NEW INDICATORS OF EXERCISE CAPACITY AND RESPIRATORY FUNCTION IN COPD PATIENTS: THE ROLE OF GASTROCNEMIUS MUSCLE OXYGENATION AND ELASTOGRAPHY LEVELS

Objectve: In our study, we wanted to evaluate the correlaton of gastrocnemus muscle oxygenaton (SmO2) and shear wave elastography (SWE) levels wth exercse capacty and respratory functon test (PFT) parameters. Methods: Our study ncluded 20 stable group E COPD patents and 20 healthy control groups who appled to our outpatent clnc between December 2023 and March 2024. The patents' dagnoses were confrmed after PFT measurement, and blateral gastrocnemus SmO2 and SWE levels were measured. Results: A postve correlaton was observed between forced expratory volume 1 (FEV1) level and rght and left maxmum gastrocnemus SmO2 and rght and left gastrocnemus SWE levels (R = 0.61, p = 0.01, R = 0.66, p = 0.01, R = 0.69, p=0.01, R=0.44, p=0.05, respectvely). A pos tve correlaton was observed between 6MWT d stance and rght and left maxmum gastrocnem us SmO2, rght and left gastrocnemus SWE, and FEV1, and a negatve correlaton was observed wth the number of days of sterod treatment (R = 0.59, p = 0.01, R = 0.56, p = 0.01, R = 0.87)., p=0.01, R=0.76, p=0.01, R=0.66, p=0.01, R=-0.73, p=0.01 respectvely). Only n COPD patents was a postve correlaton observed between rght and left gastrocnemus SWE levels and 6MWT dstance (R = 0.72, p = 0.01, R = 0.46, p =0.05). Concluson: Gastrocnemus SWE measurement s an easly applcable method that shows exercse capacty better than muscle SmO2 and PFT parameters. Therefore, gastrocnemeus SWE level may be a helpful test n the follow-up of COPD patents Keywords: Gastrocnemus, SmO2, shear wave elastography, PFT, 6MWT