Relationship Between Methylene Tetrahydrofolate Reductase Gene, Angiotensin Converting Enzyme Gene Polymorphisms And Lowerextremity Deep Venous Thrombosis

Objective: To investigate the relationship between methylene tetrahydrofolate reductase(MTHFR) gene C677T polymorphism,angiotensin converting enzyme (ACE) gene I/D polymorphism and lowerextremity deep venous thrombosis(LEDVT) respectively and jointly.Methods: In order to undertake a case-control study, 88 LEDVT hospitalizd patients(case group) and 108 normal subjects(control group) were studied. Basic clinical data such as age, gender, weight, height were collected; Biochemical parameters such as serum creatinine, urea nitrogen, fasting plasma glucose, lipids were measured; Polymerase chain reaction(PCR) was used to characterize ACE genotypes(ID, II, DD); PCR and restriction fragment length polymorphism(RFLP) were used to characterize MTHFR genotypes(CT, CC, TT). Both of them were confirmed by DNA sequencing. T(t') test, Chi-square test and Logistic regression were used to analyze the data.Result: 1.The levels of age had significant difference between two groups (P<0.05), and the levels of gender, body mass index, aminotransferase, triglyceride, total cholesterol, low-density lipoprotein cholesterol, fasting plasma glucose, urea nitrogen, serum creatinine had no significant difference between two groups (P>0.05). 2.LEDVT becomes more common in people with age above 40, especially with age 71-80. 3.Left lower limb was more common site than the right one(2.67:1). 4.The distributions of ACE and MTHFR genotypes in LEDVT group and control group were under the assumption of the Hardy-Weinberg equilibrium by non-parametricχ2 test(P>0.05). 5.Chi-square test showed that the distributions of ACE-DD, MTHFR-TT and ACE-DD+MTHFR-CT/TT genotypes in LEDVT group(18.2%, 17.0%, 15.9% respectively) were higher than the ones in control group(5.6%, 6.5%, 2.8% respectively). The differences were significant(P<0.05). 6.Binary Logistic regression showed that age, ACE-DD+MTHFR-CT/TT genotypes entered the equation at last and were significantly associated with LEDVT by adjusting other confounding factors (P<0.05). The odds ratio(OR) were 1.027(95%CI:1.009-1.045), 6.557(95%CI:1.776-24.214) respectively.Conclusions: 1. Lowerextremity deep venous thrombosis becomes more frequent in subjects with advancing age. Left lower limb was more common site than the right one. 2. Both ACE-DD genotype and MTHFR-TT genotype were associated with LEDVT respectively. Subjects carrying ACE-DD genotype and MTHFR-CT/TT genotype at the same time were exposed to greater risk of LEDVT than ones carring other genotypes. ACE-DD+MTHFR-CT/TT genotypes might be independent risk factors of LEDVT.