Association Of Apolipoprotein A5 Gene Polymorphism With Type 2 Diabetes Mellitus

Object To investigate the distribution of apolipoprotein A5 (APOA5) -1131T/C polymorphism and C.553G/T polymorphism in the Han population in Zhenjiang, and to explore its effects on lipid metabolism and its relationship with type 2 diabetes mellitus (DM) patients.Methods The genotypes of APOA5 -1131T/C polymorphism and C.553G/T polymorphism were determined in 152 healthy individuals and 71 type 2 DM patients by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and agarose gel electrophoresis methods. Serum levels of lipids, glucose and insulin in these subjects were also estimated by biochemical methods.Results (1) The frequency of the APOA5 -1131C allele was 0.296 similar with that of Japanese, which was significantly higher than that of Caucasians, African-Americans and Hispanics. The frequency of the APOA5 553T allele was 0.049 similar with that of Taiwanese, which was significantly higher than that of Caucasians and Americans. (2) The serum levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-c) and apolipoprotein B (ApoB) in APOA5 -1131C-carriers (TC+CC) had a 63.7% (P=0.002), 87.8% (P=0.000), 70.8% (P=0.000) and 20.8% (P=0.000) increase as compared to non-C carriers (TT), respectively, and had a 11.1% (P=0.002) decrease in high density lipoprotein-cholesterol (HDL-c) levels. The serum levels of TG in APOA5 553T-carriers (GT+TT) had a 97.9% (P=0.005) increase as compared to non-T carriers (GG), and had a 56.9% (P=0.022) increase in LDL-c levels. (3) The serum levels of FPG, FINS, HOMA-IR in APOA5 -1131TC genotypes and CC genotypes were increasing compared with TT genotypes, but statistical difference was not found (P>0.05), and there was no significant difference with H0MA-βlevels. There was no significant difference between the serum levels of FPG, FINS, HOMA-IR and HOMA-βof APOA5 553GT+TT genotypes and 553GG genotypes (P>0.05). (4) The frequency of APOA5 -1131C allele in DM group is significantly higher than that of control group (P=0.006). When compared with the non-C carriers, C-carriers had a significantly increased DM risk (OR=3.28 and OR=2.56 using unadjusted and adjusted logistic regression models, respectively). -1131TC+CC/553GT+TT genotypes had a significantly increased DM risk (OR=4.04 and OR=3A2 using unadjusted and adjusted logistic regression models, respectively) as compared to -1131TT/553GG genotypes.Conclusion (1) There was -1131T/C and C.553G/T polymorphism of APOA5 gene in the Han population of Zhenjiang and there was difference in various ethic and regional people. (2) The APOA5 -1131T/C and c.553G/T polymorphism was associated with serum TG level in the population, and -1131C allele and 553T allele were contributed to the increase of serum levels of TG and LDL-c. (3) The APOA5 -1131T/C and C.553G/T polymorphism were not associated with insulin resistance in DM patients. (4) The APOA5 -1131T/C polymorphism but not C.553G/T polymorphism might contribute to an increased risk of DM among Chinese.