Association Of C-Reactive Protein-related Gene Polvniorphisms With Risk Of Ischemic Stroke:A Nested Case-Control Study

Backgrounds and ObjectivesIschemic stroke is a disorder of blood supply in the brain tissue,with high rates of incidence,disability rate and recurrence rate.China is one of the countries with the highest incidence of stroke.C-reactive protein(CRP)is an acute phase reactive protein,which is a marker of atherosclerosis and can promote the development of atherosclerosis.Environmental factors and genetic factors can affect the expression of C-reactive protein,thus affecting the risk of ischemic stroke.Genome-wide association analysis(GWAS)has reported that CRP related genes could be associated with risk of ischemic stroke,including C-reactive protein gene(CRP gene),hepatocyte nuclear factor 1A gene(HNF1A gene),apolipoprotein E gene(ApoE gene),leptin receptor gene(LEPR gene),Interleukin 6 gene(IL-6 gene)and arginase I gene(ARGI gene).A number of studies have indicated the susceptibility genes of ischemic stroke,which are also related to CRP.However,the genetic role of CRP-related genes remains unclear.In previous studies,susceptibility genes of ischemic stroke,single gene and a few loci were often used as research indicators,and limited environmental factors were used to examine the interaction effects between genes and environment.Therefore,we used a nested case-control study,to examine the association between C-reactive protein-related gene polymorphisms and the risk of ischemic stroke,to evaluate the interaction effects between gene polymorphisms and environmental factors,and to assess the association between genetic risk score and the risk of ischemic stroke.Material and MethodsThe study was designed as a nested case-control study.The cohort was established from April 2010 to September 2011.A total of 15,236 people were enrolled in the cohort.Baseline information of all subjects in the cohort was obtained through questionnaires,and 10 ml peripheral venous blood was extracted and stored in a refrigerator at-80 C.During the follow-up period(October 2011-July 2017).141 patients with newly diagnosed atherosclerotic ischemic stroke were enrolled in the case group.At the same time,normal individuals who did not suffer from stroke,cardiovascular disease.tumors,renal insufficiency during the follow-up period were selected from the same cohort as a control group.Subjects in the control group were matched as those in the case group by 2:1 with the same sex and the age of ±2 years.A total of 282 individuals were included in the control group.We extracted the DNA for all subjects in these two groups,and 11 SNPs were screened and genotyped in the protein coding regions of six genes(CRP gene.HNF1A gene.ApoE gene,LEPR gene,IL-6 gene,ARGI gene)by second generation sequencing S AS9.4 software was used for statistical analysis.Median and interquartile range(IQR)were used to describe the distribution of continuous variables.Categorized variables were presented by the rate(%).Wilcoxon rank test was used for continuous variables and Pearson ?2 test was used for categorized variables.Three genetic models(additive,dominant and recessive)were calculated by multivariate conditional logistic regression,and the association between genetic polymorphisms and risk of ischemic stroke was evaluated.The gene-environment interaction effects were calculated by a crossover analysis.Genetic risk scores were calculated by a simple count GRS(SSC-GRS)and an odds ratio weighted GRS(OR-GRS),respectively.ResultsThree cases with unqualified DNA extraction and six controls were excluded.Finally,there were 138 cases and 276 controls.There were significant differences in BMI,fruit and vegetable intake and white meat intake distribution between case and control groups.Rs 1800947 in CRP gene was associated with the risk of ischemic stroke(additive model:OR]2.231,95%CI:1.0054.951).The rs1169288 in HNF1a gene was associated with the risk of ischemic stroke(additivcmeodel:OR=1.487.95%CI:1.002-2.207;dominant model:OR=1.386,95%CI=1.001-2.109:recessive model:OR=1.641,95%CI=1.013-2.207).Rs440446 in APOE gene was associated with the risk of ischemic stroke(additive model:OR=0.611,95%CI:0.385,0.972;dominant model:OR=0.646,95%CI=0.396-0.985;recessive model:OR=0.483,95%CI=0.238-0.798).Results from the crossover analysis showed interaction effects of CRP gene rs1800947 and HNF1A gene rs1169288 with smoking,tea drinking,fruit and vegetable intake and red meat intake,respectively(all P interaction values<0.05),and the effect of APOE gene rs440446 was modified by smoking status(P interaction<0.05).Results from the SSC-GRS and OR-GRS analyses showed a dose-response relationship between genetic risk score and risk of ischemic stroke(P trend<0.05).ConclusionsOverall,in this nested case-control study,CRP rs1800947,HNF1 A rs1169288 and APOE rs440446 are associated with risk of ischemic stroke.The effects of CRP rs1800947 andHNF1A rs1169288 are modified by smoking status,tea drinking,fruit and vegetable intake,red meat intake;and the effect of APOE rs440446 is modified by smoking status;There is a dose-response relationship between genetic risk score and risk of ischemic stroke.