COPD and T4
There is a higher rate of abnormal thyroid function in COPD patients, and low thyroid levels are associated with COPD exacerbations.
There is no known thyroid condition that causes COPD. Some speculate that systemic inflammatory responses could cause COPD and thyroid problems.
See: Thyroid gland in chronic obstructive pulmonary disease. Adv Respir Med 2017;85(1):28-34.