Multicollinearity in associations between multiple environmental features and body weight and abdominal fat: using matching techniques to assess whether the associations are separable.

Because of the strong correlations among neighborhoods' characteristics, it is not clear whether the associations of specific environmental exposures (e.g., densities of physical features and services) with obesity can be disentangled. Using data from the RECORD (Residential Environment and Coronary Heart Disease) Cohort Study (Paris, France, 2007-2008), the authors investigated whether neighborhood characteristics related to the sociodemographic, physical, service-related, and social-interactional environments were associated with body mass index and waist circumference. The authors developed an original neighborhood characteristic-matching technique (analyses within pairs of participants similarly exposed to an environmental variable) to assess whether or not these associations could be disentangled. After adjustment for individual/neighborhood socioeconomic variables, body mass index/waist circumference was negatively associated with characteristics of the physical/service environments reflecting higher densities (e.g., proportion of built surface, densities of shops selling fruits/vegetables, and restaurants). Multiple adjustment models and the neighborhood characteristic-matching technique were unable to identify which of these neighborhood variables were driving the associations because of high correlations between the environmental variables. Overall, beyond the socioeconomic environment, the physical and service environments may be associated with weight status, but it is difficult to disentangle the effects of strongly correlated environmental dimensions, even if they imply different causal mechanisms and interventions.

Are associations between neighborhood socioeconomic characteristics and body mass index or waist circumference based on model extrapolations?

BACKGROUND: We investigated whether neighborhood socioeconomic characteristics, measured within person-centered areas (ie, centered on individuals' residences) are associated with body mass index (BMI [kg/m²]) and waist circumference. We used propensity-score matching as a diagnostic and validation tool to examine whether socio-spatial segregation (and related structural confounding) allowed us to estimate neighborhood socioeconomic effects adjusted for individual socioeconomic characteristics without excessive model extrapolations. METHODS: Using the RECORD (Residential Environment and CORonary heart Disease) Cohort Study, we conducted cross-sectional analyses of 7230 adults from the Paris region. We first estimated the relationships of 3 neighborhood socioeconomic indicators (education, income, real estate prices) with BMI and waist circumference using traditional multilevel regression models adjusted for individual covariates. Second, we examined whether these associations persisted when estimated among participants exchangeable based on their probability of living in low-socioeconomic-status neighborhoods (propensity-score matched samples). RESULTS: After adjustment for covariates, BMI/waist circumference increased with decreasing neighborhood socioeconomic status, especially with neighborhood education measured within 500-m radius buffers around residences; associations were stronger for women. With propensity-score matching techniques, there was some overlap in the odds of exposure between exposed and unexposed populations. As a function of socio-spatial segregation and an indicator of whether the data support inferences, sample size decreased by 17%-59% from the initial to the propensity-score matched samples. Propensity-score matched models confirmed relationships obtained from models in the entire sample. CONCLUSIONS: Overall, adjusted associations between neighborhood socioeconomic variables and BMI/waist circumference were empirically estimable in the French context, without excessive model extrapolations, despite the extent of socio-spatial segregation.

Neighborhood-level confounding in epidemiologic studies: unavoidable challenges, uncertain solutions.

In early contextual studies, the aim was to demonstrate overall neighborhood influences rather than dissecting such influences into their components. Researchers did not need to worry about neighborhood-level confounding. However, as our interest shifts to the exploration of specific environmental effects, failure to consider neighborhood-level confounding may result in severely biased associations. We argue that neighborhood socioeconomic position and similar area structural factors may constitute powerful sources of confounding in studies of specific environmental factors and health. Controlling for neighborhood socioeconomic position is a convenient (but imperfect) adjustment strategy. Such control entails a minimal risk of overadjustment, but conveys a non-negligible risk of collider bias. Balancing the advantages and disadvantages, we suggest that researchers should often provide complementary analyses controlling for neighborhood socioeconomic position in studies of associations between specific environmental factors and health. Researchers should provide DAG-based descriptions of plausible scenarios to explore whether any decrease in the association of interest after adjustment for neighborhood socioeconomic position is likely due to neighborhood-level confounding, indirect pathway biases, or collider bias.

Associations of supermarket characteristics with weight status and body fat: a multilevel analysis of individuals within supermarkets (RECORD study).

PURPOSE: Previous research on the influence of the food environment on weight status has often used impersonal measures of the food environment defined for residential neighborhoods, which ignore whether people actually use the food outlets near their residence. To assess whether supermarkets are relevant contexts for interventions, the present study explored between-residential neighborhood and between-supermarket variations in body mass index (BMI) and waist circumference (WC), and investigated associations between brands and characteristics of supermarkets and BMI or WC, after adjustment for individual and residential neighborhood characteristics. METHODS: Participants in the RECORD Cohort Study (Paris Region, France, 2007-2008) were surveyed on the supermarket (brand and exact location) where they conducted their food shopping. Overall, 7 131 participants shopped in 1 097 different supermarkets. Cross-classified multilevel linear models were estimated for BMI and WC. RESULTS: Just 11.4% of participants shopped for food primarily within their residential neighborhood. After accounting for participants' residential neighborhood, people shopping in the same supermarket had a more comparable BMI and WC than participants shopping in different supermarkets. After adjustment for individual and residential neighborhood characteristics, participants shopping in specific supermarket brands, in hard discount supermarkets (especially if they had a low education), and in supermarkets whose catchment area comprised low educated residents had a higher BMI/WC. CONCLUSION: A public health strategy to reduce excess weight may be to intervene on specific supermarkets to change food purchasing behavior, as supermarkets are where dietary preferences are materialized into definite purchased foods.

Why socially deprived populations have a faster resting heart rate: impact of behaviour, life course anthropometry, and biology--the RECORD Cohort Study.

Although studies have shown that resting heart rate (RHR) is predictive of cardiovascular morbidity/mortality, few studies focused on the epidemiology and social aetiology of RHR. Using the RECORD Cohort Study (7158 participants, 2007-2008, Paris region, France), we investigated individual/neighbourhood socioeconomic variables associated with resting heart rate, and assessed which of a number of psychological factors (depression and stress), behaviour (sport-related energy expenditure, medication use, and alcohol, coffee, and tobacco consumption), life course anthropometric factors (body mass index, waist circumference, and leg length as a marker of childhood environmental exposures), and biologic factors (alkaline phosphatase and gamma-glutamyltransferase) contributed to the socioeconomic disadvantage-RHR relationship. Combining individual/neighbourhood socioeconomic factors in a socioeconomic score, RHR increased with socioeconomic disadvantage: +0.9 [95% credible interval (CrI): +0.2, +1.6], +1.8 (95% CrI: +1.0, +2.5), and +3.6 (95% CrI: +2.9, +4.4) bpm for the 3 categories reflecting increasing disadvantage, compared with the lowest disadvantage category. Twenty-one percent of the socioeconomic disadvantage-RHR relationship was explained by sport practise variables, 9% by waist circumference, 7% by gamma-glutamyltransferase, 5% by alkaline phosphatase, and 3% by leg length. Future research should further clarify the mechanisms through which socioeconomic disadvantage influences resting heart rate, as a pathway to social disparities in cardiovascular morbidity/mortality.

Individual/neighborhood social factors and blood pressure in the RECORD Cohort Study: which risk factors explain the associations?

Recent studies have started to suggest that, beyond effects of individual socioeconomic profiles, socioeconomic characteristics of residential neighborhoods are independently associated with blood pressure. However, mechanisms involved in these associations remain unknown. To distinguish between different mechanisms, we investigated whether specific risk factors of hypertension (physical inactivity, alcohol consumption, smoking, body mass index, waist circumference, and resting heart rate) intervene as mediators in the associations between individual or neighborhood socioeconomic characteristics and systolic blood pressure. We relied on data from the RECORD Cohort Study (Residential Environment and CORonary heart Disease) on 5941 participants recruited in 2007-2008, aged 30 to 79 years, residing in 1824 neighborhoods in the Paris metropolitan area. Systolic blood pressure increased independently and regularly with both decreasing individual education and decreasing residential neighborhood education. Body mass index/waist circumference and resting heart rate mediated an appreciable share of the associations between education and blood pressure and, adding validity to the finding, were the 2 most significant mediators for the effects of both individual education and neighborhood education. We found that 52% (95% CI: 25% to 79%) of the association between neighborhood education and blood pressure was mediated by body mass index/waist circumference and 20% (95% CI: 5% to 36%) by resting heart rate. Future research will have to clarify the exact mechanisms through which body weight and shape and resting heart rate intervene as mediators in the associations between individual/neighborhood education and blood pressure.

Atividade antibacteriana in vitro da tintura de aroeira (Schinusterebinthifolius) na descontaminação de escovas dentaiscontaminadas pelo s. mutans / Antibacterial activity in vitro of the tincture of aroeira (schinus terebinthifolius) in the decontamination of dental brushs contamined by S. mutans

Objetivo: Avaliar a atividade antibacteriana in vitro da tintura dacasca da aroeira a 20 porcento sobre o Streptococcus mutans e observara eficácia deste fitoterápico na descontaminação de escovasdentais in vitro contaminadas com este microorganismo.Método: Determinou-se a atividade antibacteriana in vitro sobre alinhagem padrão de S. mutans (ATCC 2575), através da técnica dedifusão em ágar para determinação da Diluição Inibitória Máxima(DIM). As placas de Petri contendo o meio de cultura icgar MuellerHinton foram semeadas pela técnica da inundação, sendo realizados7 poços, de 6mm de diâmetro, onde foram inoculados 50ul da tinturade aroeira nas formas pura (1:0) e diluída de 1:1 até 1:32. Comocontrole positivo utilizou-se a clorexidina a 0,12 por cento. Em seguidaavaliou-se a descontaminação das escovas dentais, in vitro. Asescovas foram contaminadas em meio de cultura BHI contendo oS. mutans, através da imersão das cerdas por 1min, sendo realizadaa descontaminação com as seguintes soluções sob a forma despray: tintura da aroeira, clorexidinha 0,12 porcento (controle positivo) eágua destilada (controle negativo). Para verificação da inibição docrescimento, observou-se a turvação do meio líquido, apósincubação por 24h em microaerofilia, e realizou-se a semeadurana concentração de 10-3 em meio de cultura Mitis-SalivariusBacitracina para contagem das UFC/ml.Resultados: Os resultados referentes à atividade antibacterianasobre o S. mutans, demonstraram ação da tintura de aroeira até adiluição de 1:8, e da clorexidina até a diluição de 1:32. Com relaçãoà descontaminação das escovas dentárias, verificou-se que oinóculo da solução de clorexidina a 0,12% foi único totalmentelímpido após as 24 horas. Ao realizar-se a semeadura para contagemdas UFC/ml, observou-se que a clorexidina apresentou UFC/ml iguala zero, a tintura...

Atividade antibacteriana in vitro da tintura de aroeira (Schinusterebinthifolius) na descontaminação de escovas dentaiscontaminadas pelo s. mutans / Antibacterial activity in vitro of the tincture of aroeira (schinus terebinthifolius) in the decontamination of dental brushs contamined by S. mutans

Objetivo: Avaliar a atividade antibacteriana in vitro da tintura dacasca da aroeira a 20 porcento sobre o Streptococcus mutans e observara eficácia deste fitoterápico na descontaminação de escovasdentais in vitro contaminadas com este microorganismo.Método: Determinou-se a atividade antibacteriana in vitro sobre alinhagem padrão de S. mutans (ATCC 2575), através da técnica dedifusão em ágar para determinação da Diluição Inibitória Máxima(DIM). As placas de Petri contendo o meio de cultura Ágar MuellerHinton foram semeadas pela técnica da inundação, sendo realizados7 poços, de 6mm de diâmetro, onde foram inoculados 50ul da tinturade aroeira nas formas pura (1:0) e diluída de 1:1 até 1:32. Comocontrole positivo utilizou-se a clorexidina a 0,12 por cento. Em seguidaavaliou-se a descontaminação das escovas dentais, in vitro. Asescovas foram contaminadas em meio de cultura BHI contendo oS. mutans, através da imersão das cerdas por 1min, sendo realizadaa descontaminação com as seguintes soluções sob a forma despray: tintura da aroeira, clorexidinha 0,12 porcento (controle positivo) eágua destilada (controle negativo). Para verificação da inibição docrescimento, observou-se a turvação do meio líquido, apósincubação por 24h em microaerofilia, e realizou-se a semeadurana concentração de 10-3 em meio de cultura Mitis-SalivariusBacitracina para contagem das UFC/ml.Resultados: Os resultados referentes à atividade antibacterianasobre o S. mutans, demonstraram ação da tintura de aroeira até adiluição de 1:8, e da clorexidina até a diluição de 1:32. Com relaçãoà descontaminação das escovas dentárias, verificou-se que oinóculo da solução de clorexidina a 0,12% foi único totalmentelímpido após as 24 horas. Ao realizar-se a semeadura para contagemdas UFC/ml, observou-se que a clorexidina apresentou UFC/ml iguala zero, a tintura...

Avaliação de chupetas disponíveis no mercado nacional segundo os requisitos da ABNT e ANVISA / Evaluation of the pacifers available in the nacional market following the ABNT and ANVISA requisitions

Este trabalho objetivou avaliar chupetas disponíveis no mercado nacional segundo requisitos definidos pela legislação vigente. A amostra constou de 31 tipos de 6 marcas comerciais nacionais de chupetas, sendo para cada uma adquiridas 3 exemplares de lotes diferentes. Foi analisada descritivamente a adequação ou não dos aspectos: bico, escudo, botão, pino, argola e embalagem, atendendo aos critérios de construção de chupetas definidos pela NBR 10334/2003 da ABNT e a Resolução nº 221 da ANVISA. As chupetas foram divididas em grupos (G), conforme as características do bico: G1 – universal < 6 meses; G2 – convencional < 6 meses; G3 – ortodôntica < 6 meses; G4 – universal > 6 meses; G5 – convencional > 6 meses; G6 – ortodôntica > 6 meses. Verificou-se a inadequação nos itens: A – comprimento do bico; B – embalagem segundo a NBR; C – embalagem segundo a ANVISA. O percentual de inadequação encontrado para os grupos foi: A: G2 – 20%, G6 – 11,1%; B: G2 – 40%, G3 – 33,3%, G5 – 40%, G6 – 33,3%; C: G2 – 20%, G3 – 33,3%, G4 – 33,3%, G5 – 20%, G6 – 22,2%. Para os demais itens avaliados: material e forma do bico; concavidade do escudo, quantidade e diâmetro dos furos, distância do furo ao bico e à borda externa, distância entre os furos, tamanho do escudo; projeção do botão; orifício de ventilação e projeção do pino e largura e comprimento da argola constataram- se adequação para as chupetas analisadas. Conclui-se que a maioria das chupetas se apresentou adequada para os requisitos de construção, sendo a inadequação freqüentemente registrada no item embalagem.

Susceptibilidade in vitro de bactérias bucais a tinturas fitoterápicas / Susceptibility in vitro of the buccal bacterias to phytotherapics tinctures

O Brasil dispõe de uma diversidade de substâncias naturais com propriedades terapêuticas bastante difundidas dentro da Odontologia Preventiva. Neste trabalho, objetivou-se avaliar a atividade antibacteriana das tinturas de jucá, aroeira, gengibre, alfavaca, própolis, romã e hortelã da folha graúda, sobre as linhagens de S. aureus (ATCC 25923), S. mutans (ATCC 2575), S. sobrinus (ATCC 27609), S. mitis (ATCC 9811), S. sanguis (ATCC 10557) e L. casei (ATCC 7469), utilizando-se a clorexldina 0,12% como controle positivo. Determinou-se a diluição inibitória máxima (DIM) em meio de cultura Agar Mueller Hlnton, das tinturas nas formas pura (1:0) e diluídas de 1:1 até 1:32. Observou-se susceptibilidade variada das bactérias, sendo o S. aureus o microorganismo mais sensível. Dentre as tinturas, o jucá, a aroeira e a própolis apresentaram uma significativa atividade antibacteriana sobre S. mutans, S. sobrinus, S. mitis, S. sanguis e L.casei, sendo que o gengibre e a alfavaca apresentaram os menores espectros de ação frente às linhagens bacterianas avaliadas.