Changes in functional outcomes, serum creatine kinase, and systemic ınflammatory markers in patients with myopathy during inpatient rehabilitation: a retrospective cohort study

Objective. Myopathies comprise biologically and clinically heterogeneous disorders, and responses to therapeutic exercise may differ by underlying mechanism, residual metabolic capacity, muscle-membrane stability, baseline function, and exercise dose. Inappropriate modalities or doses may cause direct mechanical myofiber damage and, in susceptible disorders, may aggravate inflammation or fibrosis. Serum creatine kinase (CK) reflects muscle membrane injury rather than inflammation. In contrast, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), mean platelet volume (MPV), and platelet count (PLT) are nonspecific systemic inflammatory measures. This study described admission-to-discharge changes in physical function, CK, and systemic inflammatory markers during individualized inpatient rehabilitation.

Patients and methods. This retrospective, single-arm cohort study included 52 patients, of whom 24 had muscular dystrophy, eight had congenital myopathy, eight had mitochondrial myopathy, two had myositis, three had Miyoshi myopathy, one had Bethlem myopathy, and six had unclassified myopathy. All patients completed an individualized four-week inpatient rehabilitation program at the Physical Medicine and Rehabilitation Clinic of Etlik City Hospital between October 2022 and April 2024. Demographic and clinical characteristics, Motor Functional Independence Measure (Motor FIM), Functional Ambulation Classification (FAC), 6-Minute Walk Test (6MWT), serum creatine kinase (CK), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), mean platelet volume (MPV), and platelet count (PLT) were retrieved from medical records. Admission and discharge measurements were compared.

Results. Among the 52 patients, serum CK decreased from a median of 862.0 to 555.5 U/L (p < 0.001), mean 6MWT distance increased from 318.0 to 349.5 m (p = 0.015), Motor FIM improved from 62.68 to 65.40 points (p < 0.001), and FAC distribution shifted toward higher mobility levels (p = 0.011). Mean platelet volume, platelet count, and CRP did not change significantly (all p > 0.05); ESR showed a nonsignificant upward trend (p = 0.092). Changes in 6MWT distance were not significantly correlated with changes in the measured laboratory parameters.

Conclusion. Following a four-week individualized inpatient rehabilitation program, patients with heterogeneous myopathies showed short-term improvements in walking capacity, mobility, and motor independence, accompanied by lower serum CK and no statistically significant increase in the measured systemic inflammatory markers. These observational findings warrant further investigation in prospective controlled experimental studies to establish the efficacy and safety of individualized rehabilitation in this population.