The Deletion/Insertion Polymorphism Of The Angiotensin Converting Enzyme In Chinese Patients With Sporadic Hypertrophic Cardiomyopathy

Background and purpose:Hypertrophic cardiomyopathy(HCM)is a common disease which represents a main cause of sudden death.Despite extensive physiologic investigation,the primary determinants of HCM,as well as the factors which determine specific clinical outcomes,such as left ventricular hypertrophy and remodeling,remain unknown.The rennin-angiotensin system has an independent direct role in modulating cardiac growth.There has been few reports about deletion/insertion (D/I) polymorphism of the angiotensin converting enzyme (ACE) gene in patients with HCM and the results remained controvertial.The aim of the study was to analysize:1.The distribution of the I/D polymorphism of ACE gene in the Chinese population in comparison with that in the Caucasian and the Japanese population;2.The association between the ACE genotype and left ventricular hypertrophy or remodeling in patients with HCM;3.The influence of the ACE genotype on the intermediat phenotype of ACE;interacting effect between the ACE and genotype of the risk of HCMAThe association between the ACE gene I/D polymorphism and the phenotype of ventricular arrthymia in patients with HCM.Methods:200 subjects were examined including 98 normal individuals (group I),aged 18~65 years,and 102 patients with HCM (group â…¡),aged 20~68 years. 1.Investigate and record the case history of the subjects such as hypertention ,diabetes,mellitus,renal diseaseetc.especially the family history of HCM.2.Perform systemic physical examination and record the body height , body weight to calculate the body surface area(BSA).3.Determine the serum total cholesterol(TC),blood glucose, ACE and so on.4.Assess left ventricular mass(LVM) and geometry with sonarography in HCM.Two dimentional echocardiography was performed and images of the left ventricle were obtained in the parasternal long-axis and short-axis and apical two-chamber and four-chamber views.The magnitude of LVH was determined by calculating echocarcardiographic LVM by the area-length method as recommended by the American Society of Echocardiography and was index to BAS(LVMI).The extent of asymmetric hypertrophy. 5.The insertion/deletion(I/D) polymorphism of ACE gene was studied using polymerase chain rection(PCR)..6.Ventricular arrthymia recorded with 24 hours monitoring system typed PI200A made by U.S.A.7.Statistical methods:q test,t test,ANOVA, x ~2 test,covariance test,multivariate linear stepwise regression analysis.Results: l.The frequency of DD genotype and rare D(deletion) allele were significantly lower than that reported in Caucasian(P<0.001),but similar with Japanese.2.Higher frequency of DD genotype and rare D allele were found in HCM patients compared with controls(P<0.05).3.LV mass index (LVMI)and the left ventricular hypertrophy score (LVHS) were calculated in HCM patients.After adjustment for other covariables,the DD genotype was associated with significantly higher LVMI and LVHS than those in II genotype.On multiple regression analysis,the ACE genotype were independently related to LVMI and LVHS respectively.The ACE genotypes accounted for 3.9 % and 6.5 % of the variability of the LVMI and the extent of hypertrophy,respectively.4.DD genotype was associated with higher level of serum ACE in comparison with the level of II genotype in HCM and normal groups.5.DD genotype was associated significantly with higher total percentage of ventricular premature beat (VPB) and the percentage Grade III on Lown's classification of VBP in comparison with those of II genotype in HCM group.Conclusions:l.The distribution of I/D polymorphism of the ACE gene was...