Thyroid dysfunction in patients with type 2 diabetes mellitus in Jordan

ABSTRACT

To investigate the prevalence of thyroid dysfunction and autoimmunity in type 2 diabetic patients. The study was conducted at the National Center for Diabetes, Endocrinology and Genetics, Jordan University Hospital, Amman, Jordan, between March 2000 and September 2000. A group of 908 type 2 diabetic patients [T2DM] were recruited in the study and underwent investigations for thyroid functions; free thyroxine [FT4], free tri-iodothyronine [FT3] and thyroid stimulating hormone [TSH]. Six hundred had performed thyroid autoantibodies, thyroid peroxidase antibodies [TPOab] or antimicrosomal antibodies [AMA] and thyroglobulin antibodies [Tgab]. They were compared with 304 non-diabetics, of those 282 had performed thyroid antibodies. Fifty-three [5.9%] of diabetic patients were known to have thyroid disease. As a direct result of screening, new thyroid disease cases were diagnosed in 6.6% of the patients. Thus, the overall prevalence of thyroid disease was found to be 12.5%. The most common was subclinical hypothyroidism [4.1%]. In the control group, the prevalence of thyroid disease was 6.6%. The most common was subclinical hypothyroidism [5%]. There was a significant difference between diabetics and control subjects p=0.0064. Positive TPOab was found in 8.3% of T2DM patients [N=600] versus 10.3% in the control group [N=282] p=0.412. Positivity for both TPOab and Tgab was found to be 2.5% of T2DM versus 6% of the control subjects p=0.0155. This study suggests that diabetic patients should be screened for asymptomatic thyroid dysfunction