Researchers recently investigated the link between thyroid gland function and idiopathic pulmonary hypertension, finding subclinical hypothyroidism in almost half of patients observed. The study, “Assessment of Thyroid Function in Idiopathic Pulmonary Hypertension,” was published in the Research in Cardiovascular Medicine journal.
Idiopathic pulmonary hypertension is a rare and ultimately fatal disease, with delayed treatment leading to right heart failure, multiple organ damage, and death.
The thyroid is one of the largest glands of the endocrine system in our body, and its major function is the release of hormones that control metabolism. Several cases of pulmonary arterial hypertension have been reported to occur in patients with thyroid problems, including hypothyroid and hyperthyroid disorders. However, the thyroid function can also be affected in idiopathic pulmonary hypertension, and measuring the levels of the thyroid stimulating hormone (TSH) is a good screening strategy to assess thyroid function.
Researchers evaluated thyroid function in idiopathic pulmonary hypertension patients, and correlated it with right ventricular function, hemodynamic parameters, and patients’ pulmonary arterial pressures. In total, they analyzed 53 patients with idiopathic pulmonary arterial hypertension (IPAH), ages 16 to 75, the majority of whom were women (84.8 percent).
Mean pulmonary arterial pressure was found to be 51.6 mmHg (values ranging from 31 to 87 mmHg), and mean TSH level was 4.2 mIU/ml. In 26 patients (corresponding to 49.1 percent of the cohort analyzed), authors detected subclinical hypothyroidism, a common disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormones, triiodothyronine and its prohormone, thyroxine.
Authors observed an increased right ventricular size and reduced function in most IPAH patients. More specifically, they noted a significant correlation between the level of TSH and right ventricular end diastolic dimension, and with triiodothyronine with the tricuspid annular plane systolic excursion; and an inverse correlation in six-minute walk test results and TSH levels. No significant correlations were noted with age or sex.
In conclusion, subclinical hypothyroidism is detected in some patients with idiopathic pulmonary hypertension, which may be associated with an increased size of the right ventricle and limited functional capacity. Notably, no correlation was observed with pulmonary arterial pressures. Future studies are required to understand if treatments based on thyroid hormones treatments could be of some benefit to idiopathic pulmonary hypertension patients.