Does euthyroid mean healthy? Effect of restoration of thyroid function on body composition, insulin resistance and visfatin concentrations in women with hypo- and hyperthyroidism.

Abstract

Background We aimed to investigate the effect of restoration of euthyroidism on serum visfatin in severe thyroid dysfunction, and its associations with insulin resistance and body composition. Methods This was an observational study with consecutive enrollment. We included females newly diagnosed with overt hypo- or hyperthyroidism caused by autoimmune thyroid diseases. Laboratory parameters and body composition analysis were assessed before and after the therapy. Results Initially, 105 females were enrolled: 49 hyperthyroid (median age of 34 years) and 44 hypothyroid (median age of 46) completed the study. In the hyperthyroid group, visfatin levels increased (< 0.0001), while glucose levels decreased (< 0.0001). Total body mass and fat mass in the trunk and limbs significantly increased during the treatment. In the hypothyroid group, significant weight loss resulted from decrease of fat and muscle masses in trunk and limbs. Visfatin serum concentrations positively correlated with total fat mass(r = 0.19,p = 0.01) and insulin levels(r = 0.17,p = 0.0.18). Conclusions We may conclude that restoration of thyroid function is not associated with beneficial changes in body composition, especially among hyperthyroid females, reflected by the significant increase of fat mass followed by the increase of circulating visfatin concentrations.