72 patients with mild to moderate chronic obstructive pulmonary disease were planned to be enrolled in this study and then treated with olodaterol combined with thiotropium bromide, and thiotropium bromide, respectively, for 52 weeks. To assess the effect of the test drug on small airway remodeling in patients.

Studies have confirmed that thiotropium bromide combined with olodaterol can significantly improve airway inflammation, quality of life and pulmonary function in patients with stable COPD, without significantly increasing adverse reactions, which is worthy of clinical promotion. At present, there are few reports on the effect of thiotropium combined with olodaterol on airway remodeling in COPD patients, so this randomized, double-blind, parallel-controlled, single-center clinical trial was designed to compare the long-term effects of thiotropium combined with olodaterol, and thiotropium on small airway remodeling in patients with mild to moderate chronic obstructive pulmonary disease.

72 patients with mild to moderate chronic obstructive pulmonary disease were planned to be enrolled in this study. After screening examination, eligible subjects were randomly assigned to the test group or the control group in a 1:1 ratio and received olodaterol combined with thiotropium bromide, and thiotropium bromide, respectively, for 52 weeks. The effect of the test drug on small airway remodeling was assessed at 12, 26, and 52 weeks after treatment.

Inclusion Criteria:

• Male or female, aged ≥ 40 years;
• Meet the diagnostic criteria of COPD, and GOLD grade I - II;
• FEV1/FVC < 70% and FEV1 ≥ 50% of the expected value after the use of bronchodilators;
• Patients must be able to complete all study-related steps, voluntarily participate in this study and sign the informed consen.

Exclusion Criteria:

• Patients with asthma, active tuberculosis, lung cancer, bronchiectasis, sarcoidosis, pulmonary fibrosis, pulmonary hypertension, pulmonary embolism, bronchiolitis obliterans, paradoxical bronchospasm;
• Patients with blood eosinophilia;
• Patients with upper respiratory tract infection;
• Patients with liver or renal insufficiency;
• Patients with severe unstable systemic diseases or malignant tumors;
• Patients with glaucoma, benign prostatic hyperplasia or bladder neck obstruction;
• Patients with hypokalemia, hyperglycemia, diabetes, ketoacidosis or other serious systemic diseases such as heart, brain, liver, kidney, digestive system, endocrine system, immune system, blood;
• Women of childbearing age who are pregnant, lactating or plan to become pregnant;
• Patients who have undergone previous pneumonectomy or received lung volume reduction surgery within 12 months before screening;
• Patients with mental illness;
• Patients who have participated in other clinical trials within 3 months before screening;
• Allergic constitution or known allergy to atropine or its derivatives (such as isopropylamine or oxytoluium) Or those who are allergic to the intervention drugs and their ingredients;
• The researchers believe that it is not appropriate to participate in this clinical trial.