Aim: To investigate the effect of apolipoprotein E (APOE), cholesteryl ester transfer protein (CETP) and proprotein convertase subtilisin kexin type 9 (PCSK9) polymorphisms on the lipid-lowering response to simvastatin therapy in Thai hypercholesterolemic patients.
Method: Two hundred and twenty-five hypercholesterolemic patients in southern Thailand were enrolled and treated with simvastatin 20 or 40 mg per day for 3 months. Serum lipids were measured before and after the therapy. APOE, CETP TaqIB, and PCSK9 (R46L, I474V, and E670G) polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results: After 3 months of simvastatin therapy, subjects with APOE2 (Total cholesterol [TC]: -30.89% vs-13.56%, P < .05, LDL-C: -45.00% vs -17.73%, P < .05) and APOE3 carriers (TC: -26.22% vs -13.56%, P < .05, LDL-C: -37.14% vs -17.73%, P < .05) had greater TC and LDL-C reduction compared to APOE4 carriers, whereas CETP TaqIB B2B2 genotype showed lower TC (-16.37% vs -24.92%, P = .016) and LDL-C (-22.54% vs -35.19%, P = .028) reduction compared to CETP TaqIB B1 carriers. In addition, PCSK9 474IV carriers showed greater LDL-C (-50.57% vs -32.99%) reduction compared to PCSK9 474II carriers. Combined effect analyses showed that individuals carrying more risk alleles tended to have lower TC and LDL-C (P for trend = .000 and .000, respectively) reduction in response to simvastatin therapy.
Conclusion: APOE4 carriers and the CETP TaqIB B2B2 genotype were associated with a decreased response, but PCSK9 474IV carriers tended to be associated with an increased response to simvastatin therapy in Thai hypercholesterolemic patients.
Keywords: APOE; CETP; PCSK9; Polymorphisms; Simvastatin.
© 2017 John Wiley & Sons Ltd.