Study of thyroid dysfunction in patients with type 1 diabetes mellitus

Abstract

Background: The association of autoimmune thyroid disease with type 1 diabetes mellitus has been well documented across populations, with it being most prevalent immunological disease in patients with type 1 diabetes. The aim of this study was to ascertain the association between type 1 diabetes and thyroid dysfunction clinically, biochemically and immunologically.Methods: Serum TSH, free T3 and free T4 values were compared between cases of type 1 diabetes mellitus and non-diabetic age and sex matched controls. Cases of type 1 diabetes mellitus were further divided in two groups, depending upon the presence or absence of antibodies against thyroid peroxidase (Anti-TPO antibodies). Mean serum TSH, free T3, free T4 levels were compared between these two groups to find or refute any association.Results: Abnormal thyroid function was reported in total 6 (14.63%) cases. Comparison of TSH, T3 and T4 levels showed statistically insignificant differences (p<0.05) in TSH levels (µIU/ml) (Cases- 3.44±2.41, controls- 3.34±0.78); T3 levels (pg/ml) (cases- 3.31±1.06, controls- 3.36±0.52) and T4 levels (ng/dl) (cases- 0.92±0.31, controls- 0.95±0.23). Total of 6 cases (14.63%) cases of type 1 diabetes mellitus were positive for anti-TPO antibodies (4- females, 2- males).Conclusions: Thyroid dysfunction is more common amongst type 1 diabetics, especially females. Estimation of anti-TPO antibodies is valuable in detecting thyroid dysfunction in type 1 diabetics.