Effect of Low-Dose Theophylline on Airway Resistance, Respiratory Muscle Strength, and High-Sensitivity C-reactive Protein in Patients with Chronic Obstructive Pulmonary Disease

The purpose of this study was to evaluate the effect of low-dose theophylline on airway resistance(Raw),respiratory muscle strength and high-sensitivity CRP in patients with chronic obstructive pulmonary disease(COPD).The subjects were 11 patients with COPD(8 males ; 3 females).Raw and other pulmonary function parameters were measured by means of body plethysmography.Maximal expiratory pressure(MEP)and the maximal inspiratory pressure(MIP),the parameters of respiratory muscle strength,were measured after 4 weeks of administering low-dose theophylline when serum concentrations of theophylline were 4.7±2.9 micro g/mL.The administration of theophylline decreased Raw,significantly increased FEV 1.0,decreased CRP levels and increased MEP.High-sensitivity CRP levels were negatively correlated with MEP and MIP (R2=0.474,R2=0.657 respectively).The results of the present study suggested that high-sensitivity CRP can be used as an indicator of respiratory muscle strength in patients with COPD.