An Overview of the Influence of Breastfeeding on the Development of Inflammatory Bowel Disease

The first 1000 days of life is a critical period that contributes significantly to the programming of an individual's future health. Among the many changes that occur during this period early in life, there is growing evidence that the establishment of healthy gut microbiota plays an important role in the prevention of both short- and long-term health problems. Numerous publications suggest that the quality of the gut microbiota colonisation depends on several dietary factors, including breastfeeding. In this respect, a relationship between breastfeeding and the risk of inflammatory bowel disease (IBD) has been suggested. IBDs are chronic intestinal diseases, and perinatal factors may be partly responsible for their onset. We review the existence of links between breastfeeding and IBD based on experimental and clinical studies. Overall, despite encouraging experimental data in rodents, the association between breastfeeding and the development of IBD remains controversial in humans, partly due to the considerable heterogeneity between clinical studies. The duration of exclusive breastfeeding is probably decisive for its lasting effect on IBD. Thus, specific improvements in our knowledge could support dietary interventions targeting the gut microbiome, such as the early use of prebiotics, probiotics or postbiotics, in order to prevent the disease.

Are anxiety and depression associated with cognition and cardiovascular function in young male and female adults?

The results of recent studies suggested that emotional disorders (such as anxiety and depression), cognitive impairments and cardiovascular disorders are related on the subclinical level. These major health issues are often concomitant and have complex, sex-dependent relationships; it is therefore important to study these issues concomitantly in the general population, in order to gain a better understanding of early-stage subclinical relationships between these conditions. The objective of this exploratory study was to assess correlations between anxiety, depression, cognition, and endothelial function in young adults from the general population. Endothelial function (via the reactive hyperaemia index (RHI) was assessed with a plethysmographic device. Depression and anxiety were self-reported via the Beck Disorder Inventory II and the State-Trait Anxiety Inventory, respectively. The Cambridge Neuropsychological Test Automated Battery was used to measure performances in visuospatial memory, visuospatial working memory, and sustained attention. Performances in inhibition and flexibility were evaluated with the Color Word Interference Test. Forty-four young adults (21 males; mean ± standard deviation age: 25.8 ± 1.1; 23 females; mean age: 25.6 ± 1.4) were included in the study. Anxiety was correlated with a low RHI (r = -0.40, p = 0.015, 95% CI [-0.64, -0.08]). In females, the depression score was positively correlated with the number of errors in the visuospatial memory task (r = 0.42, p = 0.049; 95% CI [-0.002, 0.70]) and visuospatial working memory (r = 0.57, p = 0.005; 95% CI [0.10, 0.79]). In males, high anxiety and depression scores were negatively correlated with the number of errors in visuospatial working memory task (anxiety: r = -0.77, p = 0.001; 95% CI [-0.91, -0.43]; depression r = -0.61, p = 0.004, 95% CI [-0.82, -0.22], respectively). However, the relationship between cognitive performance and RHI was not significant. Our data suggest that anxiety and depression could be differentially related to cognitive and endothelial functions in a non-clinical population of young adults. More research is needed to confirm these results, understand the pathophysiological mechanisms in more details, and assess the importance of a sex-specific approach.

Differential decline of physical fitness with age according to Body Mass Index levels

BACKGROUND

The main objective of this study was to assess the association between age and physical fitness and motor fitness components according to BMI levels, in men and women separately, and to test if this association is different between BMI levels.

METHODS

This cross-sectional study was based on a pre-existing database from the DiagnoHealth battery, a French series of physical fitness and motor fitness tests designed by the Institut des Rencontres de la Forme (IRFO; Wattignies, France). Analyses were perfomed on 6830 women (65.8%) and 3356 men (34.2%) aged from 50 to 80 years. In this French series several physical fitness and motor fitness components were measured: cardiorespiratory fitness (CRF), speed, upper muscular endurance, lower muscular endurance, lower body muscular strengh, agility, balance, and flexibility. From the results of these tests, a specific score named Quotient of Physical Condition was calculated. Associations between age and physical fitness and motor fitness components according to BMI levels were modelized using linear regression for quantitative components, and ordinal logistic regression for ordinal components. Analyses were performed separately for women and men.

RESULTS

A significant association of age with physical fitness and motor fitness performance in each BMI levels were observed in women except for lower muscular endurance, muscular strength and flexibility in obese women. A significant association of age with physical fitness and motor fitness performance in each BMI levels were observed in men except for upper/lower muscular endurance and flexibility in obese men.

CONCLUSIONS

The present results shown that most of physical fitness and motor fitness decrease with age in women and men. Lower muscular endurance, muscular strength and flexibility did not change in obese women, thereas upper/lower muscular endurance and flexibility did not change in obese men. This finding is particularly revelant for guiding prevention strategies for maintaining physical fitness and motor fitness performance, which is one of the most important component of healthy aging and wellbeing.

Developing a risk assessment tool for insulin resistance in European adolescents: the HELENA-IR score

OBJECTIVES

To develop and validate an easy-to-use screening tool for identifying adolescents at high-risk for insulin resistance (IR).

METHODS

Α total of 1,053 adolescents (554 females), aged 12.5 to 17.5 years with complete data on glucose and insulin levels were included. Body mass index (BMI), fat mass index (FMI) and the homeostasis model assessment for insulin resistance (HOMA-IR) were calculated. VO₂max was predicted using 20 m multi-stage fitness test. The population was randomly separated into two cohorts for the development (n=702) and validation (n=351) of the index, respectively. Factors associated with high HOMA-IR were identified by Spearman correlation in the development cohort; multiple logistic regression was performed for all identified independent factors to develop a score index. Finally, receiver operating characteristic (ROC) analysis was performed in the validation cohort and was used to define the cut-off values that could identify adolescents above the 75th and the 95th percentile for HOMA-IR.

RESULTS

BMI and VO₂max significantly identified high HOMA-IR in males; and FMI, TV watching and VO₂max in females. The HELENA-IR index scores range from 0 to 29 for males and 0 to 43 for females. The Area Under the Curve, sensitivity and specificity for identifying males above the 75th and 95th of HOMA-IR percentiles were 0.635 (95%CI: 0.542-0.725), 0.513 and 0.735, and 0.714 (95%CI: 0.499-0.728), 0.625 and 0.905, respectively. For females, the corresponding values were 0.632 (95%CI: 0.538-0.725), 0.568 and 0.652, and 0.708 (95%CI: 0.559-0.725), 0.667 and 0.617, respectively. Simple algorithms were created using the index cut-off scores.

CONCLUSIONS

Paediatricians or physical education teachers can use easy-to-obtain and non-invasive measures to apply the HELENA-IR score and identify adolescents at high risk for IR, who should be referred for further tests.

Physical fitness in children and adolescents with inflammatory bowel disease: protocol for a case-control study

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic disorder of the gastrointestinal tract, associated with adverse health consequences that may adversely influence physical activity and body composition in youth. These effects may lead to changes in physical fitness, which is positively associated with health-related outcomes. The aim is to assess health-related physical fitness levels in paediatric patients with IBD and to compare these levels with those in healthy matched controls.

METHODS AND ANALYSIS

This trial is a bicentric case-control study. Fifty paediatric patients with IBD and 50 matched healthy controls will be recruited (1:1), and physical fitness levels (cardiorespiratory fitness, muscular strength, speed/agility and flexibility) will be assessed. The primary outcome is cardiorespiratory fitness, which will be compared between children and adolescents with IBD and healthy controls matched for age, sex and body mass index class. We will assess whether the two groups differ with respect to other physical fitness components and cardiovascular risk in adulthood according to sex-specific cut-offs for a healthy cardiorespiratory fitness level in adolescents. We will identify relationships between physical fitness and characteristics of IBD, quality of life and daily physical activity.

ETHICS AND DISSEMINATION

This study was approved by the Research Ethics Committee (Comité de Protection des Personnes, Centre-Ouest I, Tours, France; No 2019-A02651-56) and was declared to the Commission Nationale de l'Informatique et des Libertés. All procedures will be performed according to the ethical standards of the 1975 Declaration of Helsinki, as revised in 2008, and the European Union's Guidelines for Good Clinical Practice. Written informed consent will be obtained from the youths and their parents. Research findings will be disseminated in peer-reviewed journals and scientific meetings, as well as in social media and IBD family support groups.

TRIAL REGISTRATION NUMBER

NCT04647578.

Social Environment and Food and Beverage Intake in European Adolescents: The Helena Study

BACKGROUND

The family environment influences food consumption and behaviours, which impact adolescent's eating habits, diet and health. Young individuals who frequently eat family meals are less likely to develop risk- and behaviour-related outcomes as obesity.

AIM

To assess the relationship between the family meal environment and food and macronutrient consumption in European adolescents.

METHODS

1,703 adolescents aged 12.5-17.5 years (46.5% male) from the European HELENA cross-sectional study were selected. Sociodemographic variables and dietary intake using two non-consecutive self-reported 24-hour dietary recalls were collected from all the included participants. The relationship between family meals' environment and food and macronutrient consumption was analized using analysis of covariance.

RESULTS

Adolescents who used to take their main meals with their family were associated with high consumption of healthy foods and beverages (i.e. vegetables, fruit, milk, water) and low consumption of energy dense food and beverages as chocolate, savoury snacks, sugar or juices compared with those who used to eat alone, with friends or other people (p < 0.05).

CONCLUSION

The company/people with whom adolescents consume their meal have an important influence on the adolescent's consumption of different types of food (especially at lunch). Family's environment during meals has been associated with a high consumption of healthy foods.

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.govNCT02086214. 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).

Impact of early life nutrition on gut health in children: a prospective clinical study

INTRODUCTION

The first 1000 days of life could contribute to individual susceptibility to the later development of chronic non-communicable diseases. Nutrition in early life appears to be an important determinant factor for a sustainable child's health. In this study, we propose to investigate the impact of exclusive breast feeding on gut health in children.

METHODS AND ANALYSIS

A prospective cohort of newborns (n=350) will be recruited at birth and followed up to 4 years of age. The main objective is to evaluate the link between exclusive breast feeding for at least 3 months and the gut health of the child at 4 years. The primary endpoint of assessment of gut health will be based on the non-invasive measurement of faecal secretory IgA (sIgA) as a sensitive biomarker of the intestinal ecosystem. The presence of gastrointestinal disorders will be defined according to the clinical criteria of Rome IV. Information on parent's nutritional habits and life style, breastfeeding duration and child's complementary feeding will be collected along the follow-up. Cord blood cells and plasma at birth will be purified for further analysis. The meconium and stools collected at birth, 6 months, 2 years and 4 years of age will allow sIgA analysis.

ETHICS AND DISSEMINATION

This clinical study has obtained the approval from the national ethical committee. We plan to publish the results of the study in peer-review journals and by means of national and international conference.

TRIAL REGISTRATION NUMBER

NCT04195425.

Interaction Effect of the Mediterranean Diet and an Obesity Genetic Risk Score on Adiposity and Metabolic Syndrome in Adolescents: The HELENA Study

Obesity and metabolic syndrome (MetS) are worldwide major health challenges. The Mediterranean diet (MD) is associated with a better cardiometabolic profile, but these beneficial effects may be influenced by genetic variations, modulating the predisposition to obesity or MetS. The aim was to assess whether interaction effects occur between an obesity genetic risk score (obesity-GRS) and the MD on adiposity and MetS in European adolescents. Multiple linear regression models were used to assess the interaction effects of an obesity-GRS and the MD on adiposity and MetS and its components. Interaction effects between the MD on adiposity and MetS were observed in both sex groups (p < 0.05). However, those interaction effects were only expressed in a certain number of adolescents, when a limited number of risk alleles were present. Regarding adiposity, a total of 51.1% males and 98.7% females had lower body mass index (BMI) as a result of higher MD adherence. Concerning MetS, only 9.9% of males with higher MD adherence had lower MetS scores. However, the same effect was observed in 95.2% of females. In conclusion, obesity-related genotypes could modulate the relationship between MD adherence and adiposity and MetS in European adolescents; the interaction effect was higher in females than in males.

[Association between screen time and sleep habits in 11-to-12-year-old French middle school students]

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.

Influence of meteorological conditions on physical activity in adolescents

Background

It has been shown that meteorological conditions and season affect physical activity (PA) during adolescence. Today, meteorological conditions have never been combined to study their influence on PA level in a single sample of a large adolescent multicountries population. The aim of this study was to explore the influence of meteorological conditions on PA in adolescents from several European countries.

Methods

The study included 2024 healthy adolescents aged 12.5–17.4 years who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study. Participants wore a uniaxial accelerometer for 7 consecutive days to measure total PA and moderate to vigorous physical activity (MVPA) in a one-off measurement manner. Comparison of PA according to meteorological conditions was done using linear mixed models.

Results

The highest difference of MVPA was observed in boys on free days when comparing the best meteorological conditions versus the worse (ie, +39% with highest temperature, +29% without rainfall, +39% with highest sunlight duration and +21% with highest length of day) and in girls on free days (ie, +26% with highest sunlight duration). This increase in MVPA contributed to a simultaneous increase in total PA when considering the same meteorological condition parameters.

Conclusions

Meteorological conditions act as a determinant of PA differentially between boys and girls. PA and MVPA in boys are mainly modified by meteorological conditions on free days whereas PA and MVPA in girls are modified by sunlight duration.

Mediation of psychosocial determinants in the relation between socio-economic status and adolescents' diet quality

PURPOSE

To examine the underlying reasons for the positive relation between socio-economic status (SES) and the diet quality of adolescents.

METHODS

In 2081 adolescents (12.5-17.5 years) of the European HELENA study, a continuous variable on diet quality via 2-day 24-h recalls was available. SES was reflected by parental education, parental occupation and family affluence. Mediation by several psychosocial determinants was tested: self-efficacy, availability at school and home, social support, barriers, benefits, awareness and some self-reported influencers (parents, school, taste, health, friends, food readily available, easy preparation, hunger, price and habits). Multiple mediation analyses were adjusted for age, sex and country.

RESULTS

The availability of soft drinks and fruit at home, social support, parental influence, barriers, price influence, taste influence, health influence and food being readily available were significant mediators. The multiple mediation indirect effect accounted for 23-64% of the total effect. Both occupation and education and both maternal and paternal factors could be explained by the mediation. The unavailability of soft drinks was the strongest mediator (17-44% of the total effect).

CONCLUSION

Up to 64% of the positive relation between SES and the diet quality in adolescence could be explained by several healthy eating determinants. Focusing on these factors in low-SES populations can minimize social inequalities in diet and health by improving the diet of these specific adolescents.

Abdominal obesity and its association with socioeconomic factors among adolescents from different living environments

BACKGROUND

Socioeconomic status has been associated with obesity in children and adolescents. This association may be dependent according with where adolescents lives.

OBJECTIVE

The aim of this study was to evaluate the association between different socioeconomic indicators such as parental education and occupation and socioeconomic status with abdominal obesity in adolescents from two observational studies: the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study (HELENA-CSS) and the Brazilian Cardiovascular Adolescent Health (BRACAH) study.

METHODS

European (n = 3192, aged 12.5-17.5 years, with 53.1% girls from HELENA-CSS) and Brazilian (n = 991, aged 14-18 years, with 54.5% girls from BRACAH study) adolescents from two cross-sectional studies were included in this analysis. Complete data on waist circumference (WC), height, socioeconomic status indicators and several confounders were collected. Socioeconomic indicators were measured using a self-reported questionnaire in order to assess the family social status of the adolescents. Multilevel linear regression models were used to examine associations, and results were adjusted for potential confounders.

RESULTS

Adjusted results showed inverse associations between mother's and father's education levels (p < 0.001) and father's occupation level (p < 0.001) with waist-to-height ratio (WHtR) and WC in HELENA-CSS girls. Similarly in European girls, socioeconomic indicators by socioeconomic status and maternal occupation level were associated with WHtR. In HELENA-CSS boys, the same significant association was found between WHtR and WC with maternal occupation level. Moreover, in European boys WHtR was also associated with parental education. In Brazilian adolescents, both indicators of abdominal obesity did not remain associated with the independents variables, after adjustment for potential confounders.

CONCLUSIONS

Abdominal obesity was associated with socioeconomic indicators in higher-income countries, but this association was not observed in a lower-middle-income country.

Comparison of definitions for the metabolic syndrome in adolescents. The HELENA study

Various definitions are used to define metabolic syndrome in adolescents. This study aimed to compare, in terms of prevalence and differences, five frequently used definitions for this population: International Diabetes Federation, National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP) modified by Cook, pediatric American Heart Association (AHA), World Health Organization, and Jolliffe and Janssen. A sample of 1004 adolescents (12.5-17.0 years) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study was considered. The components of the definitions (waist circumference/BMI, plasma lipids, glycemia, and blood pressure) were applied, and definitions were compared by using crosstabs, sensitivity, specificity, and kappa coefficient. The prevalence of metabolic syndrome varied from 1.6 to 3.8% depending on the used definitions. Crosstabs comparing the definitions showed the fewest cases being misclassified (having metabolic syndrome or not) between NCEP-ATP and AHA. Analyses for kappa coefficient, sensitivity, and specificity confirmed this finding.

CONCLUSION

The different definitions do not classify the same adolescents as having MS and prevalence varied between diagnostic methods. The modified NCEP-ATP and the AHA definitions were most analogous in defining subjects as having metabolic syndrome or not. What is known? • Metabolic syndrome is not only a problem of adulthood but is already present in children and adolescents. • Several diagnostic methods are used to define metabolic syndrome in adolescents. What is new? • Comparing the most frequently used definitions of metabolic syndrome in adolescents showed that they do not indicate the same adolescents as having metabolic syndrome. • The modified National Cholesterol Education Program Adult Treatment Panel III and the pediatric American Heart Association definitions were most analogous in defining subjects as having metabolic syndrome or not.

[From the influence of genes to the influence of family and urban environment on the nutritional status, activity, and physical condition of european urban adolescents]

HELENA was a cross-sectional study carried out from 2006 to 2007 in more than 3500 adolescents aged from 12.5 to 17.5 years old through 10 Europeans towns from 9 countries. Its objective was to assess adolescent nutritional status including: body composition, biological markers, physical activity and fitness. This study shown the high impact of socio-economic condition, life style and personal and collective environment, dietary pattern (including breastfeeding), some genetic mutations involved in adiposity and metabolism, physical activity level and fitness on adolescent nutritional status.

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.

Fractional Relaxation Equations and Brownian Crossing Probabilities of a Random Boundary

In this paper we analyze different forms of fractional relaxation equations of order ν ∈ (0, 1), and we derive their solutions in both analytical and probabilistic forms. In particular, we show that these solutions can be expressed as random boundary crossing probabilities of various types of stochastic process, which are all related to the Brownian motion B. In the special case ν = ½, the fractional relaxation is shown to coincide with Pr{sup0≤s≤tB(s) < U} for an exponential boundary U. When we generalize the distributions of the random boundary, passing from the exponential to the gamma density, we obtain more and more complicated fractional equations.

Effects of clustering of multiple lifestyle-related behaviors on blood pressure in adolescents from two observational studies

BACKGROUD

Several lifestyle-related behaviors are associated with cardiovascular health outcomes in adolescents. To examine the associations between clustered lifestyle-related behaviors and blood pressure (BP) levels in adolescents.

METHODS

Participants were recruited by multistage random cluster in two cross-sectional studies; one conducted in 2006 and 2007 in ten cities from nine European countries: Athens and Heraklion in Greece, Dortmund in Germany, Ghent in Belgium, Lille in France, Pécs in Hungary, Rome in Italy, Stockholm in Sweden, Vienna in Austria, and Zaragoza in Spain; and another conducted in 2007 one city in Brazil (Maringá/PR). Systolic BP (SBP) and diastolic BP (DBP) (outcomes) and clustered behaviors (weekly consumption of fruits and vegetables, weekly consumption of sugar-sweetened beverages, sleep duration, screen time and physical activity) were analyzed.

RESULTS

The Healthy Eating cluster was negatively associated with DBP in European girls, β=-2.46 (-4.62; -0.30), and with SBP in Brazilian boys, β=-2.79 (-3.10; -0.15). Furthermore, the Unhealthy Eating cluster was associated with increased SBP in European girls, β=4.54 (1.29; 7.79), and in Brazilian boys, β=4.10 (0.80; 7.40).

CONCLUSION

The Healthy Eating cluster was associated with lower blood pressure, whereas the Unhealthy Eating cluster was associated with increased SBP in adolescents.

Physical Activity Is Associated with Attention Capacity in Adolescents

OBJECTIVE

To assess the relationships among physical activity, measured objectively, and attention capacity in European adolescents.

STUDY DESIGN

The study included 273 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Participants wore a uniaxial accelerometer for 7 days to measure physical activity. The d2 Test of Attention was administered to assess attention capacity. Multivariate analyses were used to study the association of attention capacity with each measure of physical activity. Receiver operating characteristic analysis was performed to determine thresholds that best discriminate between low and good attention capacity.

RESULTS

After controlling for potential confounding variables (age, sex, body mass index, parental educational level, fat mass, aerobic fitness, and center), adolescents' attention capacity test performances were significantly and positively associated with longer time spent in moderate or moderate-to-vigorous physical activity (MVPA) in free-living conditions (P < .05). Receiver operating characteristic curve analyses revealed that the physical activity thresholds that best discriminated between low/good attention capacities were ≥41 min·day(-1) for moderate, ≥12 min·day(-1) for vigorous, and ≥58 min·day(-1) for MVPA.

CONCLUSION

These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.

Educating Asthmatic Children in European Ambulatory Pediatrics: Facts and Insights

The aim of this study was to assess the role of European ambulatory pediatricians in caring for asthmatic children, especially in terms of their therapeutic education. We developed a survey that was observational, declarative, retrospective and anonymous in nature. 436 ambulatory pediatricians in Belgium, France, Germany, Italy, Luxembourg and Slovenia were asked to participate in the survey providing information on three children over 6 years old suffering from persistent asthma, who had been followed for at least 6 months. We considered the pediatricians' profile, and their role in the therapeutic education of children. 277 pediatricians (64%) responded: 81% were primary care pediatricians; 46% participated in networks; 4% had specific training in Therapeutic Patient Education; 69% followed more than 5 asthmatic children per month, and over long periods (7 ± 4 years). The profiles of 684 children were assessed. Answers diverged concerning the provision of a Personalized Action Plan (60-88%), training the child to measure and interpret his Peak Expiratory Flow (31-99%), and the prescription of pulmonary function tests during the follow-up programme of consultations (62-97%). Answers converged on pediatricians' perception of their role in teaching children about their condition and its treatment (99%), about inhalation techniques (96%), and in improving the children's ability to take preventive measures when faced with risk situations (97%). This study highlights the role of European pediatricians in caring for asthmatic children, and their lack of training in Therapeutic Patient Education. Programmes and tools are required in order to train ambulatory pediatricians in Therapeutic Patient Education, and such resources should be integrated into primary health care, and harmonized at the European level.

Ready-to-eat cereals improve nutrient, milk and fruit intake at breakfast in European adolescents

Purpose

Breakfast consumption has been recommended as part of a healthy diet. Recently, ready-to-eat cereals (RTEC) became more popular as a breakfast item. Our aim was to analyse the dietary characteristics of an RTEC breakfast in European adolescents and to compare them with other breakfast options.

Methods

From the European multi-centre HELENA study, two 24-h dietary recalls of 3137 adolescents were available. Food items (RTEC or bread, milk/yoghurt, fruit) and macro- and micronutrient intakes at breakfast were calculated. Cross-sectional regression analyses were adjusted for gender, age, socio-economic status and city.

Results

Compared to bread breakfasts (39 %) and all other breakfasts (41.5 %), RTEC breakfast (19.5 %) was associated with improved nutrient intake (less fat and less sucrose; more fibre, protein and some micronutrients like vitamin B, calcium, magnesium and phosphorus) at the breakfast occasion. Exceptions were more simple sugars in RTEC breakfast consumers: more lactose and galactose due to increased milk consumption, but also higher glucose and fructose than bread consumers. RTEC consumers had a significantly higher frequency (92.5 vs. 50.4 and 60.2 %) and quantity of milk/yoghurt intake and a slightly higher frequency of fruit intake (13.4 vs. 10.9 and 8.0 %) at breakfast.

Conclusions

Among European adolescents, RTEC consumers showed a more favourable nutrient intake than consumers of bread or other breakfasts, except for simple sugars. Therefore, RTEC may be regarded as a good breakfast option as part of a varied and balanced diet. Nevertheless, more research is warranted concerning the role of different RTEC types in nutrient intake, especially for simple sugars.

Family socioeconomic factors are negatively associated with blood pressure in European boys, but not girls, and Brazilian adolescents: Results from two observational studies

OBJECTIVE

We aimed to estimate the attributable fraction of systolic (SBP) and diastolic blood pressure (DBP) that can be explained by family socioeconomic factors (FSFs) in adolescents using two observational studies.

METHODS

Participants were recruited by multistage random cluster in two cross-sectional studies performed in Europe [Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, n = 3308] and Brazil [Brazilian Cardiovascular Adolescent Health (BRACAH) study, n = 991]. SBP and DBP were measured, and FSFs (socioeconomic status and parental education) were self-reported in both studies. The correlations of SBP and DBP with FSFs were examined by multilevel linear regression through two different models (hierarchical and fully adjusted). The generalized attributable fractions of the FSFs were estimated by comparing the models.

RESULTS

Our results showed a significant inverse relationship between parental education (father and mother) and SBP in European boys. The higher generalized attributable fraction to SBP was observed in boys (13.2-22.4%). In girls, we found lower generalized attributable fractions to DBP (10.8-12.1% in Brazilian girls and 3.1-3.8% in European girls).

CONCLUSIONS

Our findings revealed a significant inverse relationship between parental education and SBP in European boys. FSF also significantly influenced blood pressure in adolescents, mainly in Brazilian adolescents.

Dietary animal and plant protein intakes and their associations with obesity and cardio-metabolic indicators in European adolescents: the HELENA cross-sectional study

Background

Previous studies suggest that dietary protein might play a beneficial role in combating obesity and its related chronic diseases. Total, animal and plant protein intakes and their associations with anthropometry and serum biomarkers in European adolescents using one standardised methodology across European countries are not well documented.

Objectives

To evaluate total, animal and plant protein intakes in European adolescents stratified by gender and age, and to investigate their associations with cardio-metabolic indicators (anthropometry and biomarkers).

Methods

The current analysis included 1804 randomly selected adolescents participating in the HELENA study (conducted in 2006–2007) aged 12.5-17.5 y (47% males) who completed two non-consecutive computerised 24-h dietary recalls. Associations between animal and plant protein intakes, and anthropometry and serum biomarkers were examined with General linear Model multivariate analysis.

Results

Average total protein intake exceeded the recommendations of World Health Organization and European Food Safety Authority. Mean total protein intake was 96 g/d (59% derived from animal protein). Total, animal and plant protein intakes (g/d) were significantly lower in females than in males and total and plant protein intakes were lower in younger participants (12.5-14.9 y). Protein intake was significantly lower in underweight subjects and higher in obese ones; the direction of the relationship was reversed after adjustments for body weight (g/(kg.d)). The inverse association of plant protein intakes was stronger with BMI z-score and body fat percentage (BF%) compared to animal protein intakes. Additionally, BMI and BF% were positively associated with energy percentage of animal protein.

Conclusions

This sample of European adolescents appeared to have adequate total protein intake. Our findings suggest that plant protein intakes may play a role in preventing obesity among European adolescents. Further longitudinal studies are needed to investigate the potential beneficial effects observed in this study in the prevention of obesity and related chronic diseases.

Reference values for leptin, cortisol, insulin and glucose, among European adolescents and their association with adiposity: the HELENA study

BACKGROUND AND OBJECTIVE

Adequate concentrations of leptin, cortisol, and insulin are important for a suitable metabolism and development during adolescence. These hormones jointly with glucose play a major role in fat metabolism and development of childhood obesity. Our main objective was to quantify biomarkers as leptin, cortisol, insulin and glucose status in European adolescents to contribute to establish reference ranges.

METHODS

A representative sample of 927 adolescents (45% males, 14.9±1.2 years for the overall population) from ten European cities of the HELENA study was used to obtain fasting blood samples for these biomarkers. The percentile distributions were computed by sex and age and percentiles were associated with BMI classification.

RESULTS

Serum leptin concentration in adolescents varied significantly according to BMI, sex and age (all p < 0.001). Cortisol presented a tendency to increase with age, both for females and males, while insulin and glucose were stable with age. Leptin and insulin were highest in obese adolescents (p < 0.001), whilst cortisol and glucose did not vary with BMI. Percentiles 5, 25, 50, 75 and 95, for hormones values were, respectively: 1.27, 4.06, 11.54, 26.70 and 65.33 ng/ml for leptin; 5.00, 8.11, 11.14, 15.00 and 24.51 μg/dl for cortisol and 3.65, 6.15, 8.52, 11.90 and 20.53 μlU/ml for insulin.

CONCLUSIONS

In adolescents, leptin, cortisol, insulin and glucose concentrations are differently affected by age, sex and BMI. Establishment of reference ranges (percentiles) of these biomarkers would be of great interest when pediatricians have to assess the trend of an adolescent to develop obesity years after.

Infrequent stools in exclusively breastfed infants

BACKGROUND

Few data are available on the number of stools in exclusively breastfed infants. Two studies aimed to assess the stool pattern in exclusively breastfed infants and to evaluate the reactions of mothers in the case of infrequent stools and the decisions of healthcare providers.

MATERIALS AND METHODS

Infrequent stools were defined as an interval of >24 hours between bowel movements. Study 1 concerned 198 infants. Mothers responded to a questionnaire where they described their knowledge and attitude toward infrequent stools. Study 2 was performed using the Internet with 85 French-speaking mothers worldwide responding to a questionnaire on bowel movements and reactions of mothers and healthcare providers. Using the scale provided, mothers evaluated their anxiety and the discomfort of their infants.

RESULTS

In Study 1, 37% of exclusively breastfed infants experienced at least one episode of infrequent stools that occurred at <1 month of age in 19% of cases. Mothers who were aware of infrequent stools intervened less frequently (17%) than mothers who were unaware of this condition (79%) (p<0.0001). In Study 2, the median duration of all combined episodes of infrequent stools was 10 weeks (range, 1-34 weeks) with a maximal duration of 28 days. The most frequent action for infants was abdominal massage (79%), whereas in mothers it was consumption of fruit juice/mineral water rich in magnesium/vegetables (73%). There was a correlation between the maternal anxiety score and the infant's discomfort score (p=0.0001).

CONCLUSIONS

Parents/health professionals should be informed of the prevalence of infrequent stools in exclusively breastfed infants and adopt a wait-and-see attitude.

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.

Technical variability of the Vivago® wrist-worn accelerometer

The aim was to assess the technical variability of a new wrist-worn accelerometer under controlled conditions with a shaker device and during normal daily physical activities (PAs). In the first experiment, 10 wrist-worn accelerometers (Vivago(®) Wellness, Paris, France) were attached to the shaker device. Variability was tested at five shaking frequencies (1.1, 2.1, 3.1, 4.1, and 10 Hz) for 10 min at each frequency. In the second experiment, 21 participants wore wrist-worn accelerometers and performed six consecutive 10-min periods of activity at increasing levels of intensity from sedentary to vigorous. Results from the first experiment show a modest inter- and intra-instrument reliability at low frequencies and that reliability improved as frequency increased. The inter-instrument coefficient of variation (CV) was 2.6-18.3%. The intra-instrument CV was 4.1-23.2%. Variability was similar in the second experiment with a CV inversely related to PA intensity. The inter- and intra-instrument CV varied from 24.2% and 19.9% for sedentary activities to 3.7% and 4.3% for vigorous PA, respectively. Results suggest that reliability was higher at high intensities, corresponding to moderate and vigorous PA, intensities generally recommended for public health purposes.

Health inequalities in urban adolescents: role of physical activity, diet, and genetics

OBJECTIVE

Coordinated European projects relying on standardized methods are needed to identify health inequalities across Europe. This study aimed to compare fitness, fatness, and cardiometabolic risk between urban adolescents from the south and center-north of Europe and to explore whether physical activity (PA) and other factors might explain these differences.

METHODS

The Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional project comprised 3528 adolescents from the south (4 cities) and central-north (6 cities) of Europe, 1089 of whom provided blood samples for analysis. Fitness (strength, speed-agility, and cardiorespiratory fitness), total and abdominal fatness (anthropometry and bioelectrical impedance), and cardiometabolic risk (z scores including fitness, fatness, blood lipids, insulin resistance, and blood pressure) were assessed. The analyses were adjusted for socioeconomic factors, objectively measured PA (accelerometry), total energy intake and diet quality, and genetic variants of the FTO rs9939609 polymorphism.

RESULTS

Adolescents from southern Europe were less fit and fatter according to all markers (P < .001). Differences in cardiometabolic risk scores were not consistent. Adolescents from the south were less active and this would largely explain the differences observed in speed-agility and cardiorespiratory fitness. Differences in total and abdominal fatness could not be explained by PA, energy intake, diet quality, or FTO rs9939609 polymorphism.

CONCLUSIONS

Fitness and fatness levels indicate that urban adolescents from the south are less healthy than those from central-northern Europe. Our data suggest that differences in PA might explain differences in important health-related fitness components, yet factors explaining the differences in fatness encountered remain unknown.

Mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis children

AIM

To analyze breathing pattern and mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis (CF) children.

METHODS

Thirteen healthy children and 6 children with cystic fibrosis volunteered to perform an incremental test on a treadmill. Exercise tidal flow/volume loops were plotted every minute within a maximal flow/volume loop (MFVL). Expiratory flow limitation (expFL expressed in %Vt) was evaluated and end-expiratory and end-inspiratory lung volumes (EELV and EILV) were estimated from expiratory reserve volume relative to vital capacity (ERV/FVC) and from inspiratory reserve volume relative to vital capacity (IRV/FVC).

RESULTS

During the incremental exercise, expFL was first observed at 40% of maximal aerobic speed in both groups. At maximal exercise, 46% of healthy children and 83% of CF children presented expFL, without significant effect of cystic fibrosis on the severity of expFL. According to the two-way ANOVA results, both groups adopted similar breathing pattern and breathing strategies as no significant effect of CF has been revealed. But, according to one-way ANOVA results, a significant increase of ERV/FVC associated with a significant decrease of IRV/FVC from resting value shave been observed in healthy children at maximal exercise, but not in CF children.

DISCUSSION

The hypothesis of this study was based on the assumption that mild cystic fibrosis could induce more frequent and more severe mechanical ventilatory constraints due to pulmonary impairment and breathing pattern disturbances. But, this study did not succeed to highlight an effect of mild cystic fibrosis on the mechanical ventilatory constraints (expFL and dynamic hyperinflation) that occur during an incremental exercise. This absence of effect could be due to the absence of an impact of the disease on spirometric data, breathing pattern regulation during exercise and breathing strategy.

Nutrient intake of European adolescents: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

OBJECTIVE

An adequate nutritional intake in childhood and adolescence is crucial for growth and the prevention of youth and adult obesity and nutrition-related morbidities. Improving nutrient intake in children and adolescents is of public health importance. The purpose of the present study was to describe and evaluate the nutrient intake in a European sample using the D-A-CH nutrient intake recommendations and the Nutritional Quality Index (NQI).

DESIGN

The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, the main objective of which is to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years.

SETTING

Eight cities in Europe.

SUBJECTS

The initial sample consisted of 3528 European adolescents. Among these, 1590 adolescents (54% female) had sufficient and plausible dietary data on energy and nutrient intakes from two 24 h recalls using the HELENA-DIAT software.

RESULTS

The intakes of most macronutrients, vitamins and minerals were in line with the D-A-CH recommendations. While the intakes of SFA and salt were too high, the intake of PUFA was too low. Furthermore, the intakes of vitamin D, folate, iodine and F were less than about 55% of the recommendations. The median NQI was about 71 (of a maximum of 100).

CONCLUSIONS

The intakes of most nutrients were adequate. However, further studies using suitable criteria to assess nutrient status are needed. Public health initiatives should educate children and adolescents regarding balanced food choices.

More physically active and leaner adolescents have higher energy intake

OBJECTIVE

To test whether youths who engage in vigorous physical activity are more likely to have lean bodies while ingesting relatively large amounts of energy. For this purpose, we studied the associations of both physical activity and adiposity with energy intake in adolescents.

STUDY DESIGN

The study subjects were adolescents who participated in 1 of 2 cross-sectional studies, the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study (n = 1450; mean age, 14.6 years) or the European Youth Heart Study (EYHS; n = 321; mean age, 15.6 years). Physical activity was measured by accelerometry, and energy intake was measured by 24-hour recall. In the HELENA study, body composition was assessed by 2 or more of the following methods: skinfold thickness, bioelectrical impedance analysis, plus dual-energy X-ray absorptiometry or air-displacement plethysmography in a subsample. In the EYHS, body composition was assessed by skinfold thickness.

RESULTS

Fat mass was inversely associated with energy intake in both studies and using 4 different measurement methods (P ≤ .006). Overall, fat-free mass was positively associated with energy intake in both studies, yet the results were not consistent across measurement methods in the HELENA study. Vigorous physical activity in the HELENA study (P < .05) and moderate physical activity in the EYHS (P < .01) were positively associated with energy intake. Overall, results remained unchanged after adjustment for potential confounding factors, after mutual adjustment among the main exposures (physical activity and fat mass), and after the elimination of obese subjects, who might tend to underreport energy intake, from the analyses.

CONCLUSION

Our data are consistent with the hypothesis that more physically active and leaner adolescents have higher energy intake than less active adolescents with larger amounts of fat mass.

Independent and combined effects of physical activity and sedentary behavior on blood pressure in adolescents: gender differences in two cross-sectional studies

Objectives

To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies.

Methods

Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression.

Results

Performing the recommended amount of PA (≥60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2–4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies.

Conclusions

Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings.

Add-on omalizumab in children with severe allergic asthma: a 1-year real life survey

Omalizumab has been shown to reduce exacerbation rates in moderate to severe allergic asthma. Our aim was to evaluate omalizumab efficacy and safety in a real-life setting in severe asthmatic children. 104 children (aged 6-18 years), followed up in paediatric pulmonary tertiary care centres, were included at the beginning of omalizumab treatment. Asthma control levels, exacerbations, inhaled corticosteroid dose, lung function and adverse events were evaluated over 1 year. Children were characterised by allergic sensitisation to three or more allergens (66%), high IgE levels (mean 1125 kU · L(-1)), high rate of exacerbations (4.4 per year) and healthcare use during the previous year, and high inhaled corticosteroid dose (mean 703 μg equivalent fluticasone per day). Asthma control levels defined as good, partial or poor, improved from 0%, 18% and 82% at entry to 53%, 30% and 17% at week 20, and to 67%, 25% and 8% at week 52, respectively (p<0.0001). Exacerbation and hospitalisation rates dropped by 72% and 88.5%, respectively. At 12 months, forced expiratory volume in 1 s improved by 4.9% (p=0.023), and inhaled corticosteroid dose decreased by 30% (p<0.001). Six patients stopped omalizumab for related significant adverse events. Omalizumab improved asthma control in children with severe allergic asthma and was generally well tolerated. The observed benefit was greater than that reported in clinical trials.

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.

The effect of ponderal index at birth on the relationships between common LEP and LEPR polymorphisms and adiposity in adolescents

This study examined the effect of ponderal index (PI) at birth on the relationships between eight common polymorphisms of the leptin (LEP) and leptin receptor (LEPR) genes and adiposity in adolescents. A total of 823 European adolescents (45.4% girls) aged 14.8 ± 1.4 years were genotyped for the LEP (rs2167270, rs12706832, rs10244329, rs2071045, and rs3828942) and LEPR (rs1137100, rs1137101, and rs8179183) polymorphisms. The PI was calculated from parental reports of birth weight and length. Fat mass index (FMI) was calculated. Analyses were adjusted for relevant confounders. An "adiposity-risk-allele score" based on genotypes at the three single-nucleotide polymorphisms (SNPs) associated with adolescents' FMI in adolescents within the lower tertile of PI was calculated. The LEP rs10244329 and rs3828942 polymorphisms were associated with higher FMI only in adolescents within the lower PI tertile (+0.55 kg/m(2) per minor T allele, P = 0.040, and +0.58 kg/m(2) per major G allele, P = 0.028, respectively). The LEPR rs8179183 polymorphism was significantly associated with higher FMI in adolescents within the lower PI tertile (+0.87 kg/m(2) per minor C allele, P = 0.006). After correction for multiple comparisons, only the association between the LEPR rs8179183 and FMI persisted. However, each additional risk allele conferred 0.53 kg/m(2) greater FMI in adolescents within the lower tertile of PI (P = 0.008). In conclusion, our results suggest that those adolescents born with lower PI could be more vulnerable to the influence of the LEP rs10244329 and rs3828942 polymorphisms and LEPR rs8179183 polymorphism on total adiposity content. Due to the relatively small sample size, these findings should be replicated in further larger population samples.

Comparison of mechanical ventilatory constraints between continuous and intermittent exercises in healthy prepubescent children

BACKGROUND

The aim of this study was to evaluate the occurrence and severity of mechanical ventilatory constraints in healthy prepubescent children during continuous and intermittent exercise.

METHODS

Twelve prepubescent children (7-11 years old) performed 7 exercises on a treadmill: one graded test for the determination of maximal aerobic speed (MAS), three continuous exercises (CE) at 60, 70, and 80% of MAS and three intermittent exercises (IE), alternating 15 sec of exercise with 15 sec of passive recovery, at 90, 100, and 110% of MAS. During each CE and IE, tidal flow/volume loops were plotted within a maximal flow/volume loop (MFVL) measured at rest before each exercise. Expiratory flow limitation (expFL expressed in %Vt) was defined as the part of exercise tidal volume (Vt) meeting the boundary of MFVL. Breathing strategy was estimated by measuring inspiratory capacity relative to forced vital capacity and tidal volume relative to inspiratory capacity. Other breathing pattern parameters (ventilation VE, Vt, respiratory frequency f) were continuously recorded during exercise.

RESULTS

An "intensity" effect was found for VE during CE (P < 0.001) but not during IE (P = 0.08). The increase in VE was predominantly assumed by an increase in f for both exercise modalities. During each exercise, several children heterogeneously experienced expFL ranging between 10 and 90%Vt. For all exercises, Vt was predominantly regulated by an increase in Vt/IC with no change in IC/FVC from rest to exercise. Finally, no significant "modality" effect was found for mechanical ventilatory constraint parameters (expFL, Vt/IC, and IC/FVC).

DISCUSSION

We could conclude that neither of the modalities studied induced more mechanical ventilatory constraints than the other, but that exercise intensities specific to each modality might be greater sources of exacerbation for mechanical ventilatory constraints.

Objectively measured physical activity and sedentary time in European adolescents: the HELENA study

The authors' aim in this cross-sectional study was to characterize levels of objectively measured physical activity and sedentary time in adolescents from 9 European countries. The study comprised 2,200 European adolescents (1,184 girls) participating in the HELENA cross-sectional study (2006-2008). Physical activity was measured by accelerometry and was expressed as average intensity (counts/minute) and amount of time (minutes/day) spent engaging in moderate- to vigorous-intensity physical activity (MVPA). Time spent in sedentary behaviors was also objectively measured. Cardiorespiratory fitness was measured by means of the 20-m shuttle run test. Level of maternal education was reported by the adolescents. A higher proportion of boys (56.8% of boys vs. 27.5% of girls) met the physical activity recommendations of at least 60 minutes/day of MVPA. Adolescents spent most of the registered time in sedentary behaviors (9 hours/day, or 71% of the registered time). Both average intensity and MVPA were higher in adolescents with high cardiorespiratory fitness, and sedentary time was lower in the high-fitness group. There were no physical activity or sedentary time differences between maternal education categories. These data provide an objective measure of physical activity and amount of time spent in sedentary behaviors in a relatively large number of European adolescents.

Associations between common genetic polymorphisms in angiopoietin-like proteins 3 and 4 and lipid metabolism and adiposity in European adolescents and adults

CONTEXT

Plasma-borne angiopoietin-like proteins (ANGPTL) act as endocrine factors on their target tissues. Because ANGPTL3 and ANGPTL4 play important roles in lipid metabolism and the regulation of adiposity in mice, we hypothesized that genetic variability at the ANGPTL3 and ANGPTL4 genes loci might influence lipid metabolism and fat deposition in humans.

OBJECTIVE

The aim of the study was to examine the association between ANGPTL3 and ANGPTL4 genetic polymorphisms and metabolic phenotypes in adolescent and adult samples.

DESIGN AND PARTICIPANTS

Two independent population-based studies, one composed of 1144 adolescents (mean age, 14.8 +/- 1.4 yr) from nine European countries (the HELENA study) and the other composed of 1155 adults (age range, 35-65 yr) from Northern France (the MONICA Lille study), were genotyped for one ANGPTL3 polymorphism and four ANGPTL4 polymorphisms.

RESULTS

The ANGPTL3 rs11207997 polymorphism (minor allele frequency, 0.32) was associated with lower plasma HDL-cholesterol and apolipoprotein A-I levels in both adolescents (P = 0.0004, P = 0.00006, respectively) and adults (P = 0.03, P = 0.02, respectively). The ANGPTL4 rs4076317 polymorphism (minor allele frequency, 0.29) was associated with a higher percentage of body fat (P = 0.02) in adolescents and a higher waist-to-hip ratio (in interaction with the peroxisome proliferator-activated receptor gamma Pro12Ala polymorphism) in adults (P = 0.0004).

CONCLUSION

The present study underlines the role of ANGPTL3 in HDL-cholesterol metabolism as early as in adolescence. Our data also suggest possible associations between ANGPTL4 polymorphisms and body fat, but these findings require replication.

Equivalence of accelerometer data for walking and running: treadmill versus on land

The aim of this study was to compare equivalence and agreement of physical activity output data collected by a Research Tri-axial accelerometer (R3T) during walking and running on a treadmill versus on land. Fifty healthy volunteers, 35 males (age 21.9 +/- 1.8 years) and 15 females (age 21.6 +/- 0.7 years), underwent a series of tests on a treadmill and on land with the order of testing administered randomly. Each participant walked for 10 min at 4 km x h(-1) and 6 km x h(-1), and ran at 8 km x h(-1) and 10 km x h(-1), with the same accelerometer. Analysis of output data was assessed by two statistical tests: the equivalence test and Bland and Altman method. Mean differences for walking were 41.2 +/- 129.8 counts per minute and -68.8 +/- 173.15 counts per minute at 4 km . h(-1) and km x h(-1), respectively. Mean differences for running were 19.1 +/- 253.20 counts per minute and 38.9 +/- 270.2 counts per minute at 8 km x h(-1) and 10 km x h(-1), respectively. The physical activity output data from the treadmill were higher by an average of 3.5% than the data collected on land. The differences obtained between the treadmill and on land were small and non-significant. The equivalence test showed that output data from the treadmill versus on land were equivalent (P < 0.05). The Bland and Altman method showed good agreement between the counts obtained on the treadmill and on land (P < 0.05). In conclusion, physical activity output data were similar as measured by the RT3 accelerometer on a treadmill and on land. The findings suggest that the RT3 may be used in a laboratory and extrapolated to data obtained on land.