盐敏感性高血压候选基因的验证及其风险预测模型的构建

Salt-sensitive hypertension increases the morbidity and mortality and was identified as an idependent risk factor for cadiovascular disease. However, there is lack of the reports that integrating genetic and environmental fators to construct the risk predictive model for salt-sensitive hypertension. Based on the results of our previous researches focusing on screening the candidate genes for salt-sensitive hypertension in a Japanese population, we propose to conduct a case-control study to examine the association between the environmental risk factors and genetic factors with salt-sensitive hypertention. A modified Sulliran's acute salt load method is conducted among essential hypertensive and normotensive to identify the salt-sensitivity and salt-resistant. A medical history, lifestyle risk factors are obtained by questionnaire, while blood pressure and weight are measured by physical examination, and blood and urine specimens are collected to test the biochemical indicators. The daily sodium intake of individuals is assessed by food frequecy questionnaire and 24 hours urinary sodium excretion. Candidate single nucleotide polymorphisms (SNPs) are summarized from three approches: tag-SNPs of candidate genes in pathogenic passway of salt-sensitive hypertension; literature retrieval of association studies in candidate SNPs and GWAS results of salt sensitivity. All SNPs are genotyped using high throughput sequencing method by Sequenom MassARRAY Platform, and multiple logistic analysis and latent class model based on bayesian network are used to analyse the overall effect of high-dimensional, multiple SNPs on salt-sensitive hypertension. Decision tree analysis is used to construct a genetic and environmental risk predictive model, ROC curve are used to assess the predictive performance of the model. This research will contribute significantly to knowledge about predicting salt-sensitive high risk population, and is useful for development of targeted intervention for the prevention and treatment of salt-sensitive hypertension.

盐敏感性高血压增加心血管疾病发病风险和死亡率，是导致心血管事件发生的独立危险因素。目前尚缺乏综合环境危险因素和遗传易感基因多态性构建盐敏感性高血压风险预测模型的研究报道。本研究在前期完成的日本人群盐敏感性高血压候选基因筛选工作基础上，拟采用病例对照研究方法，选取原发性高血压患者和血压正常对照者作为研究对象，利用急性盐负荷试验判定盐敏感者，采用问卷调查、体格检查和生化指标检测筛选环境危险因素；综合致病通路上的候选基因并选取tagSNPs、循证检索已发表的关联性研究和GWAS研究报道的易感SNPs，采用Sequenom高通量检测技术进行基因分型，利用贝叶斯网潜类模型分析高维多位点SNPs整体效应与盐敏感性高血压的关联；整合传统危险因素和遗传易感SNPs，利用决策树分析方法构建盐敏感性高血压风险预测模型并进行评价。为预测盐敏感性高危人群，实施早期筛查和个体化治疗提供理论依据。

盐敏感性高血压增加心血管疾病发病风险和死亡率，是导致心血管事件发生的独立危险因素。采用改良的Sullivan急性口服盐水负荷及呋塞米排钠缩容试验判定盐敏感者和盐抵抗者，使用问卷调查、体格检查和生化指标检测筛选环境危险因素。利用Sequenom高通量检测技术对39个候选基因和14个miRNA共99个SNPs进行基因分型筛选和验证遗传生物标志物。本研究建立了2057例中国北方两城市“血压盐敏感性系统流行病学队列”（A Cohort Study of Systems Epidemiology on Salt-Sensitivity of Blood Pressure），简称EpiSS队列。利用基于人群的病例对照研究，选取583例盐敏感者和1474例盐抵抗者，分析影响血压盐敏感性的环境和遗传危险因素并构建预测模型。结果发现：①原发性高血压患者中携带PRKG1 rs7897633-A、SLC8A1 rs434082-A、ADRB2 rs1042714-G及PRKG1-AG单倍型者患盐敏感性高血压的风险增加，遗传风险评分分析发现携带2-4个危险等位基因组风险增加3.32倍；SLC8A1 rs434082-A高血压患者在急性盐水负荷过程中，DBP升高2.8mmHg，MAP升高3.1mmHg。②第二阶段验证性结果一致的SNPs为PRKG1 rs7897633-AA，新发现BCAT1 rs7961152-AA、CYBA rs4673-AA与盐敏感性高血压相关。FGF5-rs16998073-TT、GRK4 rs1801058-CC、STK39 rs3754777-CC、EDNRB-AS1 rs5351-CC、SLC24A3 rs6112470-TT、CYBArs4673-AA与血压正常者的盐敏感性相关。③多因素非条件Logistic回归分析发现hsa-mir-382-5p rs4906032 -GG等6个SNPs是影响血压盐敏感性的遗传危险因素。改进经典蚁群聚类算法并进行评价，首次把该方法应用到高维度SNPs数据挖掘中，结果发现其与潜在类别分析方法具有相似的聚类效果。利用Logistics回归和决策树分析方法构建盐敏感性高血压风险预测模型并进行评价，为预测盐敏感性高危人群，实施早期筛查和个体化治疗提供理论依据。