Relationship Between CAT And CAT Gene-262C/T Polymorphism And Diabetic Peripheral Neuropathy Of Type 2 Diabetes Mellitus In Han Chinese Of YunNan

Objective To explore the relationship between serum catalase (CAT)activity and CAT gene promoter region-262C/Tpolymorphism and diabetic peripheral neuropathy(DPN) of type 2 diabetes mellitus (T2DM) in han Chinese of Yunnan.Methods Six hundred unrelated subjects of Han Ethnics in Yunnan,T2DM group(n= 307) and volunteer without DM as normal control group(n=293) were included in the study. Those in T2DM group were further divided into T2DM-DPN (+) group (with DPN, n=161) and T2DM-DPN (-) group (without DPN, n=146),DPN is complement diagnosed by TCSS(≥6point as cut off) and MNSI(≥2point as cut off). Examined serum CAT activity by colorimetry, and compared the activity of CAT among the groups and analyze the correlate between CAT and other variables. PCR-restriction fragment length polymorphism (PCR-RFLP) was employed to detect genotypes of promoter region-262C/T polymorphism of CAT gene, and genotypic, allelic frequencies and clinical characteristics were compared among the groups.Results 1.Serum CAT activity (In CAT:4.567±1.163) in T2DM group was lower than NC group(In CAT:5.046±1.168); serum CAT activity(ln CAT:4.316±1.233) in T2DM-DPN(+) group was lower than T2DM-DPN (-) group (ln CAT:4.868±1.001) too (P<0.05), after ajustment for age,gender body mass index (BMI) serum CAT activity in T2DM,T2DM-DPN(+) group were also significantly different compared with control group(P<0.05); grouping NC group by different age bracket and gender, CAT activity in older group was lower than younger group,and CAT activity in male group was higher than female group (P<0.05).2. CAT was positively associated with TG,FC-P in NC group and negtively with HDL-C; CAT was positively associated with TG,2hC-P in T2DM group,T2DM-DPN(+) group and negtively with HDL-C; CAT was positively associated with TG,0.5hC-P in T2DM-DPN(-) group.3.Logistic regression analysis indicates that the reduction of CAT activity is a risk factor for T2DM,and acatalasemia is lead to risk increment 2.002 times of T2DM than the people with hypocatalasemia[OR=2.002,95%CI (1.221-3.280)].At the same time, that the reduction of CAT activity is a risk factor for DPN too,and the patients who with acatalasemia is lead to risk increment 2.247 times of DPN than that with hypocatalasemia [OR=2.247,95%CI (1.226-4.120)].4. Only one TT genetype homozygote mutation of the CAT gene promoter region -262C /T was found in T2DM-DPN(-) group,no CAT-262C/T mutation was observed in either NC group or T2DM-DPN(+)group.There was no significant difference in genotypic and allelic frequencies between NC group and T2DM group and between T2DM-DPN(-) group and DPN(+) group (P>0.05).5. CAT activity with CC genotypic in T2DM group (In CAT:4.637±1.123) was significantly higher than that with CT+TT genotypic (In CAT:4.051±1.347),and CAT activity with CC genotypic in T2DM-DPN(+) group (In CAT:4.394±1.198) was also significantly higher than that with CT+TT genotypic (In CAT:3.481±1.216) (P<0.05)Conclusion CAT activity was significantly lower than control in T2DM and DPN groups, CAT activity may associate with T2DM,DPN,suggesting the reduction of CAT activity is might be one of the risk factors for T2DM,DPN; The CAT gene promoter region-262C/T polymorphism is not associated with T2DM and DPN in Han ethnics of Yunnan, However, suggesting T allelic might be have an effect on the serum CAT activity in the T2DM and DPN population.