Thyroid dysfunction in type 2 diabetics seen at the University College Hospital, Ibadan, Nigeria

Thyroid dysfunction complicates the metabolic derangement observed in Diabetes Mellitus (DM). It is necessary to recognize and treat it when present in order to achieve stability of metabolic control in these patients. The prevalence of thyroid dysfunction in type-2 diabetics in our environment is not known. This study was therefore designed to determine the prevalence of thyroid dysfunction in Type 2 diabetics seen at the Metabolic Research Unit of University College Hospital, Ibadan, Nigeria. Serum TSH, Free T3 and Free T4 assays were performed using Automated Enzyme Immunoassay platform on fresh sera from volunteers comprising 64 adult type 2 diabetics and 36, age matched, non diabetic controls; weight, height and blood pressures were measured in all subjects. In addition, past lipid profile results of type 2 diabetics were retrieved from medical records. Thyroid dysfunction was present in 19 (29.7%) of 64 type 2 diabetics and 1 (2.8%) of 36 non diabetic controls (P< 0.05). The prevalence of thyroid dysfunction is 32.4% in females and 25.9% in males. Secondary hypothyroidism was seen in 78.9%, sub-clinical hypothyroidism in 15.8%, and sub-clinical hyperthyroidism 5.2% of subjects with thyroid dysfunction. Abnormal lipid profiles were seen in 35.4% of euthyroid type 2 diabetics and 100% of hypothyroid type 2 diabetics (P<0.05). 87.5% of type 2 diabetics and 38.8% of controls were hypertensive (P<0.05). 7.8% of type 2 diabetics and 50% of controls were obese (P<0.05). The prevalence of thyroid dysfunction in type 2 is higher in type 2 diabetics than in controls. More of Type 2 diabetics were obese and more of them were hypertensive compared to controls. The approach of using TSH first in screening for thyroid dysfunction is not sufficient in type 2 diabetics. Routine screening for thyroid dysfunction should be carried out in type 2 diabetics.