COPD and thyroid dysfunctions

Chronic obstructive pulmonary (COPD) is one of the major causes of morbidity and mortality in the world. COPD is characterized by chronic inflammation in the pulmonary compartment and in the systemic circulation. This disorder is associated with clinically significant alterations in biochemistry and organ function; thyroid dysfunctions are common in chronic diseases, such as COPD. Several characteristics of COPD patients could increase their likelihood of developing hypothyroidism or hyperthyroidism. The purpose of our study was to assess the impact of thyroid dysfunction in patients with COPD.

We evaluated the pulmonary function tests, arterial blood gases, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and thyroid functions in patients with COPD, recruited between admissions in Respiratory Diseases Unit, Policlinico Umberto I, Rome, Italy, from June 2012 to May 2013. We selected patients with subclinical hypothyroidism (ScH), overt hypothyroidism, and hyperthyroidism, and a control group without thyroid disturbance.

Our results indicate that patients with overt hypothyroidism have lower levels of pO2, MIP, and MEP compared with subjects with ScH, hyperthyroidism, and the control group. We also found a substantial tendency towards pCO2 levels increase in patients with hypothyroidism (p = 0.06).

Patients with thyroid dysfunctions have a greater impairment of MIP and MEP and a negative correlation was observed between hypoxemia and TSH. Further studies are needed to investigate whether the treatment of thyroid disfunction could have a beneficial effect on COPD patients' lung function and prognosis.