Changes And Correlation Of Visfatin And NT-proBNP In Patients With Thyroid Dysfunction

Objective To compare the changes of plasma visfatin levels between hyperthyroid and hypothyroid patients before and after treating; Analyze their correlation with N-terminal pro-B- type natriuretic peptide (NT-proBNP). To investigate the relationship and mechanism between visfatin and thyroid hormones level, myocardial metabolism while thyroid dysfunction.Methods 18 hyperthyroid and 20 hypothyroid patients were chosen, 12 euthyroid people as control. Fasting plasma visfatin, NT-proBNP(N-terminal pro-B-type natriuretic peptide), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triacylglycerol (TG), free Triiodothyronine(FT3), free thyroxineindex(FT4), thyrotropin-releaxing homone (TSH), fasting blood glucose,fasting plasma insulin were measured and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated in hyperthyroid and hypothyroid patients before and after treating.Results (1) Compared with control group, the visfatin levels of hyperthyroid group incresed before antithyroid treating(6.05±3.03ng/ml vs.3.25±2.31ng/ml, P＜0.05)while after antithyroid treating, the visfatin levels decreased compared to pretherapy patients (2.89±1.88ng/ml vs. 6.05±3.03 ng/ml, P<0.05) and there was no difference between after euthyroid treating group and control group (P>0.005). There was no difference between visfatin levels in hypothyroid patients and controls before and after treating (P>0.005). Compared with pre-treatment ones, the visfatin levels of hypothyroid group incresed after treating (3.83±2.65ng/ml vs.1.94±1.68ng/ml, P＜0.05). NT-proBNP levels decreased after treating compared with pre-treatment patients (15.11±24.25pg/ml vs.103.70±274.49pg/ml, P<0.05) and there were no differences between and control group(P>0.005) in hyperthyroid group.There were no differences among pre-treatment, treatmented hypothyroid patients and controls(P>0.005). (2)Visfatin and NT-proBNP positively correlated with FT3 and FT4 in hyperthyroidism. No correlations among visfatin and NT-proBNP, FINS, FBG, HOMA-IR, TC, LDL-C, HDL-C or TG were found in either hyper- or hypothyroidism. (3)Stepwise multiple regression analysis suggested that in hyperthyroidism, NT-proBNP was the only predictor of visfatin(P <0.005), FT4 was the only predictor of NT-proBNP(P<0.005), and after antithyroid treatment, TSH was the only predictor of NT-proBNP (P＜0.005).Conclusion Visfatin increased significantly and positively correlated with FT3 and FT4 in hyperthyroidism.The results indicated that visfatin is mediated by thyroid hormones and perhaps take part in the hormone stabilization processes. NT-proBNP was the only predictor of visfatin in hyperthyroidism imply that visfatin may play a role in the myocardial metabolism so as to protect cardiac function. Plasma visfatin levels are not associated with HOMA-IR and BMI in either hyper- or hypothyroidism.