Background: Subclinical hypothyroidism (SCH) has been found to be associated with cardiovascular disease including atherosclerosis which is also called inflammatory disorder. The objective of this study was, to investigate the efficacy of L-thyroxine therapy on inflammation in patients with SCH and to determine whether treatment of SCH would reduce inflammation.
Methods: Twenty patients with thyroid stimulating hormone levels between 5 and 10 mU/L and twenty healthy persons (control) were enrolled to the study. 0.025-0.075 mg/d L-thyroxine therapy was given to the patients. Patients were followed till they became euthyroid. C-reactive protein (CRP), lipid profile and thyroid function tests were evaluated. CRP was determined by a high sensitivity immunoassay.
Results: CRP, total cholesterol and low-density lipoprotein (LDL) were significantly elevated in patients with subclinical hypothyroidism compared to the control group at baseline (p<0.01, p<0.05, p<0.001, respectively). L-thyroxine therapy significantly decreased CRP (p<0.01) and low-density lipoprotein in treatment group (p<0.05). Nevertheless, no significant change was found in other lipid parameters.
Conclusion: These findings demonstrate that patients with SCH are characterized by inflammatory disorders and higher lipid profile.