Apolipoprotein A5 gene polymorphism -1131T→C:: association with plasma lipids and type 2 diabetes mellitus with coronary heart disease in Chinese

Type 2 diabetes mellitus (DM) is associated with significant abnormalities of lipoprotein metabolism and coronary heart disease (CHID). The most commonly recognized lipid abnormality in type 2 DM is hypertrig lyceridemia, which is known to be an independent risk factor for CHD in diabetics. The -1131T -> C polymorphism found in the newly identified apolipoprotein A5 (APOA5) gene has been found to be associated with elevated plasma triglyceride (TG) concentrations in different racial groups. In this study, DNA samples from 155 control subjects, 172 type 2 diabetics and 113 type 2 DM patients with CHD were analyzed to examine the influence of APOA5 1131T -> C polymorphism on plasma lipids and the susceptibility to CHID in type 2 diabetics. The frequency of the APOA5 -1131C allele in the DM +CHD group was significantly higher than that of control subjects (37.2% vs. 27.7%, p=0.021). The distribution of the APOA5 -1131T-C genotypes (TT, TC and CC) was 36.3%, 53.1% and 10.6% in type 2 DM patients with CHD, and 53.6%, 37.4% and 9.0% in controls, respectively (p=0.018).. The frequencies of alleles and genotypes in type 2 diabetics were not significant compared to controls. In controls, plasma TG concentrations in subjects with the TT genotype were significantly lower than in those with TC/CC (0.92, 1.28 and 1.35 mmol/L for TT, TC and CC, respectively; p = 0.003 by ANOVA). These data suggest that the APOA5 -1131T-C polymorphism might play a role in elevated plasma TG levels in type 2 diabetic patients in the Chinese population.