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Background: Telomere length (TL) serves as a marker of cellular senescence and appears to plateau between the age of 4 y and young adulthood, after which the gut microbiota are supposed to be established. However, scarce data are available regarding the correlation between gut microbiota composition and TL in the pediatric population.Objectives: We aimed to investigate whether the gut microbiota and the concentrations of SCFAs in feces are associated with leukocyte TL in children.Methods: In total, 401 children aged 6-9 y from Guangzhou were enrolled in this cross-sectional study. qPCR was used to determine relative TL in peripheral blood leukocytes. The gut microbiota was characterized by 16S ribosomal RNA amplicon sequencing and the fecal concentrations of total SCFAs and SCFA subtypes were determined using HPLC. The multivariate methods with an unbiased variable selection (MUVR) algorithm and partial least square models were used to select predictable operational taxonomic units (OTUs). Further correlation analyses were performed based on multiple linear regression models with adjustment for covariates and false discovery rate.Results: With the use of MUVR, 35 relevant and minimal optimal OTUs were finally selected. Multiple linear regression analysis showed that the abundance of several OTUs, including OTU334 (belonging to the genus Family XIII AD3011 group), OTU726 (belonging to the species Lachnoclostridium phocaeense), OTU1441 (belonging to the genus Ruminococcus torques group), OTU2553 (belonging to the genus Lachnospiraceae UCG-010), and OTU3375 (belonging to the family Lachnospiraceae), was negatively associated with leukocyte TL (β: -0.187 to -0.142; false discovery rate (FDR)-corrected P value (PFDR) = 0.009-0.035]. However, neither SCFA subtype nor total SCFA content in feces exhibited significant associations with TL (β: -0.032 to 0.048; PFDR = 0.915-0.969).Conclusions: The gut microbiota, but not fecal SCFA concentration, was significantly associated with TL in this pediatric population. [ABSTRACT FROM AUTHOR]

Background: Vitamin D status at birth is reliant on maternal-fetal transfer of vitamin D during gestation.Objectives: We aimed to examine the vitamin D status of newborn infants in a diverse population and to subsequently identify the modifiable correlates of vitamin D status.Methods: In this cross-sectional study, healthy mother-infant dyads (n = 1035) were recruited within 36 h after term delivery (March 2016-March 2019). Demographic and lifestyle factors were surveyed. Newborn serum 25-hydroxyvitamin D [25(OH)D] was measured (standardized chemiluminescence immunoassay) and categorized as deficient [serum 25(OH)D <30 nmol/L] or adequate (≥40 nmol/L). Serum 25(OH)D was compared among categories of maternal characteristics using ANOVA; each characteristic was tested in a separate model. Subgroups (use of multivitamins preconception and continued in pregnancy compared with during pregnancy only) were matched (n = 352/group) for maternal factors (ancestry, age, income, education, parity, and prepregnancy BMI) using propensity scores; logistic regression models were generated for odds of deficiency or adequacy.Results: Infants' mean serum 25(OH)D was 45.9 nmol/L (95% CI: 44.7, 47.0 nmol/L) (n = 1035), with 20.8% (95% CI: 18.3%, 23.2%) deficient and 60.7% (95% CI: 55.2%, 66.2%) adequate. Deficiency prevalence ranged from 14.6% of white infants to 41.7% of black infants. Serum 25(OH)D was higher (P < 0.0001) in infants of mothers with higher income, BMI < 25 kg/m2, exercise and sun exposure in pregnancy, and use of multivitamins preconception. In the matched-subgroup analysis, multivitamin supplementation preconception plus during pregnancy relative to only during pregnancy was associated with lower odds for vitamin D deficiency (ORadj: 0.55; 95% CI: 0.36, 0.86) and higher odds for adequate vitamin D status (ORadj: 1.47; 95% CI: 1.04, 2.07).Conclusions: In this study most newborn infants had adequate vitamin D status, yet one-fifth were vitamin D deficient with disparities between population groups. Guidelines for a healthy pregnancy recommend maternal use of multivitamins preconception and continuing in pregnancy. An emphasis on preconception use may help to achieve adequate neonatal vitamin D status.This trial was registered at clinicaltrials.gov as NCT02563015. [ABSTRACT FROM AUTHOR]

Background: Dietary inequities in childhood may shape dietary and health inequities across the life course. Quantifying the magnitude and direction of trends in absolute and relative gaps and gradients in diet quality according to multiple indicators of socioeconomic position (SEP) can inform strategies to narrow these inequities.Objectives: We examined trends in absolute and relative gaps and gradients in diet quality between 2004 and 2015 according to 3 indicators of SEP among a nationally representative sample of children in Canada.Methods: Data from children (aged 2-17 y; n = 18,670) who participated in the cross-sectional Canadian Community Health Survey-Nutrition in 2004 or 2015 were analyzed. SEP was based on total household income, household educational attainment, and neighborhood deprivation. Dietary intake data from 1 interviewer-administered 24-h dietary recall were used to derive a Healthy Eating Index-2015 (HEI-2015) score for each participant as a measure of diet quality. Inequities in diet quality were quantified using 4 indices: absolute and relative gaps (between highest and lowest SEP) and absolute (Slope Index of Inequality) and relative gradients (Relative Index of Inequality). Overall and age-stratified multivariable linear regression and generalized linear models examined trends in HEI-2015 scores between 2004 and 2015.Results: Although mean HEI-2015 total scores improved from 52.3 to 57.3 (maximum 100 points; P < 0.001), absolute and relative gaps and gradients in diet quality remained mostly stable for all 3 SEP indicators. However, among children aged 6-11 y, absolute and relative gradients in diet quality according to household educational attainment and neighborhood deprivation widened.Conclusions: The diet quality of children in Canada was poor and inequitably patterned in 2004 and 2015. Although mean diet quality improved between 2004 and 2015, absolute and relative gaps and gradients in diet quality persisted, with some evidence of widening absolute and relative gradients among 6- to 11-y-olds. [ABSTRACT FROM AUTHOR]

Background: Detoxification of inorganic arsenic (iAs) occurs when it methylates to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of urinary iAs and MMA, and higher proportions of DMA indicate efficient methylation. The role of B-vitamins in iAs methylation in children with low-level arsenic exposure is understudied.Objectives: Our study objective was to assess the association between B-vitamin intake and iAs methylation in children with low-level arsenic exposure (<50 µg/L in water; urinary arsenic 5-50 µg/L).Methods: We conducted a cross-sectional study in 290 ∼7-y-old children in Montevideo. Intake of thiamin, riboflavin, niacin, vitamin B-6, and vitamin B-12 was calculated by averaging 2 nonconsecutive 24-h recalls. Total urinary arsenic concentration was measured as the sum of urinary iAs, MMA, and DMA, and adjusted for urinary specific gravity; iAs methylation was measured as urinary percentage As, percentage MMA, and percentage DMA. Arsenic concentrations from household water sources were assessed. Linear regressions tested the relationships between individual energy-adjusted B-vitamins and iAs methylation.Results: Median (range) arsenic concentrations in urine and water were 9.9 (2.2-48.7) and 0.45 (0.1-18.9) µg/L, respectively. The median (range) of urinary percentage iAs, percentage MMA, and percentage DMA was 10.6% (0.0-33.8), 9.7% (2.6-24.8), and 79.1% (58.5-95.4), respectively. The median (range) intake levels of thiamin, riboflavin, niacin, and vitamin B-6 were 0.81 (0.19-2.56), 1.0 (0.30-2.24), 8.6 (3.5-23.3), and 0.67 (0.25-1.73) mg/1000 kcal, respectively, whereas those of folate and vitamin B-12 were 216 (75-466) and 1.7 (0.34-8.3) µg/1000 kcal, respectively. Vitamin B-6 intake was inversely associated with urinary percentage MMA (β = -1.60; 95% CI: -3.07, -0.15). No other statistically significant associations were observed.Conclusions: Although vitamin B-6 intake was inversely associated with urinary percentage MMA, our findings suggest limited support for a relation between B-vitamin intake and iAs methylation in children exposed to low-level arsenic. [ABSTRACT FROM AUTHOR]

Background: Few studies, to our knowledge, have examined the longitudinal association of snacking with child body mass index (BMI), especially in China, where the incidence of overweight and obesity has increased rapidly.Objectives: Our objective was to examine the longitudinal association between snacking and BMI z score and to test whether this association differs by baseline weight status.Methods: Using data from the China Health and Nutrition Survey (2006, 2009, and 2011), we characterized snack intake for 9 provinces and 3 megacities. We used linear mixed-effects models to examine longitudinally the association between snacking (none, low, medium, and high tertiles according to energy) and BMI z score in children aged 2-13 y at baseline, controlling for sex, urbanicity, parental education, physical activity, and foods consumed at meals (n = 2277 observations). We tested whether this association differed by baseline underweight, normal weight, or overweight/obese.Results: Snacking is prevalent in Chinese children, with fruit being the most common snack. Snacking was not associated with meaningful BMI z score changes in normal-weight children. However, in children who were underweight at baseline, snacking in the top tertiles was associated with increases in BMI z scores from 2006 to 2011 (+1.2 and +1.1 BMI z score units for ages 2-6 and 7-13 y, respectively) (P < 0.05). In overweight/obese 2- to 6-y-old children at baseline, being in the lowest snacking tertile was associated with declines in BMI z score (-3.3), whereas in overweight 7- to 13-y-old children, being in the top tertile of snacking was associated with the greatest decline in BMI z score (-2.1) (P < 0.05). The direction and magnitude of associations did not vary regardless of adjustment for total energy intake.Conclusions: Snacking in China, dominated by fruit consumption, is associated with decreased BMI in overweight/obese children and increased BMI in underweight children. More work will be needed to monitor this relation as Chinese diets continue to westernize. [ABSTRACT FROM AUTHOR]