[Tracking of physical fitness during chilhood: Longitudinal findings from the Diagnoform program]. / Évaluation de la condition physique durant l'enfance dans le nord de la France : le programme Diagnoform.

BACKGROUND: A high level of physical fitness is associated with cardiovascular health in adolescents. We describe change in physical fitness levels assessed at two time points over 3 years. METHODS: The study presents a longitudinal design, with the first phase data collection at 8 years and the second phase carried out at 11 years. A total of 516 children (254 boys) aged to 7.7±0.4 years (in 2010) and 10.9±0.4 years (in 2010) and 10.9 ± 0.4 years (in 2013) participated to the study. Cardiorespiratory fitness, muscular strength, speed, and agility were assessed in this study. For each physical fitness test, determination of the situation (in terms of percentiles) of each child in 2010 and then in 2013 compared to national standards. The 2010 and 2013 percentiles are then compared using the Wilcoxon signed rank test. RESULTS: Muscular strength, agility and cardiorespiratory fitness decrease in both sex (p<0.01). A significant decrease was also found for all physical fitness components in normal weight children (p<0.05). For normal weight children in 2010 who became overweight or obese in 2013, there was a significant decrease in scores of cardiorespiratory fitness and agility tests (p<0.05). For overweight children in 2010 becoming from to normal weight status in 2013, only the agility test decreased significantly (p<0.05). Children being overweight or obese in 2010 and remaining in 2013, had a significant decrease in their physical fitness levels (p<0.05). CONCLUSIONS: Our results indicate that the physical fitness of French youth decrease between childhood and early adolescence. Developing and introducing a health promotion curriculum in the French schools is suggested to improve health and physical fitness.

[Association between screen time and sleep habits in 11-to-12-year-old French middle school students]. / Associations entre les temps d'écran et les habitudes de sommeil chez des jeunes collégiens.

BACKGROUND: Screen media usage has become increasingly commonplace in daily life with children initiating themselves to screen media at an early age. Given the high prevalence of screen viewing among children worldwide, its impact on children's health has become a cause for concern. Unfortunately, little information on the independent association between sleep habits and screen time in French children is currently available. The main aim of this study was to assess possible relationships between screen time and sleep habits (quality, duration, etc.) among young middle school students in France. METHODS: A total of 448 (55 % girls) 11-to-12-year-olds from 5 schools were included. Body weight and height were measured according to standard procedures and BMI percentiles were determined based on international reference values. Sleep parameters were obtained by sleep diaries and visual estimations. A sleep diary was maintained for one week to record sleeping and waking times and related information. Information on lifestyle habits (sedentary behaviours, physical activity, and dietary intake) was obtained via standardised questionnaires. RESULTS: Participants were 11.5 (±0.4) years of age. From total sample, 25.5 % reported screen time ≥2hours/d during school days and 62.7 % during school-free days. High screen time was associated with significantly poorer sleep habits and these results remained valid after adjustment for several confounding factors (body mass index, sex, center and parental level of educational attainment) (P<0.05). CONCLUSION: This study highlights an association between longer screen time and shorter sleep duration in French middle school students aged 11 to 12 years. Preventive measures on use of and exposure to screens are called for. Further studies are necessary to confirm our findings.

Gender influences physical activity changes during adolescence: The HELENA study.

BACKGROUND: We compared differences in physical activity (PA) between pre/mid-pubertal and post-pubertal participants according to gender. METHODS: The study included a total of 1842 healthy participants aged 12.5-17.4 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Participants wore a uniaxial accelerometer (ActiGraph© GT1M, Pensacola, FL, USA) attached to their lower back for seven consecutive days to measure PA. Pubertal status was assessed by physical examination and the population was classified as pre/mid-pubertal (Tanner stages 1-3) or post-pubertal (Tanner stages 4-5). PA was compared between these groups according to gender during the whole week, on school-free days and on school days, before and after school, and during lessons and recesses. RESULTS: When comparing the pre/mid-pubertal group with the post-pubertal group, girls' total PA did not differ between groups. However, a slight difference was observed in boys, among whom PA on school-free days showed a difference of 17.6% between the pre/mid-pubertal group and the post-pubertal group (679 kcounts vs 564 kcounts, respectively; P = 0.0007) and 20% (162 kcount vs 135 kcounts; P = 0.006) for school recess. There was no difference among girls. CONCLUSIONS: A reduced level of PA in the post-pubertal groups was only observed in boys during non-organized times such as on school-free days and during school recesses, with a moderate impact on total PA.

[Physical activity assessment using accelerometry]. / Quantification de l'activité physique par l'accélérométrie.

Physical activity is an important determinant of health in children and adults. Assessment of physical activity is therefore an important factor in the promotion of health and in several childhood and adulthood pathological situations. Physical activity can be estimated by various methods: pedometry, heart rate monitoring, questionnaires, the doubly labelled water method, and accelerometry. The choice of the type of device depends on the objectives of the clinician or researcher. Accelerometry currently represents the best objective method for measuring physical activity and is widely used in clinical or epidemiological studies. The purpose of this paper is to help practitioners and researchers to make better decisions when using accelerometry as a device for measuring physical activity measurement in order to obtain the most accurate and comparable information.

[Physical fitness levels in French adolescents: The BOUGE program]. / Condition physique des enfants et adolescents en France de 2009 à 2013 et prévalence du risque de maladie cardiovasculaire à l'âge adulte - le programme « Bouge Une priorité pour ta santé ¼.

BACKGROUND: A high level of physical fitness is associated with cardiovascular health in adolescents. The aims of this study were to assess the levels of physical fitness of French adolescents and to determine the prevalence of these adolescents below the minimum level of cardiorespiratory fitness needed to guarantee future favorable cardiovascular profile. METHODS: Participants were 12,082 French children and adolescents (5975 boys, 6107 girls) aged to 9 from 16 years. Cardiorespiratory fitness, muscular endurance, speed, flexibility and speed agility were tested. The associations of physical fitness measures with adolescent's characteristics were analyzed using Student t test, one-way ANOVA, or Pearson correlations as appropriate. RESULTS: Boys were physically fitter than girls, expected for flexibility (P<0.0001). Subjects of normal weight adolescents had significantly better results than overweight or obese adolescents (P<0.05 for all comparisons), but also in comparison with underweight adolescents for muscular endurance, flexibility, cardiorespiratory fitness test (P<0.05). Our findings indicate that, on the basis of cardiorespiratory fitness, 16% of French boys and 7.7% of French girls have a risk of future cardiovascular disease (P<0.0001). This subgroup also performed poorly in all other tests of physical fitness used (P<0.0001). Aerobic fitness decreased significantly with the age (r=-0.168 for boys; r=-0.261 for girls). CONCLUSIONS: Our results indicate that the physical fitness of French adolescents must be improved to help protect against cardiovascular disease in adulthood, especially in boys. The study showed also a dramatically decrease of the cardiorespiratory fitness during the adolescence period. Developing and introducing a health promotion curriculum in the French schools is suggested to improve health and physical fitness.

[Assessment of nutritional status in pediatric ambulatory research]. / Evaluation des paramètres nutritionnels en recherche clinique ambulatoire chez L'Enfant.

Nutritional status, an important measure in health promotion and certain childhood and adolescent pathologies, includes anthropometric, diet and physical activity evaluation. Choosing the best assessment of nutritional status for your research must consider objectives of clinician, study design, number of subjects, frequency of measurement, and cost. The purpose of this paper is to present reliable and valid field techniques available for pediatric ambulatory clinical research. These techniques do not interfere with free living conditions and represent a good alternative compared to reference assessment. The techniques are compatible with the quality assurance and ethics in clinical and epidemiological research requirements.

Raised immunoglobulin A and circulating T follicular helper cells are linked to the development of food allergy in paediatric liver transplant patients.

BACKGROUND: Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated. OBJECTIVE: To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant food-allergic children (FA). METHODS: We studied serum Ig levels in 29 LTFA, 43 non-food-allergic LT patients (LTnoFA), 21 FA patients and 36 HC. Serum-specific IgA and IgE against common food allergens in LTFA, IgA1 , IgA2 and joining-chain-containing polymeric IgA (pIgA) were measured. Peripheral blood mononuclear cells were analysed by flow cytometry for B and T cell populations of interest. RESULTS: Serum IgA and specific IgA were higher in LTFA compared to LTnoFA. LTFA patients had the highest proportion of circulating T follicular helper cells (cTfh). The percentage of cTfh correlated positively with serum IgA. Unique in LTFA was also the significant increase in serum markers of mucosal IgA and the decrease in the Th17 subset of CXCR5(-) CD4(+) cells compared to HC. Both LT patients exhibited a rise in IgA(+) memory B cells and plasmablasts compared to HC and FA. CONCLUSIONS: LT has an impact on humoral immunity, remarkably in those patients developing FA. The increase in serum markers of mucosal IgA, food allergen-specific IgA and cTfh cells observed in LTFA, point towards a disturbance in intestinal immune homoeostasis in this patient group.

[BOUGE-fitness test battery: health-related field-based fitness tests assessment in children and adolescents]. / La condition physique des enfants et adolescents: comment la mesurer en milieu scolaire? L'exemple de la batterie BOUGE.

Physical fitness is an important determinant of global health in children and adolescents. Key components of physical fitness include cardiorespiratory fitness, flexibility, speed, and muscular and endurance strength. The school environment provides a great opportunity to assess the physical fitness level in children and adolescents. The french national program "Bouge... Une priorité pour ta santé! "(Move ... A priority for your health!) aims to assess the physical fitness of children and adolescents aged 6 to 18 years old in French schools. The aim of this paper is to describe the interest to assess different health-related physical fitness components. It presents the chosen tests within said battery for children and adolescents and explains how the battery was conceived. The health-related physical fitness tests included in "BOUGE" were chosen for their validity, reliability, low cost and feasibility for all schools.

Muscular fitness, fatness and inflammatory biomarkers in adolescents.

BACKGROUND: Muscular fitness, cardiorespiratory fitness (CRF) and fatness are mutually related with chronic inflammation. PURPOSE: To examine the independent association of muscular fitness with inflammatory biomarkers in adolescents from nine European countries. METHODS: A total of 639 adolescents (296 boys) aged from 12.5 to 17.5 year were included in this report. Data collection took place in 2006-2007 and analyses in 2012. A muscular fitness score was computed from handgrip strength and standing long jump. CRF was measured using the 20 m shuttle run test. Z-scores of C-reactive protein, complement factors C3 and C4, leptin and white blood cell counts were summed to create a cluster of inflammatory biomarkers. Sex, age, pubertal stage and centre were used as main confounders. Additional models were further adjusted for insulin resistance (HOMA-IR) and sum of four skinfolds. RESULTS: Muscular fitness was negatively associated with single and clustered inflammatory biomarkers (standardized ß from -0.399 to -0.100, all P-values < 0.05). Additional adjustments for CRF and HOMA-IR weakened the associations, but they still remained significant. The association was no longer significant when adjusting for skinfolds. Decreasing values of inflammatory score were observed across incremental levels of muscular fitness in both non-overweight and overweight adolescents (P ≤ 0.05). CONCLUSIONS: Adolescents with higher levels of muscular fitness present a lower chronic inflammation, and this seems to be explained by lower levels of fatness. Yet, overweight and obese adolescents may exhibit a less adverse profile if they maintain appropriate levels of muscular fitness.

[Assessment of cardiorespiratory functional fitness in children: walking tests and running tests]. / Evaluation de la capacité fonctionnelle cardiorespiratoire chez l'enfant : tests de marche et tests de course.

Cardiorespiratory fitness (CF) is an important factor in treating various paediatric pathologies. As a consequence, assessing CF has widespread clinical application as part of paediatric intervention programs. Several methods have been developed for the purpose of measuring CF. The aim of this review is to describe and evaluate test procedures that are currently in use. Direct measurement in a laboratory setting has the advantage of high validity and reliability. The disadvantage, however, is that laboratory assessment of CF requires trained personnel, takes more time than field tests, and necessitates costly equipment. Conversely, field tests are easier to administer, require less time and utilise less expensive equipment. The choice of the test mode must take into account the age and health of the subject. The availability of a variety of tests makes it possible for the clinician/researcher to choose the most assessment that is most appropriate for the target population, study objectives, and available resources according to the research methods of the study.

Relationship between sleep habits, anthropometric characteristics and lifestyle habits in adolescents with intellectual disabilities.

The aim was to explore the relationship between sleep habits and overweight/obesity, physical activity and sedentary behaviours in French adolescents with intellectual disabilities. This observational study was conducted on 535 French adolescents with intellectual deficiency. Sleep habits were analyzed and related to anthropometric measures, physical activity and sedentary behaviours. The study was conducted using a self-administered questionnaire. Adolescents completed the questionnaire during an interview with the principle investigator. Sleep timing behaviour was classified into 4 sleep patterns: Early-bed/Early-rise, Early-bed/Late-rise, Late-bed/Late-rise, and Late-bed/Early-rise. Of 573 eligible participants, 125 were excluded because of missing data on age, weight or height. The number of participants identified in each of the four sleep patterns was as follows: Early-bed/Early-rise, N=59 (15.4%), Early-bed/Late-rise, N=164 (43%), Late-bed/Early-rise, N=56 (15%), Late-bed/Late-rise N=102 (27%). Adolescents who woke up early were more active than those from the late rise group (p<0.001). The number of adolescents who are sedentary was higher in late rise vs. early rise subjects (p<0.001). Subjects in the late-bed group were more likely overweight and obese (p<0.05). Results suggest that sleep behaviour was associated with overweight/obesity, physical activity and sedentary behaviour in adolescents with intellectual deficiency. Sleep behaviours should be considered in planning health promotion strategies.

[Technical aspects and relevance of physical activity assessment in children and adolescents in free-living conditions]. / Intérêt et techniques de la mesure de l'activité physique chez l'enfant et l'adolescent dans les conditions habituelles de vie.

Physical activity accounts for 25-30 % of total daily energy expenditure. Total energy expenditure varies according to the physical activity, which can be voluntarily modulated. Assessment of physical activity is therefore an important factor in the promotion of health and in several childhood and adolescent pathological situations. Questionnaires are widely used for assessing physical activity patterns in youth because of their low cost and ease of use, but they systematically overestimate physical activity. Heart rate monitoring requires individual calibration in the laboratory and a number of factors other than physical activity can affect heart rate (i.e., stress, temperature, etc.). Pedometers are objective devices but give only information on the number of steps and do not assess physical activity patterns. Accelerometers seem the best compromise between feasibility and validity in the assessment of physical activity in children in free-living conditions because this is an objective and accurate method whose cost is low. The choice of the type of device depends on the objectives of the clinician or researcher.

Changes in obesity, cardiorespiratory fitness and habitual physical activity following a one-year intervention program in obese youth: a pilot study.

AIM: The aim To assess the effects of a unique twelve month program of physical activity and health education on body mass index, cardiorespiratory fitness and physical activity habits in obese youth. METHODS: Thirty-seven physician referred subjects, nineteen girls (12.7 ± 3.1 years) and eighteen boys (12.2 ± 2.8 years) participated in the study. Treatment consisted of a unique program of physical activity that emphasized playing games. Activity sessions were offered one time per week, two hours each session, for twelve months. A two hour health education class was provided every 3 months. Weight, height, Body Mass Index, cardiorespiratory fitness and habitual physical activity were measured. RESULTS: Findings of the study demonstrated a significant improvement in body mass index, cardiorespiratory fitness (P<0.001), and habitual physical activity (P<0.05). CONCLUSION: Results of the pilot study were favorable in addressing serious health issues in young obese boys and girls.