Efficacy of Levothyroxine Therapy on Diastolic Dysfunction in Patients with Subclinical Hypothyroidism

Background: Hypothyroidism is a cause of left ventricular diastolic dysfunction especially in cases with positive history of coronary artery disease. It is suggested that cardiac dysfunction may be improved with thyroxin replacement therapy. However, it is controversial. Hence, in this study the efficacy of levothyroxine therapy on diastolic dysfunction in patients with subclinical hypothyroidism was assessed. Materials and Methods: In this, randomized clinical trial 40 consecutive patients with subclinical hypothyroidism attending to Loghman Hospital in 2018 for the treatment were enrolled. The treatment was 25-50 microgram per day of levothyroxine for one year. During this period, the patients were followed up with visit or phone call with a monthly manner. The echocardiography indices were rechecked after one year beside the thyroid tests by initial lab and operators. Results: The mean BMI was significantly decreased (P=0.001). The T3 and TSH were significantly differed but The T4 had no significant alteration (P>0.05). Among the echocardiographic indices the MV.E, MV.A to MV. E ratio, EF, Eʹ septal, Eʹ lateral had significant increase and the MV.A and PV. Adur had significant reduction. After intervention among 40 patients, there were 17 cases with normal diastolic function. The BMI, MV. A, PV Adur, Eʹ Septal, Eʹ Lateral, and E to Eʹ ratio showed significant correlation. Conclusion: Totally, according to the obtained results, it is concluded that diastolic dysfunction as a common problem in patients with subclinical hypothyroidism may be treated with administration of levothyroxine. In addition, screening for diastolic dysfunction in patients with subclinical hypothyroidism is recommended to decrease the burden of problem.