George Moschonis

Vitamin D deficiency in Europe: pandemic?

Background: Vitamin D deficiency has been described as being pandemic, but serum 25-hydroxyvitamin D [25(OH)D] distribution data for the European Union are of very variable quality. The NIH-led international Vitamin D Standardization Program (VDSP) has developed protocols for standardizing existing 25(OH)D values from national health/nutrition surveys. Objective: This study applied VDSP protocols to serum 25(OH)D data from representative childhood/teenage and adult/older adult European populations, representing a sizable geographical footprint, to better quantify the prevalence of vitamin D deficiency in Europe. Design: The VDSP protocols were applied in 14 population studies [reanalysis of subsets of serum 25(OH)D in 11 studies and complete analysis of all samples from 3 studies that had not previously measured it] by using certified liquid chromatography–tandem mass spectrometry on biobanked sera. These data were combined with standardized serum 25(OH)D data from 4 previously standardized studies (for a total n = 55,844). Prevalence estimates of vitamin D deficiency [using various serum 25(OH)D thresholds] were generated on the basis of standardized 25(OH)D data. Results: An overall pooled estimate, irrespective of age group, ethnic mix, and latitude of study populations, showed that 13.0% of the 55,844 European individuals had serum 25(OH)D concentrations <30 nmol/L on average in the year, with 17.7% and 8.3% in those sampled during the extended winter (October–March) and summer (April–November) periods, respectively. According to an alternate suggested definition of vitamin D deficiency (<50 nmol/L), the prevalence was 40.4%. Dark-skinned ethnic subgroups had much higher (3- to 71-fold) prevalence of serum 25(OH)D <30 nmol/L than did white populations. Conclusions: Vitamin D deficiency is evident throughout the European population at prevalence rates that are concerning and that require action from a public health perspective. What direction these strategies take will depend on European policy but should aim to ensure vitamin D intakes that are protective against vitamin D deficiency in the majority of the European population.

Overweight and obesity in infants and pre-school children in the European Union: a review of existing data

The objective of this study was to synthesize available information on prevalence and time trends of overweight and obesity in pre‐school children in the European Union. Retrieval and analysis or re‐analysis of existing data were carried out. Data sources include WHO databases, Medline and Google, contact with authors of published and unpublished documents. Data were analysed using the International Obesity Task Force reference and cut‐offs, and the WHO standard. Data were available from 18/27 countries. Comparisons were problematic because of different definitions and methods of data collection and analysis. The reported prevalence of overweight plus obesity at 4 years ranges from 11.8% in Romania (2004) to 32.3% in Spain (1998–2000). Countries in the Mediterranean region and the British islands report higher rates than those in middle, northern and eastern Europe. Rates are generally higher in girls than in boys. With the possible exception of England, there was no obvious trend towards increasing prevalence in the past 20–30 years in the five countries with data. The use of the WHO standard with cut‐offs at 1, 2 and 3 standard deviations yields lower rates and removes gender differences. Data on overweight and obesity in pre‐school children are scarce; their interpretation is difficult. Standard methods of surveillance, and research and policies on prevention and treatment, are urgently needed.

Single nucleotide polymorphisms in the FADS gene cluster are associated with delta-5 and delta-6 desaturase activities estimated by serum fatty acid ratios

Genetic variability in the FADS1-FADS2 gene cluster [encoding delta-5 (D5D) and delta-6 (D6D) desaturases] has been associated with plasma long-chain PUFA (LCPUFA) and lipid levels in adults. To better understand these relationships, we further characterized the association between FADS1-FADS2 genetic variability and D5D and D6D activities in adolescents. Thirteen single nucleotide polymorphisms (SNPs) were genotyped in 1,144 European adolescents (mean ± SD age: 14.7 ± 1.4 y). Serum phospholipid fatty acid levels were analyzed using gas chromatography. D5D and D6D activities were estimated from the C20:4n-6/C20:3n-6 and C20:3n-6/C18:2n-6 ratios, respectively. Minor alleles of nine SNPs were associated with higher 18:2n-6 levels (1.9E-18 ≤ P ≤ 6.1E-5), lower C20:4n-6 levels (7.1E-69 ≤ P ≤ 1.2E-12), and lower D5D activity (7.2E-44 ≤ P ≤ 4.4E-5). All haplotypes carrying the rs174546 minor allele were associated with lower D5D activity, suggesting that this SNP is in linkage disequilibrium with a functional SNP within FADS1. In contrast, only the rs968567 minor allele was associated with higher D6D activity (P = 1.5E-6). This finding agrees with an earlier in vitro study showing that the minor allele of rs968567 is associated with a higher FADS2 promoter activity. These results suggest that rare alleles of several SNPs in the FADS gene cluster are associated with higher D6D activity and lower D5D activity in European adolescents.

Genome wide analysis reveals association of a FTO gene variant with epigenetic changes

Variants of the FTO gene show strong association with obesity, but the mechanisms behind this association remain unclear. We determined the genome wide DNA methylation profile in blood from 47 female preadolescents. We identified sites associated with the genes KARS, TERF2IP, DEXI, MSI1, STON1 and BCAS3 that had a significant differential methylation level in the carriers of the FTO risk allele (rs9939609). In addition, we identified 20 differentially methylated sites associated with obesity. Our findings suggest that the effect of the FTO obesity risk allele may be mediated through epigenetic changes. Further, these sites might prove to be valuable biomarkers for the understanding of obesity and its comorbidites.

Changes in BMI and blood pressure after a school based intervention: The CHILDREN study

BACKGROUND Identification of the behavioural, normative and control beliefs influencing childrens behaviour is an important prerequisite in designing effective interventions. The current study aims to evaluate the effectiveness of an intervention program, based on the Theory of Planned Behaviour (TPB), on obesity indices and blood pressure (BP) in Ioannina, Greece. METHODS Participants were 646 fifth grade pupils (360 girls and 286 boys). The intervention group (IG) consisted of 321 children in 13 randomly selected schools while the rest (n = 325 children) served as the control group (CG). Based on the outcome of the TPB questionnaire, the intervention focused on overcoming the barriers in accessing physical activity areas, increasing the availability of fruits and vegetables and increasing parental support. General linear mixed model and mediating variable analysis were used to evaluate the differences between the two groups and to test whether changes in certain dietary, physical activity and anthropometrical indices mediated the effect of the intervention on BP. RESULTS IG had higher consumption of fruits and lower consumption of fats/oils and sweets/beverages compared with the CG. Interventions effect on BMI could be explained by the changes in fruit and fats/oils intake whereas the reduction of systolic and diastolic BP could be explained by the reduction of BMI. CONCLUSIONS The findings indicate favourable changes in BP and obesity indices after the implementation of a 1-year school-based intervention program based on the TPB. These results highlight the importance of developing a social and physical environment that promotes balanced eating behaviours and extra-curricular access to physical activity venues.

Perinatal predictors of overweight at infancy and preschool childhood: the GENESIS study

Objective:To identify those perinatal parameters and characteristics predisposing children to an increased risk of overweight during infancy and preschool years.Design:The analyses were performed using data from the Growth, Exercise and Nutrition Epidemiological Study In preSchoolers.Subjects:A representative sample of 2374 Greek preschoolers 1–5 years old.Measurements:Anthropometric data, such as body weight, recumbent length and standing height, were obtained by using standard procedures and measuring equipment. Structured interviews were conducted with both parents to collect information on anthropometric, demographic, medical and behavioral data. Finally, childrens anthropometric data at birth, 6 and 12 months of age were recorded from their birth certificates and medical records.Results:Children born large for gestational age were 4.59 and 2.19 times more likely for being overweight at 6 and 12 months of age, respectively, than children born appropriate for gestational age. On the other hand, children that were exclusively breastfed were 0.49 and 0.54 times less likely for being overweight at 6 and 12 months of age, respectively, than children that were exclusively formula fed. Furthermore, 3- to 5-year-old children born to mothers who were both active and passive smokers during pregnancy were 1.79 times more likely of being overweight compared to children born to nonsmoking mothers. Finally, having an overweight father significantly increased the likelihood of childhood overweight at 12 months, 1–3 and 3–5 years of age.Conclusion:Our findings showed that some of the perinatal parameters and characteristics examined in the current study predict overweight at infancy, while others at preschool years. Priority should be given to size at birth, breastfeeding, maternal smoking during pregnancy and parental overweight, when developing public health strategies to reduce the prevalence of childhood overweight and related chronic disease later in life.

Relations between obesity and hypertension: preliminary data from a cross-sectional study in primary schoolchildren: the children study.

Objective:To record the prevalence of overweight, obesity and hypertension in primary schoolchildren living in one of the poorest regions in Europe and furthermore to identify certain behavioural, lifestyle and physiological parameters associated with body mass index (BMI) and blood pressure (BP).Design:Cross-sectional study.Setting:Nineteen primary schools within the county of Ioannina, Greece.Subjects and methods:Demographic, dietary and physical activity data as well as anthropometrical, BP and cardiorespiratory fitness measurements were obtained from a representative sample of 312 school children (153 boys and 159 girls) attending 5th grade. Inclusion of subjects in the study was voluntary. One-way analysis of variance and multiple linear regression analysis were mainly applied for the evaluation of the tested hypotheses.Results:The prevalence of overweight and obesity was 29.4 and 11.8% for boys and 39.0 and 7.5% for girls. The prevalence of systolic and diastolic hypertension was 28.1 and 7.8% for boys and 26.4 and 17.0% for girls. Furthermore, BMI and BP (systolic and diastolic) were positively related to frequency of fast food meals (rho: +0.28, P=0.033, rho: +1.09, P=0.03 and rho: +0.86, P=0.014, respectively) but negatively to leisure time physical activity (rho: −5.55, P=0.005, rho: −3.32 × 10−2, P<0.001 and rho: −2.08 × 10−2, P<0.001, respectively).Conclusions:The current study revealed an increased prevalence of overweight, obesity and hypertension among schoolchildren in Ioannina, indicating the need for early preventive measures in one of the less privileged regions of Europe.

Obesity in adolescence is associated with perinatal risk factors, parental BMI and sociodemographic characteristics

Background/objective:To record the prevalence of overweight and obesity in primary-school children in relation to perinatal risk factors, parental body mass index and sociodemographics.Subjects/methods:A sample of 2294 schoolchildren aged 9–13 years was examined in municipalities from four Greek counties. Weight and height were measured using standard procedures, whereas international thresholds were used for the definition of overweight and obesity. Perinatal and parental data were also recorded via standardized questionnaires.Results:The prevalence of overweight and obesity was 30.5% and 11.6%, respectively, with a higher prevalence of obesity in boys compared with girls (13.7% vs 9.5%, P<0.02). Maternal smoking at pregnancy (odds ratio (OR) 1.37; 95% confidence interval (CI) 1.05–1.98), rapid infant weight gain (OR 1.69; 95% CI 1.20–2.38), paternal and maternal obesity (OR 2.25; 95% CI 1.45–3.48 and OR 2.14; 95% CI 1.28–3.60) were found to significantly increase the odds of children’s obesity (apart from overweight), whereas Greek nationality (OR 1.06; 95% CI 1.01–1.39) was found to significantly increase only the odds of children’s overweight. Maternal pre-pregnancy obesity (OR 2.15; 95% CI 1.27–3.70) and introduction of solid foods at weaning later than 5 months of life (OR 1.60; 95% CI 1.02–2.51) were also found to increase the likelihood of childhood obesity. On the contrary, children having older fathers (OR 0.55; 95% CI 0.37–0.80) or more educated mothers (OR 0.57; 95% CI 0.36–0.90) were less likely to be obese.Conclusions:The current study identified certain perinatal factors (that is, maternal pre-pregnancy obesity, maternal smoking at pregnancy, rapid infant weight gain and late introduction of solid foods at weaning) and parental characteristics (that is, younger fathers, Greek nationality, less educated and overweight parents) as important risk factors for children’s overweight and obesity, indicating the multifactorial nature of their etiology and the need to extend our understanding beyond positive energy equilibrium.

Determinants of childhood obesity and association with maternal perceptions of their children's weight status: the "GENESIS" study.

Prevention of early childhood obesity requires a clear understanding of its determinants. This study examined perinatal, parental, and lifestyle determinants of childhood obesity and how these factors are associated with maternal misperceptions of their childrens weight status. The current work presents a cross-sectional analysis of 2,374 children, age 1 to 5 years, living in Greece (April 2003 to July 2004). The 2000 Centers for Disease Control and Prevention growth charts were used to classify children as overweight (≥85th and <95th body mass index [BMI]-for-age percentile for children older than 24 months) and obese (≥95th weight-for-length percentile for children younger than 24 months and ≥95th BMI-for-age percentile for children older than 24 months). Maternal perceptions about their childrens weight status were assessed via interviews with the mothers. Early infancy growth data were obtained from pediatric medical records. The present study showed that the prevalence of overweight and obesity was 16.2% and 17.5%, respectively. Each unit increase of maternal and paternal BMI significantly increased the likelihood of childhood obesity by a factor of 1.03 (95% confidence interval [CI]: 1.01 to 1.07) and 1.15 (95% CI: 1.10 to 1.20), respectively. Furthermore, children with a rapid weight gain in infancy were 1.9 (95% CI: 1.3 to 2.7) times more likely to be overweight and 1.5 (95% CI: 1.2 to 1.9) times more likely to have their weight status underestimated by their mother. In conclusion, rapid infancy weight gain and higher parental BMI were the main determinants of obesity in preschool years. Maternal underestimation of childrens weight status was more likely for children with rapid weight gain in infancy.

FTO genotype and adiposity in children: physical activity levels influence the effect of the risk genotype in adolescent males

Studies of the fat mass and obesity-associated (FTO) gene provide compelling evidence of genetic variation in the general population that influences fat levels and obesity risk. Studies of the interaction between genetic and environmental factors such as physical activity (PA) will promote the understanding of how lifestyle can modulate genetic contributions to obesity. In this study, we investigated the effect of FTO genotype, and interactions with PA or energy intake, in young children and adolescents. In all, 1–5-year-old children from the Growth, Exercise and Nutrition Epidemiological Study in preSchoolers (GENESIS) study (N=1980) and 11–18-year-old Greek adolescents (N=949) were measured for adiposity-related phenotypes and genotyped at the FTO single-nucleotide polymorphism (SNP) marker, rs17817449. Adolescents were classified as physically active or inactive based on self-reported levels of PA. In adolescents, FTO genotype influenced weight (P=0.001) and BMI (P=0.007). There was also a significant SNP*PA*gender interaction (P=0.028) on BMI, which reflected the association between FTO genotype and BMI in males (P=0.016), but not females (P=0.15), and significant SNP*PA interaction in males (P=0.007), but not females (P=0.74). The FTO genotype effect was more pronounced in inactive than active males. Inactive males homozygous for the G allele had a mean BMI 3 kg/m2 higher than T carriers (P=0.008). In the GENESIS study, no significant association between FTO genotype and adiposity was found. The present findings highlight PA as an important factor modifying the effect of FTO genotype.