Hyperthyroidism is a common endocrine disorder; it affects the function of various body systems particularly respiratory system.  However pulmonary function in hyperthyroidism and the effect of antithyroid medication is not thoroughly studied. Therefor this study aimed to evaluate pulmonary function in hyperthyroid patients by measuring spirometric parameters and to study the effect of antithyroid therapy on these parameters. The study was carried out in Al-Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC), Al-Faiha hospital, Basrah, Iraq. The study included 110 subjects, they classified into 3 groups: 1) recently diagnosed hyperthyroid group (n=20, male/female 8/12, age 20-64 year), 2) treated hyperthyroid groups (n=30, male/female 12/18, age 27-67 years) and 3) control group consist of age and sex matched euthyroid subjects (n=60, male/female 25/35, age 22-46 year). Assessment of pulmonary function and thyroid hormones were done to all participants. Age, gender distribution, BMI were comparable in all studied groups. A significantly lower FVC, FVC%, FEV1, FEV1%, PEF, PEF%, FEF25-75 and FEF25-75% were noticed in hyperthyroid groups compared with euthyroid group, these parameters are insignificantly more in treated than in recently diagnosed hyperthyroid group. A significantly more abnormal spirometry tests, mostly of restrictive pattern, were noticed in hyperthyroid groups compared with euthyroid group. It could be concluded that pulmonary function is adversely affected in hyperthyroidism and insignificantly improved by medical therapy.

Keywords: hyperthyroidism, pulmonary function, spirometry, Basrah, Iraq