The background of the study. Primary pulmonary hypertension is a rare disorder that is characterized by a progressive increase in pulmonary artery blood pressure in the absence of heart or lung disease. It may be an autoimmune disease. In this study, the frequency of thyroid dysfunction and autoimmunity was determined in patients with primary pulmonary hypertension.
How the study was done. Sixty-three patients with primary pulmonary hypertension were studied. The diagnosis was based on a high resting pulmonary artery blood pressure (>25 mm Hg) and the absence of heart or lung disease. The patients were evaluated for thyroid disease by history, physical examination, and measurements of serum thyrotropin, free thyroxine, and antithyroid peroxidase and antithyroglobulin antibodies. The patients were categorized as having Graves' disease (hyperthyroidism and diffuse goiter), Hashimoto's disease (two of the following-diffuse goiter, a high serum antithyroid antibody concentration, and repeatedly high serum TSH concentrations), and autoimmune thyroid disease (any one of the three findings).
The results of the study. The mean age of the 63 patients (53 women; 10 men) was 47 years. The cause of pulmonary hypertension was not known in 24 patients; it was associated with a connective-tissue disorder in 13 patients, liver disease in 6 patients, anorexigenic drugs or drug abuse (cocaine, amphetamine) in 17 patients, and HIV infection in 3 patients. Thirty-one patients (49 percent) had a thyroid disorder. Among these 31 patients, 45 percent had Hashimoto's disease, 26 percent had Graves' disease, and 26 percent had autoimmune thyroid disease (3 percent had autoimmune pituitary disease).
The conclusions of the study. Approximately half of patients with pulmonary hypertension have thyroid autoimmune disease.
The original article. Chu JW, Kao PN, Faul JL, Doyle RL. High prevalence of autoimmune thyroid disease in pulmonary arterial hypertension. Chest 2002;122:1668-73