A Pilot Metabolomic Study of the Effects of Vitamin D and Calcium Supplementation

北卡罗来纳大学教堂山分校和埃默里大学的这项合作提案是一项正在进行的多中心、随机、双盲、安慰剂对照、改良的2 x 2因素化学预防临床试验(R01 CA98286；PI：J.Baron)(n=2,259)的附属试点代谢组学研究，该试验正在测试补充维生素D3(每天1,000 IU)和钙(每天1,200毫克元素钙)单独和联合使用与安慰剂在3~5年内预防散发性结肠腺瘤复发的疗效(家长研究)。这项建议的目的是在母体研究的临床研究人员和代谢组学专家之间建立一种新的互动合作，并将一种新的高分辨率代谢组学方法纳入母体研究，以更好地了解维生素D和钙在人类中的独立和协同抗肿瘤作用及其他影响。我们的创新方法利用高分辨率质谱学来测量&gt；20,000种代谢物，并提供独特的工作流程，使用错误发现率(FDR)来确定后续研究的代谢物的优先顺序，使用相关性分析来增强与这些优先代谢物相关的代谢模块的识别，使用可用的在线工具来确定相关代谢途径的路径图，以及在特定情况下将离子解离(MS/MS)光谱应用于代表性代谢物以确认路径识别。在试点研究中，我们将获得补充维生素D和/或钙对参与者(n=120)个体代谢物和代谢途径的影响的初步数据，并对正常外观的直肠粘膜进行基线和后续活检。从这项初步研究中获得的初步结果将导致更大的、全面的代谢组调查，以阐明1)维生素D和钙对人类代谢组途径的单独和联合影响(从而更全面地评估这些大力促进的制剂作为补充剂的益处和风险)，2)这些代谢组变化是否与人类的遗传变异以及系统和组织特异性生物标记物相关(因此，它们与结直肠癌的化学预防直接相关)，以及3)代谢变化是否预测人类散发性结肠腺瘤的发生，从而为开发可治疗的结直肠肿瘤风险生物标记物铺平了道路，这些标记物类似于预防缺血性心脏病的血脂谱。阐明维生素D和/或钙补充剂对个体代谢物和代谢途径的影响可能有助于这些化学预防药物用于预防结直肠肿瘤，并可能预防其他慢性疾病。

This collaborative proposal between the University of North Carolina ¿ Chapel Hill and Emory University is an adjunct pilot metabolomic study to an ongoing multi-center, randomized, double-blind, placebo-controlled, modified 2 x 2 factorial chemoprevention clinical trial (R01 CA98286; PI: J. Baron) (n = 2,259) that is testing the efficacy of supplemental vitamin D3 (1,000 IU daily) and calcium (1,200 mg elemental calcium daily), alone and in combination vs. placebo over 3 ¿ 5 years in preventing sporadic colorectal adenoma recurrence (the ¿parent study¿). The objective of this proposal is to establish a new interactive collaboration between clinical researchers in the parent study and metabolomics experts, and to incorporate a novel high-resolution metabolomics approach into the parent study to better understand the independent and synergistic antineoplastic actions and other effects of vitamin D and calcium in humans. Our innovative approach utilizes high-resolution mass spectrometry to measure >20,000 metabolites, and provides a unique workflow using false discovery rates (FDR) to prioritize metabolites for subsequent study, correlation analysis to enhance identification of relevant metabolic modules associated with these prioritized metabolites, pathway mapping using available online tools to identify relevant metabolic pathways, and post-hoc application of ion dissociation (MS/MS) spectroscopy to representative metabolites to confirm pathway identification. In the pilot study we will obtain preliminary data on the effects of supplementation with vitamin D and/or calcium on individual metabolites and metabolic pathways in a sub-set of participants (n = 120) with baseline and follow-up biopsies of normal-appearing rectal mucosa. The preliminary results obtained from this pilot study will lead to larger, full-scale, metabolomic investigations to elucidate 1) the individual and combined effects of vitamin D and calcium on metabolomic pathways in humans (thus providing a more comprehensive assessment of the benefits and risks of these heavily promoted agents as supplements), 2) whether these metabolomic changes correlate with genetic variation and systemic and tissue-specific biomarkers in humans (and thus their direct relevance to the chemoprevention of colorectal neoplasms), and 3) whether the metabolomic changes predict the occurrence of sporadic colorectal adenomas in humans, thus paving the way for the development of treatable biomarkers of risk for colorectal neoplasia that are analogous to lipid profiles for the prevention of ischemic heart disease. Elucidating the effects of vitamin D and/or calcium supplementation on individual metabolites and metabolomic pathways may inform the potential use of these chemopreventive agents for preventing colorectal neoplasms, and, possibly, other chronic diseases.