe the effect of physical activity in reducing mortality risk, and there was a significant interaction between sex and energy expenditure, which should be considered in the analysis of this association in different populations.

Socioeconomic Position, But Not African Genomic Ancestry, Is Associated With Blood Pressure in the Bambui-Epigen (Brazil) Cohort Study of Aging

The study objective is to examine the role of African genome origin on baseline and 11-year blood pressure trajectories in community-based ethnoracially admixed older adults in Brazil. Data come from 1272 participants (aged ≥60 years) of the Bambui cohort study of aging during 11 years of follow-up. Outcome measures were systolic blood pressure, diastolic blood pressure, and hypertension control. Potential confounding variables were demographic characteristics, socioeconomic position (schooling and household income), and health indicators (smoking, sedentary lifestyle, high-density lipoprotein cholesterol, waist circumference, diabetes mellitus, and cardiovascular diseases), including antihypertensive drug use. We used 370 539 single-nucleotide polymorphisms to estimate each individual’s African, European, and Native American trihybrid ancestry proportions. Median African, European, and Native American ancestry were 9.6%, 84.0%, and 5.3%, respectively. Among those with African ancestry, 59.4% came from East and 40.6% from West Africa. Baseline systolic and diastolic blood pressure, controlled hypertension, and their respective trajectories, were not significantly (P>0.05) associated with level (in quintiles) of African genomic ancestry. Similar results were found for West and East African subcontinental origins. Lower schooling level (<4 years versus higher) showed a significant and positive association with systolic blood pressure (Adjusted &bgr;=2.92; 95% confidence interval, 0.85–4.99). Lower monthly household income per capita (<USD 180.00 versus higher) showed an inverse association with hypertension control (&bgr;=−0.35; 95% confidence interval, −0.63 to −0.08, respectively). Our results support the view that favors social and environmental factors as determinants of blood pressure and hypertension control.

Mortality risk attributable to smoking, hypertension and diabetes among English and Brazilian older adults (The ELSA and Bambui cohort ageing studies).

Background: The main aim of this study was to quantify and compare 6-year mortality risk attributable to smoking, hypertension and diabetes among English and Brazilian older adults. This study represents a rare opportunity to approach the subject in two different social and economic contexts. Methods: Data from the data from the English Longitudinal Study of Ageing (ELSA) and the Bambuí Cohort Study of Ageing (Brazil) were used. Deaths in both cohorts were identified through mortality registers. Risk factors considered in this study were baseline smoking, hypertension and diabetes mellitus. Both age–sex adjusted hazard ratios and population attributable risks (PAR) of all-cause mortality and their 95% confidence intervals for the association between risk factors and mortality were estimated using Cox proportional hazards models. Results: Participants were 3205 English and 1382 Brazilians aged 60 years and over. First, Brazilians showed much higher absolute risk of mortality than English and this finding was consistent in all age, independently of sex. Second, as a rule, hazard ratios for mortality to smoking, hypertension and diabetes showed more similarities than differences between these two populations. Third, there was strong difference among English and Brazilians on attributable deaths to hypertension. Conclusions: The findings indicate that, despite of being in more recent transitions, the attributable deaths to one or more risk factors was twofold among Brazilians relative to the English. These findings call attention for the challenge imposed to health systems to prevent and treat non-communicable diseases, particularly in populations with low socioeconomic level.

Components of the metabolic syndrome and depressive symptoms in community-dwelling older people: the Bambuí Cohort Aging Study

Objective: To investigate the moderating effect of an increasing number of clustered metabolic syndrome (MetS) components on the association between MetS and depressive symptoms in a population-based cohort of older adults in Brazil. Methods: This analysis used data from the Bambuí Cohort Aging Study. Participants in this cross-sectional study comprised 1,469 community-dwelling older people aged ≥ 60 years. Analyses were performed to assess both the association between depressive symptoms and each individual MetS component and the association between depressive symptoms and clustering of an increasing number of MetS components. Results: High triglyceride level was the individual component that showed the strongest association with depressive symptoms (odds ratio [OR]: 1.47; 95% confidence intervals [95%CI] 1.19-1.81; p < 0.0001). Only the presence of three MetS components was associated with depressive symptoms (OR = 1.53; 95%CI 1.05-2.23; p = 0.025). No graded association was detected between increasing number of clustered MetS components and depressive symptoms. Conclusions: Increasing the number of MetS components did not impact the association with depressive symptoms. The association between high triglyceride level and depressive symptoms highlights the relevance of lipid metabolism abnormalities for the emergence of depressive symptoms in older adults.