Antenatal Asthma Reduction Trial Research Articles

Association of Prenatal Maternal and Infant Vitamin D Supplementation with Offspring Asthma.

Rationale: The role and timing of vitamin D supplementation in the prevention of asthma has not been fully elucidated. Objective: To describe the association between prenatal and postnatal vitamin D with offspring asthma outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial. Methods: We classified 748 mother-offspring pairs into four groups based on the mother's randomization to receive high-dose versus low-dose (4,400 IU vs. 400 IU) vitamin D supplementation during pregnancy and the offspring parent-reported high-dose versus low-dose (⩾400 IU vs. <400 IU) vitamin D supplementation as estimated by intake of vitamin D drops or infant formula. We used logistic regression to test the association of the four vitamin D exposure groups-"mother-low/infant-low (reference)," "mother-high/infant-high," "mother-high/infant-low," and "mother-low/infant-high"-with offspring asthma and/or recurrent wheeze at age 3 years, active asthma at age 6 years, and atopic asthma at age 6 years. Results: The risk of asthma and/or recurrent wheeze at 3 years was lowest in the mother-high/infant-low group (adjusted odds ratio vs. mother-low/infant-low, 0.39; 95% confidence interval, 0.16-0.88, P = 0.03). When stratifying by history of exclusive breastfeeding until age 4 months, the protective effect in the mother-high/infant-low group was seen only among exclusively breastfed infants (odds ratio vs. mother-low/infant-low, 0.19; 95% confidence interval, 0.04-0.68; P = 0.02). We did not observe any significant associations with active or atopic asthma at age 6 years. Conclusions: We observe that high-dose prenatal and low-dose postnatal vitamin D supplementation may be associated with reduced offspring asthma or recurrent wheeze by age 3 years, but this association may be confounded by the protective effect of breastfeeding.

Preschool impulse oscillometry predicts active asthma and impaired lung function at school age

Asthmatic symptoms often start during early childhood. Impulse oscillometry (IOS) is feasible in preschool children who may be unable to reliably perform spirometry measurements. We sought to evaluate the use of IOS in a multicenter, multiethnic high-risk asthma cohort titled the Vitamin D Antenatal Asthma Reduction Trial. The trial recruited pregnant women whose children were followed from birth to age 8 years. Lung function was assessed with IOS at ages 4, 5, and 6 years and spirometry at ages 5, 6, 7, and 8 years. Asthma status, respiratory symptoms, and medication use were assessed with repeated questionnaires from birth to age 8 years. In total, 220 children were included in this secondary analysis. Recent respiratory symptoms and short-acting β2-agonist use were associated with increased respiratory resistance at 5 Hz at age 4 years (β= 2.6; 95% CI, 1.0 to 4.4; P= .002 and β= 3.4; 95% CI, 0.7 to 6.2; P= .015, respectively). Increased respiratory resistance at 5 Hz at age 4 years was also associated with decreased lung function from ages 5 to 8 years (β= -0.3; 95% CI, -0.5 to -0.1; P< .001 for FEV1 at 8 years) and active asthma at age 8 years (β= 2.0; 95% CI, 0.2 to 3.8; P= .029). Increased respiratory resistance in preschool IOS is associated with frequent respiratory symptoms as well as school-age asthma and lung function impairment. Our findings suggest that IOS may serve as a potential objective measure for early identification of children who are at high risk of respiratory morbidity.

Cord blood DNA methylation signatures associated with preeclampsia are enriched for cardiovascular pathways: insights from the VDAART trial

Preeclampsia has been associated with maternal epigenetic changes, in particular DNA methylation changes in the placenta. It has been suggested that preeclampsia could also cause DNA methylation changes in the neonate. We examined DNA methylation in relation to gene expression in the cord blood of offspring born to mothers with preeclampsia. This study included 128 mother-child pairs who participated in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), where assessment of preeclampsia served as secondary outcome. We performed an epigenome-wide association study of preeclampsia and cord blood DNA methylation (Illumina 450K chip). We then examined gene expression of the same subjects for validation and replicated the gene signatures in independent DNA methylation datasets. Lastly, we applied functional enrichment and network analyses to identify biological pathways that could potentially be involved in preeclampsia. In the cord blood samples (n=128), 263 CpGs were differentially methylated (FDR <0.10) in preeclampsia (n=16), of which 217 were annotated. Top pathways in the functional enrichment analysis included apelin signaling pathway and other endothelial and cardiovascular pathways. Of the 217 genes, 13 showed differential expression (p's<0.001) in preeclampsia and 11 had been previously related to preeclampsia (p's<0.0001). These genes were linked to apelin, cGMP and Notch signaling pathways, all having a role in angiogenic process and cardiovascular function. Preeclampsia is related to differential cord blood DNA methylation signatures of cardiovascular pathways, including the apelin signaling pathway. The association of these cord blood DNA methylation signatures with offspring's long-term morbidities due to preeclampsia should be further investigated. VDAART is funded by National Heart, Lung, and Blood Institute grants of R01HL091528 and UH3OD023268. HMK is supported by Jane and Aatos Erkko Foundation, Paulo Foundation, and the Pediatric Research Foundation. HM is supported by K01 award from NHLBI (1K01HL146977-01A1). PK is supported by K99HL159234 from NIH/NHLBI.

Integration of circulating microRNAs and transcriptome signatures identifies early-pregnancy biomarkers of preeclampsia.

MicroRNAs (miRNAs) have been implicated in the pathobiology of preeclampsia, a common hypertensive disorder of pregnancy. In a nested matched case-control cohort within the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we previously identified peripheral blood mRNA signatures related to preeclampsia and vitamin D status (≤30ng/mL) during gestation from 10 to 18weeks, using differential expression analysis. Using quantitative PCR arrays, we conducted profiling of circulating miRNAs at 10-18weeks of gestation in the same VDAART cohort to identify differentially expressed (DE) miRNAs associated with preeclampsia and vitamin D status. For the validation of the expression of circulating miRNA signatures in the placenta, the HTR-8/SVneo trophoblast cell line was used. Targets of circulating miRNA signatures in the preeclampsia mRNA signatures were identified by consensus ranking of miRNA-target prediction scores from four sources. The connected component of target signatures was identified by mapping to the protein-protein interaction (PPI) network and hub targets were determined. As experimental validation, we examined the gene and protein expression of IGF1R, one of the key hub genes, as a target of the DE miRNA, miR-182-5p, in response to a miR-182-5p mimic in HTR-8/SVneo cells. Pregnant women with preeclampsia had 16 circulating DE miRNAs relative to normal pregnancy controls that were also DE under vitamin D insufficiency (9/16=56% upregulated, FDR<.05). Thirteen miRNAs (13/16=81.3%) were detected in HTR-8/SVneo cells. Overall, 16 DE miRNAs had 122 targets, of which 87 were unique. Network analysis demonstrated that the 32 targets of DE miRNA signatures created a connected subnetwork in the preeclampsia module with CXCL8, CXCL10, CD274, MMP9 and IGF1R having the highest connectivity and centrality degree. In an in vitro validation experiment, the introduction of an hsa-miR-182-5p mimic resulted in significant reduction of its target IGF1R gene and protein expression within HTR-8/SVneo cells. The integration of the circulating DE miRNA and mRNA signatures associated preeclampsia added additional insights into the subclinical molecular signature of preeclampsia. Our systems and network biology approach revealed several biological pathways, including IGF-1, that may play a role in the early pathophysiology of preeclampsia. These pathways and signatures also denote potential biomarkers for the early stages of preeclampsia and suggest possible preventive measures.

The relationship of fetal sex and maternal race and ethnicity with early and late pregnancy C-reactive protein and interleukin-8.

Promotion of a healthy pregnancy is dependent on a coordinated immune response that minimizes inflammation at the maternal-fetal interface. Few studies investigated the effect of fetal sex on proinflammatory biomarkers during pregnancy and whether maternal race could impact this association. We aimed to examine whether fetal sex could, independently of maternal race/ethnicity and the condition of pregnancy (normal vs. complicated), impact inflammatory markers (C-reactive protein [CRP] and interleukin-8 [IL-8] levels) in early and late pregnancy. This study was a cohort analysis using prospectively collected data from pregnant women who participated in the Vitamin Antenatal Asthma Reduction Trial (VDAART, N=816). Maternal serum CRP and IL-8 levels were measured in early and late pregnancy (10-18 and 32-38weeks of gestation, respectively). Five hundred and twenty-eight out of 816 pregnant women who participated in the trial had available CRP and IL-8 measurements at both study time points. We examined the association of fetal sex with early and late CRP and IL-8 levels and their paired sample difference. We further investigated whether maternal race/ethnicity, pregnancy complications (i.e., preeclampsia and gestational diabetes), and early pregnancy body mass index (BMI) could affect the association between these two biomarkers and fetal sex adjusting for potential confounders. For this purpose, we used generalized linear and logistic regression models on log-normalized early and late CRP and IL-8 levels as well as their split at median to form high and low groups. Women pregnant with male fetuses (266/528=56.5%) had higher CRP levels in early to mid-pregnancy (β=.18: 95% confidence interval [CI]: CI=0.03-0.32; p=.02). Twenty-seven percent (143/528) of the study subjects were Hispanic. Hispanic African American [AA] women and women of races other than White and AA had higher levels of CRP at early to mid-pregnancy compared with White women (β=.57; 95% CI: 0.17-0.97; p<.01 and β=.27; 95% CI: 0.05-0.48; p=.02, respectively). IL-8 levels were not associated with fetal sex in early and late pregnancy (p's>.05). Other factors such as gestational diabetes and early pregnancy BMI were associated with higher CRP levels and higher CRP and IL-8 levels, respectively. Dichotomizing log-normalized cytokine levels at the median in a sensitivity analysis, women with male fetuses had lower odds of high (above-median) IL-8 levels at early pregnancy. Also, women with races other than AA and White carrying male fetuses had higher odds of having high (above-median) late-pregnancy CRP and early-pregnancy IL-8 levels (adjusted odds ratio [aOR]=3.80, 95% CI: 0.24-1.23; p=.02 and aOR=3.57; 95% CI: 0.23-1.03; p=.02, respectively). Of the pregnancy complications, women with gestational diabetes mellitus had a higher paired difference of early and late pregnancy CRP levels (β=.38; 95% CI: 0.09-0.68; p=.01), but no difference in IL-8 levels (p's>.05). No associations between the inflammatory markers and preeclampsia were found. Fetal sex is associated with CRP in early pregnancy and an association with IL-8 in early pregnancy is implied. Our study further indicates that maternal race/ethnicity could be a contributing factor in the relationship between fetal sex and inflammatory responses during pregnancy. However, the specificity and level of the contribution might vary by type of cytokine, pregnancy stage, and other confounding factors such as BMI that may impact these associations.

Early-Life Weight Status and Risk of Childhood Asthma or Recurrent Wheeze in Preterm and Term Offspring.

Excessive weight is associated with the development of childhood asthma. However, trends among preterm and term offspring may differ. To assess whether the association of longitudinal weight for age (WFA) and odds of asthma/recurrent wheeze in early life differs between children born preterm and those born at term. This study used prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial. Children (n= 804) were followed-up and anthropometric measurements, including WFA, were taken at birth and annually until the age of 6 years. The primary outcome was asthma/recurrent wheeze by age 3 and 6 years. Among the offspring, 71 (8.8%) were premature. In all the children, the odds of asthma/recurrent wheeze increased by 15% (adjusted odds ratio [aOR], 1.15; 95% CI, 1.10-1.20; P < .001) by age 3 years and 9% (aOR, 1.09; 95% CI, 1.07-1.11; P < .001) by age 6 years for each unit increase in WFA z score. Odds were different between term and preterm offspring (Pinteraction < .001). In term offspring, the odds of having asthma/recurrent wheeze by age 3 and 6 years increased by 22% and 15%, respectively (aOR, 1.22, 95% CI, 1.16-1.27, P < .001, and aOR, 1.15, 95% CI, 1.11-1.18, P < .001). In preterm offspring, by age 3 years, odds of asthma/recurrent wheeze decreased by 10% for each unit increase in WFA z score (aOR, 0.90; 95% CI, 0.81-0.99; P= .030) and decreased by 27% by age 6 years (aOR, .73; 95% CI, 0.61-0.86; P < .001). During early life, increasing standardized WFA is associated with higher odds of asthma/recurrent wheeze in term children. In contrast, in preterm children, a higher standardized WFA during catch-up growth may decrease the odds of asthma/recurrent wheeze associated with prematurity.

Omega-3 Fatty Acids Interact with DPP10 Region Genotype in Association with Childhood Atopy.

Associations of omega-3 fatty acids (n-3) with allergic diseases are inconsistent, perhaps in part due to genetic variation. We sought to identify and validate genetic variants that modify associations of n-3 with childhood asthma or atopy in participants in the Vitamin D Antenatal Asthma Reduction Trial (VDAART) and the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC). Dietary n-3 was derived from food frequency questionnaires and plasma n-3 was measured via untargeted mass spectrometry in early childhood and children aged 6 years old. Interactions of genotype with n-3 in association with asthma or atopy at age 6 years were sought for six candidate genes/gene regions and genome-wide. Two SNPs in the region of DPP10 (rs958457 and rs1516311) interacted with plasma n-3 at age 3 years in VDAART (p = 0.007 and 0.003, respectively) and with plasma n-3 at age 18 months in COPSAC (p = 0.01 and 0.02, respectively) in associationwith atopy. Another DPP10 region SNP, rs1367180, interacted with dietary n-3 at age 6 years in VDAART (p = 0.009) and with plasma n-3 at age 6 years in COPSAC (p = 0.004) in association with atopy. No replicated interactions were identified for asthma. The effect of n-3 on reducing childhood allergic disease may differ by individual factors, including genetic variation in the DPP10 region.

The Impact of Baseline 25-Hydroxyvitamin D Level and Gestational Age on Prenatal Vitamin D Supplementation to Prevent Offspring Asthma or Recurrent Wheezing

BackgroundPrenatal vitamin D deficiency is associated with asthma or recurrent wheezing in offspring. However, evidence from randomized trials on the efficacy of vitamin D supplementation is inconclusive. ObjectivesWe aimed to examine the differential efficacy of prenatal vitamin D supplementation based on the maternal baseline vitamin D status and the starting time of supplementation to prevent early life asthma or recurrent wheezing. MethodsWe conducted a secondary analysis of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized double-blind trial of prenatal vitamin D supplementation initiated at 10–18 weeks (wks) of gestation (4400 IU of intervention/day compared with 400 IU of placebo/day) to prevent offspring asthma or recurrent wheezing by the age of 6 years. We assessed the effect of modification of supplementation by maternal baseline vitamin D status at enrollment and the timing of initiation of supplementation. ResultsAn inverse relationship was observed between maternal 25-hydroxyvitamin D (25(OH)D) levels at trial entry and 25(OH)D levels during late pregnancy (32–38 wks of gestation) in both supplementation arms (P < 0.001). Overall, supplementation efficacy was not dependent on the maternal baseline 25(OH)D status. However, a trend toward the reduction of asthma or recurrent wheezing was observed across the baseline groups in the intervention arm (P = 0.01), with the greatest reduction observed in the most severely vitamin D–deficient women (25(OH)D < 12 ng/mL; adjusted odds ratio [aOR] = 0.48; confidence interval [CI]: 0.17, 1.34). Gestational age at trial enrollment modified supplementation efficacy, showing a greater reduction of offspring asthma or recurrent wheezing with earlier intervention during pregnancy (aOR = 0.85; CI = 0.76, 0.95), particularly in women who were 9–12 wk pregnant (aOR = 0.45; CI = 0.24, 0.82). ConclusionsPregnant women with severe vitamin D deficiency show the greatest 25(OH)D improvement because of supplementation. In these women, a vitamin D dose of 4400 IU might have a preventive role in the development of early life offspring asthma or recurrent wheezing. Gestational age is suggested to modify the efficacy of prenatal vitamin D supplementation, showing the highest beneficial effect if supplementation is started during the first trimester of pregnancy.This study is an ancillary analysis from the VDAART, which is registered in ClinicalTrials.gov as NCT00902621.

Benchmarking omics-based prediction of asthma development in children

BackgroundAsthma is a heterogeneous disease with high morbidity. Advancement in high-throughput multi-omics approaches has enabled the collection of molecular assessments at different layers, providing a complementary perspective of complex diseases. Numerous computational methods have been developed for the omics-based patient classification or disease outcome prediction. Yet, a systematic benchmarking of those methods using various combinations of omics data for the prediction of asthma development is still lacking.ObjectiveWe aimed to investigate the computational methods in disease status prediction using multi-omics data.MethodWe systematically benchmarked 18 computational methods using all the 63 combinations of six omics data (GWAS, miRNA, mRNA, microbiome, metabolome, DNA methylation) collected in The Vitamin D Antenatal Asthma Reduction Trial (VDAART) cohort. We evaluated each method using standard performance metrics for each of the 63 omics combinations.ResultsOur results indicate that overall Logistic Regression, Multi-Layer Perceptron, and MOGONET display superior performance, and the combination of transcriptional, genomic and microbiome data achieves the best prediction. Moreover, we find that including the clinical data can further improve the prediction performance for some but not all the omics combinations.ConclusionsSpecific omics combinations can reach the optimal prediction of asthma development in children. And certain computational methods showed superior performance than other methods.

The Association of Prenatal C-Reactive Protein and Interleukin-8 Levels with Maternal Characteristics and Preterm Birth.

The determinants of preterm birth remain unknown. Excessive maternal inflammation during pregnancy may play an important role in the pathogenesis of preterm birth. Our objective was to describe the association of prenatal levels of proinflammatory C-reactive protein (CRP) and interleukin-8 (IL-8) with preterm birth in participants of the Vitamin D Antenatal Asthma Reduction Trial. Five hundred and twenty-eight patients with available samples of both first- and third-trimester plasma were included in this analysis. CRP and IL-8 were measured from maternal prenatal samples. We examined the association between prenatal CRP and IL-8 with maternal health characteristics and the outcome of preterm birth. We also described the patterns of change in CRP and IL-8 from first to third trimester and their association with preterm birth. A subgroup analysis comparing only those with a spontaneous preterm birth phenotype to those with term birth was also performed. Maternal characteristics including lower educational attainment, higher prepregnancy body mass index, gestational diabetes, lower vitamin D, and an unhealthy diet were associated with elevated levels of prenatal CRP and IL-8. Higher third trimester CRP and an increase in CRP from first to third trimester were associated with an increased odds of preterm birth when compared to lower levels of CRP (adjusted odds ratio [aOR] = 1.49, 95% confidence interval: 1.02, 2.23, p = 0.04) or a decrease in CRP over pregnancy (aOR = 3.06, 95% CI = 1.31,7.55, p = 0.01), after adjusting for potential confounders. These associations were strengthened when comparing only patients with spontaneous preterm birth (n = 22) to those with term births. Higher levels of the proinflammatory markers CRP and IL-8 are associated with indicators of poor maternal health and preterm birth. Prenatal CRP levels may reflect maternal prenatal health status and serve as a predictor of preterm birth, especially among those with spontaneous preterm birth. · Elevated prenatal CRP is associated with poor maternal health.. · High prenatal CRP may predict premature birth, especially spontaneous premature birth phenotypes.. · Vitamin D insufficiency may be a modifiable risk factor for prenatal inflammation..

Early-life fecal metabolomics of food allergy.

Intestinal microenvironmental perturbations may increase food allergy risk. We hypothesize that children with clinical food allergy, those with food sensitization, and healthy children can be differentiated by intestinal metabolites in the first years of life. In this ancillary analysis of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we performed untargeted metabolomic profiling in 824 stool samples collected at ages 3-6months, 1year and 3 years. Subjects included 23 with clinical food allergy at age 3 and/or 6 years, 151 with food sensitization but no clinical food allergy, and 220 controls. We identified modules of correlated, functionally related metabolites and sought associations of metabolite modules and individual metabolites with food allergy/sensitization using regression models. Several modules of functionally related intestinal metabolites were reduced among subjects with food allergy, including bile acids at ages 3-6months and 1year, amino acids at age 3-6months, steroid hormones at 1year, and sphingolipids at age 3 years. One module primarily containing diacylglycerols was increased in those with food allergy at age 3-6months. Fecal caffeine metabolites at age 3-6months, likely derived from breast milk, were increased in those with food allergy and/or sensitization (beta=5.9, 95% CI 1.0-10.8, p=.02) and were inversely correlated with fecal bile acids and bilirubin metabolites, though maternal plasma caffeine levels were not associated with food allergy and/or sensitization. Several classes of bioactive fecal metabolites are associated with food allergy and/or sensitization including bile acids, steroid hormones, sphingolipids, and caffeine metabolites.

Maternal Inflammatory Biomarkers during Pregnancy and Early Life Neurodevelopment in Offspring: Results from the VDAART Study

Maternal infection and stress during the prenatal period have been associated with adverse neurodevelopmental outcomes in offspring, suggesting that biomarkers of increased inflammation in the mothers may associate with poorer developmental outcomes. In 491 mother-child pairs from the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we investigated the association between maternal levels of two inflammatory biomarkers; interleukin-8 (IL-8) and C-Reactive Protein (CRP) during early (10-18 wks) and late (32-38 wks) pregnancy with offspring scores in the five domains of the Ages and Stages Questionnaire, a validated screening tool for assessing early life development. We identified a robust association between early pregnancy IL-8 levels and decreased fine-motor (β: -0.919, 95%CI: -1.425, -0.414, p = 3.9 × 10-4) and problem-solving skills at age two (β: -1.221, 95%CI: -1.904, -0.414, p = 4.9 × 10-4). Associations between IL-8 with other domains of development and those for CRP did not survive correction for multiple testing. Similarly, while there was some evidence that the detrimental effects of early pregnancy IL-8 were strongest in boys and in those who were not breastfed, these interactions were not robust to correction for multiple testing. However, further research is required to determine if other maternal inflammatory biomarkers associate with offspring neurodevelopment and work should continue to focus on the management of factors leading to increases in IL-8 levels in pregnant women.

The maternal prenatal and offspring early-life gut microbiome of childhood asthma phenotypes.

The infant fecal microbiome is known to impact subsequent asthma risk, but the environmental exposures impacting this association, the role of the maternal microbiome, and how the microbiome impacts different childhood asthma phenotypes are unknown. Our objective was to identify associations between features of the prenatal and early-life fecal microbiomes and child asthma phenotypes. We analyzed fecal 16 s rRNA microbiome profiling and fecal metabolomic profiling from stool samples collected from mothers during the third trimester of pregnancy (n=120) and offspring at ages 3-6months (n=265), 1 (n=436) and 3 years (n=506) in a total of 657 mother-child pairs participating in the Vitamin D Antenatal Asthma Reduction Trial. We used clinical data from birth to age 6 years to characterize subjects with asthma as having early, transient or active asthma phenotypes. In addition to identifying specific genera that were robustly associated with asthma phenotypes in multiple covariate-adjusted models, we clustered subjects by their longitudinal microbiome composition and sought associations between fecal metabolites and relevant microbiome and clinical features. Seven maternal and two infant fecal microbial taxa were robustly associated with at least one asthma phenotype, and a longitudinal gut microenvironment profile was associated with early asthma (Fisher exact test p=.03). Though mode of delivery was not directly associated with asthma, we found substantial evidence for a pathway whereby cesarean section reduces fecal Bacteroides and microbial sphingolipids, increasing susceptibility to early asthma. Overall, our results suggest that the early-life, including prenatal, fecal microbiome modifies risk of asthma, especially asthma with onset by age 3 years.

The Association of Prenatal C-Reactive Protein Levels With Childhood Asthma and Atopy

The pathogenesis of childhood asthma is complex, and determinants of risk may begin in utero. To describe the association of systemic prenatal inflammation, measured by plasma C-reactive protein (CRP), with childhood asthma, eczema, and allergic rhinitis. A total of 522 maternal-offspring pairs from the Vitamin D Antenatal Asthma Reduction Trial were included. Prenatal plasma CRP level was measured between 10 and 18 weeks of gestation and between 32 and 38 weeks of gestation. Offspring asthma, eczema, and allergic rhinitis were assessed quarterly between birth and age 6 years. We performed mediation analyses of prenatal CRP on the association between several maternal characteristics and offspring asthma. Elevated early and late prenatal CRP and an increase in CRP from early to late pregnancy were associated with asthma by age 6 years (early: adjusted odds ratio [aOR], 1.76, 95% CI, 1.12-2.82, P= .02; late: aOR, 2.45, 95% CI, 1.47-4.18, P < .001; CRP increase: aOR, 2.06, 95% CI, 1.26-3.39, P < .004). Prenatal CRP and childhood asthma associations were strengthened among offspring with atopic asthma (early: aOR, 3.78, 95% CI, 1.49-10.64, P= .008; late: aOR, 4.84, 95% CI, 1.68-15.50, P= .005; CRP increase: aOR, 3.01, 95% CI, 1.06-9.16, P=.04). Early and late prenatal CRP mediated 96% and 86% of the association between maternal prepregnancy body mass index and offspring asthma, respectively. Higher prenatal CRP and an increase in CRP from early to late pregnancy are associated with childhood asthma. Systemic inflammation during pregnancy associated with modifiable maternal characteristics may be an important determinant of childhood asthma risk.

Association of the gut microbiome and metabolome with wheeze frequency in childhood asthma

While the microbiome has an established role in asthma development, less is known about its contribution to morbidity in children with asthma. In this ancillary study of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we analyzed the gut microbiome and metabolome of wheeze frequency in children with asthma. Bacterial 16S ribosomal RNA microbiome and untargeted metabolomic profiling were performed on fecal samples collected from 3-year-old children with parent-reported physician-diagnosed asthma. We analyzed wheeze frequency by calculating the proportion of quarterly questionnaires administered between ages 3 and 5 years in which parents reported the child had wheezed (wheeze proportion). Taxa and metabolites associated with wheeze were analyzed by identifying log fold changes with respect to wheeze frequency and correlation/linear regression analyses, respectively. Microbe-metabolite and microbe-microbe correlation networks were compared between subjects with high and low wheeze proportion. Specific taxa, including the genus Veillonella and histidine pathway metabolites, were enriched in subjects with high wheeze proportion. Among wheeze-associated taxa, Veillonella and Oscillospiraceae UCG-005, which was inversely associated with wheeze, were correlated with the greatest number of fecal metabolites. Microbial networks were similar between subjects with low versus high wheeze frequency. Gut microbiome features are associated with wheeze frequency in children with asthma, suggesting an impact of the gut microbiome on morbidity in childhood asthma.

Circulating levels of maternal vitamin D and risk of ADHD in offspring: results from the Vitamin D Antenatal Asthma Reduction Trial.

Low levels of circulating 25-hydroxy-vitamin D [25(OH)D] have been shown to associate with prevalent attention-deficit/hyperactivity disorder (ADHD), but few studies have examined the association between 25(OH)D during fetal development and risk of childhood ADHD. Maternal plasma 25(OH)D was measured at 10-18 and 32-38 weeks of gestation, with sufficiency defined as 25(OH)D ≥ 30 ng/ml. Offspring ADHD status between ages 6-9 years was measured by parent report of clinical ADHD diagnosis among 680 mother-child pairs from the Vitamin D Antenatal Asthma Reduction Trial. Association between maternal 25(OH)D and child ADHD was assessed using logistic regression, adjusting for maternal age, race and ethnicity. Effect modification by offspring sex was also assessed. No associations between maternal 25(OH)D at 10-18 weeks of gestation and offspring ADHD were observed. In the third trimester, we observed associations between maternal vitamin D sufficiency and offspring ADHD [odds ratio (OR) 0.47, 95% confidence interval (CI) 0.26-0.84], in addition to maternal 25(OH)D sufficiency category, comparing the deficient (OR 0.34, 95% CI 0.12-0.94), insufficient (OR 0.41, 95% CI 0.15-1.10) and sufficient (OR 0.20, 95% CI 0.08-0.54) categories against highly deficient 25(OH)D, respectively. Stratified analyses revealed a protective association for sufficient maternal 25(OH)D and child ADHD among males (OR 0.47, 95% CI 0.23-0.94); the synergy index for additive effect modification of risk was 1.78 (95% CI 0.62-5.08). Higher levels of maternal vitamin D in the third trimester are associated with lower risk of ADHD in offspring, with modest evidence for a stronger effect among male offspring. However, larger studies will be necessary to confirm these findings.

The Association of Prenatal Vitamin D Sufficiency With Aeroallergen Sensitization and Allergic Rhinitis in Early Childhood

The role of prenatal vitamin D sufficiency and supplementation in the development of childhood aeroallergen sensitization and allergic rhinitis remains uncertain. To describe the association of prenatal vitamin D sufficiency with childhood allergic outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial, a randomized controlled trial of prenatal vitamin D supplementation. We included 414 mother-offspring pairs with offspring aeroallergen sensitization data available at age 6 years in this analysis. We examined the association between prenatal vitamin D sufficiency status, based on vitamin D levels measured in the first and third trimesters, or vitamin D supplementation treatment assignment with the outcomes of aeroallergen sensitization, parent-reported clinical allergic rhinitis, parent-reported clinical allergic rhinitis with aeroallergen sensitization, food sensitization, any sensitization, eczema, and total IgE at ages 3 and 6 years. Compared with early and late insufficiency, early prenatal vitamin D insufficiency with late sufficiency was associated with reduced development of clinical allergic rhinitis with aeroallergen sensitization at 3 years (adjusted odds ratio [aOR]= 0.34; 95% confidence interval [CI], 0.13-0.82; P= .02) and 6 years (aOR= 0.54; 95% CI, 0.29-0.98; P= .05). At 6 years, clinical allergic rhinitis with sensitization was significantly decreased in offspring whose mothers received high-dose vitamin D (aOR= 0.54; 95% CI, 0.32-0.91; P= .02) compared with offspring whose mothers who received low-dose vitamin D. Associations of prenatal vitamin D with aeroallergen sensitization were strengthened among children who also developed asthma or who had a maternal history of atopy. Among mothers with first-trimester vitamin D insufficiency, we detected a protective effect of third-trimester prenatal vitamin D sufficiency on the development of clinical allergic rhinitis with aeroallergen sensitization at ages 3 and 6 years.

Circulating MicroRNA: Incident Asthma Prediction and Vitamin D Effect Modification.

Of children with recurrent wheezing in early childhood, approximately half go on to develop asthma. MicroRNAs have been described as excellent non-invasive biomarkers due to their prognostic utility. We hypothesized that circulating microRNAs can predict incident asthma and that that prediction might be modified by vitamin D. We selected 75 participants with recurrent wheezing at 3 years old from the Vitamin D Antenatal Asthma Reduction Trial (VDAART). Plasma samples were collected at age 3 and sequenced for small RNA-Seq. The read counts were normalized and filtered by depth and coverage. Logistic regression was employed to associate miRNAs at age 3 with asthma status at age 5. While the overall effect of miRNA on asthma occurrence was weak, we identified 38 miRNAs with a significant interaction effect with vitamin D and 32 miRNAs with a significant main effect in the high vitamin D treatment group in VDAART. We validated the VDAART results in Project Viva for both the main effect and interaction effect. Meta-analysis was performed on both cohorts to obtain the combined effect and a logistic regression model was used to predict incident asthma at age 7 in Project Viva. Of the 23 overlapped miRNAs in the stratified and interaction analysis above, 9 miRNAs were replicated in Project Viva with strong effect size and remained in the meta-analysis of the two populations. The target genes of the 9 miRNAs were enriched for asthma-related Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. Using logistic regression, microRNA hsa-miR-574-5p had a good prognostic ability for incident asthma prognosis with an area under the receiver operating characteristic (AUROC) of 0.83. In conclusion, miRNAs appear to be good biomarkers of incident asthma, but only when vitamin D level is considered.

High-dose vitamin D during pregnancy and pathway gene polymorphisms in prevention of offspring persistent wheeze.

Randomized controlled trials (RCTs) suggest a protective effect of high-dose vitamin D supplementation in pregnancy on offspring risk of persistent wheeze, but only in some individuals, which might be explained by variations in vitamin D pathway genes. This study aimed to investigate the effect of vitamin D supplementation by maternal and offspring vitamin D receptor (VDR) genotype and GC genotype, encoding vitamin D binding protein (VDBP), in two RCTs. In the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010 ) RCT, we analyzed the effect of high-dose vitamin D during pregnancy on the risk of persistent wheeze age 0-3years by variants in single nucleotide polymorphisms (SNPs) in VDR (rs1544410, rs2228570, rs7975128, rs7975232) and GC (rs4588, rs7041). Replication was sought in the Vitamin D Antenatal Asthma Reduction Trial (VDAART). In COPSAC2010 , VDR SNP rs1544410 influenced the effect of high-dose vitamin D: maternal Pinteraction =.049 and child Pinteraction =.001, with the largest effect in offspring from mothers with TT genotype: hazard ratio (95% CI), 0.26 (0.10-0.68), P=.006, and no effect among CT or CC genotypes: 0.85 (0.48-1.51), P=.58 and 0.94 (0.47-1.89), P=.87, respectively. However, these findings were not replicated in VDAART. There was no significant effect modification from maternal or offspring GC genotype in either COPSAC2010 or VDAART: all Pinteraction ≥.17. We found that the effect of high-dose vitamin D supplementation during pregnancy on offspring risk of persistent wheeze was significantly influenced by VDR genotype in the COPSAC2010 RCT, but not VDAART, which may be due to population differences.

Association of the Gut Microbiome and Metabolome with Wheeze Frequency in Childhood Asthma

While the gut microbiome has an established role in asthma development, less is known about its contribution to morbidity in children with asthma. In this ancillary study of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we analyzed the gut microbiome and metabolome of wheeze frequency in children with asthma. Microbiome profiling by 16S rRNA gene sequencing and metabolomic profiling by mass spectrometry were performed on fecal samples collected from 3 year-olds with parent-reported doctor-diagnosed asthma. We tabulated the proportion of quarterly questionnaires in which parents/guardians reported wheeze between months 39 and 63 of life (“wheeze proportion”). Associations of bacterial taxa with wheeze proportion were tested in negative binomial regression models including potential confounders and associations of metabolites with wheeze proportion were tested in correlation, linear regression and pathway analyses. Microbe-metabolite and microbial correlation networks were constructed. In 111 children with asthma, several bacterial taxa were associated with wheeze proportion. Among those with higher wheeze proportion, Veillonella spp. were enriched (log2FoldChanges: 3.1 for V dispar (FDR = 0.01); 3.2 for V parvula (FDR = 0.01); 3.1 for unidentified Veillonella spp. (FDR = 0.02)) and Bifidobacterium longum was depleted (log2FoldChange -2.1, FDR = 0.01). Histidine pathway metabolites were enriched in those with higher wheeze proportion (p < 0.05 using two different pathway analysis methods). V dispar and V uniformis correlated with each other and with numerous metabolites. Gut microbiome features are associated with wheeze frequency in children with asthma, suggesting an impact of the gut microbiome on morbidity in childhood asthma.