The impact of familial, behavioural and psychosocial factors on the SES gradient for childhood overweight in Europe. A longitudinal study.

BACKGROUND: In highly developed countries, childhood overweight and many overweight-related risk factors are negatively associated with socioeconomic status (SES). OBJECTIVE: The objective of this study is to investigate the longitudinal association between parental SES and childhood overweight, and to clarify whether familial, psychosocial or behavioural factors can explain any SES gradient. METHODS: The baseline and follow-up surveys of the identification and prevention of dietary and lifestyle induced health effects in children and infants (IDEFICS) study are used to investigate the longitudinal association between SES, familial, psychosocial and behavioural factors, and the prevalence of childhood overweight. A total of 5819 children (50.5% boys and 49.5% girls) were included. RESULTS: The risk for being overweight after 2 years at follow-up in children who were non-overweight at baseline increases with a lower SES. For children who were initially overweight, a lower parental SES carries a lower probability for a non-overweight weight status at follow-up. The effect of parental SES is only moderately attenuated by single familial, psychosocial or behavioural factors; however, it can be fully explained by their combined effect. Most influential of the investigated risk factors were feeding/eating practices, parental body mass index, physical activity behaviour and proportion of sedentary activity. CONCLUSION: Prevention strategies for childhood overweight should focus on actual behaviours, whereas acknowledging that these behaviours are more prevalent in lower SES families.

Adherence to combined lifestyle factors and their contribution to obesity in the IDEFICS study.

BACKGROUND: The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study investigated the aetiology of childhood obesity and developed a primary prevention programme. METHODS: Pre-intervention adherence to key behaviours related to childhood obesity, namely water/sweetened drink, fruit/vegetable consumption, daily TV time, physical activity, family time and adequate sleep duration, was measured at baseline. Adherence to international recommendations was converted into a composite score ranging from 0 (none) to 6 (adhering to all). Data on adherence were available for 7,444 to 15,084 children aged 2-9.9 years, depending on the behaviour. By means of multi-level logistic regression models adjusted for age, sex and country, we calculated odds ratios (OR) and 95% confidence intervals (CI) to estimate the relationship between adherence to these recommendations and the risk of being overweight/obese. RESULTS: Adherence ranged from 15.0% (physical activity) to 51.9% (TV time). As adherence increased, a lower chance of being overweight/obese was observed; adhering to only one key behaviour (score = 1) meant an OR = 0.81 (CI: 0.65-1.01) compared with non-adherence (score = 0), while adhering to more than half of the key behaviours (score ≥ 4) halved the chance for overweight/obesity (OR = 0.54, CI: 0.37-0.80). Adherence to physical activity, TV and sleep recommendations was the main driver reducing the chance of being overweight. Overweight/obese children were more likely not to adhere to at least one of the recommended behaviours (19.8%) than normal-weight/thin children (12.9%) CONCLUSION: The selected key behaviours do not contribute equally to a reduced chance of being overweight. Future interventions may benefit most from moving more, reducing TV time and getting adequate sleep.

Clustering of lifestyle behaviours and relation to body composition in European children. The IDEFICS study.

BACKGROUND: Dietary patterns, physical activity (PA) and sedentary behaviours are some of the main behavioural determinants of obesity; their combined influence in children has been addressed in a limited number of studies. SUBJECTS/METHODS: Children (16,228) aged 2-9 years old from eight European countries participated in the baseline survey of the IDEFICS study. A subsample of 11,674 children (50.8% males) were included in the present study. Children's food and beverage consumption (fruit and vegetables (F&V) and sugar-sweetened beverages (SSBs)), PA and sedentary behaviours were assessed via parental questionnaires. Sex-specific cluster analysis was applied to identify behavioural clusters. Analysis of covariance and logistic regression were applied to examine the association between behavioural clusters and body composition indicators (BCIs). RESULTS: Six behavioural clusters were identified (C1-C6) both in boys and girls. In both sexes, clusters characterised by high level of PA (C1 and C3) included a large proportion of older children, whereas clusters characterised by low SSB consumption (C5 and C6) included a large proportion of younger children. Significant associations between derived clusters and BCI were observed only in boys; those boys in the cluster with the highest time spent in sedentary activities and low PA had increased odds of having a body mass index z-score (odds ratio (OR)=1.33; 95% confidence interval (CI)=(1.01, 1.74)) and a waist circumference z-score (OR=1.41; 95%CI=(1.06, 1.86)) greater than one. CONCLUSION: Clusters characterised by high sedentary behaviour, low F&V and SSB consumption and low PA turned out to be the most obesogenic factors in this sample of European children.

Usual energy and macronutrient intakes in 2-9-year-old European children.

OBJECTIVE: Valid estimates of population intakes are essential for monitoring trends as well as for nutritional interventions, but such data are rare in young children. In particular, the problem of misreporting in dietary data is usually not accounted for. Therefore, this study aims to provide accurate estimates of intake distributions in European children. DESIGN: Cross-sectional setting-based multi-centre study. SUBJECTS: A total of 9560 children aged 2-9 years from eight European countries with at least one 24-h dietary recall (24-HDR). METHODS: The 24-HDRs were classified in three reporting groups based on age- and sex-specific Goldberg cutoffs (underreports, plausible reports, overreports). Only plausible reports were considered in the final analysis (N=8611 children). The National Cancer Institute (NCI)-Method was applied to estimate population distributions of usual intakes correcting for the variance inflation in short-term dietary data. RESULTS: The prevalence of underreporting (9.5%) was higher compared with overreporting (3.4%). Exclusion of misreports resulted in a shift of the energy and absolute macronutrient intake distributions to the right, and further led to the exclusion of extreme values, that is, mean values and lower percentiles increased, whereas upper percentiles decreased. The distributions of relative macronutrient intakes (% energy intake from fat/carbohydrates/proteins) remained almost unchanged when excluding misreports. Application of the NCI-Method resulted in markedly narrower intake distributions compared with estimates based on single 24-HDRs. Mean percentages of usual energy intake from fat, carbohydrates and proteins were 32.2, 52.1 and 15.7%, respectively, suggesting the majority of European children are complying with common macronutrient intake recommendations. In contrast, total water intake (mean: 1216.7 ml per day) lay below the recommended value for >90% of the children. CONCLUSION: This study provides recent estimates of intake distributions of European children correcting for misreporting as well as for the daily variation in dietary data. These data may help to assess the adequacy of young children's diets in Europe.

Dietary energy density in young children across Europe.

OBJECTIVES: To describe energy density (ED; kcal g(-1)) of dietary intake of European children. METHODS: From 16, 228 children who participated in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) baseline examination, 8551 children with 24-h dietary recalls (24-HDR), with plausible reported energy intakes and complete covariate information were included in the present analysis. ED was calculated using two methods: (1) ED including solid foods (EDF) and (2) ED including solid foods and energy-containing beverages (EDF&B). Beverage energy was calculated in kcal per day. Dietary characteristics and body mass index (BMI) z-score of children aged 2 to <6 years and 6 to <10 years were compared between children with an overall EDF below the <25th percentile, between the 25th and 75th percentile as well as above the >75th percentile. Standardised regression coefficients were estimated to assess the association between dietary characteristics, BMI z-score and ED of the diet. RESULTS: Children with low EDF and EDF&B diets consumed less energy but higher quantity of food and beverages than children with high EDF and EDF&B diets. Consumption of caloric beverages decreased with increasing EDF&B of the diet owing to the relatively low ED of the beverages, in relation to solid foods. Generally, children with low EDF and EDF&B diets showed healthier food choices than peers with higher EDF and EDF&B diets. In this sample, EDF and EDF&B were not associated with BMI z-score. CONCLUSION: Health promotion strategies should proclaim lower ED diets by means of foods with high water and low fat content and mainly fruit and vegetable components. Excluding caloric beverages from EDF calculation is a useful method to avoid misinterpretation of true exposure to a high energy dense diet. We recommend excluding caloric beverages from EDF calculation when investigating the effect of ED on a certain (health) outcome.

Adherence to the obesity-related lifestyle intervention targets in the IDEFICS study.

BACKGROUND/OBJECTIVES: To address behaviours associated with childhood obesity, certain target values are recommended that should be met to improve children's health. In the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study such lifestyle recommendations were conveyed as six key messages. Here, we investigate the adherence of European children to these messages. METHODS: The IDEFICS intervention was based on the intervention mapping approach with the following six targets: increase water consumption (to replace sugar-containing beverages), increase fruit/vegetable consumption, reduce daily screen time, increase daily physical activity, improve the quality of family life and ensure adequate sleep duration. Internationally recommended target values were applied to determine the prevalence of children meeting these targets. RESULTS: In a cohort of 18,745 children participating in the IDEFICS baseline survey or newly recruited during follow-up, data on the above lifestyle behaviours were collected for a varying number of 8302 to 17,212 children. Information on all six behaviours was available for 5140 children. Although 52.5% of the cohort was classified in the highest category of water consumption, only 8.8% met the target of an intake of fruits/vegetables five times a day. The prevalence of children adhering to the recommendation regarding total screen time-below 1 h for pre-school children and 2 h for school children-was 51.1%. The recommended amount of at least 60 min of moderate-to-vigorous physical activity per day was fulfilled by 15.2%. Family life of the child measured by various indicators was considered as satisfactory in 22.8%. Nocturnal sleep duration of 11 (10) hours or more in pre-school (school) children was achieved by 37.9%. In general, children in northern countries and younger children showed better adherence to the recommendations. Only 1.1% of the children adhered to at least five of these recommendations. CONCLUSIONS: Current adherence of children to lifestyle recommendations to prevent childhood obesity is low where observed differences with respect to country, age and gender call for targeted intervention.

Metabolic syndrome in young children: definitions and results of the IDEFICS study.

OBJECTIVE: To estimate the prevalence of the metabolic syndrome (MetS) using reference standards obtained in European children and to develop a quantitative MetS score and describe its distribution in children. DESIGN AND METHODS: Population-based survey in eight European countries, including 18745 children 2.0 to 10.9 years, recruited during a second survey. Anthropometry (weight, height and waist circumference), blood pressure and serum-fasting triglycerides, HDL cholesterol, glucose and insulin were measured. We applied three widely accepted definitions of the pediatric MetS and we suggest a new definition, to guide pediatricians in decisions about close monitoring or even intervention (values of at least three of the MetS components exceeding the 90th or 95th percentile, respectively). We used a z-score standardisation to calculate a continuous score combining the MetS components. RESULTS: Among the various definitions of MetS, the highest prevalence (5.5%) was obtained with our new definition requiring close observation (monitoring level). Our more conservative definition, requiring pediatric intervention gives a prevalence of 1.8%. In general, prevalences were higher in girls than in boys. The prevalence of metabolic syndrome is highest among obese children. All definitions classify a small percentage of thin or normal weight children as being affected. The metabolic syndrome score shows a positive trend with age, particularly regarding the upper percentiles of the score. CONCLUSIONS: According to different definitions of pediatric MetS, a non-negligible proportion of mostly prepubertal children are classified as affected. We propose a new definition of MetS that should improve clinical guidance. The continuous score developed may also serve as a useful tool in pediatric obesity research. It has to be noted, however, that the proposed cutoffs are based on a statistical definition that does not yet allow to quantify the risk of subsequent disease.

Reference values of bone stiffness index and C-terminal telopeptide in healthy European children.

BACKGROUND/OBJECTIVE: Quantitative ultrasound measurements and bone metabolic markers can help to monitor bone health and to detect impaired skeletal development. Population-based reference values for children may serve as a basis for preventive measures to reduce the risk of osteoporosis and osteoporotic fractures in later life. This is the first paper providing age-, sex- and height-specific reference values for bone stiffness index (SI) and serum carboxy-terminal cross-linking telopeptide of type I collagen (CTX) in healthy, apparently prepubertal children. SUBJECTS/METHODS: In the population-based IDEFICS baseline survey (2007-2008) and follow-up (2009-2010), 18,745 children from eight European countries were newly recruited. A total of 10,791 2-10.9-year-old and 1646 3-8.9-year-old healthy children provided data on SI of the right and left calcaneus and serum CTX, respectively. Furthermore, height and weight were measured. Percentile curves were calculated using the General Additive Model for Location Scale and Shape (GAMLSS) to model the distribution of SI and CTX depending on multiple covariates while accounting for dispersion, skewness, and the kurtosis of this distribution. RESULTS: SI was negatively associated with age and height in children aged 2-5 years, whereas a positive association was observed in children aged 6-10 years. The dip in SI occurred at older age for higher SI percentiles and was observed earlier in taller children than in smaller children. The CTX reference curves showed a linear-positive association with age and height. No major sex differences were observed for the SI and CTX reference values. CONCLUSION: These reference data lay the ground to evaluate bone growth and metabolism in prepubertal children in epidemiological and clinical settings. They may also inform clinical practice to monitor skeletal development and to assess adverse drug reactions during medical treatments.

Prevalence of overweight and obesity in European children below the age of 10.

BACKGROUND: There is a lack of common surveillance systems providing comparable figures and temporal trends of the prevalence of overweight (OW), obesity and related risk factors among European preschool and school children. Comparability of available data is limited in terms of sampling design, methodological approaches and quality assurance. The IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study provides one of the largest European data sets of young children based on state-of-the-art methodology. OBJECTIVE: To assess the European distribution of weight status according to different classification systems based on body mass index (BMI) in children (2.0-9.9 years). To describe the prevalence of weight categories by region, sex, age and socioeconomic position. DESIGN: Between 2007 and 2010, 18,745 children from eight European countries participated in an extensive, highly standardised protocol including, among other measures, anthropometric examinations and parental reports on socio-demographic characteristics. RESULTS: The combined prevalence of OW/obesity ranges from more than 40% in southern Europe to less than 10% in northern Europe. Overall, the prevalence of OW was higher in girls (21.1%) as compared with boys (18.6%). The prevalence of OW shows a negative gradient with social position, with some variation of the strength and consistency of this association across Europe. Overall, population groups with low income and/or lower education levels show the highest prevalence of obesity. The use of different reference systems to classify OW results in substantial differences in prevalence estimates and can even reverse the reported difference between boys and girls. CONCLUSIONS: There is a higher prevalence of obesity in populations from southern Europe and in population groups with lower education and income levels. Our data confirm the need to develop and reinforce European public health policies to prevent early obesity and to reduce these health inequalities and regional disparities.

Adherence to a Mediterranean-like dietary pattern in children from eight European countries. The IDEFICS study.

BACKGROUND: Despite documented benefits of a Mediterranean-like dietary pattern, there is a lack of knowledge about how children from different European countries compare with each other in relation to the adherence to this pattern. In response to this need, we calculated the Mediterranean diet score (MDS) in 2-9-year-old children from the Identification and prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) eight-country study. SUBJECTS AND METHODS: Using 24 h dietary recall data obtained during the IDEFICS study (n=7940), an MDS score was calculated based on the age- and sex-specific population median intakes of six food groups (vegetables and legumes, fruit and nuts, cereal grains and potatoes, meat products and dairy products) and the ratio of unsaturated to saturated fats. For fish and seafood, which was consumed by 10% of the population, one point was given to consumers. The percentages of children with high MDS levels (>3) were calculated and stratified by sex, age and by having at least one migrant parent or both native parents. Demographic (sex and age) and socioeconomic characteristics (parental education and income) of children showing high (>3) vs low (⩽3) MDS levels were examined. RESULTS: The highest prevalence of children with MDS>3 was found among the Italian pre-school boys (55.9%) and the lowest among the Spanish school-aged girls (26.0%). Higher adherence to a Mediterranean-like dietary pattern was not associated with living in a Mediterranean country or in a highly educated or high-income family, although with some exceptions. Differences in adherence between boys and girls or age groups varied between countries without any general pattern. CONCLUSIONS: With the exception of Italian pre-schoolers, similar adherence levels to a Mediterranean-like dietary pattern have been observed among European children.

Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study.

INTRODUCTION: To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references. OBJECTIVES: The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS). METHODS: Overall 18,745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N=5915) were excluded from the analysis. Anthropometric measurements (BMI (N=12 830); triceps, subscapular, fat mass and fat mass index (N=11,845-11,901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N=8129-8205), neck circumference (N=12,241); waist circumference and waist-to-height ratio (N=12,381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS. RESULTS: Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age- and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5- to <5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years. CONCLUSION: The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children.

Clustering of multiple lifestyle behaviours and its association to cardiovascular risk factors in children: the IDEFICS study.

BACKGROUND/OBJECTIVES: Individual lifestyle behaviours have independently been associated with cardiovascular diseases (CVD) risk factors in children. This study aimed to identify clustered lifestyle behaviours (dietary, physical activity (PA) and sedentary indicators) and to examine their association with CVD risk factors in children aged 2-9 years. SUBJECTS/METHODS: Participants included 4619 children (51.6% boys) from eight European countries participating in the IDEFICS cross-sectional baseline survey (2007-2008). Insulin resistance, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, sum of two skinfolds and systolic blood pressure (SBP) z-scores were summed to compute a CVD risk score. Cluster analyses stratified by sex and age groups (2 to <6 years; 6-9 years) were performed using parental-reported data on fruit, vegetables and sugar-sweetened beverages (SSB) consumption, PA performance and television video/DVD viewing. RESULTS: Five clusters were identified. Associations between CVD risk factors and score, and clusters were obtained by multiple linear regression using cluster 5 ('low beverages consumption and low sedentary') as the reference cluster. SBP was positively associated with clusters 1 ('physically active'; ß=1.34; 95% confidence interval (CI): 0.02, 2.67), 2 ('sedentary'; ß=1.84; 95% CI: 0.57, 3.11), 3 ('physically active and sedentary'; ß=1.45; 95% CI: 0.15, 2.75) and 4 ('healthy diet'; ß=1.83; 95% CI: 0.50, 3.17) in older boys. A positive association was observed between CVD risk score and clusters 2 (ß=0.60; 95% CI: 0.20, 1.01), 3 (ß=0.55; 95% CI: 0.14, 0.97) and 4 (ß=0.60, 95% CI: 0.18, 1.02) in older boys. CONCLUSIONS: Low television/video/DVD viewing levels and low SSB consumption may result in a healthier CVD profile rather than having a diet rich in fruits and vegetables or being physically active in (pre-)school children.

[International cohort studies]. / Internationale Kohortenstudien.

Among observational studies, cohort studies, i.e. longitudinal observations of selected population groups, provide the highest possible evidence of a causal association between specific risk factors (exposure) and the occurrence of disease in populations. Besides the fact that many exposures cannot be investigated in experimental designs, cohort studies have the advantage over randomized clinical trials that they are conducted in free living populations and not in restrictive, clinical settings. In this paper we describe the aims and features of international cohorts that have been selected because of their impact, their size or their endpoints. We do not only present the study designs and survey instruments used but we also highlight some of the most important results gained by these studies. Most of these prospective studies investigated common chronic diseases in the elderly, such as cancer, diabetes, cardiovascular or neurodegenerative diseases, osteoporosis and ophthalmologic disorders. Newer cohorts and recent reassessments of existing cohorts almost always include the collection and storage of biological samples. In recent years technological developments allowed the implementation of cutting edge measurement procedures, such as imaging techniques for phenotyping. Finally, we discuss on the one hand whether these designs can be transferred to the German situation and on the other hand to what degree the results obtained from foreign cohorts can be generalized for the German population. We conclude with recommendations for future cohort studies.

Understanding and preventing childhood obesity and related disorders--IDEFICS: a European multilevel epidemiological approach.

The environment of children has drastically changed in Europe during the last decades as reflected in unhealthy dietary habits and sedentary lifestyle. Nutrition obviously plays a part in the development of overweight in childhood. However, dietary factors and physical activity are also involved in the development of metabolic syndrome, type II diabetes, cardiovascular diseases, osteoporosis, and postural deformities like scoliosis, effects related in part to excessive weight gain. To stop the resulting epidemic of diet- and lifestyle-induced morbidity, efficient evidence-based approaches are needed. These issues are the focus of IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants), a five-year project proposed under the sixth EU framework. The IDEFICS consortium comprises 25 research centres and SMEs across Europe. The planned prospective study will identify risk profile inventories for children susceptible to any of these disorders with emphasis on obesity and its co-morbid conditions. Genetic and non-genetic factors, psychosocial factors and social settings will be considered. The project will devise tailored prevention strategies that are effective, easy to implement and that account for the needs of different social groups. Population-based studies will investigate the impact of sensory perception and provide results concerning internal and external triggers of food choices and children's consumer behaviour. The ethical implications of a "right not to know" of genetic factors will be addressed. We will propose knowledge-based guidelines on dietary and lifestyle activities for health promotion and disease prevention in children for health professionals, stakeholders and consumers.

[Databases as a source for monitoring systems of drug safety]. / Datenbanken als Grundlage für Monitoring-Systeme in der Arzneimittelsicherheit. Ein Kurzbeitrag.

Clinical trials only allow for a limited assessment of adverse drug reactions (ADRs) due to their restricted number of patients, their short duration, and their narrow inclusion criteria. To assess potential ADRs in the population actually treated after drug approval, different systems for signal generation such as spontaneous reporting systems have been established and are required by drug laws in many countries. As of today epidemiological methods for signal confirmation for rare adverse events or events with long induction periods use record linkage databases such as the United Health Care (Ingenix) in the USA or the practice databases such as the General Practice Research Database in Great Britain. However, this approach also has its limitations. This type of database will be presented in this paper. In addition, databases operated by German public health insurance will be described. The topic of linking different data sources in Germany to support pharmaco-vigilance activities will be addressed.