Prevalence and Impact of Thyroid Dysfunction in Patients With Chronic Pulmonary Obstructive Pulmonary Disorder: A Systematic Review and Meta-Analysis.

Thyroid gland dysfunction (TGD) has been increasingly recognized as a potential comorbidity in patients with chronic obstructive pulmonary disease (COPD). This study was designed to determine the prevalence of TGD in COPD patients. This systematic review and meta-analysis was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). To comprehensively identify relevant studies, a systematic search was conducted in major electronic databases, including PubMed, Embase, and the Cumulative Index to Nursing and Allied Health Literature (CINAHIL). The search was limited to English-language studies published after 31 December 2000. To determine the prevalence of TGD and assess the impacts, we compared forced vital capacity (FVC) (%), forced expiratory volume in one second (FEV1) (%), partial pressure of oxygen (PaO2) (mmHg), and partial pressure of carbon dioxide (PaCO2) (mmHg) between patients with and without TGD. A total of nine articles were included in this meta-analysis. The sample size of included studies ranged from 50 to 309. The pooled prevalence of TGD in patients with COPD was 45% (95% CI: 25% to 65%). The most common form of TGD was hypothyroidism. The study identified a lack of significant associations between TGD and COPD severity or various characteristics, highlighting the need for future prospective multi-center research, particularly with larger sample sizes to determine the clinical factors and biomarkers affecting the development of thyroid dysfunction in this population.