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International audience; The objective of this work is to synthesize current knowledge about the effects of maternal physical activity during pregnancy on children's health. During the prenatal and postnatal periods, maternal physical activity has protective effects against the risks of macrosomia, obesity, and other associated cardiometabolic disorders. Even though longitudinal studies in humans are still necessary to validate them, these effects have been consistently observed in animal studies. A remarkable effect of maternal physical activity is its positive role on neurogenesis, language development, memory, and other cognitive functions related to learning.

Common compartmental modeling for COVID-19 is based on a priori knowledge and numerous assumptions. Additionally, they do not systematically incorporate asymptomatic cases. Our study aimed at providing a framework for data-driven approaches, by leveraging the strengths of the grey-box system theory or grey-box identification, known for its robustness in problem solving under partial, incomplete, or uncertain data. Empirical data on confirmed cases and deaths, extracted from an open source repository were used to develop the SEAIRD compartment model. Adjustments were made to fit current knowledge on the COVID-19 behavior. The model was implemented and solved using an Ordinary Differential Equation solver and an optimization tool. A cross-validation technique was applied, and the coefficient of determination R2 was computed in order to evaluate the goodness-of-fit of the model. Key epidemiological parameters were finally estimated and we provided the rationale for the construction of SEAIRD model. When applied to Brazil’s cases, SEAIRD produced an excellent agreement to the data, with an R2 ≥ 90%. The probability of COVID-19 transmission was generally high (≥ 95%). On the basis of a 20-day modeling data, the incidence rate of COVID-19 was as low as 3 infected cases per 100,000 exposed persons in Brazil and France. Within the same time frame, the fatality rate of COVID-19 was the highest in France (16.4%) followed by Brazil (6.9%), and the lowest in Russia (≤ 1%). SEAIRD represents an asset for modeling infectious diseases in their dynamical stable phase, especially for new viruses when pathophysiology knowledge is very limited. Supplementary Information The online version contains supplementary material available at 10.1007/s10489-021-02379-2.

To date, few data on how the COVID-19 pandemic and restrictions affected children’s physical activity in Europe have been published. This study examined the prevalence and correlates of physical activity and screen time from a large sample of European children during the COVID-19 pandemic to inform strategies and provide adequate mitigation measures. An online survey was conducted using convenience sampling from 15 May to 22 June, 2020. Parents were eligible if they resided in one of the survey countries and their children aged 6–18 years. 8395 children were included (median age [IQR], 13 [10–15] years; 47% boys; 57.6% urban residents; 15.5% in self-isolation). Approximately two-thirds followed structured routines (66.4% [95%CI, 65.4–67.4]), and more than half were active during online P.E. (56.6% [95%CI, 55.5–57.6]). 19.0% (95%CI, 18.2–19.9) met the WHO Global physical activity recommendation. Total screen time in excess of 2 h/day was highly prevalent (weekdays: 69.5% [95%CI, 68.5–70.5]; weekend: 63.8% [95%CI, 62.7–64.8]). Playing outdoors more than 2 h/day, following a daily routine and being active in online P.E. increased the odds of healthy levels of physical activity and screen time, particularly in mildly affected countries. In severely affected countries, online P.E. contributed most to meet screen time recommendation, whereas outdoor play was most important for adequate physical activity. Promoting safe and responsible outdoor activities, safeguarding P.E. lessons during distance learning and setting pre-planned, consistent daily routines are important in helping children maintain healthy active lifestyle in pandemic situation. These factors should be prioritised by policymakers, schools and parents. HIGHLIGHTS: To our knowledge, our data provide the first multi-national estimates on physical activity and total screen time in European children roughly two months after COVID-19 was declared a global pandemic. Only 1 in 5 children met the WHO Global physical activity recommendations. Under pandemic conditions, parents should set pre-planned, consistent daily routines and integrate at least 2-hours outdoor activities into the daily schedule, preferable on each day. Schools should make P.E. lessons a priority. Decision makers should mandate online P.E. be delivered by schools during distance learning. Closing outdoor facilities for PA should be considered only as the last resort during lockdowns.

Objective Endometriosis is a complex full-body inflammation disease with an average time to diagnosis of 7–10 years. Social networks give opportunity to patient to openly discuss about their condition, share experiences, and seek advice. Thus, data from social media may provide insightful data about patient's experience. This study aimed at applying a text-mining approach to online social networks in order to identify early signs associated with endometriosis. Methods An automated exploration technique of online forums was performed to extract posts. After a cleaning step of the built corpus, we retrieved all symptoms evoked by women, and connected them to the MedDRA dictionary. Then, temporal markers allowed targeting only the earliest symptoms. The latter were those evoked near a marker of precocity. A co-occurrence approach was further applied to better account for the context of evocations. Results Results were visualised using the graph-oriented database Neo4j. We collected 7148 discussions threads and 78,905 posts from 10 French forums. We extracted 41 groups of contextualised symptoms, including 20 groups of early symptoms associated with endometriosis. Among these groups of early symptoms, 13 were found to portray already known signs of endometriosis. The remaining 7 clusters of early symptoms were limb oedema, muscle pain, neuralgia, haematuria, vaginal itching, altered general condition (i.e. dizziness, fatigue, nausea) and hot flush. Conclusion We pointed out some additional symptoms of endometriosis qualified as early symptoms, which can serve as a screening tool for prevention and/or treatment purpose. The present findings offer an opportunity for further exploration of early biological processes triggering this disease.

The objective of this study was to test the feasibility of automatically extracting and exploiting data from the YouTube platform, with a focus on the videos produced by the French YouTuber HugoDécrypte during COVID-19 quarantine in France. For this, we used the YouTube API, which allows the automatic collection of data and meta-data of videos. We have identified the main topics addressed in the comments of the videos and assessed their polarity. Our results provide insights on topics trends over the course of the quarantine and highlight users sentiment towards on-going events. The method can be expanded to large video sets to automatically analyse high amount of user-produced data.

ResumeObjectif Ce travail est une analyse de la litterature sur les risques lies a l’activite physique (AP) pendant la grossesse. Methode Une recherche electronique a ete realisee sur Cochrane Library, Google Scholar PubMed (Medline) et Web of Sciences, en combinant des termes MeSH associes a « Pregnancy », « Physical activity » et « Adverse events » ou « Risks ». Seules les revues publiees depuis la creation de ces bases a novembre 2016 ont ete retenues pour notre analyse. Resultats La recherche documentaire a abouti a un total de 104 publications. Apres une etude critique des resumes et/ou textes complets, seules une revue systematique et une etude de cohorte sur les blessures liees a l’AP pendant la grossesse sont apparues pertinentes. Les donnees suggerent une tres faible proportion (

RATIONALE, AIMS AND OBJECTIVES: The aim of this study was to describe the cohort of persons having experiences fatal and non-fatal drowning events, registered in the French cardiac arrest registry and to identify termination of resuscitation criteria. METHODS: We performed a prospective multicenter study based on data from French cardiac arrest registry database. All patients with cardiac arrest after drowning (CAD) recorded between July 2011 and November 2014 were included. The population description was carried out by medians [interquartile ranges (IQR)] or frequencies. The characteristics were compared in terms of the primary endpoint (alive vs dead at hospital admission) using chi-square or Fisher's exact and the Mann-Whitney U test. The predictive model was carried out using the multivariate logistic regression. RESULTS: The analysis included 234 CAD. The majority of patients were adults (83.6%) and males (64.5%). Most of the submersions occurred out of home (75.6%). We recorded 66.7% of incidents in fresh water. About a third of CAD was witnessed of which 33.8% had an immediate basic life support. Most of CAD patients received an advanced cardiac life support (87.2%). The median Mobile Medical Team response time was 22 [15-30] minutes. At hospital, 40.6% of patients were alive. Twenty one patients (9.0%) were discharged alive. Among them, 17 had a good neurological outcome. Faster interventions generally resulted in higher survival chances (Mobile Medical Team response time OR: 0.960[0.925; 0.996]; P = 0.0.031; no flow duration OR: 0.535[0.313; 0.913]; P = 0.022) if associated with ventilation (OR: 6.742[2.043; 22.250]; P = 0.002). Age (OR: 0.971[0.955; 0.988]; P = 0.001) and location outside (OR: 0.203[0.064; 0.625]; P = 0.007) are the other criteria of our model. CONCLUSIONS: The model is helpful to highlight explanative variables concerning CAD patients' outcome. The next step is the validation of these five factors by a larger study. Prevention and public training to lifesaving behaviours must be considered as priorities in French public health programmes.© 2016 John Wiley & Sons, Ltd. Language: en

Introduction L’exposition des employes des EFS a des particules fines et ultrafines (PF/PUF) peut induire un stress oxydant potentiellement responsable de plusieurs pathologies inflammatoires, dont la bronchopneumopathie chronique obstructive (BPCO). L’augmentation des biomarqueurs du stress oxydant a la fois au niveau systemique et local (au sein des voies respiratoires dans le cas d’une BPCO) pourrait constituer un marqueur d’interet pour le suivi des travailleurs exposes et le depistage precoce des pathologies. L’exposition aux PF/PUF des employes n’etant pas exclusive des EFS, son evaluation globale, necessite l’identification et la documentation des differents types et sources d’expositions (air exterieur, tabagisme, etc.) et leurs determinants. Objectif Identifier les principaux determinants de l’exposition aux PF/PUF et du stress oxydant resultant chez les employes des EFS. Methodes Une revue bibliographique a porte sur les determinants du potentiel oxydant et de l’exposition aux PF/PUF de toutes les origines possibles. Cette revue, couplee a un examen des conditions de travail des employes des EFS a permis d’identifier les determinants potentiels specifiques aux EFS et de definir les conditions optimales de leur evaluation. Pour collecter l’information necessaire, un questionnaire standardise selon une administration par enqueteur a ete developpe. Resultats Le questionnaire porte sur les principaux determinants de l’exposition aux PF/PUF d’origine professionnelle (type de tâches, historique des activites, etc.) et non professionnelle, ainsi que les facteurs pouvant influencer le niveau du stress oxydant. Le questionnaire sera teste dans le cadre d’une etude-pilote du projet ROBoCoP aupres de neuf employes des EFS sur trois postes (conducteurs de metro, agents de station, agents de securite). Les mesures d’exposition aux PF/PUF couplees a celles du potentiel oxydant (dans l’air ambiant et l’air exhale) ainsi que d’autres biomarqueurs d’exposition et du stress oxydant (dans le condensat d’air exhale et l’urine) permettront d’examiner la performance du questionnaire, d’identifier les leviers d’amelioration eventuels et de le valider en vue de son administration dans l’etude de terrain. Conclusion La documentation des determinants de l’exposition aux PF/PUF et du stress oxydant resultant permettra leur prise en compte appropriee lors de l’analyse de la relation entre l’exposition des agents des EFS et les effets sanitaires.

To determine the effect of preconception body mass index (BMI) and/or gestational weight gain (GWG) on the occurrence of sleep disorders over the whole pregnancy.A sample of 2,366 pregnant women, recruited in their 1st trimester (TM), was evaluated until delivery for their sleeping characteristics, using the Pittsburgh Sleep Quality Index (PSQI). Mixed or multinomial logistic modeling was applied, as appropriate.When compared with TM 1, PSQI score was the lowest at TM 2 (β = -1.03; 95% CI: -1.17 to -0.89) and highest in TM 3 (β = 0.27; 95% CI: 0.10-0.45). Obese (β = 0.48; 95% CI: 0.17-0.78) and overweight women (β = 0.24; 95% CI: 0.00-0.48) exhibited an overall greater PSQI than normal-weight women over the whole pregnancy. When sociodemographic factors were accounted for, the effect size was reduced by 25% among obese women (β = 0.36; 95% CI: 0.06-0.68), but was no more not significant in overweight women (β = 0.06; 95% CI: -0.17 to 0.30). Both obese and overweight women still exhibited, although at a lower extend, a greater PSQI than normal-weight women. Further adjustment for GWG had no effect on these observations. Obese women almost had a four-fold increased risk (OR = 3.89; 95% CI: 2.50-6.06) of being snorers in the three TMs. While GWG had only a minor effect (aOR = 3.83; 95% CI: 2.43-6.03), sociodemographic factors increased the odds of being habitual snorer (aOR = 4.04; 95% CI: 2.57-6.35).High prepregnancy BMI together with sociodemographic correlates appear as the most critical for sleep disturbances across pregnancy. GWG is of marginal importance, especially regarding snoring. These findings confirm the importance of considering the initial body weight status of women in tailoring sleep hygiene advises irrespective of the recommendations for weight gain during pregnancy. The results also underscore the need to providing as early as possible during a pregnancy, supportive tools to ethnic minorities, multiparous, and women from deprived socioeconomic neighborhoods.

International audience; This paper aims to test and illustrate the utility and extensibility of an existing model, SimNCD (Simulation of NonCom-municable Diseases). It also proposes a way to include questionnaires-widely used in epidemiology-in the individual's reasoning mechanism in order to identify his/her attitude and personal choices. SimNCD is a formal agent-based model. It helps researchers and health practitioners study and simulate the complex dynamics of noncommunicable diseases. It models individuals that evolve within a social network, and behave while engaging in activities offered by their physical environment. The literature strongly supports the influence of the individual's behavioral choices on their health, particularly, the acquirement and maintainability of noncommunicable diseases. Therefore, we propose to extend SimNCD in order to acquire the agents with a reasoning process that allows them to choose the activities to practice. Thus, we model their attitude via preferences that are modeled based on the available literature and expressed with the linguistic 2-tuple method. Our solution also employs a multi-attribute decision-making method. We specify the proposed solution in the study of childhood obesity and use it to predict children's corpulence variations in different scenarios.

Objectives The aim of this study was to better characterize the moderate intensity of PA among children by applying fuzzy logic as the most appropriate analytical approach. In this perspective, the 6-MWT was selected as a pertinent exercise modality, which covers as a whole, this intensity level. Design Methodological study. Methods Fuzzy logic was applied to accelerometer output obtained on 46 children aged 9–11 years. A fuzzy subset A was defined from the reference set E using a membership function (degree of truth). To adequately tap the moderate PA, a core of X ¯ ± σ and a support of X ¯ ± 2 σ (with X ¯ the mean, and σ the standard deviation of the distribution) were selected. Results The walking speed during the exercise averaged 6.1 ± 0.6 km h −1 and the mean HR was 135 ± 14 bpm. The movement count (419 ± 127 to 433 ± 148 counts) exhibited no significant changes during the test. A value of 260 counts per 5-s (i.e., 3120 cpm) had equally 50% of degree of truth to encompass both “light” and “moderate” intensities of PA. Results suggest that the cut-point of >2296 cpm covers a low PA at 100% and a moderate PA at 0%. Conclusions Fuzzy logic provides a robust basis to processing accelerometer data, and brings a reliable solution to the concern about the in-between of PA intensities. Its application to calibration studies should not support the use of a cut-point of about 2000 cpm in children, and linguistic variables should now be preferred to numbered data in defining PA intensities.

This study explored the proportion of European youth who are sufficiently active according to physical activity (PA) recommendations, based exclusively on objective assessment through accelerometers. A systematic electronic search of studies published up to March 2012 was conducted. PubMed was used to identify accelerometry-assessed PA studies that involved European youth. Within the 131 European studies, only 35 clearly reported the proportion of youth meeting the PA recommendations. Different thresholds lying between 1000 and 4000 counts/min (cpm) were used to define moderate-to-vigorous PA (MVPA). Overall, up to 100% of youth may be sufficiently active when using a threshold of approximately >1000-1500 cpm. With the most cited cut-off point (i.e. >2000 cpm), up to 87% of European youth might be considered physically active with reference to the current recommendations. Alternatively, with a cut-off point >3000 cpm, no more than 3-5% of them appeared to achieve these recommendations. The large discrepancy in outcomes released by accelerometer data is mainly due to the variety of cut-off points for MVPA among youth, hindering the definition of a clear goal towards PA promotion in Europe. Standardization of methods is urgently required. © 2013 The Royal Society for Public Health.

International audience; OBJECTIVE: To evaluate the association between maternal physical activity and infant's birth weight or risk of inappropriate weight for gestational age (GA), and whether this association differs by infant's sex, maternal body mass index (BMI) or pregnancy complications in a prospective cohort study.METHODS: 1913 pregnant women from the 3D Birth Cohort (Québec, Canada) completed the Pregnancy Physical Activity Questionnaire at each trimester. Energy expenditure (metabolic equivalent of task (MET)*hours/week) for total activity, sports and exercise and vigorous intensity activities was calculated. The associations with birth weight and risk of inappropriate weight for GA were evaluated by regression modelling. Interactions were tested with infant's sex, maternal prepregnancy BMI, gestational diabetes, hypertensive disorders and prematurity.RESULTS: Each 1 MET/hours/week increase in sports and exercise in the first trimester was associated with a 2.5 g reduction in infant's birth weight (95% CI -4.8 to -0.3) but was not associated with the risk of small weight for GA. In contrast, although not significant, a 17% reduction in the risk of large weight for GA was observed with increasing sports and exercise. Furthermore, in women with subsequent pre-eclampsia (but not normotensive or hypertensive women), each 1 MET/hours/week increment spent in any vigorous exercise in the first trimester reduced the infant's birth weight by 19.8 g (95% CI -35.2 to -4.3).CONCLUSIONS: Pregnant women with higher sports and exercise levels in the first trimester delivered infants with a lower birth weight. The risk of reducing infant's birth weight with vigorous exercise in women who develop pre-eclampsia later in pregnancy requires evaluation.

The current high prevalence of childhood obesity and its co-morbidities is concomitant with a low level of physical activity and an abundance of sedentary pastimes for Westernised children. To increase the participation of a majority of children in a sustained physical activity, interventions require a fair understanding and consideration of the influences of this behaviour, especially as children are overweight or obese. Basically, the physical activity behaviour of children depends on biological, sociocultural and psychosocial factors and their interplay. The recent literature lends support to the fact that some psychosocial factors such as self-efficacy and physical competence may be solid anchor points upon which to improve the participation of overweight and obese children in free-living physical activity. Thus, interventionists should first concentrate on improving these personal dimensions around which physiological and environmental factors might revolve. The development of motor skills may be a good means for enhancing the self-image of obese children.

This study is aimed at updating the relationships between physical activity (PA) and the metabolic syndrome (MetS) and/or insulin resistance (IR) in youth. Cross-sectional, prospective cohort and intervention studies, which examined the effect of PA on MetS, its components and IR in children and adolescents (18 yrs), were searched by applying a combination of criteria in the PubMed database. The electronic search of studies published from 2000-2010 yielded150 references. Of these, 37 studies were included. Twenty-six studies (70%) were cross-sectional observation studies, and two studies (8%) were prospective cohort studies. The remaining eight studies (22%) were interventions, of which three (10% of all included studies) were randomized controlled trials. Commonly, higher PA levels were consistently associated with an improved metabolic profile and a reduced risk for MetS and/or IR in these populations. The impact of PA on MetS and/or IR appeared to be either independent of other factors, or alternatively or simultaneously mediated by the physical fitness and adiposity of youth. However, more-robustly designed interventions (i.e., some mega-randomized controlled trials based on lifestyle interventions) and additional cohort studies are required to make definitive inference about the magnitude and role of PA as a single genuine preventive and treatment strategy for the metabolic and cardiovascular risk of youth in the current obesogenic context.

Metabolic syndrome (MetS) is increasingly reported in children, mainly in the presence of overweight/obesity. From the most recent report, up to 60% of overweight and obese children can be affected by this syndrome. MetS acquired during childhood has been shown to track into adulthood, including its clinical complications, such as type 2 diabetes and cardiovascular diseases. Among the practical preventive and therapeutic measures to be taken in children, physical activity (PA) appears to be at least as efficient as the most adequate pharmacology. The current literature suggests that exercise programs based either on aerobic-or resistance-type exercises, or a combination of these 2 types of structured activity, may promote insulin sensitivity and weaken or suppress MetS in children. Furthermore, daily-living activities such as brisk walking were found to substantially reduce the risk of MetS among children. Regardless of their weight status, PA needs to be promoted among children as early as possible.

Background For their health and an appropriate development, it is recommended that schoolchildren get on a daily basis a minimum of 60 min of moderate-to-vigorous physical activity (MVPA). With only about 11% of girls and 25% of boys completing these recommendations, French children are among the least active in the world. In addition, most of them spend almost 3 h/day in front of a screen while it is generally suggested to limit children's screen time to less than 2 h/day. Methods An inspection of available opportunities in the French context reveals many occasions for sufficient physical activity at school, at home, in the neighbourhood, and during commuting to and from school. Results Available opportunities which encompass about 245 min/day, could contribute to at least 100 min/day of MVPA to all children, considering sport as a subsidiary and economically constraint opportunity. Moreover, in France there is an interesting legal background and political willpower to promote physical activity in the general population, and especially among children. Several factors may explain the high level of physical inactivity among French children, including the lack of investments for strategies aiming to uphold physical activity when compared to other major risks of diseases such as smoking or alcoholism. Furthermore, there may be a failure of the main actors (e.g., parents, teachers, health, sport and physical activity professionals) directly involved in the promotion of physical activity in children. Given its influence on many dimensions of a child's health, it is necessary that adults’ attitudes towards physical activity and sedentary lifestyles change more quickly. Conclusion It is important to increase awareness of the adult population, in that education/knowledge, role modelling, encouragement and counselling in physical activity undertaken by trained professionals are of paramount value for the integration of physical activity as part of the children's routine. These actions should be based on an accurate assessment/surveillance system and an adequate characterization of physical activity profiles of children.

Le but de cette etude est de caracteriser l’environnement « obesogenique » d’un groupe d’enfants d’âge scolaire en utilisant une analyse factorielle des correspondances multiples (AFCM), comme approche alternative aux choix methodologiques traditionnels, applicable, meme aux echantillons de taille modeste. Quatre-vingt-onze enfants (39 filles et 52 garcons) âges de 10,0 ± 0,9 ans ont ete aleatoirement recrutes au sein de 2 etablis-sements scolaires publics francais. Les donnees concernant leur cadre familial, l’implication des parents, leur temps televisuel et leur comportement alimentaire ont ete obtenues par questionnaire. Leur niveau d’activite physique et leur temps sedentaire ont ete evalues au moyen d’un accelerometre (MTI Actigraph, modele 7164) pendant 3 jours, y compris un jour ferie. Les donnees ont ete traitees au moyen d’une AFCM. Une methode d’estimation du risque a ensuite ete appliquee en considerant la distribution des enfants suivant leur statut vis-a-vis du surpoids/obesite dans le plan factoriel produit par l’AFCM. Les caracteristiques « obesogeniques » sont apparues comme 4 possibilites de combinaison entre l’environne-ment familial et des comportements varies vis-a-vis de l’activite physique, la sedentarite et?l’alimentation. Le risque relatif (RR) de surpoids/obesite etait de 2,64 [1,52 ; 4,57] (p < 0,0001) pour une combinaison entre un environnement familial « defavorise » + une association activite physique faible et alimentation riche en matieres grasses et de 0,36 [0,14 ; 0,94] (p < 0,05) pour un environnement familial « favorise » + une association activite physique forte et alimentation pauvre en matieres grasses. L’AFCM apparait suffisamment robuste et pertinente pour orienter efficacement les hypotheses etiologiques et les decisions concernant les strategies d’intervention individuelle ou collective.

Les bienfaits d’une activite physique reguliere sont desormais unanimement reconnus par les communautes medicale et scientifique. Paradoxalement, les donnees epidemiologiques suggerent qu’une proportion importante (> 60 %) de la population mondiale ne realise pas suffisamment d’activite physique pour sa sante. En Europe par exemple, la prevalence de l’activite physique est seulement de 29 %. La France apparait dans ce contexte comme le pays le plus sedentarise. La participation des medecins et surtout du medecin traitant a l’effort de sante publique visant a generaliser les modes de vie actifs dans la population generale est capitale. Pour une contribution efficace du medecin a la promotion de l’activite physique, cet article s’est destine a actualiser une demarche systematique du conseil en activite physique simple et applicable en routine, apres une formation specifique : la methode des « 5A » a savoir : « A pprecier » ; « A viser » ; « A greer » ; « A ssister » ; « A rranger ».

With the steady rise in the prevalence of overweight/obesity and its comorbidities in the pediatric population, it seems necessary to watch and stimulate the engagement of a majority of children in a regular physical activity. To do this, it seems crucial to know and handle properly the determinants or influences of the habitual physical activity (HPA) of children, especially when it is about overweight/obesity children. This article is an update and a review of existing data on the determinants of HPA with reference to overweight/obesity in childhood. Current data suggest that self-efficacy and physical competence are key motivators and solid anchor points for the initiation and engagement of children in a regular physical activity. In particular, for overweight/obese children, intervention strategies should first concentrate on improving these psychosocial dimensions around which other physiological components (capacity factors) and environmental (reinforcement factors) could revolve. These strategies should involve a multidisciplinary professional team (epidemiologists, actiphysists, teachers, physicians, psychologists, urban planners, local councillors) not only pursuing the same objective but with sufficiently varied skills to be effective at their respective levels.

Metabolic syndrome defined as the joint manifestation on the same subject of several risk factors (at least 3 in the majority of definitions) within the following parameters : hypertriglyceridemia, hypertension, abdominal obesity, low concentration of HDL-Cholesterol (HDL-C), and high fasting blood glucose is increasingly reported in children, mainly in the presence of overweight/obesity. In fact, up to 50 % of overweight/obese children can be affected by this syndrome. Furthermore, the metabolic syndrome acquired during childhood has been shown to impact highly into adulthood including by its clinical complications such as type 2 diabetes or cardiovascular diseases. Among the practical preventive and therapeutic measures to be taken in children, physical activity appears to be an option of choice. This review indicates that physical activity programs based either on aerobic exercise, resistance training, or a combination of these 2 types of activity may promote insulin sensibility and weaken or suppress the metabolic syndrome of children. More interestingly, usual physical activity including free-living activities of an intensity equivalent to a brisk walking should be encouraged earlier among children for its positive influence on parameters involved in the metabolic syndrome.

International audience; Noncommunicable diseases (NCDs) are multifactorial chronic illnesses that cause long-term morbidities in a person's life. Their nonlinear and complex dynamics make them difficult to control and predict. Hence, it is crucial for public health researchers and practitioners to understand and model them. This paper proposes a generic interaction-oriented agent-based modeling for NCDs, called SimNCD. It models individuals living within a social network and daily engaging in activities from the physical environment. The practice of these activities stirs the individual's health vulnerability to cure, acquire or maintain NCDs. This modeling can serve as a tool in public health policies for the study of NCDs where the in-dividual's behavior greatly influences the factors predisposing to that disease. We also propose a specified version of SimNCD for modeling childhood obesity, called SimNCD ChO. More precisely, the latter models the complex relationships between children's physical activity and the development of their corpulence during their growth.

Engaging in a regular physical activity appears to be an important factor in the prevention of childhood obesity, which became one of the major public health challenges worldwide. The literature suggests that the relationship between physical activity and obesity is complex with many intervening factors that come from different aspects of the child’s life. Yet, so far, the proposed models do not include all of the identified factors. The main objective of this study is to simulate the child’s behavior within his/her social and physical environments in order to understand precisely the relationship between the PA and childhood obesity. This paper proposes a simulation model using the multi-agent paradigm.

Objective: Validation of body adiposity index (BAI) in a paediatrics sample; and to develop, if necessary, a valid BAI for paediatrics (i.e. BAIp). Methods: A total of 1615 children (52% boys) aged 5-12 years underwent anthropometry. Their body composition was assessed using a foot-to-foot bioimpedance. The validity of BAI=(Hip circumference/Height1.5)-18 was tested by combining correlation and agreement statistics. Then, the sample was split into two sub-samples for the construction of BAIp. A regression was used to compute the prediction equation for BAIp-based percentage of body fat (%BF). Results: The initial BAI over-estimated the %BF of children by 49% (29.6±4.2% versus 19.8±6.8%; p

AimThis study aims to compare three body mass index (BMI)-based classification systems of childhood obesity: the French, the International Obesity Task Force (IOTF) and the World Health Organization (WHO) references.MethodsThe study involved 1382 schoolchildren, recruited from the Lille Academic District in France in May 2009 aged 8.4±1.7 years (4.0–12.0 years). Their mean height and body mass were 131.5±10.9cm and 30.7±9.2kg, respectively, resulting in a BMI of 17.4±3.2kg/m2. The weight status was defined according to the three systems considered in this study. The agreement between these references was tested using the Cohen's kappa coefficient.ResultsThe prevalence of overweight was higher with the WHO references (20.0%) in comparison with the French references (13.8%; P

AIM: To examine: (i) if maturity-related gender differences in moderate-to-vigorous physical activity (MVPA) depend on how maturity status is defined and measured; and (ii) the influence of maturity level on compliance with PA recommendations. METHODS: The study involved 253 children (139 boys) aged 9.9 ± 0.9 years, with mean stature and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg respectively. Their PA was evaluated using an Actigraph accelerometer (Model 7164). Maturity was assessed using the estimated age at peak height velocity (APHV) and a standardized APHV by gender (i.e. centred APHV). RESULTS: Boys engaged in significantly more MVPA than girls (P < 0.0001). There was a significant correlation between the centred APHV and MVPA in boys (r = 0.20; P = 0.016), but not in girls (r = 0.13; P = 0.155). An ancova controlling for the estimated APHV showed no significant interactions between gender and APHV, and the main effect of gender on MVPA was negated. Conversely, there was a significant main effect of APHV on MVPA (F 1,249 = 6.12; P = 0.014; η p (2) = 0.024). Only 9.1% of children met the PA recommendations, including 14.4% of boys and 2.6% of girls (P < 0.01). This observation also applies in both pre-APHV (12.7% of boys vs. 2.4% of girls, P < 0.001) and post-APHV children (23.8% of boys vs. 3.4% of girls, P < 0.0001). No differences in PA guidelines were observed between pre-APHV and post-APHV children. CONCLUSIONS: Among prepubescent children, the influence of biological maturity on gender differences in PA may be a function of how maturity status is determined. The most physically active prepubescent children were those who were on time according to APHV.

Aims: This study examined the compliance of French children with physical activity (PA) guidelines, using objective assessments of PA. Methods: The study involved 252 children aged 9.9 ± 0.9 years, with mean height and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg, respectively. Their usual PA was evaluated during a week using an Actigraph accelerometer. Results: The time spent in a moderate-to-vigorous PA (MVPA) ranged from 142 ± 44 min.d-1 to 25 ± 18 min/day according to the cut-offs used. Boys were significantly more active than girls ( p ≤ .001). Overweight/obese children spent significantly less time in MVPA as determined with cut-off points at 3200 cpm (-26%) or 3600 cpm (-35%) ( p < .01). Between 5% (8% of boys vs 1% of girls, p < .0001) and 9% (14% of boys vs 3% of girls, p < .0001) of children probably met the PA guidelines. No relationships were found with socioeconomic status. Conclusions: This high proportion of insufficiently active children (> 90%), together with the relatively high proportion of overweight children in this area, advocates a more aggressive PA promotion project, which should target all children whatever their social origins.

French children are among the least physically active in Europe. Public health actions to promote physical activity involve families, GPs and other professionals. GPs in particular can prove effective in encouraging an active lifestyle among overweight or obese children.

To examine the consistency in findings about the influence of maturity on the gender-difference in moderate-to-vigorous physical activity (MVPA) of children using different cut-off points for MVPA.Cross-sectional observation study.The sample involved 253 children (139 boys) of 9.9±0.9 years. Their physical activity was evaluated using an Actigraph accelerometer. The biological age of children was determined with their estimated age at the peak height velocity, and maturity categories were gender-specific defined.Boys spent more time in MVPA than girls (P0.0001), and no maturity-related differences were obtained on the whole sample. It was only among boys that differences were found between maturity groups with cut-off points of 3000 cpm (P=0.034), 3200 cpm (P=0.024), and 3600 cpm (P=0.011). At a given maturity level, boys spent significantly more time in MVPA than girls, except with the cut-off point of 1000 cpm (P=0.07). There were higher proportions of sufficiently active boys, but significances were reached only with cut-off points above 3000 cpm. There were no maturity-related differences in the proportion of sufficiently active children as MVPA was computed using cut-off points of 1000 cpm, 2000 cpm or 3000 cpm.The role of maturity in the gender-difference in MVPA seems unclear as one another cut-off point is used among children. Even if a relatively greater consistency was found with the three cut-off points above 3000 cpm, data comparison may require a conversion system until a consensus is reached about the exact value to be used among children.

The purpose of this study was to describe an "obesogenic" environment for a group of schoolchildren using a multiple correspondence analysis (MCA) as an alternative approach to traditional methodological choices. MCA is applicable even for small samples. Ninety-one children (39 girls and 52 boys) aged 10.0 +/- 0.9 years were randomly recruited from two French public schools. Data on their family context, parental involvement, television time and their eating habits were obtained through questionnaires. Their level of physical activity and sedentary time were assessed using an accelerometer (MTI Actigraph model 7164) for three days, including a holiday. The data were processed using an MCA together with a technique for estimating relative risks (RRs) of overweight/obesity according to the distribution of children in the factorial plane produced by the MCA. The "obesogenic" factors appeared as four possible combinations between family environments and various behaviours with regard to physical activity, sedentary behaviour and diet. The RR of overweight/obesity was 2.64 [1.52, 4.57] (P0.0001) for a combined association of a "disadvantaged" family environment + low physical activity and high fat diet. The RR of overweight/obesity was 0.36 [0.14, 0.94] (P0.05) for an association of a "privileged" family environment + high physical activity and low fat diet. Thus, MCA appears sufficiently robust and relevant to effectively guide etiological hypotheses and decisions about individual and collective intervention strategies.

Metabolic syndrome defined as the joint manifestation on the same subject of several risk factors (at least 3 in the majority of definitions) within the following parameters : hypertriglyceridemia, hypertension, abdominal obesity, low concentration of HDL-Cholesterol (HDL-C), and high fasting blood glucose is increasingly reported in children, mainly in the presence of overweight/obesity. In fact, up to 50 % of overweight/obese children can be affected by this syndrome. Furthermore, the metabolic syndrome acquired during childhood has been shown to impact highly into adulthood including by its clinical complications such as type 2 diabetes or cardiovascular diseases. Among the practical preventive and therapeutic measures to be taken in children, physical activity appears to be an option of choice. This review indicates that physical activity programs based either on aerobic exercise, resistance training, or a combination of these 2 types of activity may promote insulin sensibility and weaken or suppress the metabolic syndrome of children. More interestingly, usual physical activity including free-living activities of an intensity equivalent to a brisk walking should be encouraged earlier among children for its positive influence on parameters involved in the metabolic syndrome.

Background:This study was designed to model the relationship between an ActiGraph-based “in-school” physical activity (PA) and the daily one among children and to quantify how school can contribute to the daily PA recommendations.Method:Fifty boys and 43 girls (aged 8 to 11 years) wore ActiGraph for 2 schooldays of no structured PA. The daily moderate-to-vigorous PA (MVPAd) was regressed on the school time MVPA (MVPAs). Then, a ROC analysis was computed to define the required MVPAs.Results:Children spent 57% of their awaking time at school. School time PA opportunities (ie, recesses: ~18% of a child’s awaking time) accounted for >70% of the MVPAd among children. Then, MVPAd (Y) could be predicted from MVPAs (X) using the equation: Y = 2.06 X0.88; R2 = .889, P < .0001. Although, this model was sex-specifically determined, cross-validations showed valid estimates of MVPAd. Finally, with a sensitivity of 100% and a specificity of 90%, MVPAs, a 34 min.d−1 was required to prompt the daily recommendation.Conclusions:The current study shows the contribution of MVPA at school to recommended activity levels and suggests the value of activity performed during recesses. It also calls for encouraging both home- and community-based interventions, predominantly directed toward girls.

Cette synthese presente des principes d’action, avantages et inconvenients des 5 categories de methodes (calorimetrie, cardiofrequencemetrie, actimetrie, observation, questionnaire) permettant d’evaluer l’activite physique habituelle (APH) des enfants en pratique clinique et/ou lors de suivis epidemiologiques. L’agregation d’un ensemble de criteres associes a la validite/fiabilite, la facilite d’administration, l’ethique, le cout et les objectifs poursuivis, doit guider le choix d’une methode par rapport a une autre. L’utilisation des methodes admises comme references-etalons (i.e., calorimetrie, eau doublement marquee, observation directe) est limitee en sante publique en raison de leur cout. La cardiofrequencemetrie procede d’un certain inconfort pour l’enfant en plus des incertitudes du signal telemetrique. L’actimetrie – et l’utilisation d’accelerometres en particulier – semble etre une methode equilibree au regard des criteres de choix. Si son utilisation est bien adaptee au diagnostic individuel et a la recherche clinique, sa complexite limite son usage en epidemiologie populationnelle ou pour diffuser des messages sante. Aussi, malgre les difficultes liees a leur utilisation chez l’enfant (biais lies a l’incomprehension, l’impression, la reponse socialement acceptable et aux limites cognitives/memorielles), les methodes declaratives peuvent etre utiles pour les etudes de grande taille et pour prendre en consideration la dimension perceptuelle de l’activite physique et de l’etat de sante de l’enfant.

BACKGROUND: Paediatric research analysing the relationship between the easy-to-use anthropometric measures for adiposity and cardiometabolic risk factors remains highly controversial in youth. Several studies suggest that only body mass index (BMI), a measure of relative weight, constitutes an accurate predictor, whereas others highlight the potential role of waist-to-hip ratio (WHR), waist circumference (Waist C), and waist-to-height ratio (WHtR). In this study, we examined the effectiveness of adding anthropometric measures of body fat distribution (Waist C Z Score, WHR Z Score and/or WHtR) to BMI Z Score to predict cardiometabolic risk factors in overweight and obese youth. We also examined the consistency of these associations with the "total fat mass + trunk/legs fat mass" and/or the "total fat mass + trunk fat mass" combinations, as assessed by dual energy X-ray absorptiometry (DXA), the gold standard measurement of body composition. METHODS: Anthropometric and DXA measurements of total and regional adiposity, as well as a comprehensive assessment of cardiometabolic, inflammatory and adipokines profiles were performed in 203 overweight and obese 7-17 year-old youths from the Paediatrics Clinic, Centre Hospitalier de Luxembourg. RESULTS: Adding only one anthropometric surrogate of regional fat to BMI Z Score improved the prediction of insulin resistance (WHR Z Score, R(2): 45.9%. Waist C Z Score, R(2): 45.5%), HDL-cholesterol (WHR Z Score, R(2): 9.6%. Waist C Z Score, R(2): 10.8%. WHtR, R(2): 6.5%), triglycerides (WHR Z Score, R(2): 11.7%. Waist C Z Score, R(2): 12.2%), adiponectin (WHR Z Score, R(2): 14.3%. Waist C Z Score, R(2): 17.7%), CRP (WHR Z Score, R(2): 18.2%. WHtR, R(2): 23.3%), systolic (WHtR, R(2): 22.4%), diastolic blood pressure (WHtR, R(2): 20%) and fibrinogen (WHtR, R(2): 21.8%). Moreover, WHR Z Score, Waist C Z Score and/or WHtR showed an independent significant contribution according to these models. These results were in line with the DXA findings. CONCLUSIONS: Adding anthropometric measures of regional adiposity to BMI Z Score improves the prediction of cardiometabolic, inflammatory and adipokines profiles in youth.

International audience; Complexity science offers many theories such as chaos theory and coevolutionary theory. These theories illustrate a large set of real life systems and help decipher their nonlinear and unpredictable behaviours. Categorizing an observed Complex System among these theories depends on the aspect that we intend to study, and it can help better understand the phenomena that occur within the system. This article aims to give an overview on Complex Systems and their modelling. Therefore, we compare these theories based on their main behavioural characteristics, e.g. emergence, adaptability, and dynamism. Then we compare the methods used in the literature to model and simulate Complex Systems, and we propose and discuss simple guidelines to help understand one's Complex System and choose the most adequate model to simulate it.