Mathilde Kersting

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.

Promotion and provision of drinking water in schools for overweight prevention: randomized, controlled cluster trial.

OBJECTIVE. The study tested whether a combined environmental and educational intervention solely promoting water consumption was effective in preventing overweight among children in elementary school. METHODS. The participants in this randomized, controlled cluster trial were second- and third-graders from 32 elementary schools in socially deprived areas of 2 German cities. Water fountains were installed and teachers presented 4 prepared classroom lessons in the intervention group schools (N = 17) to promote water consumption. Control group schools (N = 15) did not receive any intervention. The prevalence of overweight (defined according to the International Obesity Task Force criteria), BMI SD scores, and beverage consumption (in glasses per day; 1 glass was defined as 200 mL) self-reported in 24-hour recall questionnaires, were determined before (baseline) and after the intervention. In addition, the water flow of the fountains was measured during the intervention period of 1 school year (August 2006 to June 2007). RESULTS. Data on 2950 children (intervention group: N = 1641; control group: N = 1309; age, mean ± SD: 8.3 ± 0.7 years) were analyzed. After the intervention, the risk of overweight was reduced by 31% in the intervention group, compared with the control group, with adjustment for baseline prevalence of overweight and clustering according to school. Changes in BMI SD scores did not differ between the intervention group and the control group. Water consumption after the intervention was 1.1 glasses per day greater in the intervention group. No intervention effect on juice and soft drink consumption was found. Daily water flow of the fountains indicated lasting use during the entire intervention period, but to varying extent. CONCLUSION. Our environmental and educational, school-based intervention proved to be effective in the prevention of overweight among children in elementary school, even in a population from socially deprived areas.

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.

Vitamin D status and parathyroid hormone in obese children before and after weight loss

OBJECTIVE The roles of vitamin D and parathyroid hormone (PTH) are discussed controversially in obesity, and studies of these hormones in obese children are limited. Therefore, we studied the relationships between PTH, 1,25-dihydroxy-vitamin D (1,25-OH Vit D), 25-hydroxy-vitamin D (25-OH Vit D), weight status, and insulin sensitivity before and after weight loss in obese children. METHODS Fasting serum PTH, 1,25-OH Vit D, 25-OH Vit D, inorganic phosphate, calcium, alkaline phosphatase (AP), insulin, glucose, and weight status (SDS-BMI and percentage body fat) were determined in 133 obese children (median age 12.1 years) and compared with 23 non-obese children. Furthermore, these parameters were analyzed in 67 obese children before and after participating in a 1-year obesity intervention program. RESULTS Obese children had significantly (P < 0.001) higher PTH and lower 25-OH Vit D concentrations compared with non-obese children, while calcium, phosphate, AP, and 1,25-OH Vit D did not differ significantly. Changes of PTH (r = 0.23, P = 0.031) and 25-OH Vit D (r = -0.27, P = 0.013) correlated significantly with changes of SDS-BMI, but not with changes of insulin sensitivity (homeostasis model assessment; HOMA-B%). Reduction of overweight in 35 children led to a significant (P < 0.01) decrease of PTH concentrations and an increase in 25-OH Vit D levels. CONCLUSIONS PTH levels were positively and 25-OH Vit D concentrations were negatively related to weight status. Since these alterations normalized after weight loss, these changes are consequences rather than causes of overweight. A relationship between PTH, vitamin D, and insulin sensitivity based on the HOMA index was not found in obese children. Further longitudinal clamp studies are necessary to study the relationship between vitamin D and insulin sensitivity.

Predictors to success in outpatient training in obese children and adolescents

OBJECTIVE: The treatment of obese children and adolescents is not yet satisfactorily effective. It is not clear which participants can profit by a long-time outpatient therapy.DESIGN: Longitudinal, clinical intervention study based on a 1-y outpatient training programme consisting of physical exercise, nutrition course and behaviour therapy for children and their parents.SUBJECTS: A total of 75 obese children (age 7–15 y; standard duration scores of body mass index(SDS-BMI)+1.9–+3.8).MEASUREMENTS: We characterised the participants as to their willingness to change their behaviour (changes in weight status, number of attempts at therapy, participation in exercise groups), somatic characteristics (BMI of children and family members, gender, age), socioeconomic status (level of education of the children and their parents, working mother), exercise and dietary habits, dietary intake as well as the quality of dietary records. These factors were related to the success of the treatment using a multiple logistic regression.RESULTS: A total of 27 (37%) of the children were unsuccessful after treatment. For 48 (63%) of the children, there was a median weight loss of about 0.4 SDS-BMI (range −0.2 to −1.1). The only significant difference (P<0.0001) between these successful children and the unsuccessful ones was that they had taken part in the exercise groups before training began.CONCLUSION: A training for the obese children and their parents enables the majority of the participants to reduce weight. Previous participation in exercise groups can be considered as a predictor to success of the treatment.

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.

Fifteen-year time trends in energy and macronutrient intake in German children and adolescents: results of the DONALD study

The DONALD study (Dortmund Nutritional and Anthropometric Longitudinally Designed study) gives the opportunity to evaluate long-term food and nutrient intake data on the basis of 3 d weighed dietary records of infants, children and adolescents since 1985. In this paper, we examine changes in energy and macronutrient intakes (protein, fat, saturated, mono- and polyunsaturated fatty acids, carbohydrates and added sugars) of 795 2-18-year-old subjects between 1985 and 2000 (4483 records). No significant changes in intakes of energy and of protein, polyunsaturated fatty acids and added sugars (as % energy intake, E %) were found. Fat intake decreased significantly in all age groups (between -0.20 and -0.26 E %/year), as well as intake of saturated fatty acids (between -0.11 and -0.14 E %/year) and monounsaturated fatty acids (between -0.07 and -0.014 E %/year). This decline was compensated for by a significant increase in carbohydrate intake (between +0.18 and +0.27 E %/year). The changes in macronutrient intake were mainly due to a decreased consumption of fats-oils (between -0.29 and -1.26 g/year) and meat-fish-eggs (between -0.21 and -2.92 g/year), whereas consumption of bread-cereals (between +0.12 and +2.42 g/year) and potatoes-pasta-rice (between +0.15 and +2.26 g/year) increased slightly. However, since recommended fat intake and fatty acid composition was not reached at the end of the study period by far, further efforts will be necessary to improve macronutrient composition and to stabilize favourable dietary habits.

Pattern of beverage consumption and long-term association with body-weight status in German adolescents--results from the DONALD study.

In the present study the relationship between the consumption of different beverage groups and body-weight status in 5 years of study participation in German adolescents was investigated. We used anthropometric and dietary data from 3 d weighed records of 244 subjects between 9 and 18 years of age participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. Only subjects with at least four out of six possible weighed dietary records were considered. A repeated-measures regression model (PROC MIXED) was used to analyse the effect of beverage consumption on body-weight status. BMI standard deviation scores (BMI-SDS) and body fat percentage (%BF) were chosen as the dependent variables. In boys, energetic beverage consumption was not associated with BMI-SDS or %BF, neither cross-sectionally nor prospectively. In girls, baseline consumption of energetic beverages did not predict baseline BMI-SDS, baseline %BF, or change in either variable over the study period. However, an increase in energetic beverage consumption over the study period was associated with an increase in BMI-SDS (+0.070 SDS/MJ increase in energetic beverage consumption; P = 0.01). Separate consideration of regular soft drinks and fruit juices revealed that, in girls, BMI-SDS increased with increased fruit juice consumption (+0.096 SDS/MJ increase in fruit juice consumption; P = 0.01), and to a lesser extent with regular soft drink consumption (+0.055 SDS/MJ increase in regular soft drink consumption; P = 0.08). In conclusion, these results suggest that an increase in energetic beverage consumption may result in weight gain, at least in adolescent girls.

Four-year follow-up of children and adolescents participating in an obesity intervention program

Background:Since obesity affects childrens health and social integration, treatment concepts with long-term efficiency are necessary.Methods:We analyzed changes of standard deviation score of body mass index (SDS-BMI) quarterly in the first year and once a year during the next 3 years in all obese children participating in the 1-year outpatient intervention program ‘Obeldicks’, which was based on physical exercise, nutrition education and behavior therapy. All analyses were performed on the intention-to-treat approach.Results:One hundred and thirty-one children (77%) of the 170 children (mean age 10.5 years, 51% female, mean BMI 26.9 kg/m2, mean SDS-BMI 2.54) attending the ‘Obeldicks’ intervention program reduced their overweight at the end of intervention (mean SDS-BMI reduction 0.41) and 122 (66%) 3 years after end of intervention (mean SDS-BMI reduction 0.48). The reduction of overweight was independent of the childs gender, age and parental age and BMI. Reduction of 0.33 SDS-BMI in the first 3 months was the best predictor for long-term success (95% predictive value).Conclusions:Participating in the 1-year outpatient obesity intervention program ‘Obeldicks’ was associated with a decrease of overweight, which was sustained 3 years after the end of intervention. Reduction of overweight in the first 3 months of the intervention was highly predictive for long-term success.

Energy intake of 1 to 18 year old German children and adolescents.

In a sample of 695 healthy well-nourished German children and adolescents covering the total age range from 1 to 18 years, 3d weighed diet records were collected and measurements of body height and weight were taken. 10% non-plausible records (reported energy intake (EI):estimated basal metabolic rate (BMR) < Cut off 1.06) were excluded from further analysis. The rate of non-plausible records was low in the childhood age groups (2-6%), higher in the male (10%), and highest in the female adolescents (30%). Recalculation of age and sex specific cut offs based on assumed light physical activity levels (PAL) reduced the exclusion rate to 6.5% (total) and 20% (female adolescents). The reported energy intake of the total sample based on plausible records (n = 627, EI:BMR > or = 1.06) was close to the new estimations of energy requirements assuming light physical activity which are proposed for the revision of the current FAO/WHO energy requirements. The sample was of normal height and weight compared to the Netherlands growth references. For a definite interpretation of the low reported energy intake in the context of health promoting physical activity patterns of children and adolescents more scientific evidence should be available.