| Part OneBackground and purpose:Vertigo can occur at any age and is caused by dysfunction of the balanced triple system.There are many types of diseases that can cause vertigo,including central and peripheral vertigo disorders.Benign paroxysm positional vertigo(BPPV)is the most common peripheral vertigo disease with transient vertigo outbreak.The incidence of BPPV accounts for 20-30%of vertigo,and its clinical manifestations include transient paroxysmal vertigo related to head movements accompanied by symptoms of nystagmus,nausea,vomiting,apart from symptoms such as tinnitus and deafness.The average age of BPPV is 40 to 70 years old.Until 1969,its pathogenesis was proposed by the theory of ear sand.Later,it was found during surgery that movable sand-like particles were found in the semicircular canal lymph fluid of patients with vertigo,which was later named as otolith(ear sand).Then,the pathogenesis was gradually accepted among medical researchers.There are many causes of BPPV,which can be generally divided into idiopathic BPPV and secondary BPPV.The prevalence of BPPV is high,and it can recur,which have effect on patients' daily work and quality of life during the onset.The non-specialist doctors have little knowledge on the disease in the past.Patients attending to emergency and medical internal clinics are often misdiagnosed as cervical dizziness,posterior circulation ischemia,Meniere syndrome and other diseases,and therefore cannot be treated symptomatically.Although the knowledge of BPPV have been widely known and the pathogenesis of BPPB have been explained partially,the related risk factors of BPPV still need to be further studied.Methods:Research subjects:Patients diagnosed with idiopathic BPPV in the Department of Neurology,Bao Tou Central Hospital from January 2016 to January 2018 were selected.The diagnostic criteria were in line with the 'Benign Paroxysmal Location' developed by the American Academy of Otolaryngology Head and Neck Surgery Guidelines for the diagnosis and treatment of dizziness(2017 edition).Research methods:?.Research subjects:idiopathic BPPV group and normal healthy control group.?.General information:collecting the name,gender,age,systolic blood pressure,diastolic blood pressure,history of hypertension,history of diabetes and smoking and drinking history of each patient with idiopathic BPPV case group and normal control group.?.Detection of biochemical indicators:2mL of peripheral venous blood was drawn from the patients on an empty stomach at least 8 hours in the morning and promptly sent to Bao Tou Central Hospital Laboratory for total cholesterol,low-density lipoprotein cholesterol,blood uric acid,and fasting blood glucose.IV.The study was approved by the Ethics Committee of Bao Tou Central Hospital,and all the subjects signed the informed consent.V.Statistical method:Statistical analysis was performed using(SPSS)20.0 software.The measurement data is indicated by(x±s),the comparison between the two groups using independent sample t test,and the comparison between multiple groups using single factor analysis of variance.Logistic regression was used to analyze the correlation between BPPV and its susceptibility factors.Results:I.General information:A total of 120 patients with idiopathic BPPV were diagnosed in the Department of Neurology,Bao Tou Central Hospital from January 2016 to January 2018,including 47 males(39.2%)and 73 females(60.8%)),The male to female ratio was 1:1.6,and the average age was(61.30±9.20)years.Among them,86 cases of semi-regular BPPV accounted for 71.6%,16 cases of horizontal semi-regulated BPPV accounted for 13.3%,12 cases of semi-regulated BPPV accounted for 10.3%,and 6 cases of mixed semi-regulated BPPV accounted for 5.3%.Of the 120 patients with BPPV,20 patients had diabetes,accounting for 16.7%.Among BPPV patients,26 patients had hypertension,accounting for 21.67%.15 cases were smoking,accounting for 15%,and 5 cases were drinking,accounting for 4.17%.Normal control group:A total of 60 healthy non-BPPV healthy subjects were randomly selected from our hospital's contemporaneous physical examination center.There were 24 males(40%)and 36 females(60%).Sixty healthy subjects had diabetes mellitus in 4 cases,accounting for 6.7%.Seven patients had hypertension,accounting for 11.67%.4 cases were smokers,accounting for 6.67%,and 3 cases were drinking,accounting for 5%.?.Age comparison between BPPV group and control group(t=-0.056,P=0.945),there is no significant difference between the two groups(p>0.05),and the two groups are comparable.Gender comparison between BPPV group and control group:x2=0.102,p=0.705,there was no significant difference between the two groups(p>0.05),and the two groups were comparable.III.Comparison of vascular risk factors:Comparison of hypertension history between BPPV group and control group:x2=2.672,p=0.102,the difference was not statistically significant(p>0.05).Comparison of diabetes history between BPPV group and control group:x2=3.462,p=0.063,the difference was not statistically significant(p>0.05).Comparison of smoking in BPPV group and control group:x2=1.442,p=0.230,the difference was not statistically significant(p>0.05).Comparison of drinking between BPPV group and control group:x2=0.065,p=0.798,the difference was not statistically significant(p>0.05).?.Comparison of quantitative data:Comparison of systolic blood pressure between the BPPV group and the control group:t=1.502,p=0.145,there was no significant difference between the two groups(p>0.05).Comparison of diastolic blood pressure between BPPV group and control group:t=0.369,p=0.702,there was no significant difference between the two groups(p>0.05).Comparison of total cholesterol between the BPPV group and the control group:t=2.356,p=0.008.The total cholesterol level of the BPPV group was significantly higher than that of the control group(p<0.05).The difference between the two groups was statistically significant.Comparison of low-density lipoprotein cholesterol between BPPV group and control group:t=-1.563,p=0.124,there was no significant difference between the two groups(p>0.05).Comparison of blood uric acid in BPPV group and control group:t=2.073,P=0.032,blood uric acid level in BPPV group was significantly higher than that in control group(p<0.05),and the difference between the two groups was statistically significant.Comparison of fasting blood glucose between BPPV group and control group:t=-1.269,p=0.215,there was no significant difference between the two groups(p>0.05).V.Logistic regression analysis:total cholesterol and blood uric acid levels were positively correlated with BPPV(OR=2.298,95%confidence interval 1.252?4.350,p=0.007;OR=1.123,95%confidence interval 0.9871.987,p=0.042).There was no significant difference in the correlation between gender,age,smoking,drinking,systolic blood pressure,diastolic blood pressure,low-density lipoprotein cholesterol,fasting blood glucose and BPPV(p>0.05).Conclusions:I.The incidence of BPPV in women is higher than that in men,and it is more common in middle-aged and elderly patients.?.Lateral semicircular canal otoliths are most common in BPPV patients.?.The levels of hypertension,diabetes,smoking,drinking,and low-density lipoprotein cholesterol in this study were not statistically significant between the BPPV group and the control group.Due to the limited number of patients participating in this study,a larger number of cohorts will be needed in the future Clinical studies to confirm whether these factors are related.?.This study confirms that total cholesterol levels and blood uric acid are risk factors for BPPV,but more patients need to be included for multi-center studies to further confirm.Part TwoBackground and purpose:With the further study of BPPV,clinicians have discovered that BPPV has a genetic tendency.Some studies have shown that there are genetic factors in the occurrence and pathogenesis of BPPV,because many patients with BPPV have a family history of BPPV.Recent studies have found that mutations in the voltage-dependent calcium channel ?1A subunit(CACNA1A)gene are related to some episodic diseases of the nervous system and episodic vestibular syndrome(EVS),such as familial hemiplegia migraine(FHM),spinal cerebellar ataxia type 6,episodic ataxia,epilepsy,etc.The CACNA1A gene is located at 19P13 and encodes Cav2.1 protein.It is involved in the ?1A subunit encoding P/Q voltage-dependent calcium channels.This channel is located on the neuronal membrane and is distributed in the brain and neuromuscular junctions,mediating nerve endings and synapses.The release of the launcher is also involved in the development of the nervous system.Previous studies have shown that the CACNA1A gene may change the function of calcium channels through mutations,affecting the release of synapses and neurotransmitters,and is related to paroxysmal attacks of neurological disease symptoms.Single nucleotide polymorphism(SNP)refers to the technology of DNA sequence polymorphism caused by the denaturation of a single nucleotide at the genome level,characterized by large number,wide distribution and high stability.And it has been applied to the research of gene mapping,association analysis,individual disease susceptibility analysis and pharmacogenomics of complex diseases.Polymorphism in a nucleic acid sequence due to a single nucleotide change.SNP is the smallest unit for examining genetic variation.It is generally believed that adjacent single nucleotide polymorphisms tend to be passed on to offspring together.A group of related SNP alleles located in a region on a chromosome is called a haplotype.The polymorphism of SNP only involves the mutation of a single base,which can be caused by a single base conversion,transversion,insertion or deletion,but SNP is generally referred to as a transition or transversion.Since the CACNA1A gene is related to spontaneous diseases of the nervous system and episodic vestibular diseases,and BPPV is also a paroxysmal disease,is there a relationship between them?It is unclear whether the CACNA1A gene polymorphism is related to the pathogenesis of BPPV.Therefore,this study enrolled patients with idiopathic BPPV to detect genetic polymorphisms at seven loci in the CACNA1A gene:rs2074880(T/G),rs492624(T/C),rs10416717(G/A),rs7254351(G/T),rs16030(A/G),rs2248069(A/G),rs4926293(C/T),and explored the relationship between CACNA1A gene polymorphism and BPPV.Methods:?.Research subject:similar to the part one.?.Research methods:Selection of research sites:The full sequence of the CACNA1A gene was found using the US NCBI website platform(http://www.ncbi.nlm.nih.gov/),and the file was downloaded and saved.Then,through Haploview software,the pairwise labeling method was used for screening.Finally,in the labeling SNPs screening software Tagger(http://www.broadinstitute.org/mpg/tagger/server.html),7 CACNA1A genes were selected.Polymorphic loci for research:rs2074880(T/G),rs4926244(T/C),rs10416717(G/A),rs7254351(G/T),rs16030(A/G),rs2248069(A/G),rs4926293(C/T).?.DNA extraction:3 mL of peripheral venous blood was drawn from the patient on an empty stomach at least 8 hours in the morning,and EDTA was anticoagulated.The samples were frozen and stored in-80? refrigerator to prepare DNA for extraction.According to the specific steps in the kit instructions,a medium-dose whole blood(Beijing BioTeke company)genomic DNA extraction kit was used for DNA extraction.IV.Determination of DNA concentration:The Nano Drop-2000 spectrophotometer from Thermo Scientific Corporation was used to measure the DNA concentration.Single Nucleotide Polymorphism(SNP)Genotyping:Use the Mass ARRAY sequencing platform of Agena Bioscience,USA to type the SNP loci studied.All polymorphic loci are passed through the convenient and fast Mass ARRAY Assay design software(V4.0)for corresponding primer design,followed by multiplex PCR process for each sample,Mass ARRAY iPLEX single base extension technology,and matrix-assisted laser desorption/ionization mass spectrometry-Time of flight(MALDI-TOF),through these steps we can get typing results.V.Statistical method:Chi-square test was used to analyze whether the genotype distribution accorded with Hardy-Weinberg equilibrium.The R x C table chi-square test was used to compare the genotype and allele frequencies of each group.Univariate analysis of variance was used to test the correlation between genotype and quantitative data.P<0.05,indicating a statistically significant difference.Results:?.General information:Two of the 120 patients in the BPPV group had a family history(1.7%).?.Genetic balance test:Chi-square test is performed on the actual and theoretical frequencies of the 3 genotypes of the 7 gene polymorphisms of the CACNA1A gene in the BPPV group and the control group,and the 7 gene polymorphisms of the CACNA1A gene The distribution of the three genotypes in both groups accorded with Hardy-Weinberg equilibrium(p>0.05).III.Comparison of genotype distribution frequency of CACNA1A gene between BPPV and control group:The distribution frequency of rs2074880(G/T)locus genotype is different between BPPV group and control group(x2=5.865,p=0.043)There was statistical significance(p<0.05).Other sites of the CACNA1A gene are rs4926244(T/C)(?2=5.826,p=0.054),rs10416717(G/A)(?2=5.209,p=0.074),rs7254351(G/T)(?2=5.482,p=0.065),rs16030(A/G)(?2=1.76,p=0.414),rs2248069(A/G)(?2=1.55,p=0.46),rs4926293(C/T)(?2=0.22,p=0.89)There was no significant difference in the distribution frequency of genotype between BPPV and the control group,there was no statistical significance(P>0.05).IV.Pairwise comparison of the genotype distribution frequency of CACNA1A gene in BPPV group and control group:CACNA1A gene rs2074880(G/T)locus.The frequency of TT,TG and GG genotypes in BPPV group were 25.00%,58.33%and 16.67%,respectively.The frequency of TT,TG,and GG genotypes in the control group were 33.33%,45.00%,and 21.67%,respectively.The frequency of TT genotype distribution was lower than that of TG type(?2=6.245,p=0.041,OR=0.579,95%confidence interval=0.282-1.188),the difference is statistically significant(p<0.05),the frequency of TT type distribution is higher than that of GG genotype(?2=5.907,p=0.034,OR=0.279,95%confidence interval=0.123?0.633),the difference There was statistical significance(p<0.05);the frequency of TG genotype distribution was higher than that of GG genotype(x2=1.544,p=0.214),and the difference was not statistically significant.Three other positions of the CACNA1A gene:rs4926244(T/C),rs10416717(G/A),rs7254351(G/T),rs16030(A/G),rs2248069(A/G),rs4926293(C/T)There was no significant difference in genotypes between BPPV and the control group,and there was no statistical significance(p>0.05).?.There was no statistical difference between the allele distribution frequencies of CACNA1A gene in the BPPV group and the control group(p>0.05).?.Correlation analysis between genotype of rs2074880 locus of CACNA1A gene in BPPV group and quantitative data:3 genotypes of CACNA1A gene rs2074880 locus in BPPV group and total cholesterol and blood uric acid(?2=3.142,p=0.006;x2=2.189,p=0.043)were statistically significant(p<0.05).Three genotypes and age of CACNA1A gene rs2074880 locus in BPPV group(?2=-0.256,p=0.276),systolic blood pressure(x2=1.436,p=0.134),diastolic blood pressure(x2=0.376,p=0.698)There was no significant correlation between low-density lipoprotein cholesterol(x2=1.453,p=0.136)and fasting blood glucose(x2=1.272,p=0.235),without statistical significance(p>0.05).Further analysis of the total cholesterol and blood uric acid levels of the three genotypes showed that the total cholesterol and blood uric acid levels of the TT genotype were significantly higher than those of the GG genotype(p<0.05).Conclusions:?.The occurrence of BPPV is related to the dominant homozygous mutation of CACNA1A gene rs2074880(T/G),while CACNA1A gene rs4926244(T/C),rs10416717(G/A),rs7254351(G/T),rs16030(A/G),rs2248069(A/G),rs4926293(C/T)loci are not related to the occurrence of BPPV.?.Among the risk factors of BPPV,elevated cholesterol and uric acid levels are related to mutations in the TT genotype of the CACNA1A gene rs2074880.However,due to the limited number of patients participating in this study,a large number of cohort clinical studies will be needed to validate these findings in the future. |
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