Role of Rs4149056 Polymorphism of SLCO1B1 Gene in Myopathy Caused by Atorvastatin in Cardiovascular Patients in West of Mazandaran Province

Background and purpose: Statins are among the most widely used drugs in treatment of cardiovascular diseases. Reducing the side effects of these drugs is of great importance in preventing treatment failure. The aim of this study was to investigate the role of rs4149056 polymorphism in statin-induced myopathy in patients with cardiovascular diseases in West of Mazandaran province, Iran. Materials and methods: A descriptive cross-sectional study was carried out in 161 patients taking atorvastatin who attended Cardiovascular Clinic in Ramsar Imam Sajjad Hospital and Tonekabon Shahid Rajaee Hospital, 2017-2018. All patients were given atorvastatin at 40 mg daily for 8 weeks and all lipid markers and CPK enzyme levels as a measure of myopathy were measured. Then, the patients received atorvastatin at 20 mg for 4 weeks and all lipid markers were measured again. PCR-ARMS method was used to determine the distribution of rs4149056 polymorphism. Results: According to findings, reducing the dose of atorvastatin caused significant differences in total cholesterol and LDL levels (P<0.05), but the mean of these changes was not significant between different genotypes (P>0.05). Drug dose change caused significant differences in levels of triglycerides in patients with TC genotype and HDL in patients with CC genotype (P<0.05). Moreover, in patients with CC genotype, the percentage of those with high levels of CPK was two times higher than patients with normal CPK. Conclusion: Current study could be of help in predicting the incidence of myopathy in patients receiving statins and preventing the side effects of these drugs.