[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.

Association of heart rate and blood pressure among European adolescents with usual food consumption: The HELENA study.

BACKGROUND AND AIM: In adults, there is some evidence that improving diet reduces blood pressure (BP) and the subsequent risk of cardiovascular diseases (CVDs). However, studies that analyse this association in adolescents are still scarce. The objective of the present study was to examine the associations between heart rate, systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP) among European adolescents and usual intake of vegetables, fruits, dairy products, meat, fish, high-sugar foods and savoury snacks. METHODS AND RESULTS: In total, 2283 adolescents from the HELENA-study (12.5-17.5 years old; 1253 girls) were included. Dietary intake was assessed using two computerized 24-hour dietary recalls. Age, sex, body mass index, maternal educational level, physical activity and Tanner stage were considered as confounders. Associations were examined by mixed model analysis stratified by sex. Tests for trend were assessed by tertiles of intake while controlling for the aforementioned confounders. Dairy products and fish intake were negatively associated with BP and heart rate. Significant decreasing trends were observed for heart rate and BP across tertiles of dairy products, fish intake and high-sugar foods intake (p < 0.05). Significant increasing trends were observed for SBP and MAP across tertiles of savoury snack intake (p < 0.05). CONCLUSION: Significant but small inverse associations between fish and dairy products consumption with blood pressure and heart rate have been found in European adolescents. Dietary intervention studies are needed to explore these associations in the context of the modification of several risk factors for the prevention of cardiovascular diseases.

[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.

Influence of parental socio-economic status on diet quality of European adolescents: results from the HELENA study.

Diet quality is influenced by socio-economic and geographical factors. The present study sought to assess whether adolescents' diet quality is affected by their parents' socio-economic status and whether the relationship between these factors is similar in northern and southern Europe. Data collected in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries were analysed. Dietary intake data were recorded via repeated 24 h recalls (using specifically developed HELENA Dietary Intake Assessment Tool software) and converted into an adolescent-specific Diet Quality Index (DQI-AM). Socio-economic status was estimated through parental educational level (Par-Educ-Lev) and parental occupation level (Par-Occ-Lev) as reported by the adolescents in a specific questionnaire. The DQI-AM data were then analysed as a function of Par-Educ-Lev and Par-Occ-Lev in northern European countries (Austria, Belgium, France, Germany and Sweden) and southern European countries (Greece, Italy and Spain). We studied a total of 1768 adolescents (age 14.7 (SD 1.3) years; percentage of girls: 52.8%; 1135 and 633 subjects from northern and southern Europe, respectively). On average, the DQI-AM score was higher in southern Europe than in northern Europe (69.1 (SD 0.1) v. 60.4 (SD 2.8), respectively; P < 0.001; Δ = 12.6%). The DQI was positively correlated with both paternal and maternal Par-Educ-Lev. However, this association was more pronounced in northern Europe than in southern Europe (P interaction = 0.004 for the mother and 0.06 for the father). The DQI was also positively correlated with Par-Occ-Lev (all P trends < 0.01), but this correlation was independent of the geographical area (P interaction = 0.51 for the mother and 0.50 for the father). In conclusion, Par-Educ-Lev and Par-Occ-Lev are associated with diet quality in adolescents in Europe. However, this association differs between northern Europe and southern Europe.

Mechanisms of stress, energy homeostasis and insulin resistance in European adolescents--the HELENA study.

BACKGROUND AND AIMS: Stress is hypothesized to facilitate the development of obesity, whose the foundations are already set during childhood and adolescence. We investigated the relationship between the stress-system, selected mechanisms of energy homeostasis and insulin resistance (IR) in a sample of European adolescents. METHODS AND RESULTS: Within HELENA-CSS, 723 adolescents (12.5-17.5 years) from 10 European cities provided all the necessary data for this study. Fasting blood samples were collected for cortisol, leptin, insulin and glucose analysis. HOMA-IR was calculated from insulin and glucose concentrations. Adolescents' body fat (BF) %, age and duration of exclusive breastfeeding were assessed. For boys and girls separately, the relationship of cortisol with leptin, insulin, glucose and HOMA-IR was examined by computing Pearson correlation coefficients and Hierarchical Linear Models (HLMs), with 'city' as cluster unit, adjusting for age, BF% and duration of exclusive breastfeeding. In boys, Pearson correlation coefficients illustrated positive correlations of cortisol with insulin (r = 0.144; p = 0.013), glucose (r = 0.315; p < 0.001) and HOMA-IR (r = 0.180; p = 0.002), whilst in girls, this positive relationship was observed for leptin (r = 0.147; p = 0.002), insulin (r = 0.095; p = 0.050) and HOMA-IR (r = 0.099; p = 0.041), but not for glucose (r = 0.054; p = 0.265). Observed associations were independent of adolescents' age, BF% and duration of exclusive breastfeeding after computing HLMs. CONCLUSION: This study suggests that the stress-system is positively related to mechanisms of energy homeostasis and IR in European adolescents, and reveals a potential small gender difference in this relationship. The hypothesis that stress might facilitate the development of obesity during adolescence is supported.

[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.

Evaluation of food and nutrient intake assessment using concentration biomarkers in European adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence study.

Accurate food and nutrient intake assessment is essential for investigating diet-disease relationships. In the present study, food and nutrient intake assessment among European adolescents using 24 h recalls (mean of two recalls) and a FFQ (separately and the combination of both) were evaluated using concentration biomarkers. Biomarkers included were vitamin C, ß-carotene, DHA+EPA, vitamin B12 (cobalamin and holo-transcobalamin) and folate (erythrocyte folate and plasma folate). For the evaluation of the food intake assessment 390 adolescents were included, while 697 were included for the nutrient intake assessment evaluation. Spearman rank and Pearson correlations, and validity coefficients, which are correlations between intake estimated and habitual true intake, were calculated. Correlations were higher between frequency of food consumption (from the FFQ) and concentration biomarkers than between mean food intake (from the recalls) and concentration biomarkers, especially for DHA+EPA (r 0·35 v. r 0·27). Most correlations were higher among girls than boys. For boys, the highest validity coefficients were found for frequency of fruit consumption (0·88) and for DHA+EPA biomarker (0·71). In girls, the highest validity coefficients were found for fruit consumption frequency (0·76), vegetable consumption frequency (0·74), mean fruit intake (0·90) and DHA+EPA biomarker (0·69). After exclusion of underreporters, correlations slightly improved. Correlations between usual food intakes, adjusted for food consumption frequency, and concentration biomarkers were higher than correlations between mean food intakes and concentration biomarkers. In conclusion, two non-consecutive 24 h recalls in combination with a FFQ seem to be appropriate to rank subjects according to their usual food intake.

Micronutrient status of children receiving prolonged enteral nutrition.

BACKGROUND AND AIMS: The aim of this study was to assess the micronutrient status of children receiving prolonged enteral nutrition. METHODS: This cross-sectional single-center study included all 64 children (median age 6.8 years) receiving enteral nutrition providing >50% of daily energy intake for more than 6 months (median duration of enteral nutrition 43 months). The characteristics of the patients and mode of enteral nutrition were recorded. The concentrations of iron, zinc, copper, selenium and vitamins A, D, E and C were measured in plasma. RESULTS: Twelve children (19%) had iron deficiency. A high 25-hydroxyvitamin D concentration was recorded in 20% of the children, but none had associated hypercalcemia. Fifty-two children (81%) had low zinc concentrations in both plasma and erythrocytes. Plasma zinc, calcium, phosphorus and vitamin D concentrations were significantly lower in children receiving fiber supplementation. Abnormal micronutrient concentrations were found more frequently in the children receiving fiber supplementation. No other predisposing factors were associated with micronutrient deficiencies. CONCLUSION: Long-term enteral nutrition can lead to micronutrient deficiencies in children, whose micronutrient concentrations may require regular checking. Fiber supplementation might reduce the bioavailability of zinc, calcium, phosphorus and vitamin D.

[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.

Home telemonitoring (forced expiratory volume in 1 s) in children with severe asthma does not reduce exacerbations.

Some children with severe asthma develop frequent exacerbations despite intensive treatment. We sought to assess the outcome (severe exacerbations and healthcare use, lung function, quality of life and maintenance treatment) of a strategy based on daily home spirometry with teletransmission to an expert medical centre and whether it differs from that of a conventional strategy. 50 children with severe uncontrolled asthma were enrolled in a 12-month prospective study and were randomised into two groups: 1) treatment managed with daily home spirometry and medical feedback (HM) and 2) conventional treatment (CT). The children's mean age was 10.9 yrs (95% confidence interval 10.2-11.6). 44 children completed the study (21 in the HM group and 23 in the CT group). The median number of severe exacerbations per patient was 2.0 (interquartile range 1.0-4.0) in the HM group and 3.0 (1.0-4.0) in the CT group (p=0.38 with adjustment for age). There were no significant differences between the two groups for unscheduled visits (HM 5.0 (3.0-7.0), CT 3.0 (2.0-7.0); p=0.30), lung function (pre-ß(2)-agonist forced expiratory volume in 1 s (FEV(1)) p=0.13), Paediatric Asthma Quality of Life Questionnaire scores (p=0.61) and median daily dose of inhaled corticosteroids (p=0.86). A treatment strategy based on daily FEV(1) monitoring with medical feedback did not reduce severe asthma exacerbations.

PROPENSIX: pressure garment therapy using compressive dynamic Lycra® sleeve to improve bi-manual performance in unilateral cerebral palsy: a multicenter randomized controlled trial protocol.

BACKGROUND: Upper limb impairment affects activity and participation in children with unilateral cerebral palsy (UCP). Pressure garment therapy (PGT) using compressive dynamic Lycra® garments is an innovative intervention proposed for the management of cerebral palsy consequences. The PROPENSIX study aims to evaluate the efficacy of a therapy using a Lycra® sleeve as compared to a placebo sleeve to improve bi-manual performance measured by the Assisting Hand Assessment (AHA) in children with unilateral cerebral palsy. METHODS: The PROPENSIX trial is a multicenter, prospective, placebo-controlled, double-blinded, randomized study. One hundred children with UCP, aged from 5 to 10, are randomly assigned as soon as they are recruited in a 1:1 ratio to perform usual daily activities, especially activities involving bimanual performances, with Lycra® sleeve or placebo sleeve during 6 months. The primary endpoint is the change in bimanual performance from inclusion to 6 months, evaluated by AHA. The secondary endpoints evaluate changes from inclusion to 6 months in other dimensions of the International Classification of Functioning (ICF), upper limb movement capacity assessed by Quality of Upper Extremity Skill Test (QUEST), and health-related quality of life evaluated by Pediatric Quality of Life Inventory 3.0 Cerebral Palsy Module (PedsQLTM 3.0 CP Module) and in body structures and functions domain assessed by neuro-orthopedic examination and somatosensory evoked potentials (SEP). DISCUSSION: The PROPENSIX study is the largest randomized controlled trial (RCT) aiming to evaluate the efficacy of a PGT using compressive dynamic Lycra® sleeve in UCP. Enhancement of children's bimanual performance at the end of the 6 months wear of the Lycra® sleeve should improve evidence regarding this type of treatment and expand discussion about their recommendation in clinical practice. Data from secondary outcomes assessments should bring interesting arguments to discuss the Lycra® sleeve action on mobility, tonus, and sensory impairments in children with unilateral cerebral palsy. TRIAL REGISTRATION: ClinicalTrials.gov NCT02086214 . Retrospectively registered on March 13, 2014 TRIAL STATUS: Study start data: December 2012. Recruitment status: completed. Primary completion date: April 2021. Estimated study completion date: December 2022. Protocol version 10 (date: February 2018).

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study.

BACKGROUND: Adequate sleep is a critical factor for adolescent's health and health-related behaviors. OBJECTIVE: (a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association. DESIGN: A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire). RESULTS: Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ≥8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters. CONCLUSIONS: In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

Physical fitness levels among European adolescents: the HELENA study.

OBJECTIVE: To report sex- and age-specific physical fitness levels in European adolescents. METHODS: A sample of 3428 adolescents (1845 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece (an inland city and an island city), Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence study between 2006 and 2008. The authors assessed muscular fitness, speed/agility, flexibility and cardiorespiratory fitness using nine different fitness tests: handgrip, bent arm hang, standing long jump, Bosco jumps (squat jump, counter movement jump and Abalakov jump), 4×10-m shuttle run, back-saver sit and reach and 20-m shuttle run tests. RESULTS: The authors derived sex- and age-specific normative values for physical fitness in the European adolescents using the LMS statistical method and expressed as tabulated percentiles from 10 to 100 and as smoothed centile curves (P5, P25, P50, P75 and P95). The figures showed greater physical fitness in the boys, except for the flexibility test, and a trend towards increased physical fitness in the boys as their age increased, whereas the fitness levels in the girls were more stable across ages. CONCLUSIONS: The normative values hereby provided will enable evaluation and correct interpretation of European adolescents' fitness status.

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.

Socioeconomic status influences physical fitness in European adolescents independently of body fat and physical activity: the HELENA study.

INTRODUCTION: The influence of socioeconomic status on health-related fitness is not clear. AIM: To examine the influence of socioeconomic status on health-related fitness in adolescents. METHODS: A total of 3,259 adolescents (15.0 +/- 1.3 y) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) participated in the study. Socioeconomic status was assessed by the family affluence scale (FAS). Speed-agility, muscular strength and cardiorespiratory fitness were assessed. Covariates included total body fat, physical activity and pubertal status. RESULTS: Adolescents with high FAS had significantly higher fitness levels than their peers of lower FAS categories except for speed-agility and handgrip in boys. Overall, the associations observed presented a medium to large effect size. CONCLUSION: These results suggest that socioeconomic status is positively associated with physical fitness in European adolescents independently of total body fat and habitual physical activity.

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.

Harmonization process and reliability assessment of anthropometric measurements in a multicenter study in adolescents.

OBJECTIVE: To describe the standardization process and reliability of anthropometric and bioelectrical impedance analysis (BIA) measurements. We examined both intra- and interobserver errors for skinfolds, circumferences and BIA. METHODS: For the intraobserver error assessment, first of all, 202 adolescents in the pilot study (110 boys, 92 girls, aged 13.64+/-0.78 years) were assessed. For the second intraobserver and interobserver assessments, 10 adolescents were studied (5 boys and 5 girls). RESULTS: The pilot study's intraobserver technical errors of measurement (TEMs) were between 0.12 and 2.9 mm for skinfold thicknesses, and between 0.13 and 1.75 cm for circumferences. Intraobserver reliability for skinfold thicknesses was greater than 69.44% and beyond 78.43% for circumferences. The final workshop's intraobserver TEMs for skinfold thicknesses and circumferences were smaller than 1; for BIA resistance TEMs were smaller than 0.1 Omega and for reactance they were smaller than 0.2 Omega. Intraobserver reliability values were greater than 95, 97, 99 and 97% for skinfold thicknesses, circumferences, BIA resistance and reactance, respectively. Interobserver TEMs for skinfold thicknesses and circumferences ranged from 1 to 2 mm; for BIA they were 1.16 and 1.26 Omega for resistance and reactance, respectively. Interobserver reliability for skinfold thicknesses and circumferences were greater than 90%, and for BIA resistance and reactance they were greater than 90%. CONCLUSIONS: After the results of the pilot study, it was necessary to optimize the quality of the anthropometric measurements before the final survey. Significant improvements were observed in the intraobserver reliabilities for all measurements, with interobserver reliabilities being higher than 90% for most of the measurements.The Healthy Lifestyle in Europe by Nutrition in Adolescence Study aims to describe total body fat percentage and anthropometric indices of body fat distribution in European adolescents.

Quality assurance of ethical issues and regulatory aspects relating to good clinical practices in the HELENA Cross-Sectional Study.

RATIONALE: Research involving humans is regulated by regulatory authorities through their specific requirements and controls. The Healthy Life Style in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) is a multicenter biomedical research study of adolescents in several representative European cities, which requires satisfying medico-regulatory requirements including Independent Ethics Committee (IEC) approval and agreement by the national or local regulatory authorities. To achieve a high level of quality assurance relating to ethical issues, we followed the good clinical practices (GCP) described at the International Conference on Harmonisation (ICH), which we adapted to the national and local situations of each of the 11 participating cities in 10 European countries. OBJECTIVE: The main objective of the HELENA-CSS is to evaluate reliable and comparable data of nutritional habits and lifestyle in a representative sample of European adolescents. The aim of this paper is to present the methods relating to the ethical and regulatory issues of this study and to describe the current state of the medico-regulatory requirements involved in conducting this kind of study in each country. MATERIALS AND METHODS: Following the GCP-ICH guidelines, a protocol describing the HELENA-CSS was written and approved by all partners. In the pilot study, a case report form adapted to the study objectives and its manual of operation was constructed and used by all partners. All information letters to adolescents and their parents and consent forms were first written in English, then translated into the local language, and adapted to each local situation. All documents were then checked centrally for any deviation and corrected if required. An operation manual relating to ethical issues and other medico-regulatory requirements was also developed. This paper presents the current status of the medico-regulatory requirements from each HELENA-CSS participant country. RESULTS: Before the beginning of the study, most centers had satisfied the medico-regulatory requirements of IEC approval and agreement with other national or local regulatory authorities/organizations. For a few centers, some problems were detected and corrective actions were taken to improve missing information to reach a high level of quality assurance of ethical issues. CONCLUSION: The GCP-ICH guidelines about nontherapeutic biomedical research are interpreted and applied differently across Europe. This study shows that high-quality nontherapeutic biomedical research can address the ethical issues included in the GCP-ICH regulations and can be harmonized among the HELENA European partners.

Socioeconomic questionnaire and clinical assessment in the HELENA Cross-Sectional Study: methodology.

RATIONALE: Environmental factors such as dietary habits, breastfeeding, socioeconomic conditions and educational factors are strong influences on nutritional and puberty status, physical activity, food choices and their interactions. Several diseases of adulthood seem to be linked to, or to originate from, lifestyle in childhood and adolescence. OBJECTIVE: The aims of this study are to describe birth parameters and socioeconomic factors and to assess clinical status in adolescents aged 13-16 years from 10 European countries participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Cross-Sectional Study (CSS). METHODOLOGY: A self-report questionnaire on the socioeconomic status, a parental questionnaire concerning neonatal period and also a case report form (CRF), in which clinical items during clinical examination (such as medical history, treatments, anthropometry, Tanner staging, blood pressure, heart rate) were assessed. To develop these documents, first a list of items was established, a search of existing documents was performed and the advice of local and international experts was taken. All documents (questionnaires and an operations manual) were discussed in plenary HELENA meetings; a final version of these documents was fixed, and the process of translation and back translation was performed. RESULTS: The questionnaires and CRF were tested for validation in all 10 participant cities; 208 adolescents were enrolled during the pilot study. All items that caused problems or questions in one or more participating centers or were completed by < 85% of the adolescents were reviewed before the beginning of the HELENA-CSS. CONCLUSION: These final questionnaires and CRF will contribute to better understanding of the inequalities in nutrition, behavior and health in the European adolescent population. The experience and process should be useful for other multicenter studies.