ABSTRACT
OBJECTIVE: Our objective was to investigate the interactions between common polymorphisms in ABCB1, CYP3A4, and CYP3A5 genes and the lipid-lowering efficacy and safety of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor simvastatin. METHODS: One hundred sixteen hypercholesterolemic patients were prospectively screened by physical examination, medical history, and clinical laboratory evaluation and were included in this study. Subjects entering the study were treated with 20 mg/d simvastatin. Plasma lipid and lipoprotein levels were measured before treatment, after 2 months of treatment, and after 6 months of treatment. Ninety-nine patients completed the 6-month follow-up and were included in the association analysis for treatment efficacy. Seventeen subjects who had adverse drug reactions (ADRs) to simvastatin (ADR group) could not complete the 6-month follow-up and were included in the association analyses for safety. Myalgia was observed in 15 of 17 subjects and was the only ADR included in the association analyses, but other common ADRs were also observed. Myalgia was defined as proximal or diffuse muscle pain, tenderness, or weakness, or both pain and weakness, with normal or slightly increased serum creatine phosphokinase levels. ABCB1 (1236C>T, 2677G>A/T, and 3435C>T), CYP3A4 (-392A>G), and CYP3A5 (6986A>G) allele variants were determined by polymerase chain reaction and restriction mapping. RESULTS: After adjustment for covariates, carriers of the ABCB1 1236T variant allele had a greater reduction in total cholesterol and low-density lipoprotein cholesterol with simvastatin treatment, as compared with homozygotes with the wild-type allele (-29.0% [95% confidence interval (CI), -25.9 to -32.5] versus -24.2% [95% CI, -19.0 to -29.3] [P = .042] and -39.6% [95% CI, -35.8 to -44.0] versus -33.8% [95% CI, -27.4 to -40.2] [P = .042], respectively). Similar results were observed for the 2677G>A/T polymorphism and haplotype data. The 1236T, 2677non-G, and 3435T alleles were less frequent in ADR cases than in the non-ADR group (P < .05 for all single-nucleotide polymorphisms). Haplotype analyses also demonstrated a reduction of the T-non-G-T haplotype frequency (20%) in patients in whom myalgia developed during simvastatin treatment, as compared with the non-ADR group (41.4%) (P = .03). No significant associations were observed between the CYP3A4 -392A>G and CYP3A5*3 allele variants and the efficacy or tolerability of simvastatin. CONCLUSIONS: Our data suggest an association of ABCB1 gene polymorphisms and the efficacy and safety of simvastatin.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Cytochrome P-450 Enzyme System/genetics , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Lipids/blood , Simvastatin/adverse effects , Simvastatin/therapeutic use , ATP Binding Cassette Transporter 1 , Adult , Aged , Aged, 80 and over , Alleles , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Cytochrome P-450 CYP3A , DNA/genetics , Female , Genetic Variation , Haplotypes , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Prospective Studies , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
BACKGROUND: In recent years, one of the focuses of genetic investigation in cardiology has been to identify the genetic factors associated with variable response to statin treatment. Polymorphisms in apolipoprotein E (APOE), cholesteryl ester transfer protein (CETP) and hepatic lipase (LIPC), proteins with major roles in lipid metabolism and homeostasis have been shown associated with lipid-lowering drugs response. METHODS: One hundred forty-six hypercholesterolemic patients of European descent were prospectively enrolled and treated with simvastatin 20 mg per day for over 6 months. Ninety-nine subjects completed the 6-month follow-up. Plasma lipids and lipoproteins were measured before and throughout the study. APOE (E*2, E*3 and E*4), LIPC-250A > G and CETP TaqIB genotypes were determined by PCR and restriction mapping. RESULTS: After a 6-month follow-up, no differences among genotypes in the percentage variation in lipid and lipoprotein concentrations for APOE and LIPC SNPs were observed. After adjustment for covariates, CETP B2B2 homozygotes showed a greater HDL-cholesterol increase compared to B1B2 and B1B1 subjects (14.1% vs. 1.7% and 1.3%, P < 0.05, respectively). CONCLUSION: Our study demonstrates that individual plasma HDL-cholesterol response to simvastatin is mediated, in part, by the CETP gene locus, with the B2 homozygotes having more benefit in HDL-C improvement than carriers of B1 allele.