Evaluation of ventilatory functions in hypothyroid patients

Introduction Respiratory muscle weakness is proportional to the degree of thyroid function and is reversible by replacement therapy with thyroxine. Aim To evaluate the changes in pulmonary functions in newly diagnosed hypothyroid patients as compare with healthy controls by spirometry and to observe the improvement in pulmonary functions after hormone replacement therapy. Patients and methods A total of 30 newly diagnosed hypothyroid patients and 30 healthy controls of age between 18 to 50 years of either sex were included in our study. Clinical criteria and biochemical tests were registered, and spirometry was done. Results Approximately 17% of the hypothyroid patients were normal, whereas 33% had mild restrictive lung impairment and the rest 50% had moderate to severe restrictive impairment on spirometry. Conclusion On comparing the hypothyroid patients with normal healthy person of same age group through spirometer, the ventilatory functions were diminished and these pulmonary functions improved after levothyroxine therapy for 6 months but could not reach the normal healthy values. A spirometric evaluation should be considered in hypothyroid patients, even in the absence of respiratory illness.