Association of apoE gene polymorphisms with lipid metabolism in renal diseases

BACKGROUND AND OBJECTIVES: Apolipoprotein E (apoE) plays a central role in the metabolism and homeostasis of lipids. ApoE gene encodes three major isoforms: ε2, ε3 a nd ε4 forming six phenotypes: E2E2, E2E3, E2E4, E3E3, E3E3 and E4E4. Disorders of the lipid metabolism and the homeostasis are frequently coexist in renal diseases. The association between gene polymorphisms of apoE and lipid metabolism were not consistent. This meta-analysis was performed to assess the association between gene polymorphisms of apoE and lipid metabolism in renal diseases. METHODS: A pre-defined literatures search and selection of eligible relevant investigations were performed to extract and collect data from electronic databases. RESULTS: Sixteen articles were enrolled for the analysis of association between apoE gene polymorphisms and lipid metabolism. Subjects with E3E4 had a higher total cholesterol (TC) than those with E3E3, and subjects with E2E3 had a lower TC than those with E3E3. Subjects with ε2, had a lower TC than those with ε3 or ε4, and subjects with ε4 had a higher TC than those with, ε3. Subjects with E2E2, E2E3 or E4E4 had a higher triglyceride (TG) than those with E3E3. Subjects with ε4 had a higher TG than those with ε3. Subjects with ε2, had a higher level of TG than those with non-ε2. Subjects with E3E4 had a slightly lower high-density lipoprotein (HDL) than those with E3E3. E3E4 appeared to be associated with lower levels of HDL. Subjects with E2E2, E2E3 had a notably lower low-density lipoprotein (LDL) than those with E3E3. Subjects with ε2, had a lower LDL than those with ε3 or ε4 ApoE gene polymorphisms were not associated with very low-density lipoprotein, and lipoprotein (a) [Lp(a)]. Subjects with E2E3 or E2E4 had higher apoE levels than those with E3E3, and subjects with E4E4 had lower apoE levels than those with E3E3. CONCLUSION: ApoE gene polymorphisms are associated with the expression of TC, TG HDL, LDL, Lp(a) or apoE.