Study Of L296Q Polymorphism In The Cholesteryl Ester Transfer Protein Gene In Type 2 Diabetes Mellitus In Chinese

Background: There are various types of dyslipidemia in type 2 diabetes mellitus(T2DM), including increased triglyceride(TG) and decreased high density lipoprotein-cholesterol(HDL-C). Many studies indicated that low HDL-C level was related to arteriosclerosis, however, the cholesteryl ester transfer protein(CETP) play an important role in HDL-C metabolism.Objective: 1, To investigate the association between L296Q polymorphism in the cholesteryl ester transfer protein(CETP) gene and type 2 diabetes mellitus(T2DM); 2, To investigate the association between CETP gene L296Q polymorphism and lipids (TG and HDL-C).Research design and methods: There are four groups in our research: (1)group of T2DM with hypertriglyceridemia: 71 T2DM patients with hypertriglyceridemia (TG＞1.7mmol/L) were recruited, including 38 male and 32 female(mean age 58.3±12.1); (2) group of T2DM with normal triglyceride (TG＜1.7mmol/L): 77 T2DM patients with normal triglyceride levels(TG＜1.7mmol/L) were recruited, including 45 male and 32 female (mean age 59.3±9.6); (3) group of hypertriglyceridemia without DM: 80 patients with hypertriglyceridemia and normal fasting plasma glucose, HbAlc＜6.2%, without diabetes family history were recruited, including 52 male and 28 female(mean age 48.4±11.1); (4) group of normal control subjects: 76 normal control subjects whose fasting plasma glucose or glucose tolerance and TG levels were normal, HbAlc＜6.2%, they had no diabetes family history, other endocrinal disease, the severe disease of heart, brain, liver, kidney and tumor, consisting of 28 male and 48 female(mean age 56.6±16.3). The glucose, TG and HDL-C were measured in all subjects. The genotypes of L296Q polymorphism in the CETP gene of total 303 subjects were analyzed by real-time fluorescent quantitative PCR(FQ-PCR).Results: 1, The 296LQ and 296QQ genotypes exist in all 4 groups; 2, The frequency of genotypes(296LQ and QQ) is 22.9% in group of T2DM with hypertriglyceridemia, 16.9% in group of T2DM with normal triglyceridemia, 15% in group of hypertriglyceridemia without T2DM, 11.8% in normal control group respectively. There is no significant difference among the four groups(x~2=3.389, P＞0.05); 3, The frequency of A allele gene is 11.4% in group of T2DM with hypertriglyceridemia, 9% in group of T2DM with normal triglyceridemia, 7.5% in group of hypertriglyceridemia without T2DM, 5.9% in normal control group respectively. There is no significant difference among the four groups(x~2=3.141, P＞0.05); 4, There is no significant difference in the frequency of genotypes(296LQ and QQ) in T2DM and non-T2DM; 5, There is no significant difference of lipid levels(TG, HDL-C, TC, LDL-C) between the carriers with A allele gene and TT homozygotes.Conclusion: No relationships were found between L296Q polymorphism in the CETP gene and T2DM as well as TG, HDL-C in all 4 groups.