Study of Thyroid Disorders among Type 2 Diabetic Patients Attending a Tertiary Care Hospital

Type 2 diabetes mellitus (T2DM) and thyroid disorders (TD) are the two most common endocrine disorders in clinical practice. Unrecognized thyroid disorders may adversely affect the metabolic control and add more risk to an already predisposing type 2 diabetes mellitus. The objective of the study is to find out the percentage of hypothyroidism and hyperthyroidism in patients with type 2 diabetes mellitus and non diabetic subjects. This cross-sectional study was conducted in the department of Biochemistry and outpatient Department of Endocrinology, BIRDEM General Hospital, Dhaka, Bangladesh from July 2014 to June 2015. Total 200 patients were selected by inclusion and exclusion criteria. Among them, 115 were T2DM subjects and 85 were non diabetic subjects. Type 2 diabetes mellitus and normoglycemia were diagnosed according to WHO criteria from previous medical records. All patients were underwent thyroid function tests; free thyroxine (FT4), free tri-iodothyronine (FT3) and S. TSH (thyroid stimulating hormone). Study sample were divided 4 groups: Group 1: Type 2 diabetic subjects with thyroid disorders; Group 2: Non diabetic subjects with thyroid disorders; Group 3: Type 2 diabetic subjects without thyroid disorders; Group 4: Non diabetic without thyroid disorders. Thyroid disorders were categorized into subclinical hypothyroidism, overt hypothyroidism, subclinical hyperthyroidism and overt hyperthyroidism. Percentage of thyroid disorders in type 2 diabetes mellitus and non diabetic patients were estimated. Comparison of all demographic characteristics was done among the groups. The percentage of thyroid disorders in type 2 diabetic patients was 23.5%. The most frequent thyroid disorders in type 2 diabetic patients were subclinical hypothyroidism (10.4%) and overt hypothyroidism (6.1%). The percentage of thyroid disorders in non diabetic subjects was 12%. Here, subclinical hypothyroidism is 5.9% and overt hypothyroidism is 3.5% were significantly higher in female, overweight and obese subjects. Patients with thyroid disorders (both type 2 diabetic and non-diabetic) had strong association with family history of thyroid disorders. This study showed that the percentage of thyroid disorders in type 2 diabetes mellitus is very high. Specially hypothyroidism (both subclinical and overt) are most frequent. So it is very necessary to provide regular screening for thyroid disorders in type 2 diabetic patients as well as initiating early treatment. Early treatment thyroid disorders in type 2 diabetic patients will help us to avoid complications and reduce morbidity and mortality of diabetes mellitus and thyroid disorders.