Kurt Widhalm

Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study.

Objective:To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.Design:Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.Results:The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.Conclusion:The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.

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.

A Proinflammatory State Is Detectable in Obese Children and Is Accompanied by Functional and Morphological Vascular Changes

Background—Obesity is generally accepted as a risk factor for premature atherosclerosis. Subclinical inflammation as quantified by blood levels of C-reactive protein (CRP) contributes to the development and progression of atherosclerosis. We hypothesized that inflammation in obese children is related to functional and early morphological vascular changes. Methods and Results—Blood levels of high sensitivity (hs) CRP, hsIL-6, the soluble intercellular adhesion molecule1 (ICAM-1), vascular cell adhesion molecule (VCAM)-1, and E-selectin were measured in 145 severely obese (body mass index [BMI], 32.2±5.8 kg/m2) and 54 lean (BMI, 18.9±3.2 kg/m2) children 12±4 years old. Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measured by high-resolution ultrasound as markers of early vascular changes were assessed in 92 (77 obese and 15 lean) and 59 (50 obese and 9 lean) children, respectively. Obese children had significantly higher levels of hsCRP, hsIL-6, and E-selectin than healthy controls (4.1±4.8 versus 0.9±1.5 mg/L, P<0.001 for hsCRP; 1.99±1.30 versus 1.42±1.01 pg/mL, P=0.05 for hsIL-6; and 78±38 versus 59±29 ng/mL, P=0.01 for E-selectin). There were no differences in the levels of ICAM-1 and VCAM-1 between groups. Obese children had lower peak FMD response (7.70±6.14 versus 11.06±3.07%, P=0.006) and increased IMT (0.37±0.04 versus 0.34±0.03 mm, P=0.03) compared with controls. Morbidly obese children (n=14, BMI 44.1±3.9 kg/m2) had highest levels of hsCRP (8.7±0.7 mg/L), hsIL-6 (3.32±1.1 pg/mL), and E-selectin (83±40 ng/mL). Conclusions—A proinflammatory state is detectable in obese children, which is accompanied by impaired vascular endothelial function and early structural changes of arteries, even in young subjects at risk. It remains to be determined whether high hsCRP in obese children predicts cardiovascular events.

Cardiovascular risk in 26,008 European overweight children as established by a multicenter database.

Objective: Although the obesity epidemic is progressing in European children too, there is no consensus on the population‐specific prevalence of comorbidities or efficient diagnostic strategies. Therefore, weight‐related risk factors, their interrelationship, and association with biological parameters were assessed in a large group of overweight (OW) children, documented by an electronic database.

Clustering patterns of physical activity, sedentary and dietary behavior among European adolescents: The HELENA study

BackgroundEvidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. A better insight in the clustering of those behaviors, could help to identify groups who are at risk in developing chronic diseases. This study examines the prevalence and clustering of physical activity, sedentary and dietary patterns among European adolescents and investigates if the identified clusters could be characterized by socio-demographic factors.MethodsThe study comprised a total of 2084 adolescents (45.6% male), from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity and sedentary behavior were measured using self-reported questionnaires and diet quality was assessed based on dietary recall. Based on the results of those three indices, cluster analyses were performed. To identify gender differences and associations with socio-demographic variables, chi-square tests were executed.ResultsFive stable and meaningful clusters were found. Only 18% of the adolescents showed healthy and 21% unhealthy scores on all three included indices. Males were highly presented in the cluster with high levels of moderate to vigorous physical activity (MVPA) and low quality diets. The clusters with low levels of MVPA and high quality diets comprised more female adolescents. Adolescents with low educated parents had diets of lower quality and spent more time in sedentary activities. In addition, the clusters with high levels of MVPA comprised more adolescents of the younger age category.ConclusionIn order to develop effective primary prevention strategies, it would be important to consider multiple health indices when identifying high risk groups.

Single nucleotide polymorphisms in the FADS gene cluster are associated with delta-5 and delta-6 desaturase activities estimated by serum fatty acid ratios

Genetic variability in the FADS1-FADS2 gene cluster [encoding delta-5 (D5D) and delta-6 (D6D) desaturases] has been associated with plasma long-chain PUFA (LCPUFA) and lipid levels in adults. To better understand these relationships, we further characterized the association between FADS1-FADS2 genetic variability and D5D and D6D activities in adolescents. Thirteen single nucleotide polymorphisms (SNPs) were genotyped in 1,144 European adolescents (mean ± SD age: 14.7 ± 1.4 y). Serum phospholipid fatty acid levels were analyzed using gas chromatography. D5D and D6D activities were estimated from the C20:4n-6/C20:3n-6 and C20:3n-6/C18:2n-6 ratios, respectively. Minor alleles of nine SNPs were associated with higher 18:2n-6 levels (1.9E-18 ≤ P ≤ 6.1E-5), lower C20:4n-6 levels (7.1E-69 ≤ P ≤ 1.2E-12), and lower D5D activity (7.2E-44 ≤ P ≤ 4.4E-5). All haplotypes carrying the rs174546 minor allele were associated with lower D5D activity, suggesting that this SNP is in linkage disequilibrium with a functional SNP within FADS1. In contrast, only the rs968567 minor allele was associated with higher D6D activity (P = 1.5E-6). This finding agrees with an earlier in vitro study showing that the minor allele of rs968567 is associated with a higher FADS2 promoter activity. These results suggest that rare alleles of several SNPs in the FADS gene cluster are associated with higher D6D activity and lower D5D activity in European adolescents.

Inter-disciplinary European guidelines on surgery of severe obesity.

In 2005, for the first time in European history, an extraordinary Expert panel named ‘The BSCG’ (Bariatric Scientific Collaborative Group), was appointed through joint effort of the major European Scientific Societies which are active in the field of obesity management. Societies that constituted this panel were: IFSO – International Federation for the Surgery of Obesity, IFSO-EC – International Federation for the Surgery of Obesity – European Chapter, EASO – European Association for Study of Obesity, ECOG – European Childhood Obesity Group, together with the IOTF (International Obesity Task Force) which was represented during the completion process by its representative. The BSCG was composed not only of the top officers representing the respective Scientific Societies (four acting presidents, two past presidents, one honorary president, two executive directors), but was balanced with the presence of many other key opinion leaders in the field of obesity. The BSCG composition allowed the coverage of key disciplines in comprehensive obesity management, as well as reflecting European geographical and ethnic diversity. This joint BSCG expert panel convened several meetings which were entirely focused on guidelines creation, during the past two years. There was a specific effort to develop clinical guidelines, which will reflect current knowledge, expertize and evidence based data on morbid obesity treatment.

The adipokine visfatin is markedly elevated in obese children.

Objective: The insulin-mimetic adipocytokine visfatin has been linked to adiposity and the metabolic syndrome. Design Cross-sectional study. Subjects: Eighty-three nondiabetic obese children and 40 healthy controls. Measurements: We analyzed plasma visfatin concentrations to assess whether this adipokine is associated with adiposity. Results: Plasma visfatin concentrations were nearly 2-fold higher in obese children (mean, 1.1 ng/mL; 95% CI, 0.2-6.6) than in controls (0.6 ng/mL, 95% CI, 0.6 to 0.6; P < 0.001). No relationship was detectable between visfatin and other subject characteristics, hsCRP or the lipid profile. Conclusions: Visfatin may be involved in the development of metabolic derangements in obese children.

Beverage consumption among European adolescents in the HELENA study.

Background/Objectives:Our objective was to describe the fluid and energy consumption of beverages in a large sample of European adolescents.Subjects/Methods:We used data from 2741 European adolescents residing in 8 countries participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS). We averaged two 24-h recalls, collected using the HELENA-dietary assessment tool. By gender and age subgroup (12.5–14.9 years and 15–17.5 years), we examined per capita and per consumer fluid (milliliters (ml)) and energy (kilojoules (kJ)) intake from beverages and percentage consuming 10 different beverage groups.Results:Mean beverage consumption was 1611 ml/day in boys and 1316 ml/day in girls. Energy intake from beverages was about 1966 kJ/day and 1289 kJ/day in European boys and girls, respectively, with sugar-sweetened beverages (SSBs) (carbonated and non-carbonated beverages, including soft drinks, fruit drinks and powders/concentrates) contributing to daily energy intake more than other groups of beverages. Boys and older adolescents consumed the most amount of per capita total energy from beverages. Among all age and gender subgroups, SSBs, sweetened milk (including chocolate milk and flavored yogurt drinks all with added sugar), low-fat milk and fruit juice provided the highest amount of per capita energy. Water was consumed by the largest percentage of adolescents followed by SSBs, fruit juice and sweetened milk. Among consumers, water provided the greatest fluid intake and sweetened milk accounted for the largest amount of energy intake followed by SSBs. Patterns of energy intake from each beverage varied between countries.Conclusions:European adolescents consume an average of 1455 ml/day of beverages, with the largest proportion of consumers and the largest fluid amount coming from water. Beverages provide 1609 kJ/day, of which 30.4%, 20.7% and 18.1% comes from SSBs, sweetened milk and fruit juice, respectively.

Recommended levels of physical activity to avoid an excess of body fat in European adolescents: the HELENA Study.

BACKGROUND It is unclear how much physical activity is necessary to prevent obesity during adolescence. PURPOSE The purpose of this study was to examine whether the current physical activity guidelines for youth are associated with a lower risk of excess of body fat in European adolescents. METHODS A sample of 2094 adolescents from the HELENA cross-sectional study was selected. Levels of moderate, vigorous, and moderate to vigorous physical activity (MVPA) were assessed using accelerometers. BMI and percentage of body fat (skinfolds) were calculated and used to categorize the adolescents as normal-weight/normal-fat, overweight/overfat, and obese. Data were collected during 2006-2007. Receiver operating characteristic (ROC) analysis, performed in 2009, was used to determine thresholds that best discriminate between weight and body fat categories. RESULTS ROC analysis showed that >/=18 minutes/day in vigorous physical activity and >/=55 minutes/day in MVPA significantly discriminated between normal-weight and overweight+obesity categories. Moreover, >/=9 minutes/day of vigorous physical activity and >/=49 minutes/day of MVPA discriminated between normal-fat and overfat/obese adolescents. Adolescents who did not meet the current physical activity guidelines for youth of 60 minutes/day in MVPA increased the risk of having overweight+obesity (OR=1.24, 95% CI=1.01, 1.534) and overfat+obesity (OR=1.79, 95% CI=1.33, 2.42). ORs increased when adolescents did not meet the guidelines of at least 15 minutes/day in vigorous physical activity. CONCLUSIONS Current physical activity guidelines seem to be appropriate to prevent excess of body fat in European adolescents. However, participation in vigorous physical activity might have additional importance in preventing obesity.