PubMed2003
Interdependencies between thyroid function and the respiratory system in physiological and pathological conditions are presented in the paper. The dependencies discussed below result from the proximity of both this structures and metabolic interactions between them. Thyroid hormones start to play a role, as early as in the foetus stage, in forming the respiratory system (including beta-receptors formation and surfactant production). They influence the respiratory volume in adults (mainly by changing the anatomical structure of the connective tissue and by influence upon respiratory muscles) and the respiratory flow (by hypersensitivity and bronchospasm induction). They also stimulate the respiratory centre in the brain stem. The respiratory flow in the airways depends also on the thyroid size. It has been proven, that the thyroid expansion (struma) causes tracheal compression and ventilation disturbances of an obstructive type. In conclusion, for a normal respiratory function it is essential to keep the homeostasis of the thyroid hormones serum concentration and the proper volume of the thyroid gland. Laboratory and clinical tests useful in estimating the impact of a wide range of thyroid pathology on the respiratory tract are described in the paper. We also emphasize the usefulness of the spirometry in these cases.