Abstract
Background: Hypothyroidism is associated with significant reduction of parameters of diffusion capacity and slight peripheral obstruction. However, it is not quite clear whether these abnormalities are reversible.
Aim: To evaluate the reversibility of diffusion capacity (DL,CO) abnormalities in patients with clinical hypothyroidism with establishment of euthyroid state.
Patients and methods: Sixteen patients with different forms of autoimmune thyroiditis in clinical hypothyroid state (male/female – 4/12; age = 43.0±13.4 (mean±SD), TSH=101.6±52.3 mIU.L-1, FT4=4.9±3.8 pmol.L-1) and 14 age and sex matched controls were included in the study. Pulmonary function assessment included slow vital capacity, forced spirometry and diffusion measurements (MasterScreen Diffusion, E. Jaeger, Germany).
Results: Most of the patients with hypothyroidism (13/16) revealed significantly reduced diffusion capacity for carbon monoxide (DL,CO %pred. = 70.5±6.7 vs 93.8±12.9 in controls; p<0.001) that correlated with the levels of TSH (r=-0.587; p<0.05) and FT4 (r=0.515; p<0.05). Following approximately six months of treatment and reaching a euthyroid state (TSH = 3.6±1.9 mIU.L-1) diffusion capacity was significantly improved (DL,CO=80.3±10.3 vs. 70.5±6.7 before treatment; p=0.020). No changes were aparent in the other pulmonary function parameters.
Conclusions: Hypothyroidism is associated with significant reduction of diffusion capacity. Restoring euthyroid state reverses these abnormalities as seen by the substantial improvement of DL,CO.
- © 2013 ERS