European children's sugar intake on weekdays versus weekends: the IDEFICS study.

OBJECTIVES: To compare the intake of total sugars, foods and drinks rich in added sugar, and energy in children on weekdays (Monday-Thursday), Fridays and weekends. METHODS: Dietary intake (g, kJ, energy %) was assessed using a computerized 24-h recall method in a sample of 2- to 9-year-old children from Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden who were participating in the IDEFICS baseline study (2007-2008). Analyses were performed in 9497 children by selecting one 24-h recall per child (for comparison of weekdays vs weekends, and Fridays vs weekdays and weekends). Selected stratified analyses were performed by country and age group. RESULTS: Intake of total sugars exceeded 20 energy % in all countries but one. In the non-stratified analyses, the intakes of total sugars and foods and drinks rich in added sugar were found to be higher on weekends compared with weekdays (both P<0.001), and intakes on Fridays were a mix between intakes on weekdays and weekends. Energy intake did not differ between weekdays and weekends. RESULTS were somewhat heterogeneous, both across countries and age groups. CONCLUSIONS: High intake of sugar remains an important nutritional problem in children of many European countries. Interventions aiming to prevent this diet pattern may optimize their impact by targeting dietary habits on Fridays and weekends. Furthermore, when conducting dietary assessment in children, data from weekends and Fridays in combination with a selection of Mondays to Thursdays are needed to capture habitual sugar intake. Age and dietary cultures should also be considered in dietary intervention and assessment as effect modifications were seen for both age and country.

Polymorphisms of matrix metalloproteinase gene and adiposity indices in European children: results of the IDEFICS study.

OBJECTIVE: We investigated the relationship between matrix metalloproteinase 3 (MMP3) polymorphisms and adiposity indices in European children of the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) project. SUBJECTS: A total of 16 224 Caucasian children (2-9 years) were recruited into a population-based survey from eight European countries. In all, 4540 children were randomly selected for genetic studies (T0); 3238 children were re-examined 2 years later (T1). Anthropometric measures were collected by standardized protocols at T0 and T1. RESULTS: Six variants of MMP3 gene were genotyped. Homozygotes for the variant A allele of rs646910 and for the H3 haplotype had higher hip circumference (P=0.002 and 0.001; age, sex and country adjusted) at T0. The association remained significant after false discovery rate (FDR) correction. At T1, subjects carrying rs646910 A/A genotype or H3/H3 diplotype showed significantly higher values of body mass index, waist and hip circumference and sum of tricipital and subscapular skinfolds, all associations remaining significant after FDR correction (P=0.020-0.048). CONCLUSIONS: We showed for the first time an association between the MMP3 rs646910 variant and indices of adiposity in European children, highlighting the involvement of metalloproteinase genes in adipose tissue remodeling and growth.

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.