Thyroid Function in Patients with Type 2 Diabetes

Objective To investigate the thyroid function in patients with type 2 diabetes mellitus(2-DM) through a comparison with healthy subjects. Methods The concentrations of free T3(FT3),free T4(FT4) and thyroid stimulating hormone(TSH) were measured in 120 inpatients with 2-DM(study group) and 60 healthy subjects(control group).In addition,levels of blood glucose,glycosylated hemoglobin(GHb),cholesterol,triglyceride and creatinine were determined in study group.Results Among the 120 2-DM patients,103 had normal thyroid function and 17 had thyroid dysfunction.Among the 17 patients,15(12.5%) had subclinical hypothyroidism with a female predominance (18.3% vs 6.7%,P0.05)and 2(1.7%) had subclinical hyperthyroidism.Among the 60 healthy subjects,2(3.3%) had subclinical hypothyroidism.Compared with control group,the incidence of thyroid dysfunction increased(14.2% vs 3.3%,P0.01)and the levels of FT4 decreased in study group(P0.05).There were no obvious differences in the levels of FT3 and TSH between the two groups(P0.05).Compared with patients with normal thyroid function,the levels of low density lipoprotein significantly increased in patients with subclinical hypothyroidism(P0.05).No obvious differences in levels of GHb,blood glucose,cholesterol,triglyceride,high density lipoprotein and creatinine between patients with normal thyroid function and patients with subclinical hypothyroidism(P0.05). Conclusion The incidence of thyroid dysfunction,especially subclinical hypothyroid,in 2-DM patients is considerably higher than that in healthy subjects and there is a female predominance of thyroid dysfunction among 2-DM patients.