Author(s): Anish Bhowmik, Arunabha Tapadar

BACKGROUND Diabetes mellitus is an ever-increasing problem in developing countries, due to rapid alterations in lifestyle. A significant percentage of longstanding diabetic patients show abnormalities in thyroid function. The present study is an attempt to study thyroid derangements in patients of diabetes mellitus. Prevalence of thyroid dysfunction in known cases of diabetes mellitus have been investigated and compared with the findings of other investigators. MATERIALS AND METHODS 50 cases were selected at random from amongst confirmed chronic cases of diabetes mellitus attending the outpatient department (OPD) of a tertiary care hospital. Side by side, another 50 control subjects were selected from patients attending the OPD who were non-diabetic and had no obvious features of thyroid disease. The glycated haemoglobin (HbA1c), free thyroxine (fT4) and thyroid stimulating hormone (TSH) levels were assayed in all the subjects and compared to study thyroid derangements in confirmed diabetics and control subjects. RESULTS The results show an increased level of thyroid disorders in diabetic patients with 54% of them being euthyroid, 30% being hypothyroid and 16% being hyperthyroid. On the other hand, among the non-diabetic controls, 84% were euthyroid, 12% hypothyroid and 04% hyperthyroid. CONCLUSION Chronic diabetes mellitus does seem to have a definite association with thyroid disorders, with increased blood glucose favouring hypo or hyperthyroidism in about half of diabetic patients. The causes of this synergy may work both ways with increased blood glucose and altered insulin and thyroid hormone levels interacting in complex ways to influence each other.