Dynamics of Airway Functions in Untreated Hypothyroidism

Abstract

Hypothyroidism is a hormonal disorder, more prevalent in females, affects respiratory systems at early stage. Objectives: Present study was carried out to observe the expiratory and inspiratory dynamics of airway functions in recently diagnosed hypothyroid females without medication and its comparison with hypothyroid females with hormonal therapy and euthyroid females. Parameters studied were forced vital capacity (FVC), forced expiratory volume (FEV1), FEV1%, forced inspiratory vital capacity (FIVC), FIV1, FIV1%, forced expiratory flow (FEF25-75%), FEF0.2-1.2%, FEF25%, FEF50%, FEF75%, peak expiratory flow (PEF), and peak inspiratory flow. Materials and Methods: Twenty-one (n = 21) recently diagnosed hypothyroid women without medication (Group-1) and 19 hypothyroid women taking medication for the last 6-8 months (Group-2) were studied. Hypothyroidism was diagnosed on the basis of serum thyroid-stimulating hormone level (<5IU). Total 22 apparently euthyroid subjects (Group-3) were studied as control. Data were analyzed by one-way ANOVA with post hoc Tukey honestly significant difference and alpha error was set at 5% level. Results: The mean values for FVC, FEV1, FIVC, and FIV1 were less in Group-1 in compare to Group-2 and 3 and the differences were statistically significant (P < 0.05). Large airway functions as FEF25-75%, FEF25%, and PEF also found the same decrease as above. Small airway functions as FEF50%, FEF75% may preserve except FEF 0.2-1.2. Conclusion: Untreated hypothyroidism extremely alters the respiratory dynamics and can be reversed by hormonal therapy. Large airway functions get diminished, but small airway functions remain unaltered. Study in large population with more disease duration will help to determine the severity of disease. Lung functions can be used as a tool to assess the effectiveness of treatment of hypothyroidism.