Analysis of serum thyroid hormone levels in type 2 diabetic patients and its relationship with HbA 1c,C-peptide

Objective To investigate the changes in thyroid hormone levels in type 2 diabetic patients and its correlation with glycated hemoglobin,C-peptide. Methods By fasting glucose values,the 84 cases of type 2 diabetes were divided into three groups. A group:slightly increased group(6. 10 mmol /L≤FBG 8. 0 mmol /L);B group:moderately increased group(8. 0 mmol /L≤FBG 12. 0 mmol /L);C group:severe increased group( FBG≥12. 0 mmol /L). The serum was collected from three groups of diabetic patients and 36 healthy control group. The levels of serum thyroid hormones T3,T4,FT3,FT4,TSH,HbA1 c,C peptide were measured. Then the changes of thyroid hormones were observed in each group of type 2 diabetic mellitus patients. And the correlation between thyroid hormones and HbA1 c,C peptide were analyzed.Results The levels of serum T3,FT3 in type 2 diabetes mellitus patients were significantly lower than those in the control group(FT3:F = 51. 101 and P 0. 01;T3:F = 31. 193 and P 0. 01),while the levels of serum FT4,T4,TSH in type2 diabetes mellitus patients were no statistically significant difference with those in the control group(P 0. 05). The levels of serum T3,FT3 in C group were significantly lower than those in group A(P 0. 01),while the levels of serum FT4,T4,TSH showed no significant difference with those in group A and group B(P 0. 05). FT3 was negatively related with HbA1c(r =- 0. 422,P 0. 01) and positively correlated with C-peptide( r = 0. 378,P 0. 05),and the other thyroid hormones and HbA1 c,C peptide had no correlation. Conclusion With the fasting blood sugar,serum FT3,T3 levels in type 2 diabetic patients were decreased,and thyroid hormones level in T2 DM patients can reflect the degree of glucose metabolism disorder.