【作者】 徐昉；

【导师】 漆洪波；

【作者基本信息】 重庆医科大学 ， 临床医学（产科）， 2016， 博士

【摘要】 目的:妊娠期糖尿病是葡萄糖耐受的病理生理状态,而脂联素在调节葡萄糖水平和脂肪酸氧化中起关键性作用和脂肪酸氧化中起关键性作用。本文主要研究GDM代谢与代谢产物脂联素水平的相关性。在代谢紊乱中,如妊娠期糖尿病状态下,脂联素在调节葡萄糖水平和脂肪酸氧化中起关键性作用。虽然已经有大量实验研究ADIPOQ+45 T/G多形性与GDM风险因子的关联,但研究结果却未能给出明确答案。本实验运用meta分析,研究GDM相关风险与ADIPOQ+45 T/G多形性的关联方法:妊娠期糖尿病尿代谢组学纵向队列研究采集临床样本并分组:选择在重庆医科大学附属第一医院产检、分娩的孕妇,入组孕妇均为生育年龄(19-35周岁),确定排除和入选标准。实验过程:收集入组孕妇尿样后行预处理,在质量控制下进行LC-MS分析;在Progenesis Qi,ver.2.1下进行数据预处理,对可信度评分≤44.5的可疑目标代谢产物进行筛选,并运用EigenMS的修改版本对数据进行均衡。纵向队列研究能运用对象间实验设计去探索数据集同时消除个体差异。运用pca建立与ipca和多元级spls-da相比较的基线后。运用ipca与多级pls-da、配对分析方法对数据进行分析处理。根据已知代谢产物变化情况,在metpa中进行途径分析,绘制路径分析与映射。妊娠期糖尿病adipoq+45t/g基因多态性的系统评价数据库中完整搜索出8篇被认为有研究价值的文献。合并文献比值比,运用meta分析方法,选择可信区间于95%的数据用于研究adipoq+45t/g多态性与gdm风险因子的关联性。结果:入组的61名孕妇,34名进入正常葡萄糖耐受组(对照组),27名孕妇进入葡萄糖耐受降低组(实验组)。尿液含有大量的生物分子,尿样收集受到很大程度的稀释效应影响,而介于尿样的复杂性,受到大量生物干扰,而lc-ms分析提示40.7%gdm孕妇在妊娠过程中尿液浓缩,而在健康对照组中,仅有19.4%孕妇尿液浓缩。研究发现加工食品的大量摄入引起维生素b5的缺乏,而维生素b5的缺乏可引起乙酰辅酶a的合成、脂肪酸的β氧化,同时色氨酸代谢产物转运至犬尿素代谢中,但色氨酸的分解代谢将会增加氮废物的再利用,如尿酸、肌酐等在妊娠晚期,与正常对照组相比,gdm组实验对象的甾类激素水平与妊娠期糖尿病有更强的关联。对过去研究进行meta分析,并未发现明确证据表明adipoq+45t/g多形性与gdm的风险相关联(杂合子:or=1.15,95%ci,0.70-1.89;纯合子:or=1.21,95%ci,0.48-3.03;显性遗传:or=0.86,95%ci,0.50-1.48;隐性遗传:or=1.21,95%ci,0.62-2.33;等位基因对比:or=1.17,95%ci,0.79-1.76)。可检测到明显的异质性,而发表偏倚未被检测出。结论:尿液内标样本被分配在一个单独的处理组中或是分析时间相距较远时,pca和ipca分析用于gdm的尿代谢组学纵向队列研究能尽可能避免实验误差。在诸多变量中,可以通过尿酸和肌酐从对照组中分离出是否发生gdm。gdm患者尿液中相对缺乏维生素b5,这与精加工食品过多摄入或维生素b5摄入不足有关,而维生素b5作为是辅酶a的前体,它的缺乏会影响线粒体柠檬酸循环、β-脂肪酸氧化和亮氨酸代谢。同时,妊娠中晚期存在的甾体类激素代谢产物的排泄量显著变化和胎盘分泌的糖尿病性激素能引发炎症反应,使gdm患者色氨酸代谢途径向“色氨酸—犬尿氨酸”途径转换,从而刺激胰岛素的分泌和敏感性,并维持乙酰辅酶a的水平,保障柠檬酸循环的顺利进行。此外,基因多态性已经成为造成gdm易感、病情严重程度增加的重要机制,adipoq(+45t/g,rs2241766)多态性在gdm中具有潜在作用meta分析我们发现adipoq+45t/g与gdm危险因素没有相关性,但这一结果需要进一步的大样本、前瞻性的研究来确认,并且这也不能否定ADIPOQ在GDM中的重要作用。更多还原

【Abstract】 Background: Gestational diabetes mellitus(GDM) is a pathological state of glucose intolerance that could adversely affect pregnancy outcome and increases the risk of developing maternal type 2 diabetes. The underlying mechanism for this state is not fully understood. Adiponectin(ADIPOQ), involving in regulating glucose levels and fatty acid oxidation, plays key roles in the metabolic derangements, such as gestational diabetes mellitus(GDM). Previously, several studies have been conducted to assess the association between ADIPOQ +45 T/G polymorphism and risk of GDM. The results, however, are inconclusive. In this study, firstly, urine from a longitudinal cohort of normal pregnancies and pregnancies complicated by gestational diabetes was investigated. Secondly, we aimed to evaluate the effect of the polymorphism on the risk of GDM using a meta-analysis.Methods:1. Urinary metabolic profiling of GDM analysis. Normal pregnancies and pregnancies complicated by gestational diabetes(19-35 years old) were chosen in first affiliated Hospital of Chongqing Medical University and urinary samples were collected. The analytical challenges in urinary metabolic profiling were first investigated, with an aim to improve the precision of the measurements and to eliminate the heteroscedastic noise. Paired statistical approaches were used to eliminate individual variability. Unsupervised and multilevel supervised models successfully discriminated the GDM subjects from the controls.2. After databases searching, 8 records were identified. Pooled odds ratios(OR) with their corresponding 95% confidenceintervals(CI) were used to evaluate the association between ADIPOQ +45 T/G polymorphism and risk of GDM.Results: 1. among selected 61 pregnancies, 34 pregnancies entered into normal glucose tolerance group(control group) and 27 entered into lower glucose tolerance group(treated group). Because the urinary consisted amount of biological molecules, the urinary sample were greatly diluted. LC-MS analysis suggested that 40.7%GDM pregnancies had urinary concentration while in control group, only 19.4% had this state。A relative deficiency of Vitamin B5 was a cause of GDM. This suppressed the synthesis of acetyl-Co A and so the b-oxidation of fatty acids. Consumption of processed foods might contribute to the deficiency of Vitamin B5. The deficiency of Vitamin B5 shifted the tryptophan metabolism toward the kynurenine pathway and so the production of acetyl-Co A, consequently, the citric acid cycle was maintained. An effect of this shift in tryptophan catabolism led to an increased disposal of nitrogenous wastes(uric acid and creatinine).2. No significant association was observed between the ADIPOQ +45 T/G polymorphism and the risk of GDM(heterozygote comparison: OR=1.15, 95%CI, 0.70-1.89; homozygote comparison: OR=1.21, 95%CI, 0.48-3.03; dominant model: OR=0.86, 95%CI, 0.50-1.48, recessive model: OR=1.21, 95%CI, 0.62-2.33, and allele comparison: OR=1.17, 95%CI, 0.79-1.76, respectively). Apparent heterogeneity was detected. However, no evidence of publication bias was found.Conclusions: A relative deficiency of Vitamin B5 and further increases in steroid hormone level in the GDM subjects compared to the controls at the late pregnancy were strongly associated with GDM. This meta-analysis provides evidence that the ADIPOQ +45 T/G polymorphism was not related to the risk of GDM. Further multicentre, prospective studies with larger sample size are valuable to confirm the result.更多还原