Plasma visfatin concentrations increase in both hyper and hypothyroid subjects after normalization of thyroid function and are not related to insulin resistance, anthropometric or inflammatory parameters

P>Objective The objective of this study was to evaluate plasma visfatin levels in thyroid dysfunction and its relationship with inflammatory, anthropometric and insulin resistance parameters. Design and patients Twenty-four hyperthyroid and 27 hypothyroid patients were studied before and after treatment. Forty-five euthyroid subjects were used as control group. Measurements Fasting plasma visfatin, IL-6, C reactive protein, adiponectin, thyroid hormones, waist-to-hip ratio, BMI, percentage of body fat and homeostasis model insulin resistance index (HOMA-IR) were measured. Results Hyperthyroid patients showed increased insulin resistance, IL-6 and visfatin levels compared with controls (3 center dot 21 +/- 3 center dot 0 vs. 1 center dot 67 +/- 0 center dot 75, P = 0 center dot 022; 3 center dot 35 +/- 0 center dot 41 vs. 2 center dot 10 +/- 0 center dot 25 pg/ml, P = 0 center dot 016; and 37 center dot 4 +/- 5 center dot 81 vs. 23 center dot 79 +/- 4 center dot 2 ng/ml, P = 0 center dot 061 respectively). After normalization of thyroid function, IL-6 levels and HOMA-IR decreased (2 center dot 35 +/- 0 center dot 37 vs. 2 center dot 10 +/- 0 center dot 25 pg/ml, P = 0 center dot 045 and 3 center dot 21 +/- 0 center dot 60 vs. 2 center dot 28 +/- 0 center dot 38, P = 0 center dot 032 respectively), while body weight, adiposity and visfatin levels increased (26 center dot 1 +/- 1 center dot 2 vs. 26 center dot 7 +/- 1 center dot 2 kg/m2, P = 0 center dot 049; 30 center dot 9 +/- 1 center dot 6 vs. 32 center dot 2 +/- 1 center dot 6%, P = 0 center dot 007; and 37 center dot 4 +/- 5 center dot 81 vs. 63 center dot 13 +/- 8 center dot 72 ng/ml, P = 0 center dot 047 respectively). C reactive protein and adiponectin levels were similar to those of the control group. Hypothyroid patients showed high visfatin levels (40 center dot 59 +/- 3 center dot 07 vs. 29 center dot 34 +/- 4 center dot 9 ng/ml, P = 0 center dot 049) that increased after treatment (81 center dot 4 +/- 9 center dot 2 ng/ml, P = 0 center dot 001) without changes in anthropometric or insulin resistance parameters. C reactive protein, IL-6 and adiponectin levels were similar to those of the control group. No correlations between visfatin and any analysed parameter were found in either hyper- or hypothyroidism. Conclusion Visfatin exhibits a marked increase after normalization of thyroid function in both hyper and hypothyroid patients. We suggest that visfatin may play a role in the hormone stabilization process independent of anthropometric, inflammatory or insulin resistance variables.