Prevalence and clinical significance of systemic sclerosis-associated myopathy in 429 patients

Objective To explore the prevalence of and clinical manifestation associated with myopathy in Chinese patients with systemic sclerosis(SSc). Methods This study was a cross-sectional study based on European Scleroderma Trials and Research group (EUSTAR) database in Peking Union Medical College Hospital(PUMCH) from February 2009 to December 2015. Demographic, clinical and laboratory data were analyzed in groups with and without myopathy. Results Of 429 Chinese SSc patients whose mean age of onset was (39.3±12.6) years old. Overall prevalence of myopathy was 22.6%. The presence of early satiety/vomiting(χ²=16.29, P<0.001), dysphagia (χ²=27.01,P<0.001), edema (χ²=17.74, P<0.001), and urine decreased(χ²=4.59, P=0.032) occurred more frequent in patients with myopathy than those without myopathy. The abnormal rate of pulmonary arterial hypertension (PAH) detected by echocardiography in the myopathy group was higher than that of non-myopathy group (χ²=6.31, P=0.012). The elevation of erythrocyte sedimentation rate (t=1.06, P=0.011) and C reactive protein (t=0.87, P=0.001) were more higher in myopathy group than in non-myopathy group. Conclusions SSc associated myopathy is not uncommon. Compared to non-myopathy patients, SSc patients associated myopathy have a more severe inflammation response, and require more attention on cardiac and renal complications.