Leandro Fórnias Machado de Rezende

Sedentary Behavior and Health Outcomes: An Overview of Systematic Reviews

Objective 1) To synthesize the current observational evidence for the association between sedentary behavior and health outcomes using information from systematic reviews. 2) To assess the methodological quality of the systematic reviews found. Methodology/Principal Findings Medline; Excerpta Medica (Embase); PsycINFO; and Web of Science were searched for reviews published up to September 2013. Additional publications were provided by Sedentary Behaviour Research Network members. The methodological quality of the systematic reviews was evaluated using recommended standard criteria from AMSTAR. For each review, improper use of causal language in the description of their main results/conclusion was evaluated. Altogether, 1,044 review titles were identified, 144 were read in their entirety, and 27 were included. Based on the systematic reviews with the best methodological quality, we found in children and adolescents, strong evidence of a relationship between time spent in sedentary behavior and obesity. Moreover, moderate evidence was observed for blood pressure and total cholesterol, self-esteem, social behavior problems, physical fitness and academic achievement. In adults, we found strong evidence of a relationship between sedentary behavior and all-cause mortality, fatal and non-fatal cardiovascular disease, type 2 diabetes and metabolic syndrome. In addition, there is moderate evidence for incidence rates of ovarian, colon and endometrial cancers. Conclusions This overview based on the best available systematics reviews, shows that sedentary behavior may be an important determinant of health, independently of physical activity. However, the relationship is complex because it depends on the type of sedentary behavior and the age group studied. The relationship between sedentary behavior and many health outcomes remains uncertain; thus, further studies are warranted.

All-Cause Mortality Attributable to Sitting Time: Analysis of 54 Countries Worldwide

INTRODUCTION Recent studies have shown that sitting time is associated with increased risk of all-cause mortality, independent of moderate to vigorous physical activity. Less is known about the population-attributable fraction for all-cause mortality associated with sitting time, and the gains in life expectancy related to the elimination of this risk factor. METHODS In November 2015, data were gathered from one published meta-analysis, 54 adult surveys on sitting time distribution (from 2002 to 2011), in conjunction with national statistics on population size, life table, and overall deaths. Population-attributable fraction for all-cause mortality associated with sitting time >3 hours/day was estimated for each country, WHO regions, and worldwide. Gains in life expectancy related to the elimination of sitting time >3 hours/day was estimated using life table analysis. RESULTS Sitting time was responsible for 3.8% of all-cause mortality (about 433,000 deaths/year) among those 54 countries. All-cause mortality due to sitting time was higher in the countries from the Western Pacific region, followed by European, Eastern Mediterranean, American, and Southeast Asian countries. Eliminating sitting time would increase life expectancy by 0.20 years in those countries. CONCLUSIONS Assuming that the effect of sitting time on all-cause mortality risk is independent of physical activity, reducing sitting time plays an important role in active lifestyle promotion, which is an important aspect of premature mortality prevention worldwide.

Produtividade de criadouro de Aedes albopictus em ambiente urbano

INTRODUCAO: O encontro de Aedes albopictus na cidade de Cananeia, regiao Sudeste do Estado de Sao Paulo, Brasil, ensejou a ocasiao de realizar observacoes que visassem avaliar a produtividade de criadouro grande e permanente. Como objetivo, apos selecionar o habitat a ser estudado, tentou-se avaliar-lhe a contribuicao para a densidade local do mosquito. MATERIAL E METODO: Em area predeterminada procedeu-se a levantamento de criadouros potenciais. Constatada a presenca da especie, foi selecionado um dos recipientes que preenchia os requisitos desejados. O acompanhamento foi feito de maneira ininterrupta, no periodo de novembro de 1996 a maio de 1997. As observacoes obdeceram a ritmo quinzenal retirando, cada vez, amostra da agua correspondente a 0,14, ou seja, um setimo do volume total de 70 litros. Procurou-se coletar, identificar e numerar, por sexo, as pupas existentes. Concomitantemente, procedeu-se a captura de formas adultas. Foi utilizada a isca humana das 15:00 as 18:00h, instalada a cerca de 6 metros do mencionado criadouro. Finda essa coleta, foi feita aspiracao com 30 min. de duracao em locais de abrigo representados pela abundante vegetacao circunjacente. RESULTADOS: Nas coletas de formas imaturas do criadouro, o Ae. albopictus compareceu com 44,9%. Ao longo de 15 amostras regularmente realizadas obteve-se a media de 31,13 pupas pertencentes a essa especie. O indice de emergencia(E) foi de 2,1. A multiplicacao desse valor por sete forneceu a media diaria de 14,7 femeas. Nas coletas de adultos desse sexo, a media de Williams para a isca humana foi de 30,7, enquanto a densidade media horaria da aspiracao dos locais de abrigo foi de 9,2. O calculo do acumulo diario concluiu pela presenca de 22,8 femeas, por dia, capazes de frequentar a isca humana, nessa situacao e condicoes. DISCUSSAO: A contagem de pupas possibilitou estimar a produtividade de criadouro de Ae. albopictus, tipo grande (dez litros ou mais) e de carater permanente. A agua acumulada no recipiente estudado apresentou-se rica em materia orgânica, predominantemente de natureza vegetal. Neste particular, nao ha como compara-lo a reservatorios destinados ao armazenamento de agua para uso domestico. A falta de manutencao desses reservatorios podera contribuir para levar a situacao, se nao identica, pelo menos proxima da evidenciada no trabalho. Embora se trate de especie ate agora nao incriminada como vetora, e de se admitir que as observacoes encontradas possam ser utilizadas no programa de erradicacao de Ae. aegypti que esta em curso no Brasil.

Sociodemographic and behavioral factors associated with physical activity in Brazilian adolescents

BackgroundPhysical activity in adolescents is associated with short- and long-term health benefits. Physical activity can occur in various domains and is influenced by a complex network of factors. The aims of this study are 1) to describe the physical activity of Brazilian adolescents in physical education classes, during leisure time, and during active commuting and 2) to investigate the socio-demographic and behavioral factors associated with physical activity.MethodsThe representative sample included 109,104 Brazilian students in the final year of elementary school from 2,842 schools. The weekly frequency and duration of physical activity were assessed. A variety of socio-demographic and behavioral factors were studied. A multiple Poisson regression analysis was used to test for associations between physical activity and the socio-demographic and behavioral variables.ResultsMost of the students (97.0%) engaged in physical activity in at least one of the domains studied, especially physical education at school (81.7%) and leisure time physical activity (67.5%). However, only 29% of the adolescents reached the recommended level of physical activity. Among the adolescents who reached the minimum recommended time for physical activity, the various domains contributed the following proportions to total physical activity: leisure time physical activity (PR 12.5; 95% CI 11.17-13.97), active commuting (PR 1.63; 95% CI 1.59-1.67), and physical education at school (PR 1.36; 95% CI 1.29-1.44). The weekly frequency of all activities was greater among boys than among girls. Moreover, nearly two-thirds (61.8%) of students spent more than two hours per day engaging in sedentary behaviors; the prevalence of sedentary behaviors was similar between boys and girls (59.0 and 64.5%, respectively).Total level of physical activity, leisure time physical activity, and active commuting were associated with higher nutritional scores.ConclusionsPhysical activity is important in any health promotion program. Therefore, it is necessary to invest in policies and interagency initiatives that promote all domains and to ensure that the general population helps determine the scope and design of such policies.

Dietary intake of Brazilian adolescents

OBJECTIVE To analyse the dietary intake of Brazilian adolescents and investigate its association with sociodemographic factors as well as health-risk and health-protective behaviours. DESIGN Cross-sectional study. SETTING The study was based on data supplied by the National Survey of Schoolchildrens Health (2012) on sociodemographic factors, dietary intake and health-risk and health-protective behaviours of schoolchildren in Brazil. A nutritional scale was elaborated combining markers of healthy and unhealthy diets. Poisson regression analysis was applied to investigate the association between the sociodemographic factors and regular intake (≥5 times/week) of selected foods; linear regression analysis was applied to investigate the association of sociodemographic and behavioural factors with nutritional scale score. SUBJECTS A total of 109 104 adolescents attending the ninth year of education at 2842 schools in Brazil. RESULTS Fewer than 30 % of the adolescents consumed raw or cooked vegetables on a regular basis, whereas more than one-third reported regular intake of sweets, soft drinks and sweet biscuits. Adolescents from the southern area and the oldest ones were those most exposed to inadequate dietary intake. The nutritional scale average score was higher in the students attending public school and exhibited a positive correlation with protective behaviours, such as being physically active, having meals with parents and eating breakfast, and a negative correlation with risk behaviours such as eating while studying or watching television and having smoked, drunk alcohol or used other drugs in the previous 30 d. CONCLUSIONS The results indicate an association between undesirable nutritional habits and other risk behaviours among Brazilian adolescents.

The Fraction of Cancer Attributable to Ways of Life, Infections, Occupation, and Environmental Agents in Brazil in 2020

Many human cancers develop as a result of exposure to risk factors related to the environment and ways of life. The aim of this study was to estimate attributable fractions of 25 types of cancers resulting from exposure to modifiable risk factors in Brazil. The prevalence of exposure to selected risk factors among adults was obtained from population-based surveys conducted from 2000 to 2008. Risk estimates were based on data drawn from meta-analyses or large, high quality studies. Population-attributable fractions (PAF) for a combination of risk factors, as well as the number of preventable deaths and cancer cases, were calculated for 2020. The known preventable risk factors studied will account for 34% of cancer cases among men and 35% among women in 2020, and for 46% and 39% deaths, respectively. The highest attributable fractions were estimated for tobacco smoking, infections, low consumption of fruits and vegetables, excess weight, reproductive factors, and physical inactivity. This is the first study to systematically estimate the fraction of cancer attributable to potentially modifiable risk factors in Brazil. Strategies for primary prevention of tobacco smoking and control of infection and the promotion of a healthy diet and physical activity should be the main priorities in policies for cancer prevention in the country.

Effect of Physical Inactivity on Major Noncommunicable Diseases and Life Expectancy in Brazil

BACKGROUND In Brazil, one-fifth of the population reports not doing any physical activity. This study aimed to assess the impact of physical inactivity on major noncommunicable diseases (NCDs), all-cause mortality and life expectancy in Brazil, by region and sociodemographic profile. METHODS We estimated the population attributable fraction (PAF) for physical inactivity associated with coronary heart disease, type 2 diabetes, breast cancer, colon cancer, and all-cause mortality. To calculate the PAF, we used the physical inactivity prevalence from the 2008 Brazilian Household Survey and relative risk data in the literature. RESULTS In Brazil, physical inactivity is attributable to 3% to 5% of all major NCDs and 5.31% of all-cause mortality, ranging from 5.82% in the southeastern region to 2.83% in the southern region. Eliminating physical inactivity would increase the life expectancy by an average of 0.31 years. This reduction would affect mainly individuals with ≥ 15 years of schooling, male, Asian, elderly, residing in an urban area and earning ≥ 2 times the national minimum wage. CONCLUSIONS In Brazil, physical inactivity has a major impact on NCDs and mortality, principally in the southeastern and central-west regions. Public policies and interventions promoting physical activity will significantly improve the health of the population.

MPO Inhibitors Selected by Virtual Screening

The hemeprotein myeloperoxidase (MPO) participates in innate immune defense through its ability to generate potent microbicidal oxidants. However, these oxidants are also key mediators of the tissue damage associated with many inflammatory diseases. Thus, there is considerable interest in developing therapeutically useful MPO inhibitors. Here, we used structure‐based drug design (SBDD) and ligand‐based drug design (LBDD) to select for potentially new and selective MPO inhibitors. A pharmacophore model was developed based on the crystal structure of human MPO in complex with salicylhydroxamic acid (SHA), a known inhibitor of the enzyme. The pharmacophore model was used to screen the ZINC database for potential ligands, which were further filtered on the basis of their physical‐chemical properties and docking score. The filtered compounds were visually inspected, and nine were purchased for experimental studies. Surprisingly, almost all of the selected compounds belonged to the aromatic hydrazide class, which had been previously described as MPO inhibitors. The compounds selected by virtual screening were shown to inhibit the chlorinating activity of MPO; the top four compounds displayed IC50 values ranging from 1.0 to 2.8 µM. MPO inactivation by the most effective compound was shown to be irreversible. Overall, our results show that SBDD and LBDD may be useful for the rational development of new MPO inhibitors.

The cysteine-rich protein thimet oligopeptidase as a model of the structural requirements for S-glutathiolation and oxidative oligomerization.

Thimet oligopeptidase (EP24.15) is a cysteine-rich metallopeptidase containing fifteen Cys residues and no intra-protein disulfide bonds. Previous work on this enzyme revealed that the oxidative oligomerization of EP24.15 is triggered by S-glutathiolation at physiological GSSG levels (10–50 µM) via a mechanism based on thiol-disulfide exchange. In the present work, our aim was to identify EP24.15 Cys residues that are prone to S-glutathiolation and to determine which structural features in the cysteinyl bulk are responsible for the formation of mixed disulfides through the reaction with GSSG and, in this particular case, the Cys residues within EP24.15 that favor either S-glutathiolation or inter-protein thiol-disulfide exchange. These studies were conducted by in silico structural analyses and simulations as well as site-specific mutation. S-glutathiolation was determined by mass spectrometric analyses and western blotting with anti-glutathione antibody. The results indicated that the stabilization of a thiolate sulfhydryl and the solvent accessibility of the cysteines are necessary for S-thiolation. The Solvent Access Surface analysis of the Cys residues prone to glutathione modification showed that the S-glutathiolated Cys residues are located inside pockets where the sulfur atom comes into contact with the solvent and that the positively charged amino acids are directed toward these Cys residues. The simulation of a covalent glutathione docking onto the same Cys residues allowed for perfect glutathione posing. A mutation of the Arg residue 263 that forms a saline bridge to the Cys residue 175 significantly decreased the overall S-glutathiolation and oligomerization of EP24.15. The present results show for the first time the structural requirements for protein S-glutathiolation by GSSG and are consistent with our previous hypothesis that EP24.15 oligomerization is dependent on the electron transfer from specific protonated Cys residues of one molecule to previously S-glutathionylated Cys residues of another one.

The Role of School Environment in Physical Activity among Brazilian Adolescents

Objective To analyze the association of physical activity facilities and extracurricular sports activities in schools with physical activity among adolescents. Methodology/Principal Findings We used data collected for the National Survey of School Health in 2012. The national representative sample comprised 109,104 Brazilian students from 2,842 schools. We calculated the prevalence of participation in physical education classes, leisure-time physical activity, and total physical activity level. We also evaluated the following physical activity facilities: sports courts, running/athletics tracks, schoolyard with teacher-directed physical activities, swimming pools, locker rooms; and the offer of extracurricular sports activities. Schools with at least one physical activity facility had increased odds of participation in physical education (OR 1.59; 95% CI 1.20 to 2.10). However, in order to increase leisure-time physical activity (OR1.14; 95% CI 1.03 to 1.26) and total physical activity level (OR 1.15; 95% CI 1.06 to 1.24) at least four and two facilities, respectively, were necessary. Extracurricular sports activities in schools were positively associated with leisure-time physical activity and physical activity level. The number of sports courts and swimming pool in a school were associated with participation in physical education classes. Availability of sports courts, running/athletics tracks, and swimming pool in schools were associated with leisure-time physical activity. Total physical activity was associated with schools with sports courts, schoolyard with teacher-directed physical activities, and swimming pool. Conclusions School-level characteristics have important potential to increase the possibility of engagement in physical activity in and out of school, and therefore have a fundamental role in promoting these practices.