Xinfeng Capsule (新风胶囊) for the treatment of rheumatoid arthritis patients with decreased pulmonary function — A randomized controlled clinical trial

Objective To determine the effectiveness and safety of Xinfeng Capsules (新风胶囊, XFC) for the treatment of rheumatoid arthritis (RA) patients with decreased pulmonary function. Methods This was a randomized controlled clinical trial of 80 RA patients. Participants were assigned to the trial group (40 cases) and the control group (40 cases) by block randomization. The trial group was treated with XFC, three pills each time three times daily for 2 months. The control group was treated with tripterygium glycoside (TPT), two pills each time three times daily for 2 months. Both groups were followed up after 2 months. The clinical effects, changes in joint and pulmonary function, and quality of life before and after treatment were observed; safety indices were also evaluated. Results Pain, swelling, tenderness, and duration of morning stiffness of joints were obviously decreased after treatment in both the trial and the control groups compared with baseline ( P <0.01). Compared with before treatment, hand grip strength increased significantly after treatment in the trial group ( P =0.0000); pulmonary function parameters such as forced expiratory volume in the first second of expiration/forced vital capacity (FEV 1 /FVC), 50% of the expiratory flow of forced vital capacity (FEF 50 ), carbon monoxide diffusing capacity (DLco) were increased ( P <0.01 or P <0.05); measures of quality of life such as role-physical, body pain, vitality and mental health were also improved after treatment in the trial group (all P <0.05). Joint swelling in the trial group decreased compared with the control group ( P =0.0043), while hand grip strength was increased after treatment ( P =0.0000). The increase in FEF 50 , DLco, and the dimensions of quality of life such as vitality and mental health were all significantly greater in the trial group than the control group ( P <0.05 or P <0.01). Conclusions XFC not only relieved joint pain in RA patients, but also significantly improved the ventilation and diffusion function of the lungs. Therefore, XFC could improve the whole body function and enhance the quality of life of RA patients.