Christophe Enaux

Spatial heterogeneity of the relationships between environmental characteristics and active commuting: towards a locally varying social ecological model

BackgroundAccording to the social ecological model of health-related behaviors, it is now well accepted that environmental factors influence habitual physical activity. Most previous studies on physical activity determinants have assumed spatial homogeneity across the study area, i.e. that the association between the environment and physical activity is the same whatever the location. The main novelty of our study was to explore geographical variation in the relationships between active commuting (walking and cycling to/from work) and residential environmental characteristics.Methods4,164 adults from the ongoing Nutrinet-Santé web-cohort, residing in and around Paris, France, were studied using a geographically weighted Poisson regression (GWPR) model. Objective environmental variables, including both the built and the socio-economic characteristics around the place of residence of individuals, were assessed by GIS-based measures. Perceived environmental factors (index including safety, aesthetics, and pollution) were reported by questionnaires.ResultsOur results show that the influence of the overall neighborhood environment appeared to be more pronounced in the suburban southern part of the study area (Val-de-Marne) compared to Paris inner city, whereas more complex patterns were found elsewhere. Active commuting was positively associated with the built environment only in the southern and northeastern parts of the study area, whereas positive associations with the socio-economic environment were found only in some specific locations in the southern and northern parts of the study area. Similar local variations were observed for the perceived environmental variables.ConclusionsThese results suggest that: (i) when applied to active commuting, the social ecological conceptual framework should be locally nuanced, and (ii) local rather than global targeting of public health policies might be more efficient in promoting active commuting.

Descriptive study of sedentary behaviours in 35,444 French working adults: cross-sectional findings from the ACTI-Cités study

BackgroundGiven the unfavourable health outcomes associated with sedentary behaviours, there is a need to better understand the context in which these behaviours take place to better address this public health concern. We explored self-reported sedentary behaviours by type of day (work/non-work), occupation, and perceptions towards physical activity, in a large sample of adults.MethodsWe assessed sedentary behaviours cross-sectionally in 35,444 working adults (mean ± SD age: 44.5 ± 13.0 y) from the French NutriNet-Santé web-based cohort. Participants self-reported sedentary behaviours, assessed as domain-specific sitting time (work, transport, leisure) and time spent in sedentary entertainment (TV/DVD, computer and other screen-based activities, non-screen-based activities) on workdays and non-workdays, along with occupation type (ranging from mainly sitting to heavy manual work) and perceptions towards physical activity. Associations of each type of sedentary behaviour with occupation type and perceptions towards physical activity were analysed by day type in multiple linear regression analyses.ResultsOn workdays, adults spent a mean (SD) of 4.17 (3.07) h/day in work sitting, 1.10 (1.69) h/day in transport sitting, 2.19 (1.62) h/day in leisure-time sitting, 1.53 (1.24) h/day viewing TV/DVDs, 2.19 (2.62) h/day on other screen time, and 0.97 (1.49) on non-screen time. On non-workdays, this was 0.85 (1.53) h/day in transport sitting, 3.19 (2.05) h/day in leisure-time sitting, 2.24 (1.76) h/day viewing TV/DVDs, 1.85 (1.74) h/day on other screen time, and 1.30 (1.35) on non-screen time. Time spent in sedentary behaviours differed by occupation type, with more sedentary behaviour outside of work (both sitting and entertainment time), in those with sedentary occupations, especially on workdays. Negative perceptions towards physical activity were associated with more sedentary behaviour outside of work (both sitting and entertainment time), irrespective of day type.ConclusionsA substantial amount of waking hours was spent in different types of sedentary behaviours on workdays and non-workdays. Being sedentary at work was associated with more sedentary behaviour outside of work. Negative perceptions towards physical activity may influence the amount of time spent in sedentary behaviours. These data should help to better identify target groups in public health interventions to reduce sedentary behaviours in working adults.

Socioeconomic Indicators Are Independently Associated with Nutrient Intake in French Adults: A DEDIPAC Study

Studies have suggested differential associations of specific indicators of socioeconomic position (SEP) with nutrient intake and a cumulative effect of these indicators on diet. We investigated the independent association of SEP indicators (education, income, occupation) with nutrient intake and their effect modification. This cross-sectional analysis included 91,900 French adults from the NutriNet-Santé cohort. Nutrient intake was estimated using three 24-h records. We investigated associations between the three SEP factors and nutrient intake using sex-stratified analysis of covariance, adjusted for age and energy intake, and associations between income and nutrient intake stratified by education and occupation. Low educated participants had higher protein and cholesterol intakes and lower fibre, vitamin C and beta-carotene intakes. Low income individuals had higher complex carbohydrate intakes, and lower magnesium, potassium, folate and vitamin C intakes. Intakes of vitamin D and alcohol were lower in low occupation individuals. Higher income was associated with higher intakes of fibre, protein, magnesium, potassium, beta-carotene, and folate among low educated persons only, highlighting effect modification. Lower SEP, particularly low education, was associated with lower intakes of nutrients required for a healthy diet. Each SEP indicator was associated with specific differences in nutrient intake suggesting that they underpin different social processes.

Active Mobility and Environment: A Pilot Qualitative Study for the Design of a New Questionnaire

It is generally accepted that active mobility, mainly walking and cycling, contributes to people’s physical and mental health. One of the current challenges is to improve our understanding of this type of behaviour. This study aims to identify factors from the daily-life environment that may be related to active mobility behaviours, in order to design a new questionnaire for a quantitative study of a large adult population. The new questionnaire obtained through this pilot study combines information from interviews with existing questionnaires materials in order to introduce new factors while retaining the factors already assessed. This approach comprises three stages. The first was a content analysis (Reinert method) of interviews with a sample of participants about daily living activities as well as mobility. This stage led to a typology of factors suggested by interviews. The second was a scoping review of the literature in order to identify the active mobility questionnaires currently used in international literature. The last stage was a cross-tabulation of the factors resulting from the written interviews and the questionnaires. A table of the inter-relationships between the interview-based typology and the questionnaires shows discrepancies between factors considered by the existing questionnaires, and factors coming from individual interviews. Independent factors which were ignored in or absent from the questionnaires are the housing situation within the urban structure, overall consideration of the activity space beyond the limits of the residential neighbourhood, the perception of all the transportation modes, and the time scheduling impacting the modes actually used. Our new questionnaire integrates both the usual factors and the new factors that may be related to active mobility behaviours.

Measuring Functional Integration by Identifying the Trip Chains and the Profiles of Cross-Border Workers: Empirical Evidences from Luxembourg

ABSTRACT The number of cross-border workers in Luxembourg has steadily increased over the last 30 years. In the collective imagination these cross-border workers come to the Grand Duchy just to work. This paper challenges this representation by measuring the functional integration of cross-border workers in Luxembourg. Using some useful tools linked to the field of Time Geography, it is possible to analyze their activity spaces according to the spatial and temporal organization of their daily activities and trip chains. The spatial distribution and organization of their activities on both sides of the border provide the methodological and analytical support for the findings presented in this paper. The juxtaposition of trip chains with activity spaces allows the identification and characterization of the degree of functional integration of cross-border workers in Luxembourg. Moreover, based on a quantitative survey conducted in three different countries, our results show there are five types of cross-border worker profiles in terms of the degree of integration: commuter-only, home-centered, dispersed, hybrid, and functionally integrated.

Differential Associations of Walking and Cycling with Body Weight, Body Fat and Fat Distribution - the ACTI-Cités Project

Background: Research on the associations between walking and cycling with obesity-related phenotypes is growing but relies mostly on the use of BMI. The purpose of this study was to analyze associations of walking and cycling behaviors assessed separately with various obesity markers in French adults. Methods: In 12,776 adult participants (71.3% women) of the on-going NutriNet Santé web-cohort, we assessed by self-report past-month walking and cycling (for commuting, errands and leisure), and obesity measures were taken during a visit at a clinical center (weight, height, waist circumference, and percent body fat by bioimpedance). Results: In analyses not taking into account other types of physical activity (household, leisure), walking more than 2.5 h/week was associated in women with lower weight (-1.8 kg), waist circumference (-1.7 cm) and percent body fat (-1.1%) (all p < 0.001). Cycling more than 1.5 h/week was associated in men and women with lower weight (-4.3 and -1.4 kg, respectively), waist circumference (-4.4 and -2.1 cm, respectively), and percent body fat (-2.5 and -1.9 % respectively) (all p < 0.001). Results were unaltered when analyses were further adjusted on household and leisure physical activity. Conclusion: These results show important differences between walking and cycling in their association with obesity markers in men and women. These findings provide some evidence for the need to consider separately walking and cycling when designing public health measures for prevention of obesity in adults.