Is It Statin Induced Polymyalgia Rheumatica or Just a Coincidence?

Abstract

©2015 Turkish League Against Rheumatism. All rights reserved. A 53-year-old female presented with pain in her bilateral shoulders, hips and neck, stiffness (lasting one hour), and proximal weakness for three months. She declared that her symptoms had ensued one week after the usage of daily 40 mg atorvastatin for hyperlipidemia. As such, atorvastatin was discontinued; however, her complaints did not decline. Physical examination revealed painful and restricted shoulder and neck movements, weakness in shoulder and hip muscles, and a swollen, warm right knee. Laboratory investigations including creatine kinase (CK), rheumatoid factor and anti-nuclear antibody levels were within normal values, except for the increased C-reactive protein (0.744 mg/dL, N: 0-0.5) and erythrocyte sedimentation rate (75 mm/h, N: 0-20). X-rays of the hand, knee, hip and shoulder were non-contributory. Ultrasound illustrated biceps tenosynovitis and trochanteric bursitis bilaterally, and increased suprapatellar fluid in right knee (Figure 1). Overall, the patient was diagnosed with polymyalgia rheumatica (PMR) according to the 2012 European League Against Rheumatism/American College of Rheumatology classification criteria.1 Her symptoms and clinical findings (erythrocyte sedimentation rate and C-reactive protein levels) responded to medium dose of prednisolone (20 mg/d) treatment dramatically. Although statins have been reported to be associated with some musculoskeletal side effects such as myalgia, myositis, myopathy, and elevated CK, statin induced PMR is a very rare condition which has been reported only in a few anecdotal reports.2-4 Likewise, statin treatment might trigger the development of PMR in our patient. Since statin induced PMR and myalgia have similar clinical features, the exact diagnosis can be challenging. Statin induced myalgia presents with/without increased CK levels with normal erythrocyte sedimentation rate and C-reactive protein levels. Therefore, patients with statin induced myalgia may have normal serum CK levels, which sometimes make it difficult to distinguish PMR from myopathy syndromes. In case of drug discontinuation, symptoms heal in a period of one-week to four-month in statin, myopathy and treatment of steroid is rarely required.5 PMR patients do not recover spontaneously and corticosteroid treatment is usually needed.6