Dénes Molnár

Presence of metabolic cardiovascular syndrome in obese children.

Abstract The aim of the present study was to investigate the aggregation of cardiovascular risk factors (hyperinsulinaemia, impaired glucose tolerance, dyslipidaemia, and hypertension) in 180 (77 female, 103 male) obese and 239 control children. Blood glucose, serum insulin and lipid levels were determined from blood samples taken after an overnight fast. Oral glucose tolerance tests were performed and blood glucose concentrations were monitored. The body mass index, body fat (on the basis of skinfold measurements), lean body mass and waist/hip ratio were calculated and blood pressure was measured five times in all subjects. It was shown that only 14.4% of obese children were free from any risk factors, in contrast to 79.1% of the control children. Four risk factors (metabolic cardiovascular syndrome) were found in 8.9% of the obese children (8.7% in males and 9.l % in females) while none could be detected in controls. Considerable differences were also detected in the prevalence of one, two or three risk factors between control and obese children. Patients with the metabolic cardiovascular syndrome could not be characterized by any of the investigated anthropometric characteristics, but the duration of obesity was significantly longer in these children. Conclusion Potential risk factors for cardiovascular diseases already tend to cluster in childhood and they are strongly associated with obesity. Our observations suggest that the development of the metabolic cardiovascular syndrome has its origin in childhood.

The IDEFICS cohort: design, characteristics and participation in the baseline survey.

Background:The European IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study was set up to determine the aetiology of overweight, obesity and related disorders in children, and to develop and evaluate a tailored primary prevention programme.Objective:This paper focuses on the aetiological element of the multicentre study, the measures and examinations, sociodemographic characteristics of the study sample and proportions of participation.Design:Prospective cohort study with an embedded intervention study that started with a baseline survey in eight countries in 2007–2008.Subjects and measurements:Baseline participants of the prospective cohort study were 16 224 children aged 2–9 years. Parents reported sociodemographic, behavioural, medical, nutritional and other lifestyle data for their children and families. Examinations of children included anthropometry, blood pressure, fitness, accelerometry, DNA from saliva and physiological markers in blood and urine. The built environment, sensory taste perception and other mechanisms of childrens food choices and consumer behaviour were studied in subgroups.Results:Between 1507 and 2567, children with a mean age of 6.0 years and an even sex distribution were recruited from each country. Of them, 82% lived in two-parent families. The distribution of standardised income levels differed by study sample, with low-income groups being strongly represented in Cyprus, Italy and Germany. At least one 24-h dietary recall was obtained for two-thirds of the children. Blood pressure and anthropometry were assessed in more than 90%. A 3-day accelerometry was performed in 46%, motor fitness was assessed in 41%, cardiorespiratory fitness in 35% and ∼11% participated in taste perception tests. The proportion of children donating venous blood, urine and saliva was 57, 86 and 88%, respectively.Conclusion:The IDEFICS cohort provides valuable data to investigate the interplay of social, environmental, genetic, physiological and behavioural factors in the development of major diet- and lifestyle-related disorders affecting children at present.

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 adolescents 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.

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 studys 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 workshops intraobserver TEMs for skinfold thicknesses and circumferences were smaller than 1; for BIA resistance TEMs were smaller than 0.1 Ω and for reactance they were smaller than 0.2 Ω. 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 Ω 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.

Physical activity in relation to overweight and obesity in children and adolescents.

Abstract Fitness and physical activity levels of children and adolescents are commonly addressed but data on scientific investigations are both equivocal and methodologically diverse. The intensity and type of physical activity that benefit health and development during childhood are not known. Measurement of activity in children is problematic since there is no valid method of assessing activity levels that is feasible for use in large field studies. Most studies using self-report methods, heart rate studies using low heart rate threshold and doubly labelled water studies indicate relatively high levels of activity in children. The three national surveys on large representative samples reported that 60% to 70% of all children were involved in sufficient physical activity according to various definitions. Heart rate studies demonstrate that children generally perform short bouts of moderate to vigorous activities and seldom participate in long-sustained vigorous activities. They also proved that children perform large volumes of activity in the lower heart rate zones. It is generally accepted that boys are more active than girls and physical activity declines by age (peak around 13 to 14 years of age). The difference between the physical activity of European and North American children or between children living in different European countries is difficult to judge due to the diversity of methodology and definitions. Conclusion There is a need to identify more clearly the quantity and type of activity which improves the health and promotes the normal development of children and to improve the methods assessing physical activity.

Muscular and cardiorespiratory fitness are independently associated with metabolic risk in adolescents: the HELENA study

Artero EG, Ruiz JR, Ortega FB, España‐Romero V, Vicente‐Rodríguez G, Molnar D, Gottrand F, González‐Gross M, Breidenassel C, Moreno LA, Gutiérrez A; on behalf of the HELENA Study Group. Muscular and cardiorespiratory fitness are independently associated with metabolic risk in adolescents: the HELENA study.

Is there any relationship between obesity and mental flexibility in children

Cognitive profiles of 12 schoolboys with obesity were compared with their peers with normal weight. For the cognitive assessment five clinical tasks were selected: digit span memory, Ravens progressive matrices (intelligence), semantic verbal fluency, D2 attention endurance and Wisconsin card sorting test. We found no differences in memory, intelligence and verbal fluency between the two groups. Children with obesity performed worse on D2 and Wisconsin tests. Correlations confirmed relationships between body weight, body mass index, attention and Wisconsin measured perseveration in set-shifting. This suggests that childhood obesity involves cognitive deficits in shifting and attention abilities.

Physical fitness reference standards in European children: the IDEFICS study

Background/Objectives:A low fitness status during childhood and adolescence is associated with important health-related outcomes, such as increased future risk for obesity and cardiovascular diseases, impaired skeletal health, reduced quality of life and poor mental health. Fitness reference values for adolescents from different countries have been published, but there is a scarcity of reference values for pre-pubertal children in Europe, using harmonised measures of fitness in the literature. The IDEFICS study offers a good opportunity to establish normative values of a large set of fitness components from eight European countries using common and well-standardised methods in a large sample of children. Therefore, the aim of this study is to report sex- and age-specific fitness reference standards in European children.Subjects/Methods:Children (10 302) aged 6–10.9 years (50.7% girls) were examined. The test battery included: the flamingo balance test, back-saver sit-and-reach test (flexibility), handgrip strength test, standing long jump test (lower-limb explosive strength) and 40-m sprint test (speed). Moreover, cardiorespiratory fitness was assessed by a 20-m shuttle run test. Percentile curves for the 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentiles were calculated using the General Additive Model for Location Scale and Shape (GAMLSS).Results:Our results show that boys performed better than girls in speed, lower- and upper-limb strength and cardiorespiratory fitness, and girls performed better in balance and flexibility. Older children performed better than younger children, except for cardiorespiratory fitness in boys and flexibility in girls.Conclusions:Our results provide for the first time sex- and age-specific physical fitness reference standards in European children aged 6–10.9 years.

Reduced antioxidant status in obese children with multimetabolic syndrome

BACKGROUND: In our previous study, the negative correlation found between plasma insulin levels and plasma α-tocopherol concentrations suggested that decreased antioxidant vitamin levels and reduced antioxidant capacity might be a characteristic feature of obese children with multimetabolic syndrome (MMS).OBJECTIVE: To investigate lipid-soluble antioxidant vitamin levels and total antioxidant status (TAS) in obese children with and without MMS and in controls.SUBJECTS: In total, 16 control children (age: 16.2±1.1 y, BMI: 20.7±1.9 kg/m2, body fat (BF): 25.6±5.7%; mean±s.d.), 15 obese children (age: 13.4±2.1 y, BMI: 34.2±3.1 kg/m2, BF: 36.9±5.8%,) and 17 obese children without MMS (age: 14.4±2.3 y, BMI: 30.4±6.2 kg/m2, BF: 36.3±5.8%) were included in the study.METHODS: Body composition was determined by anthropometric methods. Vitamin analysis was carried out by high-performance liquid chromatography and TAS of the plasma was measured with commercially available kits. Plasma glucose, lipids and insulin were measured by standard laboratory methods.RESULTS: Plasma α-tocopherol and β-carotene levels corrected for plasma lipids (cholesterol + triglyceride) were significantly (P<0.05) lower in obese children with MMS (2.4 (3.1) μmol/mmol and 12.3 (24.0) pmol/mmol, respectively, median (range from the first to the third quartile)), than in the obese without MMS (3.7 (0.9) μmol/mmol and 48.2 (27.7) pmol/mmol) and in the control group (3.8 (0.7) μmol/mmol and 86.6 (44.5) pmol/mmol). Plasma TAS values of the MMS group (1.2 (0.4) mmol/l) were also significantly (P<0.05) reduced as compared to obese children without MMS (1.62 (0.14) mmol/l) and to controls (1.58 (0.21) mmol/l).CONCLUSION: Obese children with MMS are prone to oxidative stress. Further investigations are necessary to determine if these children may benefit from vitamin E and β-carotene supplementation.