Thyroid dysfunction and inflammatory biomarkers in chronic obstructive pulmonary disease: Relation to severity and exacerbation

Background: Thyroid dysfunction or non-thyroidal illness syndrome (NTIS) is frequently detected in chronic, systemic diseases. The systemic manifestations of chronic obstructive pulmonary disease (COPD) include a number of endocrine disorders. The severity of hypoxia and airway obstruction in COPD patients might cause alterations in thyroid function. The aim of this study is to assess serum levels of thyroid hormones and the inflammatory biomarkers; IL-6, TNF-α in COPD patients during stability and acute exacerbation of the disease, and also to assess the relation between severity of COPD and levels of thyroid hormones. Subjects and methods: Forty stable COPD patients and twenty COPD patients with acute exacerbation were included in this study as patient groups and twenty healthy age-matched non smoker subjects with normal pulmonary function as a control group. The diagnosis of COPD and acute exacerbation of COPD were established according to GOLD (2011) criteria. Stable COPD patients were further subdivided into Mild-to-moderate COPD patient group (FEV1 ⩾ 50% of predicted value, which included 14 patients) and Severe COPD patient group (FEV1