Dataset Information

Blood ?-tocopherol, ?-tocopherol levels and risk of prostate cancer: a meta-analysis of prospective studies.

ABSTRACT: BACKGROUND: Epidemiological studies that have examined the association of blood ?-tocopherol and ?-tocopherol (the principal bioactive form of vitamin E) levels with the risk of prostate cancer have yielded inconsistent results. In addition, a quantitative assessment of published studies is not available. METHODS AND FINDINGS: In this meta-analysis, relevant studies were sought by a search of the PubMed and Embase databases for articles published up to October 2013, with no restrictions. Bibliographies from retrieved articles also were scoured to find further eligible studies. Prospective studies that reported adjusted relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between blood tocopherol levels and the risk of prostate cancer were included. Nine nested case-control studies involving approximately 370,000 participants from several countries were eligible. The pooled RRs of prostate cancer for the highest versus lowest category of blood ?-tocopherol levels were 0.79 (95% CI: 0.68-0.91), and those for ?-tocopherol levels were 0.89 (95% CI: 0.71-1.12), respectively. Significant heterogeneity was present among the studies in terms of blood ?-tocopherol levels (p = 0.008) but not in terms of blood ?-tocopherol levels (p = 0.33). The risk of prostate cancer decreased by 21% for every 25-mg/L increase in blood ?-tocopherol levels (RR: 0.79; 95% CI: 0.69-0.91). CONCLUSIONS: Blood ?-tocopherol levels, but not ?-tocopherol levels, were inversely associated with the risk of prostate cancer in this meta-analysis.

SUBMITTER: Cui R

PROVIDER: S-EPMC3965522 | biostudies-other | 2014

REPOSITORIES: biostudies-other

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Blood α-tocopherol, γ-tocopherol levels and risk of prostate cancer: a meta-analysis of prospective studies.

Cui Ran R Liu Zhu-Qing ZQ Xu Qing Q

PloS one 20140325 3

<h4>Background</h4>Epidemiological studies that have examined the association of blood α-tocopherol and γ-tocopherol (the principal bioactive form of vitamin E) levels with the risk of prostate cancer have yielded inconsistent results. In addition, a quantitative assessment of published studies is not available.<h4>Methods and findings</h4>In this meta-analysis, relevant studies were sought by a search of the PubMed and Embase databases for articles published up to October 2013, with no restrict ...[more]

PMID: 24667740

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Project description:Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects more than 1% of children in the USA. ASD risk is thought to arise from both genetic and environmental factors, with the perinatal period as a critical window. Understanding early transcriptional changes in ASD would assist in clarifying disease pathogenesis and identifying biomarkers. However, little is known about umbilical cord blood gene expression profiles in babies later diagnosed with ASD compared to non-typically developing and non-ASD (Non-TD) or typically developing (TD) children. Genome-wide transcript levels were measured by Affymetrix Human Gene 2.0 array in RNA from cord blood samples from both the Markers of Autism Risk in Babies-Learning Early Signs (MARBLES) and the Early Autism Risk Longitudinal Investigation (EARLI) high-risk pregnancy cohorts that enroll younger siblings of a child previously diagnosed with ASD. Younger siblings were diagnosed based on assessments at 36 months, and 59 ASD, 92 Non-TD, and 120 TD subjects were included. Using both differential expression analysis and weighted gene correlation network analysis, gene expression between ASD and TD, and between Non-TD and TD, was compared within each study and via meta-analysis. While cord blood gene expression differences comparing either ASD or Non-TD to TD did not reach genome- wide significance, 172 genes were nominally differentially expressed between ASD and TD cord blood (log2(fold change) > 0.1, p < 0.01). These genes were significantly enriched for functions in xenobiotic metabolism, chromatin regulation, and systemic lupus erythematosus (FDR q < 0.05). In contrast, 66 genes were nominally differentially expressed between Non-TD and TD, including 8 genes that were also differentially expressed in ASD. Gene coexpression modules were significantly correlated with demographic factors and cell type proportions. ASD-associated gene expression differences identified in this study are subtle, as cord blood is not the main affected tissue, it is composed of many cell types, and ASD is a heterogeneous disorder. This is the first study to identify gene expression differences in cord blood specific to ASD through a meta- analysis across two prospective pregnancy cohorts. The enriched gene pathways support involvement of environmental, immune, and epigenetic mechanisms in ASD etiology.

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Dataset Information

Blood ?-tocopherol, ?-tocopherol levels and risk of prostate cancer: a meta-analysis of prospective studies.

Publications

Blood α-tocopherol, γ-tocopherol levels and risk of prostate cancer: a meta-analysis of prospective studies.

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