Efecto de variantes de los genes ABCB1 y CYP3A4 sobre la respuesta terapéutica a atorvastatina en individuos chilenos hipercolesterolémicos

background: : statins are effective in the control of hypercholesterolemia. however, the therapeutic response to these drugs presents a great inter-individual variability. factors such as age, gender and ethnicity have been associated to this variability. recent studies show that polymorphisms can influence the lipid-lowe-ring response to statins. the aim of the present study was to investigate the effect of three polymorphisms 3435c>t (abcb1), 2677g>a/t (abcb1) and -290 a>g (cyp3a4) gene on the response to atorvastatin treatment in chilean hypercholesterolemic individuals. methods: 94 hypercholesterolemic individuals, were treated with atorvastatin, 10mg/day for 4 weeks. we determined serum levels of total cholesterol, hdl-c, ldl-c and triglycerides, before and after treatment. the polymorphisms were analyzed by pcr-rflp. results: significant reductions were observed in total cholesterol (275 ± 18 vs. 235 ± 22 mg/dl, p<0.001), ldl-c (183 ± 16 vs. 146 ± 24 mg/dl, p<0.001) and triglycerides levels (225 ± 48 vs. 172 ± 51 mg/dl, polymorphisms on the therapeutic hypercholesterolemic individuals p<0.001). in addition, an increase in the hdl-c levels was observed (47 ± 10 vs. 55 ± 7, p<0.001). the genotype distribution for 3535c>t variant of abcb1 gene was: cc=47.9%, ct=41.5% and tt=10.6%. the genotype distribution for 2677g>a/t polymorphism (abcb1) was aa=1.1%, ga=14.9%, gt=28.7%, ta=9.6%, tt=8.5% and gg=37.2%. the genotype distribution for -290a>g variant of cyp3a4 gene was: aa=77.7%. ag=22.3% and gg=0.0 %. subjects carrying the g allele for the -290 a>g variant of the cyp3a4 gene, exhibited a greater reduction in total cholesterol (p=0.001) and ldl-c levels (p<0.001). no differences were observed for the other polymorphisms studied. conclusion: this study suggests that the therapeutic response to atorvastatin (10mg/day during 4 weeks) is influenced by the -290 a>g variant of cyp3a4 gene.