Objective To explore the clinical characteristics of middle-aged and elderly patients with type 2 diabetes mellitus（T2 DM） combined with abnormal thyroid function.Methods Nineteen hundred and sixteen faculty members who underwent physical examination in a hospital in Chengdu from March to December 2019 were selected as study subjects and divided into diabetic group（n=199） and non-diabetic group（n=1717） according to the presence or absence of T2 DM.The subjects with clinical hypothyroidism

subclinical hypothyroidism

clinical hyperthyroidism

and subclinical hyperthyroidism were screened according to the relevant criteria

and then the abnormal thyroid function detected in the diabetic group was compared with that in the non-diabetic group.Results The detection rate of thyroid function abnormalities in the diabetic group was 27.65 %

which was higher than that in the non-diabetic group（23.36 %）

but the difference was not statistically significant（X2=1.804

P=0.179）.The detection rate of clinical hyperthyroidism was 1.01 % in the diabetic group of study subjectswhich was higher than 0.06% in the non-diabetic group with a statistically significant difference（P=0.030）.The detection rate of thyroid function abnormalities in the diabetic group was higher in women than in men（22.12% in men and 34.88% in women）

with a statistically significant difference（X2=3.976

P=0.046）.Conclusion Middle-aged and elderly patients with T2 DM have a high rate of abnormal thyroid function

and the main clinical type of abnormal thyroid function is subclinical hypothyroidism with a higher prevalence in women.Regular screening of thyroid function in patients with T2 DM especially in women

should be emphasized clinically

and once thyroid function abnormalities are detected

they should be treated in a timely manner to prevent or delay the occurrence and development of diabetic complications.