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.

Percentiles of fasting serum insulin, glucose, HbA1c and HOMA-IR in pre-pubertal normal weight European children from the IDEFICS cohort.

OBJECTIVES: The aim of this study is to present age- and sex-specific reference values of insulin, glucose, glycosylated haemoglobin (HbA1c) and the homeostasis model assessment to quantify insulin resistance (HOMA-IR) for pre-pubertal children. METHODS: The reference population consists of 7074 normal weight 3- to 10.9-year-old pre-pubertal children from eight European countries who participated in at least one wave of the IDEFICS ('identification and prevention of dietary- and lifestyle-induced health effects in children and infants') surveys (2007-2010) and for whom standardised laboratory measurements were obtained. Percentile curves of insulin (measured by an electrochemiluminescence immunoassay), glucose, HbA1c and HOMA-IR were calculated as a function of age stratified by sex using the general additive model for location scale and shape (GAMLSS) method. RESULTS: Levels of insulin, fasting glucose and HOMA-IR continuously show an increasing trend with age, whereas HbA1c shows an upward trend only beyond the age of 8 years. Insulin and HOMA-IR values are higher in girls of all age groups, whereas glucose values are slightly higher in boys. Median serum levels of insulin range from 17.4 and 13.2 pmol l(-1) in 3-<3.5-year-old girls and boys, respectively, to 53.5 and 43.0 pmol l(-1) in 10.5-<11-year-old girls and boys. Median values of glucose are 4.3 and 4.5 mmol l(-1) in the youngest age group and 49.3 and 50.6 mmol l(-1) in the oldest girls and boys. For HOMA-IR, median values range from 0.5 and 0.4 in 3-<3.5-year-old girls and boys to 1.7 and 1.4 in 10.5-<11-year-old girls and boys, respectively. CONCLUSIONS: Our study provides the first standardised reference values for an international European children's population and provides the, up to now, largest data set of healthy pre-pubertal children to model reference percentiles for markers of insulin resistance. Our cohort shows higher values of Hb1Ac as compared with a single Swedish study while our percentiles for the other glucose metabolic markers are in good accordance with previous studies.

Blood lipids among young children in Europe: results from the European IDEFICS study.

BACKGROUND: Measurement of cholesterol and triglyceride (TG) fractions in blood has become standard practice in the early detection of atherosclerotic disease pathways. Considerable attention is given nowadays to the presence of these risk factors in children and to start preventive campaigns early in life. In this context, it is imperative to have valid comparative frameworks for interpretation of lipid levels. The aim of this study is to present sex- and age-specific reference values on blood lipid levels in European children aged 2.0-10.9 years. METHODS: Fasting blood was obtained via either venipuncture or capillary sampling. In 13,579 European non-obese children (50.3% boys), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), TG and TC/HDL-C ratio levels were measured with a point-of-care analyser (Cholestech). Sex- and age-specific reference values were computed with the GAMLSS method with the statistical software R. RESULTS: Reference curves and 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile values are presented. HDL-C showed a positive trend with age, from 2 years onwards, but was relatively stable above the age of 7. For LDL-C and TC, linear but small age-related trends were seen. The TC/HDL-C values showed a gradual negative trend from the age of 2 up to 6 and were relatively stable afterwards. For TG, no age trend was found (P=0.285). Boys had higher mean HDL-C values than girls (1.414 vs 1.368 mmol l(-1)), and lower TC, LDL-C, TC/HDL-C and TG values (3.981 vs 4.087 mmol l(-1); 2.297 vs 2.435 mmol l(-1); 2.84 vs 3.01mmol l(-1); and 0.509 vs 0.542 mmol l(-1), respectively). CONCLUSIONS: These new and recent references could serve as a European orientation of blood lipid values in children in the context of standard medical practice and for the purpose of public health screening.

No breakfast at home: association with cardiovascular disease risk factors in childhood.

BACKGROUND/OBJECTIVES: Limited data exist regarding breakfast consumption and its association with cardiovascular disease (CVD) risk factors. This study investigates the relationship between breakfast routine and CVD risk factors in a multinational sample. SUBJECTS/METHODS: Cross-sectional data from eight European countries participating in the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) survey (2007-2008) were used. The sample included ;children 2 to <10 years of age (n=8863, 51.2% boys). The Mann-Whitney ;U-test and logistic regression were used to assess CVD risk factors ;among ;no breakfast (NBrH), occasional breakfast and daily breakfast at home (DBrH) consumption. RESULTS: Male school-aged NBrH consumers, ;compared with ;DBrH consumers, ;were more likely to be overweight/obese (odds ratio (OR): 1.37, 95% confidence interval (CI)=1.05-1.79), to have higher risk for high-density lipoprotein (HDL) cholesterol levels lower than 40 mg/dl (OR: 1.69, 95% CI=1.24-2.30), triglycerides (TG) above 75 mg/dl (OR: 1.65, 95% CI=1.24-2.19) and sum of skinfolds greater than the 90th percentile (OR: 1.32, 95% CI=1.0-1.76). Female school-aged NBrH consumers ;compared with ;DBrH consumers ;had a higher risk for waist circumference greater than the 90th percentile (OR: 1.70, 95% CI=1.14-2.51), HDL cholesterol levels lower than 40 mg/dl (OR: 1.65, 95% CI=1.23-2.21), TG above 75 mg/dl (OR: 1.65, 95% CI=1.26-2.17) and total cholesterol/HDL cholesterol ratio >3.5 (OR: 1.39, 95% CI=1.09-1.77). RESULTS remained significant after adjusting for daily physical activity in moderate-to-vigorous physical activity (MVPA) periods (in min/day). Male DBrH consumers, 6 to <10 years of age, had longer daily periods of MVPA compared with ;NBrH consumers ;(32.0±21.4 vs 27.5±18.8, P<0.05). For preschoolers, breakfast consumption was negatively associated with ;CVD risk factors but results of regression models were mostly insignificant. CONCLUSIONS: Daily breakfast consumption contributes to controlling school-aged children's weight ;and lipid profile and promotes higher PA.

Food consumption and cardiovascular risk factors in European children: the IDEFICS study.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Few studies addressing the relationship between food consumption and cardiovascular disease or metabolic risk have been conducted in children. Previous findings have indicated greater metabolic risk in children with high intakes of solid hydrogenated fat and white bread, and low consumption of fruits, vegetables and dairy products. WHAT THIS STUDY ADDS: In a large multinational sample of 2 to 9 years old children, high consumption of sweetened beverages and low intake of nuts and seeds, sweets, breakfast cereals, jam and honey and chocolate and nut-based spreads were directly associated with increased clustered cardiovascular disease risk. These findings add new evidence to the limited literature available in young populations on the role that diet may play on cardiovascular health. OBJECTIVE: To investigate food consumption in relation to clustered cardiovascular disease (CVD) risk. METHODS: Children (n = 5548, 51.6% boys) from eight European countries participated in the IDEFICS study baseline survey (2007-2008). Z-scores of individual CVD risk factors were summed to compute sex- and age-specific (2-<6 years/6-9 years) clustered CVD risk scores A (all components, except cardiorespiratory fitness) and B (all components). The association of clustered CVD risk and tertiles of food group consumption was examined. RESULTS: Odds ratio (OR) of having clustered CVD risk A increased in older children with higher consumption of chocolate and nut-based spreads (boys: OR = 0.46; 95% CI = 0.32-0.69; girls: OR = 0.60; 95% CI = 0.42-0.86), jam and honey (girls: OR = 0.45; 95% CI = 0.26-0.78) and sweets (boys: OR = 0.69; 95% CI = 0.48-0.98). OR of being at risk significantly increased with the highest consumption of soft drinks (younger boys) and manufactured juices (older girls). Concerning CVD risk score B, older boys and girls in the highest tertile of consumption of breakfast cereals were 0.41 (95% CI = 0.21-0.79) and 0.45 (95% CI = 0.22-0.93) times, respectively, less likely to be at risk than those in tertile 1. CONCLUSIONS: High consumption of sugar-sweetened beverages and low intake of breakfast cereals, jam and honey, sweets and chocolate and nut-based spreads seem to adversely affect clustered CVD risk.

Influence of sample collection and preanalytical sample processing on the analyses of biological markers in the European multicentre study IDEFICS.

OBJECTIVE: To evaluate the influence of a standardised sampling protocol and process quality across the different IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) centres on the results of the biochemical measurements. DESIGN: Baseline survey within the community-based intervention study. SUBJECTS: A total of 16,224 children, aged 2-8 years, enrolled in the IDEFICS baseline survey in 8 European countries. Venous or capillary blood samples were collected from 12,430 children, urine samples from 13,890 children and saliva samples from 14,019 children. METHODS: A set of quality indicators was recorded for the biological blood, urine and saliva samples collected during the IDEFICS study. Results of blood and urine measurements were analysed and stratified by selected quality indicators. RESULTS: Concentrations of biological markers in blood and urine measured during the IDEFICS baseline survey are associated with several quality indicators assessed in this study. Between-country variations of these biomarkers are described. It was confirmed that fasting has a big influence on the concentration of certain biomarkers. Biomarkers in morning urine samples may be erroneous if the study subjects void during the night or if samples are not taken from the very first morning urine. CONCLUSIONS: The analysed data underline that a standardised sampling protocol is of major importance, especially in multicentre studies, but non-compliance is ever present in spite of well-defined standard operation procedures. Deviations from the protocol should therefore always be documented to avoid error pertaining to the concentration of biological markers.

DNA yield and quality of saliva samples and suitability for large-scale epidemiological studies in children.

OBJECTIVE: To evaluate two saliva collection methods for DNA yield and quality as applied to a large, integrated, multicentre, European project involving the collection of biological material from children. DESIGN: Cross-sectional multicentre comparative study in young children. METHODS: Saliva samples were collected from 14,019 children aged 2-9 years from eight European countries participating in the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study. This involved either the collection of 2 ml of saliva from children who were able to spit, or using a sponge to collect whole saliva and buccal mucosal cells from the inside of the mouth of younger children unable to spit. Samples were assembled centrally in each participating centre and subsequently despatched for DNA extraction and biobanking to the University of Glasgow. A subgroup of 4678 samples (∼33% of sampled individuals) were chosen for DNA extraction before genotyping. RESULTS: The whole-saliva collection method resulted in a higher DNA yield than the sponge collection method (mean±s.d.; saliva: 20.95±2.35 µg, sponge: 9.13±2.25 µg; P<0.001). DNA quality as measured by A (260)/A (280) was similar for the two collection methods. A minimum genotype calling success rate of 95% showed that both methods provide good-quality DNA for genotyping using TaqMan allelic discrimination assays. CONCLUSIONS: Our results showed higher DNA yield from the whole-saliva collection method compared with the assisted sponge collection. However, both collection methods provided DNA of sufficient quantity and quality for large-scale genetic epidemiological studies.

Design and results of the pretest of the IDEFICS study.

BACKGROUND: During the preparatory phase of the baseline survey of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study, standardised survey procedures including instruments, examinations, methods, biological sampling and software tools were developed and pretested for their feasibility, robustness and acceptability. METHODS: A pretest was conducted of full survey procedures in 119 children aged 2-9 years in nine European survey centres (N(per centre)=4-27, mean 13.22). Novel techniques such as ultrasound measurements to assess subcutaneous fat and bone health, heart rate monitors combined with accelerometers and sensory taste perception tests were used. RESULTS: Biological sampling, physical examinations, sensory taste perception tests, parental questionnaire and medical interview required only minor amendments, whereas physical fitness tests required major adaptations. Callipers for skinfold measurements were favoured over ultrasonography, as the latter showed only a low-to-modest agreement with calliper measurements (correlation coefficients of r=-0.22 and r=0.67 for all children). The combination of accelerometers with heart rate monitors was feasible in school children only. Implementation of the computer-based 24-h dietary recall required a complex and intensive developmental stage. It was combined with the assessment of school meals, which was changed after the pretest from portion weighing to the more feasible observation of the consumed portion size per child. The inclusion of heel ultrasonometry as an indicator of bone stiffness was the most important amendment after the pretest. DISCUSSION: Feasibility and acceptability of all procedures had to be balanced against their scientific value. Extensive pretesting, training and subsequent refinement of the methods were necessary to assess the feasibility of all instruments and procedures in routine fieldwork and to exchange or modify procedures that would otherwise give invalid or misleading results.

Quality management for the collection of biological samples in multicentre studies.

Large scale international multicentre studies require sophisticated quality management for the collection, processing and logistics of biological samples to ensure a maximum degree of standardisation across different environmental conditions and settings. This paper describes a quality management system for the collection of biological samples (QMS-BS) which was applied during IDEFICS, a large European multicentre study. The application was evaluated by several criteria like response rates for the different types of biological samples, measures of sample quality, compliance with the QMS-BS and efficiency of the document and sample control and of the quality assurance system. Response rates varied from 56.6% for venous blood collection to 90.1% for saliva collection. All sample types were associated with problems of sample quality (e.g. haemolysis of blood samples, lack of cooling for urine samples or desiccation of saliva samples). Overall compliance with the QMS-BS was good, with some exceptions mainly related to sample control. In conclusion the QMS-BS is a valuable tool for the management of biological sample collection in epidemiological multicentre studies.

Identification and phylogeny of eukaryotic 18S rDNA phylotypes detected in chlorinated finished drinking water samples from three Parisian surface water treatment plants.

AIMS: We performed a preliminary assessment of the eukaryotic 18S rDNA diversity present in finished drinking water samples from three different surface water treatment plants supplying water to the city of Paris (France). METHODS AND RESULTS: A molecular analysis was performed on a sample from each site based on sequencing of PCR amplified and cloned 18S ribosomal RNA genes. Overall, the 18S rDNA sequences combined from all samples could be affiliated to the Amoebozoa (20.8% of the phylotypes), Ciliophora (25%), Metazoa (33.3%), Fungi (8.3%), Cercozoa (4.2%) and unclassified eukaryotes (8.3%) groups. CONCLUSIONS: The 18S rDNA sequences affiliated to the Amoebozoa, Ciliophora and Metazoa lineages were found to be the most abundant phylotypes observed in the drinking water samples. Phylotypes found to be present in two, or all three, samples (41.7% of the total) may represent groups with members adapted to drinking water treatment plant (DWTP) ecosystem conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that finished drinking water can contain 18S rDNA sequences representing a variety of eukaryotic taxa. Further research is needed to better characterize the eukaryotic biodiversity of DWTPs and the effects of the finished drinking water diversity on the downstream water distribution network.

Isolation of novel pelagic bacteria from the German bight and their seasonal contributions to surface picoplankton.

We tested new strategies for the isolation of abundant bacteria from coastal North Sea surface waters, which included reducing by several orders of magnitude the concentrations of inorganic N and P compounds in a synthetic seawater medium. Agar plates were resampled over 37 days, and slowly growing colonies were allowed to develop by repeatedly removing all newly formed colonies. A fivefold increase of colonies was observed on plates with reduced nutrient levels, and the phylogenetic composition of the culture collection changed over time, towards members of the Roseobacter lineage and other alpha-proteobacteria. Novel gamma-proteobacteria from a previously uncultured but cosmopolitan lineage (NOR5) formed colonies only after 12 days of plate incubation. A time series of German Bight surface waters (January to December 1998) was screened by fluorescence in situ hybridization (FISH) with isolate-specific and general probes. During spring and early summer, a prominent fraction of FISH-detectable bacteria (mean, 51%) were affiliated with the Cytophaga-Flavobacterium group (CF) of the Bacteroidetes. One Cytophaga sp. lineage with cultured representatives formed almost 20% of the CF group. Members of the Roseobacter cluster constituted approximately 50% of alpha-proteobacteria, but none of the Roseobacter-related isolates formed populations of >1% in the environment. Thus, the readily culturable members of this clade are probably not representative of Roseobacter species that are common in the water column. In contrast, members of NOR5 were found at high abundances (>10(5) cells ml(-1)) in the summer plankton. Some abundant pelagic bacteria are apparently able to form colonies on solid media, but appropriate isolation techniques for different species need to be developed.