Statin-associated muscle symptoms and SLCO1B1 rs4149056 genotype in patients with familial hypercholesterolemia

Abstract

Patients with familial hypercholesterolemia (FH) may be at increased risk for statin-associated muscle symptoms because they require long-term treatment with high-intensity statin therapy. We sought to determine (1) whether other predisposing factors, including the well-known genetic variant associated with statin-associated muscle symptoms-solute carrier organic anion transporter family, member 1B1 (SLCO1B1) rs4149056-also increase the risk of statin-associated muscle symptoms in FH patients, and (2) the natural history and management for FH patients with statin-associated muscle symptoms. We queried electronic records (2004-2014) of 278 genetically screened FH patients (113 men, 165 women; mean [SD] pretreatment low-density lipoprotein cholesterol [LDL-C] 259 [72] mg/dL) recruited from lipid clinics in the Dallas, TX, area from 2004 to 2014. Statin-associated muscle symptoms were defined as muscle symptoms arising while taking a statin and interrupting therapy. The risk of muscle symptoms was associated with age (odds ratio 1.6 [95% CI 1.2-2.2]), body mass index in non-African Americans (0.90 [0.83-0.97]), and hypertension (0.4 [0.2-0.9]). Simvastatin was the most commonly used statin, and it was the statin most associated with muscle symptoms. Among FH patients with muscle symptoms, 41% (n = 40) reestablished statin therapy ("eventually tolerant") and 29% (n = 28) never reestablished statin therapy ("never tolerant"). Rosuvastatin (43%) and pravastatin (30%) were the most common eventually tolerated statins, and eventually tolerant patients achieved lower treated LDL-C levels (eventually tolerant 127 vs never tolerant 192 mg/dL, P < .001). Never tolerant patients also developed muscle symptoms on nonstatins (16% vs 50%, P = .003). SLCO1B1 rs4149056 genotyping revealed 224 wild-type patients (TT) and 49 heterozygotes (TC). SLCO1B1 genotype was not associated with the risk of statin-associated muscle symptoms (odds ratio 1.40 [95% CI 0.74-2.64]). Age, not SLCO1B1 rs4149056 genotype, was the strongest risk factor for statin-associated muscle symptoms in FH patients. After developing muscle symptoms, many patients reestablished statin therapy and achieved significant LDL-C reductions. Overall, 10% of all FH patients had statin-associated muscle symptoms and never reestablished statin therapy. Such patients developed muscle symptoms even on nonstatin lipid-lowering drugs and continued to have elevations in LDL-C. Further insight is needed into the relationship between FH and statin-associated muscle symptoms so all FH patients can be adequately treated.