New Reference Values for Thyrotropin Hormone in Diabetic Patients

Objective: The present study aimed to find out how prevalent the thyroid disorders and the association of thyroid function with cardiovascular risk factors in type 2 diabetic patients.. Material and methods: This is a retrospective study which included 186 type 2 diabetic patients. Thyroid Function Tests (TFT), Fasting Plasma Glucose (FPG), Glycosylated Haemoglobin (HbA1c), Complete Blood Count (CBC), serum lipids and clinical data including Body Mass Index (BMI), blood pressure, and pulse rate and medications were traced. Results: 9.7% of the study sample (186 patients) were on thyroxine therapy indicating previous diagnosis of clinical or subclinical hypothyroidism. Of the remaining number of patients (159), 15.1% had TSH value higher than the upper limit of reference range, 0.6% of patients showed suppressed TSH level. THS showed direct and significant association with Body Mass Index (BMI), Red cell Distribution Width (RDW) and Mean Platelet Volume (MPV). No significant association was found between thyroid function and glycemic control. At TSH value > 2.5 miU/ml, patients showed significantly higher BMI, serum triglycerides and white blood cell (WBC) count, all of which are cardiovascular risks. Conclusion: Abnormal thyroid function is common in diabetic patients. TSH is directly and significantly associated with atherosclerotic and cardiovascular risk factors. We recommend a TSH value of 2.5 uIU/ml as an upper limit of normal thyrotropin in diabetic patients, as above this level cardiovascular risks are significantly higher.