Outcome measures

Maximum inspiratory pressure (MIP)—was measured using a portable MicroRPM (Respiratory Pressure Meter)6-min walk distance (6-MWD)—a 30 m-long indoor walking corridor was used for this test.Pulmonary function tests—performed using a computerized PFT machine (RMS Helios 401). Under PFT, forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow rate (PEFR) were measured