Prevalence of thyroid dysfunction in patients with chronic obstructive pulmonary disease: a single centre study

Introduction: COPD is defined as a disease state characterized by persistent respiratory symptoms and airflow limitation that is not fully reversible and associated with multiple episodes of exacerbations. Thyroid dysfunction can be one such cause of acute worsening. Any thyroidal illness if present and leading to increased complication/exacerbation will go unnoticed and result in increased morbidity and mortality. Aims and Objectives: To determine thyroid function in COPD patients, to see if there is difference in thyroid function in COPD patients with different mMRC, Spirometry and GOLD stages. Methodology: Thyroid function tests and spirometry were conducted on 174 chronic obstructive pulmonary disease patients and compared with mMRC score, GOLD category and Spirometry stages. The statistical analysis was done using SPSS (Statistical Package for Social Sciences) Version 15.0 statistical Analysis Software. Appropriate tests were applied. Results: The most common thyroid disorder found in the study was hypothyroidism (16.1%) and subclinical hyperthyroidism was found in 15(8.6%) patients. No cases of overt hyperthyroidism or non-thyroidal illness were seen. The prevalence of hypothyroidism was significantly higher in cases compared to controls. Prevalence of thyroid disease increased as the severity of COPD increased. It is also seen that the prevalence of thyroid disease in patients with high risk of exacerbation is 20.8% as hypothyroidism and 12.3% as subclinical hypothyroidism which is significantly higher (p value = 0.006) to 8.8% and 3.3% in low risk group respectively. Conclusion: Thyroid dysfunction can be one of the major reasons for morbidity in COPD patients. The study shows a high prevalence of thyroid dysfunction in COPD patients especially the ones with more severe disease. Hence routine application of thyroid function test in COPD patients must be done.