Cross-sectional and longitudinal associations between sleep duration, sleep quality, and bone stiffness in European children and adolescents.

In this large perspective cohort among European children and adolescents, we observed that daytime napping was positively associated with bone stiffness, while short or long sleep duration combined with poor sleep quality was associated with less bone stiffness. Our findings are important for obtaining optimal bone stiffness in childhood. INTRODUCTION: To examine the cross-sectional and longitudinal associations between sleep duration, sleep quality, and bone stiffness index (SI) in European children and adolescents. METHODS: Four thousand eight hundred seventy-one children aged 2-11 years from the IDEFICS study and 861 children aged 6-15 years from the subsequent I.Family study were included. Sleep duration (i.e., nocturnal sleep and daytime napping) and sleep quality (i.e., irregularly bedtime routine, have difficulty falling asleep and trouble getting up in the morning) were reported by self-administrated questionnaires. Nocturnal sleep duration was converted into age-specific z-scores, and total sleep duration was classified into short, adequate, and long based on the National Sleep Recommendation. Calcaneal SI of both feet were measured using quantitative ultrasound. Linear mixed-effects models with country as a random effect were used, with adjustments for sex, age, pubertal status, family socioeconomic status, physical activity, screen time, body mass index, and daylight duration. RESULTS: Nocturnal sleep duration z-scores were positively associated with SI percentiles among participants with adequate sleep duration at baseline. Moreover, the positive association between daytime napping and SI percentiles was more pronounced in participants with adequate sleep duration at baseline, while at 4-year follow-up was more pronounced in participants with short sleep duration. In addition, extreme sleep duration at baseline predicted lower SI percentiles after 4 years in participants with poor sleep quality. CONCLUSION: The positive associations between nocturnal sleep, daytime napping and SI depended on total sleep duration. Long-term detrimental effect of extreme sleep duration on SI only existed in individuals with poor sleep quality.

A within-sibling pair analysis of lifestyle behaviours and BMI z-score in the multi-centre I.Family study.

BACKGROUND AND AIMS: By investigating differences in lifestyle behaviours and BMI in sibling pairs, family-level confounding is minimized and causal inference is improved, compared to cross-sectional studies of unrelated children. Thus, we aimed to investigate within-sibling pair differences in different lifestyle behaviours and differences in BMI z-scores in children and adolescents. METHODS AND RESULTS: We examined three groups of sibling pairs 1) all same-sex sibling pairs with maximum 4 years age difference (n = 1209 pairs from 1072 families in 8 countries, mean age 10.7 years, standard deviation 2.4 years), 2) sibling pairs discordant for overweight (n = 262) and 3) twin pairs (n = 85). Usual dietary intake was estimated by 24-h recalls and time spent in light (LPA) and moderate-to-vigorous physical activity (MVPA) was measured by accelerometers. Screen time, sleep and dieting for weight loss were assessed by questionnaires. Within all 3 groups of sibling pairs, more time in MVPA was associated with lower BMI z-score. Higher energy intake was associated with higher BMI z-score within twin pairs and within all sibling pairs who were not currently dieting for weight loss. Regarding LPA, screen time or sleep duration, no or inconsistent associations were observed for the three groups of sibling pairs. CONCLUSIONS: MVPA and energy intake were associated with BMI differences within sibling and twin pairs growing up in the same home, thus independent of family-level confounding factors. Future studies should explore whether genetic variants regulating appetite or energy expenditure behaviours account for weight differences in sibling pairs.

Predictors of oropharyngeal cancer survival in Europe.

OBJECTIVES: HPV16-positive oropharyngeal cancer (OPC) patients experience better outcomes compared to HPV16-negative patients. Currently, strategies for treatment de-escalation are based on HPV status, smoking history and disease stage. However, the appropriate cut-point for smoking and the role of other non-clinical factors in OPC survival remains uncertain. MATERIALS AND METHODS: We examined factors associated with OPC outcome in 321 patients recruited in a large European multi-center study. Seropositivity for HPV16 E6 was used as a marker of HPV16 positive cancer. Hazard ratios (HR) and confidence intervals (CI) were estimated using Cox proportional models adjusted for potential confounders. RESULTS: Overall 5-year survival following OPC diagnosis was 50%. HPV16-positive OPC cases were at significantly lower risk of death (aHR = 0.51, 95% CI: 0.32-0.80). A significant effect on OPC survival was apparent for female sex (aHR 0.50: 95% CI: 0.29-0.85) and being underweight at diagnosis (aHR: 2.41, 95% CI: 1.38-4.21). A 10 pack year smoking history was not associated with overall survival. Higher stage at diagnosis appeared as the only factor significantly associated with OPC recurrence (aHR: 4.88, 95% CI: 2.12-11.21). CONCLUSION: This study confirms that HPV16 status is an independent prognostic factor for OPC survival while female sex lowers risk of death and being underweight at diagnosis increases the risk of death. Smoking was not an independent predictor of OPC survival.

The association of emotion-driven impulsiveness, cognitive inflexibility and decision-making with weight status in European adolescents.

OBJECTIVE: To explore the association between emotion-driven impulsiveness, cognitive inflexibility, decision-making and weight status as reflected in body mass index (BMI) z-score (zBMI) in European adolescents. METHODS: In total, 3354 adolescents aged between 12 and 18 years from the I.Family cohort completed the questionnaire-based negative urgency subscale from the UPPS-P Impulsive Behavior Scale to measure emotion-driven impulsiveness in 2013/2014. Furthermore, 1584 adolescents completed the computer-based Bergs Card Sorting Test to measure cognitive inflexibility, and 1780 adolescents completed the Hungry Donkey Test to assess decision-making ability. Anthropometric variables were measured objectively; confounding variables (age, sex, socioeconomic status and country) were assessed using a questionnaire. Mixed-effect regression analyses were conducted for each outcome of the test or questionnaire as a predictor with standardised BMI (zBMI) as the dependent variable in order to investigate association between markers of cognitive functioning and zBMI. RESULTS: After controlling for confounders, results showed that emotion-driven impulsiveness (ß=0.18, 95% confidence interval (CI): 0.13 to 0.24, P<0.001) and cognitive inflexibility (ß=0.01, 95% CI: 0.002 to 0.02, P=0.016) were positively associated with zBMI. However, decision-making ability was not significantly related to zBMI (ß=0.001, 95% CI: -0.001 to 0.003, P=0.47). CONCLUSIONS: More emotion-driven impulsiveness and reduced cognitive flexibility were associated with a higher zBMI in adolescents across Europe. These results may indicate that being impulsive in negative situations and having difficulties changing mental sets increase the susceptibility for unhealthy weight development. Reducing impulsivity and training cognitive flexibility seem promising targets for the prevention and intervention programmes of obesity.

Socially disadvantaged city districts show a higher incidence of acute ST-elevation myocardial infarctions with elevated cardiovascular risk factors and worse prognosis.

BACKGROUND: The importance of socioeconomic status (SES) for coronary heart disease (CHD)-morbidity is subject of ongoing scientific investigations. This study was to explore the association between SES in different city-districts of Bremen/Germany and incidence, severity, treatment modalities and prognosis for patients with ST-elevation myocardial infarctions (STEMI). METHODS: Since 2006 all STEMI-patients from the metropolitan area of Bremen are documented in the Bremen STEMI-registry. Utilizing postal codes of their home address they were assigned to four groups in accordance to the Bremen social deprivation-index (G1: high, G2: intermediate high, G3: intermediate low, G4: low socioeconomic status). RESULTS: Three thousand four hundred sixty-two consecutive patients with STEMI admitted between 2006 and 2015 entered analysis. City areas with low SES showed higher adjusted STEMI-incidence-rates (IR-ratio 1.56, G4 vs. G1). This elevation could be observed in both sexes (women IRR 1.63, men IRR 1.54) and was most prominent in inhabitants <50 yrs. of age (women IRR 2.18, men IRR 2.17). Smoking (OR 1.7, 95%CI 1.3-2.4) and obesity (1.6, 95%CI 1.1-2.2) was more prevalent in pts. from low SES city-areas. While treatment-modalities did not differ, low SES was associated with more extensive STEMIs (creatine kinase > 3000 U/l, OR 1.95, 95% CI 1.4-2.8) and severe impairment of LV-function post-STEMI (OR 2.0, 95% CI 1.2-3.4). Long term follow-up revealed that lower SES was associated with higher major adverse cardiac or cerebrovascular event (MACCE)-rates after 5 years: G1 30.8%, G2 35.7%, G3 36.0%, G4 41.1%, p (for trend) = 0.02. This worse prognosis could especially be shown for young STEMI-patients (<50 yrs. of age) 5-yr. mortality-rates(G4 vs. G1) 18.4 vs. 3.1%, p = 0.03 and 5-year-MACCE-rates (G4 vs. G1) 32 vs. 6.3%, p = 0.02. CONCLUSIONS: This registry-data confirms the negative association of low socioeconomic status and STEMI-incidence, with higher rates of smoking and obesity, more extensive infarctions and worse prognosis for the socio-economically deprived.

Transcriptome analysis in blood cells from children reveals potential early biomarkers of metabolic alterations.

OBJECTIVES: The development of effective strategies to prevent childhood obesity and its comorbidities requires new, reliable early biomarkers. Here, we aimed to identify in peripheral blood cells potential transcript-based biomarkers of unhealthy metabolic profile associated to overweight/obesity in children. METHODS: We performed a whole-genome microarray analysis in blood cells to identify genes differentially expressed between overweight and normal weight children to obtain novel transcript-based biomarkers predictive of metabolic complications. RESULTS: The most significant enriched pathway of differentially expressed genes was related to oxidative phosphorylation, for which most of genes were downregulated in overweight versus normal weight children. Other genes were involved in carbohydrate metabolism/glucose homoeostasis or in lipid metabolism (for example, TCF7L2, ADRB3, LIPE, GIPR), revealing plausible mechanisms according to existing biological knowledge. A set of differentially expressed genes was identified to discriminate in overweight children those with high or low triglyceride levels. CONCLUSIONS: Functional microarray analysis has revealed a set of potential blood-cell transcript-based biomarkers that may be a useful approach for early identification of children with higher predisposition to obesity-related metabolic alterations.

Analysis of the association of leptin and adiponectin concentrations with metabolic syndrome in children: Results from the IDEFICS study.

BACKGROUND AND AIMS: Adipokines may play a role in the pathogenesis of the metabolic syndrome (MetS) in children. We aimed to evaluate the association of leptin, adiponectin, and its ratio (L/A ratio) with the metabolic syndrome (MetS) in a subsample of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) cohort. METHODS AND RESULTS: Leptin, adiponectin and MetS parameters were measured in a subsample of 1253 children (3-9.9 years) participating to the IDEFICS study, grouped as: Non-OW (underweight/normal weight) and OW/Ob (overweight/obese). MetS was defined using the sex- and age-specific cut-offs based on the distribution of MetS components in the IDEFICS cohort. The prevalence of the MetS among OW/Ob was 24.8% and 27.1% in boys and girls respectively, whereas ≤2% among Non-OW. OW/Ob had significantly higher leptin and L/A ratio as compared to Non-OW. Significantly higher leptin was found in OW/Ob with MetS as compared with OW/Ob without MetS. Significantly lower adiponectin was observed only in OW/Ob girls as compared to Non-OW. A 1SD increase in leptin and L/A ratio z-scores or a 1SD decrease in adiponectin z-score were significantly associated with higher risk of MetS. After adjustment for BMI or body fat mass (BFM) the association remained significant only for leptin. CONCLUSION: We showed that in European children, higher leptin concentration is associated with MetS, even after adjusting for BMI or BFM, confirming an early role of leptin in MetS, while the association of adiponectin with MetS seems be mediated by body fat in this age range.

Potential selection effects when estimating associations between the infancy peak or adiposity rebound and later body mass index in children.

INTRODUCTION: This study aims to evaluate a potential selection effect caused by exclusion of children with non-identifiable infancy peak (IP) and adiposity rebound (AR) when estimating associations between age and body mass index (BMI) at IP and AR and later weight status. SUBJECTS AND METHODS: In 4744 children with at least 4 repeated measurements of height and weight in the age interval from 0 to 8 years (37 998 measurements) participating in the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants)/I.Family cohort study, fractional polynomial multilevel models were used to derive individual BMI trajectories. Based on these trajectories, age and BMI at IP and AR, BMI values and growth velocities at selected ages as well as the area under the BMI curve were estimated. The BMI growth measures were standardized and related to later BMI z-scores (mean age at outcome assessment: 9.2 years). RESULTS: Age and BMI at IP and AR were not identifiable in 5.4% and 7.8% of the children, respectively. These groups of children showed a significantly higher BMI growth during infancy and childhood. In the remaining sample, BMI at IP correlated almost perfectly (r⩾0.99) with BMI at ages 0.5, 1 and 1.5 years, whereas BMI at AR correlated perfectly with BMI at ages 4-6 years (r⩾0.98). In the total study group, BMI values in infancy and childhood were positively associated with later BMI z-scores where associations increased with age. Associations between BMI velocities and later BMI z-scores were largest at ages 5 and 6 years. Results differed for children with non-identifiable IP and AR, demonstrating a selection effect. CONCLUSIONS: IP and AR may not be estimable in children with higher-than-average BMI growth. Excluding these children from analyses may result in a selection bias that distorts effect estimates. BMI values at ages 1 and 5 years might be more appropriate to use as predictors for later weight status instead.

Blood fatty acid composition in relation to allergy in children aged 2-9 years: results from the European IDEFICS study.

BACKGROUND/OBJECTIVES: Blood polyunsaturated fatty acids (PUFA) are involved in allergy development, but the etiological role of n-6 and n-3 PUFA is still controversial. A European multicenter study of children (IDEFICS) provided the opportunity to explore the cross-sectional association between fatty acids (FA) and allergy. SUBJECTS/METHODS: Blood FA levels were measured in 2600 children aged 2-9 years and were recorded as the percentage of weight of all FA detected. Logistic regression of allergy status on FA components was adjusted for age, sex, country, body mass index, family history of allergic disease, breast-feeding, and number of siblings. The results were given as odds ratios (OR) for current vs no allergy ever and an increase in FA by 1 s.d. RESULTS: Overall, higher proportions of n-6 PUFA were associated with higher odds of allergy (OR=1.21 (1.05, 1.40)). Monounsaturated FA (MUFA) were associated with reduced risk for allergy (OR=0.75 (0.65, 0.87)), whereas saturated FA did not differ by allergy status. The strongest associations were observed in children <4 years old, with ORs of allergy given as 1.62 (1.15, 2.29) for n-3 PUFA and 0.63 (0.42, 0.95) for MUFA. With regard to individual FA, these associations were independently observed for docosapentaenoic acid (22:5 n-3) and oleic acid (18:1 n-9). CONCLUSIONS: Both PUFA subtypes were positively associated with allergy in an age-dependent manner, whereas MUFA was associated with less allergy. The observation of high proportions of n-3 PUFA in allergic children younger than 4 years might help to understand the nature of early onset of atopic disease.

Influence of physical fitness on cardio-metabolic risk factors in European children. The IDEFICS study.

OBJECTIVE: The aim of the study was to assess the associations of individual and combined physical fitness components with single and clustering of cardio-metabolic risk factors in children. SUBJECTS/METHODS: This 2-year longitudinal study included a total of 1635 European children aged 6-11 years. The test battery included cardio-respiratory fitness (20-m shuttle run test), upper-limb strength (handgrip test), lower-limb strength (standing long jump test), balance (flamingo test), flexibility (back-saver sit-and-reach) and speed (40-m sprint test). Metabolic risk was assessed through z-score standardization using four components: waist circumference, blood pressure (systolic and diastolic), blood lipids (triglycerides and high-density lipoprotein) and insulin resistance (homeostasis model assessment). Mixed model regression analyses were adjusted for sex, age, parental education, sugar and fat intake, and body mass index. RESULTS: Physical fitness was inversely associated with clustered metabolic risk (P<0.001). All coefficients showed a higher clustered metabolic risk with lower physical fitness, except for upper-limb strength (ß=0.057; P=0.002) where the opposite association was found. Cardio-respiratory fitness (ß=-0.124; P<0.001) and lower-limb strength (ß=-0.076; P=0.002) were the most important longitudinal determinants. The effects of cardio-respiratory fitness were even independent of the amount of vigorous-to-moderate activity (ß=-0.059; P=0.029). Among all the metabolic risk components, blood pressure seemed not well predicted by physical fitness, while waist circumference, blood lipids and insulin resistance all seemed significantly predicted by physical fitness. CONCLUSION: Poor physical fitness in children is associated with the development of cardio-metabolic risk factors. Based on our results, this risk might be modified by improving mainly cardio-respiratory fitness and lower-limb muscular strength.

A novel association of neuropilin-1 and MUC1 in pancreatic ductal adenocarcinoma: role in induction of VEGF signaling and angiogenesis.

We report that Mucin1 (MUC1), a transmembrane glycoprotein that is overexpressed in >80% of pancreatic ductal adenocarcinoma (PDA), induced a pro-angiogenic tumor microenvironment by increasing the levels of neuropilin-1 (NRP1, a co-receptor of vascular endothelial growth factor (VEGF)) and its ligand VEGF. Expression of tumor-associated MUC1 (tMUC1) positively correlated with NRP1 levels in human and mouse PDA. Further, tMUC1hi PDA cells secreted high levels of VEGF and expressed high levels of VEGF receptor 2 (VEGFR2) and its phosphorylated forms as compared with tMUC1low/null PDA. This enabled the tMUC1hi/NRP1hi PDA cells to (a) induce endothelial cell tube formation, (b) generate long ectopic blood vessels and (c) enhance distant metastasis in a zebrafish xenograft model. Concurrently, the proteins associated with epithelial-to-mesenchymal transition, N-cadherin and Vimentin, were highly induced in these tMUC1/NRP1hi PDA cells. Hence, blocking signaling via the NRP1-VEGF axis significantly reduced tube formation, new vessel generation and metastasis induced by tMUC1hi PDA cells. Finally, we show that blocking the interaction between VEGF165 and NRP1 with a NRP1 antagonist significantly reduced VEGFR signaling and PDA tumor growth in vivo. Taken together, our data suggest a novel molecular mechanism by which tMUC1 may modulate NRP1-dependent VEGFR signaling in PDA cells.

Whole-blood fatty acids and inflammation in European children: the IDEFICS Study.

BACKGROUND/OBJECTIVES: Fatty acids are hypothesized to influence cardiovascular disease risk because of their effect on inflammation. The aim of this study is to assess the relationship between whole-blood fatty acids (WBFAs) and high-sensitivity C-reactive protein (hs-CRP) in European children. SUBJECTS/METHODS: A total of 1401 subjects (697 boys and 704 girls) aged between 2 and 9 years from the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects in Children and infantS) study were measured in this cross-sectional analysis. The sample was divided into three categories of hs-CRP. Associations between WBFA and hs-CRP were assessed by logistic regression models adjusting for body mass index (BMI), country, age, breastfeeding, mother's education and hours of physical activity. RESULTS: Linoleic acid (LA) (P=0.013, 95% confidence interval (CI): 0.822-0.977) and sum of n-6 WBFA (P=0.029, 95% CI: 0.866-0.992) concentrations were associated with lower concentrations of hs-CRP in boys. In girls, a high ratio of eicosapentaenoic acid (EPA)/arachidonic acid (AA) was associated (P=0.018, 95% CI: 0.892-0.989) with lower hs-CRP concentrations. In contrast, sum of blood n-6 highly unsaturated fatty acids (P=0.012, 95% CI: 1.031-1.284), AA (P=0.007, 95% CI: 1.053-1.395) and AA/LA ratio (P=0.005, 95% CI: 1.102-1.703) were associated (P<0.05) with higher concentrations of hs-CRP in girls. CONCLUSIONS: The n-6 WBFAs (sum of n-6 FA and LA) were associated with lower hs-CRP in boys and with higher hs-CRP in girls (AA, sum of n-6 highly unsaturated and AA/LA ratio). More studies are needed to identify the optimal levels of WBFAs to avoid low-grade inflammation in children considering the differences by sex and BMI.

Effects of a community-oriented obesity prevention programme on indicators of body fatness in preschool and primary school children. Main results from the IDEFICS study.

BACKGROUND/OBJECTIVES: Childhood obesity is a major public health concern but evidence-based approaches to tackle this epidemic sustainably are still lacking. 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. Here, we report on the effects of the IDEFICS intervention on indicators of body fatness. SUBJECTS/METHODS: The intervention modules addressed the community, school and parental level, focusing on diet, physical activity and stress-related lifestyle factors. A cohort of 16,228 children aged 2-9.9 years - about 2000 per country - was equally divided over intervention and control regions. (Participating countries were Sweden, Germany, Estonia, Hungary, Cyprus, Italy, Spain and Belgium.) We compared the prevalence of overweight/obesity and mean values of body mass index z-score, per cent body fat and waist-to-height ratio over 2 years of follow-up. Mixed models adjusting for age and socioeconomic status of the parents and with an additional random effect for country accounted for the clustered study design. RESULTS: The prevalence of overweight and obesity increased in both the intervention and control group from 18.0% at baseline to 22.9% at follow-up in the control group and from 19.0% to 23.6% in the intervention group. The difference in changes between control and intervention was not statistically significant. For the cohort as a whole, the changes in indicators of body fatness did not show any clinically relevant differences between the intervention and control groups. Changes in favour of intervention treatment in some indicators were counterbalanced by changes in favour of the control group in some other indicators. CONCLUSIONS: Over the 2-year-observation period, the IDEFICS primary prevention programme for childhood obesity has not been successful in reducing the prevalence of overweight and obesity nor in improving indicators of body fatness in the target population as a whole.

Impact of a community based health-promotion programme in 2- to 9-year-old children in Europe on markers of the metabolic syndrome, the IDEFICS study.

INTRODUCTION: One objective of 'Identification and prevention of Dietary-and lifestyle-induced health EFfects In Children and infantS', the IDEFICS study, was to implement a community-oriented childhood obesity prevention intervention in eight European countries. OBJECTIVE: To assess the effect of an obesity primary prevention programme on metabolic markers. METHODS: The study had a non-randomized cluster-experimental design. In each country, children were recruited from distinct communities serving as intervention and control regions. Health examinations were done during 2007-2008 before the intervention (T0 ) and during 2009-2010 (T1 ). Children with results available from T0 and T1 on blood pressure, waist circumference and at least one blood-marker (fasting glucose, insulin, HOMA-IR, HbA1c, HDL- and LDL-cholesterol, triglycerides, C-reactive protein) were included. A metabolic syndrome (MetS) score was calculated. RESULTS: A total of 7,406 children (age 2-9.9 years) of the 16,228 participating at T0 provided the necessary data. No effect of the intervention was seen on insulin, HOMA-IR, CRP or the MetS score. Overall fasting glucose increased less in the intervention than in the control region, a pattern driven by three of the eight countries and more pronounced in children of parents with low education. Overall, HbA1c and waist circumference increased more and blood pressure less in the intervention regions. CONCLUSION: We observed no convincing effect of the intervention on markers of the metabolic syndrome. We identified diverse patterns of change for several markers of uncertain relation to the intervention.

Effectiveness of the IDEFICS intervention on objectively measured physical activity and sedentary time in European children.

BACKGROUND: This paper reports on the effectiveness of the prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) intervention on objectively measured physical activity (PA) and sedentary time (ST) in 2- to 9.9-year-old European boys and girls. METHODS: The intervention was evaluated after 2 years through a non-randomized cluster-controlled trial in eight European countries (one control and one intervention community per country). All children in the intervention group received a culturally adapted childhood obesity prevention programme through the community, schools/kindergartens and family. A random sub-sample of children participating in the IDEFICS study wore an accelerometer at baseline and follow-up for at least 3 days (n = 9,184). Of this sample, 81% provided valid accelerometer data at baseline (n = 7,413; 51% boys; 6.21 ± 1.76 years; boys: 617 ± 170 cpm day(-1) ; girls 556 ± 156 cpm day(-1) ) and 3,010 children provided valid accelerometer data at baseline and during the follow-up survey 2 years later. RESULTS: In boys and girls, no significant differences in PA and ST were found between intervention and control groups over 2 years. Strong temporal effects were found in the total sample of boys and girls: the percentage of time spent in light PA per day decreased by 4 percentage points in both boys and girls between baseline and follow-up (both: p < 0.001), while time spent in ST per day increased by 4 percentage points in both sexes over time (both: p < 0.001). Percentage of time spent in moderate-to-vigorous PA per day remained stable over time in boys and girls. CONCLUSION: Despite the socio-ecological approach and implementation of a culturally adapted intervention in each country, no effects of the IDEFICS intervention were found on children's objectively measured PA and ST. Behavioural interventions for children may need to enhance specificity and intensity at the family level using other behaviour change techniques and more direct strategies to reach parents.

Implementation of the IDEFICS intervention across European countries: perceptions of parents and relationship with BMI.

OBJECTIVES: The primary aim of the present study was to obtain insight into parents' perception of the IDEFICS intervention at the school or preschool/kindergarten and community levels and whether they received specific materials related to the intervention. The secondary aim was to analyse whether parents who reported higher levels of exposure to the IDEFICS intervention had children with more favourable changes in body mass index (BMI) z-scores between baseline and after 2 years of intervention. METHODS: Process evaluation of the IDEFICS intervention investigated the implementation of the 2-year intervention in the intervention communities. Intervention group parents (n = 4,180) in seven countries (Belgium, Cyprus, Estonia, Germany, Italy, Spain and Sweden) answered questions about their exposure to the IDEFICS study. To analyse the relationship between exposure and BMI z-score, a composite score was calculated for exposure at the setting and at the community levels. RESULTS: The frequency of parental exposure to the IDEFICS messages not only through the community but also through the (pre)school/kindergarten was lower than what was intended and planned. The dose received by the parents was considerably higher through the (pre)school/kindergarten settings than that through the community in all countries. Efforts by the settings or communities related to fruit and vegetable consumption (range 69% to 97%), physical activity promotion (range 67% to 91%) and drinking water (range 49% to 93%) were more visible and also realized more parental involvement than those related to TV viewing, sleep duration and spending time with the family (below 50%). Results showed no relation of parental exposure at the setting or the community level on more favourable changes in children's BMI z-scores for the total sample. Country-specific analyses for parental exposure at the setting level showed an expected positive effect in German girls and an unexpected negative effect in Italian boys. CONCLUSION: Parental exposure and involvement in the IDEFICS intervention in all countries was much less than aimed for, which might be due to the diverse focus (six key messages) and high intensity and duration of the intervention. It may also be that the human resources invested in the implementation and maintenance of intervention activities by the study centres, the caretakers and the community stakeholders were not sufficient. Higher levels of parental exposure were not related to more favourable changes in BMI z-scores.

Process evaluation of the IDEFICS school intervention: putting the evaluation of the effect on children's objectively measured physical activity and sedentary time in context.

OBJECTIVES: The first aim was to describe the intervention implementation and reception with specific regard to physical activity (PA) within Belgian schools participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) intervention. Second, we examined if a higher intervention process score in schools showed more favourable effects on children's objectively measured PA and sedentary time (ST). METHODS: The IDEFICS intervention focused on improving children's health behaviour (including PA) at the community, school/kindergarten and family level. Five process evaluation questionnaires completed by school working groups, and (physical education) teachers were used for the process evaluation of four intervention modules (school working groups, healthy weeks, school environment, health-related physical education and PA). Items were summed to calculate a total intervention process score per school. Schools were subdivided into three groups (low, medium and high score). Multilevel models were used to examine if changes in PA or ST differed between schools with a low, medium or high score. In total, 333 children (54.1% girls, mean age 6.0 ± 1.5 years) from 34 intervention schools (18 pre-schools and 16 primary schools) in the town of Geraardsbergen, Belgium, provided valid accelerometer data for two weekdays and one weekend day. RESULTS: Mean intervention process score (maximum value = 44) was 20.9 ± 5.8 for schools. The breakdown per module showed which components were implemented and received well and which components could have been improved. After the intervention, the decrease in light PA and increase in ST was much higher in children from primary schools with a low intervention process score, whereas the behaviours remained relatively stable in children from primary schools with a medium or high score. The change in moderate to vigorous PA did not differ significantly between schools with a low, medium or high score. CONCLUSION: The IDEFICS intervention was relatively able to prevent unfavourable changes in ST and light PA in schools with a medium and high intervention process score. Further process evaluation research is needed to obtain a more profound picture of the IDEFICS intervention process.