Prevalence of thyroid dysfunction in ambulant patients with Type 2 diabetes attending diabetes clinics at Kenyatta national hospital

Abstract

Thyroid disease and Diabetes are two common endocrinopathies found in the general population. Thyroid disease is a pathological state which can adversely affect Diabetes control and contribute to negative patient outcomes. Hyperthyroidism contributes to hyperglycemia while hypothyroidism contributes to episodes of hypoglycemia. This not only impedes management of Type 2 Diabetes but also worsens metabolic control. However, uncontrolled diabetes on the other hand has been shown to impair TSH response to TRH which normalizes with improvement in glycemic control Objectives To determine the prevalence and patterns of thyroid dysfunction in patients with Type 2 Diabetes Mellitus. Methodology This was a cross-sectional descriptive survey of participants who were over the age of 30 years selected from patients with type 2 Diabetes attending outpatient diabetes clinics. Systematic random sampling was done on patients meeting the inclusion criteria.A sample size of 180 was obtained. Consenting participants’ had their demographic data and medical history collected by use of structured pre-tested questionnaires and a physical examination was done thereafter. This was followed by drawing of venous blood samples for assessment of, i.e. TSH & fT4. Assays for thyroid hormones were done using specific antibodies and enzyme markers for specific thyroid hormones using Enzyme Linked Immuno Sorbent Assay technology. (ELISA) Results In this study, majority of the patients were female (62.4%), with a mean age of 59 years and had a mean duration of 9.5 years with diabetes mellitus. Those with a previous diagnosis of thyroid dysfunction were about 10.6% and 22.7% had a positive family history of thyroid dysfunction. The prevalence of thyroid dysfunction in patients with type 2 Diabetes was found to be 61%, of which subclinical hypothyroidism was the most predominant type at 58%. No patient was found to have evidence of overt hyperthyroidism. Conclusion The prevalence of thyroid dysfunction among patients with type 2 Diabetes is high, particularly sub clinical hypothyroidism. The clinical significance of this thyroid status on metabolic control and outcomes need further evaluation