Assessment of Lung Dysfunction with Spirometry in Patients with Thyroid Disorders

Thyroid hormones might lead to significant decrease in pulmonary ventilation in patients with dysfunctional thyroid disorders. The aim of the study was to assess the pulmo¬nary ventilation in patients with thyroid dysfunctional states. This observational, cross-sectional study included 20 patients with hyperthyroidism, 20 patients with hypo¬thyroidism and 20 euthyroid subjects. Serum FT3, FT4 and TSH levels were determined with the ElectroChemiLuminiscent immuno¬assay. Spirometry analysis was performed on portable spirometer SpiroUSB using the software Spida 5 for the analysis. We determined VC%, FVC%, FEV1% and FVC/ FEV1% Mean VC% was significantly lower in hyperthyroid (94,18±1,24%) and hypothyroid (96,13±1,09%) compared to euthyroid group of subjects (98,54±0,93%)(p<0,05). Mean FVC% value was also significantly lower in hyperthyroid (92,5±1,47 %) and hypothyroid (94,1±1,42%) compared to euthyroid group of subjects (99,2±1,15%) (p<0,05). Mean FEV1% values in hyperthyroid and hypothy¬roid groups (90,97±2,07% and 87,6±1,4% respectively) were significantly lower com¬pared to control, euthyroid group of subjects (93,48±1,1 %)(p<0,05). In patients with hyperthyroidism significant positive cor¬relation was observed between serum TSH level and FVC% (r=0,51; p<0,05), while in patients with hypothyroidism a significant, negative correlation was observed between serum TSH level and VC% (r = -0,627; p<0,01) and between serum TSH level and FVC% values (r = -0,514; p<0,01). Our study confirmed significantly lower VC% and FVC% in patients with dysfunctional thyroid states compared to healthy subjects. In our study a significant association between VC%, FVC% and serum TSH levels suggest that duration and a degree of thyroid disorders lead to reduced ventilator lung function in patients with thyroid dysfunction.