Association Between Thyroid Function and Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Abstract

Purpose: Chronic obstructive pulmonary disease (COPD) was the fourth leading cause of death in the world. Many studies have shown that COPD often exists with thyroid dysfunction; however, the relationship between thyroid function and COPD is often ignored in clinical. We retrospectively analyze the serum thyroid hormone levels in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and explore the association between thyroid function and AECOPD.

Methods: The study included patients hospitalized for AECOPD in our institution between January 2018 and September 2020. Patients with AECOPD were divided into moderate-to-severe and very severe groups based on lung function, and into normal and abnormal thyroid function groups based on thyroid hormone levels. Collected data and compared data between groups to identify risk factors for thyroid dysfunction in patients with AECOPD.

Results: The cohort included 97 in the moderate-to-severe group (72.39%) and 37 in the very severe group (27.61%). Compared with the very severe group, the moderate-to-severe group had higher triglyceride (P=0.017), high-density lipoprotein (P<0.05), partial pressure of carbon dioxide (PaCO₂; P<0.05), and serum thyroid-stimulating hormone (TSH; P<0.001). FEV₁ as a percentage of the predicted value (FEV₁%pred) was positively correlated with TSH and FT₃ (r=0.329, r=0.192, respectively, both P<0.05). Duration of hospitalization was negatively correlated with TSH (r=-0.256, P=0.003). Among the 134 subjects, 98 (73.13%) had normal thyroid function and 36 (26.87%) had abnormal thyroid function. The two groups significantly differed regarding forced vital capacity (FVC), forced expiratory volume in 1 second, FEV₁%pred, and albumin level. Logistic regression analysis showed that high FVC correlated with a low risk of thyroid dysfunction in AECOPD.

Conclusion: In patients with AECOPD, TSH is related to lung function and duration of hospitalization, and high FVC reduces the risk of thyroid dysfunction.

Keywords: AECOPD; retrospective cohort study; risk factor; thyroid hormone.