118 research outputs found

    Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

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    Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r2>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (pinteraction= 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Concl

    First measurement of Ωc0 production in pp collisions at s=13 TeV

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    The inclusive production of the charm–strange baryon 0 c is measured for the first time via its hadronic √ decay into −π+ at midrapidity (|y| <0.5) in proton–proton (pp) collisions at the centre-of-mass energy s =13 TeV with the ALICE detector at the LHC. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 2 < pT < 12 GeV/c. The pT dependence of the 0 c-baryon production relative to the prompt D0-meson and to the prompt 0 c-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured pT interval, the ratio of the pT-integrated cross sections of 0 c and prompt + c baryons multiplied by the −π+ branching ratio is found to be larger by a factor of about 20 with a significance of about 4σ when compared to e+e− collisions

    Elliptic flow of charged particles at midrapidity relative to the spectator plane in Pb–Pb and Xe–Xe collisions

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    Measurements of the elliptic flow coefficient relative to the collision plane defined by the spectator neutrons v2{ SP} in collisions of Pb ions at center-of-mass energy per nucleon–nucleon pair √ 2.76 TeV and Xe ions at √ sNN = sNN =5.44 TeV are reported. The results are presented for charged particles produced at midrapidity as a function of centrality and transverse momentum for the 5–70% and 0.2–6 GeV/c ranges, respectively. The ratio between v2{ SP} and the elliptic flow coefficient relative to the participant plane v2{4}, estimated using four-particle correlations, deviates by up to 20% from unity depending on centrality. This observation differs strongly from the magnitude of the corresponding eccentricity ratios predicted by the TRENTo and the elliptic power models of initial state fluctuations that are tuned to describe the participant plane anisotropies. The differences can be interpreted as a decorrelation of the neutron spectator plane and the reaction plane because of fragmentation of the remnants from the colliding nuclei, which points to an incompleteness of current models describing the initial state fluctuations. A significant transverse momentum dependence of the ratio v2{ SP}/v2{4} is observed in all but the most central collisions, which may help to understand whether momentum anisotropies at low and intermediate transverse momentum have a common origin in initial state f luctuations. The ratios of v2{ SP} and v2{4} to the corresponding initial state eccentricities for Xe–Xe and Pb–Pb collisions at similar initial entropy density show a difference of (7.0 ±0.9)%with an additional variation of +1.8% when including RHIC data in the TRENTo parameter extraction. These observations provide new experimental constraints for viscous effects in the hydrodynamic modeling of the expanding quark–gluon plasma produced in heavy-ion collisions at the LHC

    Tracking of obesity and body fatness through mid-childhood

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    To explore how fat, lean and body mass index (BMI) track in childhood and how this relates to parental obesity. Design and Setting Prospective population-based cohort study: Avon Longitudinal Study of Parents and Children, UK. Height, weight and leg-to-leg bioelectrical impedance (BIA) were collected at ages 7 and 11 years, as well as pre-pregnancy parental heights and weights. For BMI International Obesity Task Force thresholds of obesity and overweight were used. Impedance data were expressed as separate lean and fat z scores, internally standardised for gender, height and age and a child was defined as over-fat if fat z score was >85th and very over-fat if >95th internal centile. Data were available for 7723 and 7252 children at ages 7 and 11 years, respectively (6066 at both time points). Of those obese at age 7, 75% were still obese at age 11, while of those who had been overweight 16% had become obese and 20% now had normal BMI. Both fat and lean z scores showed moderate levels of tracking (correlation coefficients 0.70 and 0.73, respectively). Children with one or two obese parents had higher fat z scores at age 7 and showed greater increases in fat thereafter. They were more likely to be very over-fat at age 7 and, of these, 69% remained so at age 11 compared to only 45% with non-obese parents (p <0.001). Children of obese parents already have high fat levels at age 7 and are more likely to remain very over-fat

    Family, socio-economic and prenatal factors associated with failure to thrive in the Avon Longitudinal Study of Parents and Children (ALSPAC)

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    Background The epidemiological profile of infants failing to thrive is unclear. The aim of this study is to investigate the prenatal and socioeconomic factors associated with these infants using standardized weight gain conditional on previous weight. Methods In a large UK population cohort study, 11 718 infants born at term in 1991?1992 with no major congenital abnormalities were identified. Using a weight gain criterion conditional on initial weight from birth to 6?8 weeks, 6?8 weeks to 9 months, and birth to 9 months, the slowest gaining 5% were identified. Results None of the prenatal factors was associated with failure to thrive in the multivariable analysis nor were traditional markers of socioeconomic deprivation such as poor parental education or low occupational status. Parental height was significantly correlated with slow infant weight gain in both separate periods and from birth to 9 months (Pearson's r &equals; &plus;0.20, P < 0.001). Eight times as many infants born to shorter parents (8.7%, 95% CI: 6.6, 11.3) showed slow weight gain as infants born to taller parents (1.1%, 95% CI: 0.5, 2.5). Higher parity was also related to slow infant weight gain; infants born in the fourth or subsequent pregnancy were twice as likely to fail to thrive from birth to 9 months (8.3%, 95% CI: 6.4, 10.6) as first-born infants (3.4%, 95% CI: 2.9, 10.6). Conclusions Future studies need to take account of parental height when calculating growth standards and look at why failure to thrive is more common, not in poorer families but in larger families

    Comparison of waist circumference percentiles versus body mass index percentiles for diagnosis of excessive fatness in a large cohort of children

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    Context. Waist circumference may offer improved diagnosis of obesity in youth compared with body mass index (BMI), but empirical evidence is limited. Objective. To compare the ability of BMI percentile using UK reference data and waist circumference percentile using UK reference data to diagnose high fat mass in English children. Design and Methods. In 7 722 9–10-year-olds (3 809 boys, 3 913 girls) sensitivity and specificity were calculated and receiver operator characteristic (ROC) analyses undertaken to determine the diagnostic accuracy of BMI and waist circumference z-scores to define high fat mass measured by dual energy x-ray absorptiometry (DXA). High fat mass was defined as being in the top decile of fatness for each sex (359 boys and 367 girls). Results. The area under the ROC curve was slightly higher for BMI percentile (0.92 in boys, 95% CI: 0.91 –0.93; 0.94 in girls, 95% CI: 0.93–0.95) than waist circumference percentile (0.89 in boys, 95% CI: 0.86–0.91; 0.81 in girls, 95% CI: 0.73–0.90). Specificity of BMI percentile was slightly but significantly higher than that of waist circumference percentile for both sexes (p<0.05 in each case). Conclusions. The present study suggests that waist circumference percentile has no advantage over BMI percentile for the diagnosis of high fat mass in children
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