Apolipoprotein M T-778C polymorphism is associated with serum lipid levels and the risk of coronary artery disease in the Chinese population: a meta-analysis

Background: The apolipoprotein M (APOM) T-778C gene polymorphism has been associated with serum lipid levels and the risk of coronary artery disease (CAD), but the results are inconclusive. The purpose of this meta-analysis was to detect the association between the APOM T-778C polymorphism and serum lipid levels and the risk of CAD in the Chinese population. Methods: Databases of MEDLINE, EMBASE, the Cochrane Library and CNKI were systematically searched. Data were extracted using standardized methods. The association was assessed by mean difference (MD) with 95% confidence intervals (CI) or odds ratio (OR) with 95% CI. Results: Ten studies with 4,413 patients were included in this meta-analysis. Pooled effects indicated that CT+CC group had higher levels of total cholesterol (TC) (MD: -0.36, 95% CI: -0.53 - -0.19, P < 0.0001) and low-density lipoprotein cholesterol (LDL-C) (MD: -0.08, 95% CI: -0.16 - -0.01, P = 0.03) than TT group. There was no difference in the levels of triglyceride (MD: 0.06, 95% CI: -0.04 - 0.15, P = 0.22) and high-density lipoprotein cholesterol (MD: 0.00, 95% CI: -0.03-0.03, P = 0.93) between TT and CT+CC groups. Pooled effects showed that CAD group had higher CT+CC genotype frequency than control group (OR: 1.97, 95% CI: 1.62-2.39, P < 0.00001; heterogeneity test x(2) = 2.96, P = 0.71, I-2 = 0%). Conclusions: The results of the current meta-analysis show that the CT+CC group has higher levels of TC and LDL-C than the TT group. Moreover, there is also a prominent association between APOM T-778C polymorphism and the risk of CAD in the Chinese population, the CT+CC genotype is associated with increased risk of CAD.