ABSTRACT
BACKGROUND AND AIMS: Neuromedin U (NMU) is a hypothalamic neuropeptide with important roles in several metabolic processes, recently suggested as potential therapeutic target for obesity. We analysed the associations between NMU gene variants and haplotypes and body mass index (BMI) in a large sample of European children. METHODS AND RESULTS: From a large European multi-center study on childhood obesity, 4,528 children (2.0-9.9 years, mean age 6.0±1.8 SD; boys 52.2%) were randomly selected, stratifying by age, sex and country, and genotyped for tag single nucleotide polymorphisms (SNPs; rs6827359, T:C; rs12500837, T:C; rs9999653,C:T) of NMU gene, then haplotypes were inferred. Regression models were applied to estimate the associations between SNPs or haplotypes and BMI as well as other anthropometric measures. BMI was associated with all NMU SNPs (p<0.05). Among five haplotypes inferred, the haplotype carrying the minor alleles (CCT, frequency = 22.3%) was the only associated with lower BMI values (beta = -0.16, 95%CI:-0.28,-0.04, p = 0.006; z-score, beta = -0.08, 95%CI:-0.14,-0.01, p = 0.019) and decreased risk of overweight/obesity (OR = 0.81, 95%CI:0.68,0.97, p = 0.020) when compared to the most prevalent haplotype (codominant model). Similar significant associations were also observed using the same variables collected after two years' time (BMI, beta = -0.25, 95%CI:-0.41,-0.08, p = 0.004; z-score, beta = -0.10, 95%CI:-0.18,-0.03, p = 0.009; overweight/obesity OR = 0.81, 95%CI:0.66,0.99, p = 0.036). The association was age-dependent in girls (interaction between CCT haplotypes and age, p = 0.008), more evident between 7 and 9 years of age. The CCT haplotype was consistently associated with lower levels of fat mass, skinfold thickness, hip and arm circumferences both at T0 and at T1, after adjustment for multiple testing (FDR-adjusted p<0.05). CONCLUSIONS: This study shows an association between a NMU haplotype and anthropometric indices, mainly linked to fat mass, which appears to be age- and sex-specific in children. Genetic variations within or in linkage with this haplotype should be investigated to identify functional variants responsible for the observed phenotypic variation.
Subject(s)
Genetic Predisposition to Disease , Haplotypes , Neuropeptides/genetics , Obesity/genetics , Polymorphism, Single Nucleotide , Adipose Tissue , Age Factors , Alleles , Anthropometry , Body Mass Index , Child , Child, Preschool , Cohort Studies , Europe , Female , Gene Expression , Gene Frequency , Genetic Linkage , Humans , Male , Models, Genetic , Obesity/diagnosis , Obesity/physiopathology , Sex Factors , Skinfold Thickness , Waist CircumferenceABSTRACT
OBJECTIVE: To describe sedentary behaviors in adolescents and to examine the influence of media availability on TV viewing. METHOD: The study assessed 3278 adolescents (1537 males and 1741 females, 12.5-17.5 years) involved in the HELENA study (2007). Adolescents reported hours of TV viewing, computer games, console, internet for study and non-study reasons, and study, as well as availability of TVs, computers and consoles. RESULTS: Time spent in sedentary behaviors was higher during weekends (all p<0.001). Males spent more hours on TV viewing (for > or = 15 years at weekends), playing computer games and console games while females spent more time studying and surfing for non-study reasons. During weekdays, one third of adolescents exceeded the screen time guidelines (>2h/day) based solely on TV viewing, whereas around 60% exceeded it at weekends. Having a TV or a console in the bedroom was associated with higher TV viewing (OR=2.66; 95% CI 2.23-3.18; and OR=1.92; 95% CI 1.61-2.28, respectively) whereas the presence of computer reduced it (OR=0.57; 95% CI 0.48-0.68). CONCLUSION: Adolescents living in Europe are not meeting media recommendations, especially during weekend. The absence of a TV in the adolescents' bedroom might reduce TV viewing. Further studies are needed to confirm or contrast our findings.
