Influence of glucose metabolism on thyroid hormones value

Abstract

Objective To compare the serum thyroid hormones level in patients with pre-diabetes,newly diagnosed type 2 diabetes mellitus(T2DM)and healthy people,and to investigate the association of glucose metabolism with thyroid function.Methods Sixty newly diagnosed T2DM patients(T2DM group),60 pre-diabetes patients(pre-diabetes group),and 60 healthy people(healthy group) from outpatient departments were randomly enrolled in the study.Their thyroid peroxidase antibodies(TPOAb),thyroglobulin antibodies(TGAb),thyrotropin receptor antibodies(TRAb),and thyroid color dopplar ultrasound were all normal.Thyroid hormones was measured.Glycosylated hemoglobin A1c(HbA1c),fasting plasma glucose(FPG),glycated albumin(GA) was additionally measured in T2DM patients.We compared the difference of thyroid hormones among the 3 groups and investigated the factors that influence thyroid hormones level in each T2DM patients.Results There was no significant difference found on thyroid hormones level between the pre-diabetes group and healthy group(P＜0.05).T3 and FT3 level were(1.34±0.24)nmol/L and(3.88±0.51)pmol/L in the T2DM group,respectively,which were significantly lower than those in the pre-diabetes group([1.48±0.29]nmol/L and [4.12±0.55]pmol/L,t=-0.135 and -0.145,respectively,Ps＜0.01＝ and in the healthy group([1.49±0.26]nmol/L and [4.13±0.55]pmol/L,t=-0.240 and -0.260,respectively,P＜0.05 or 0.01) .In the T2DM group,T3 and FT3 were negatively correlated with FPG,GA,HbA1c(For T3:r=-0.275,-0.318 and -0.453,respectively,Ps＜0.05;For FT3:r=-0.280,-0.291 and -0.336 ,respectively,Ps＜0.05).Conclusion In patients with abnormal glucose metabolism, thyroid hormone was influenced only when the glucose metabolism level reached a certain abnormal degree. Key words: Type 2 diabetes mellitus; Pre-diabetes; Thyroid hormones; Glycosylated hemoglobin A1c