Prevalence of thyroid dysfunction among type 2 diabetic patients attending the Diabetes Clinic, National Hospital of Sri Lanka

Abstract

Objective:To determine the prevalence of thyroid dysfunction (TD) and to identify risk factors which are associated with TD in Type 2 Diabetic (T2DM) patients attending the Diabetes Clinic, National Hospital of Sri Lanka Method:A descriptive cross sectional study was carried out at the Diabetes Clinic, National Hospital of Sri Lanka. Study subjects were selected by simple random sampling method and data was collected using an interviewer administered data collection form. TD was assessed by performing 3rd generation TSH and when required FT4/FT3 levels were measured. Statistical analysis was done using Pearson's Chi-square test, Fisher exact test, Mann Whitney U test and Wilcoxon Rank Sum test and P value < 0.05 was considered as significant.Results: TD was detected in 83 out of 393 T2DM subjects.The prevalence of TD among study subjects was 21.1% (95% CI:17.2-25.5%). The most common TD categories were subclinical hypothyroidism (9.4%, 95% CI:6.7-12.7%) and overt hypothyroidism (6.1%, 95% CI:3.9-8.9%). Subclinical hyperthyroidism and overt hyperthyroidism were detected only in 5.1% (95% CI:3.1-7.8%) and 0.5% (95% CI:0.1-1.8%) of cases respectively. The presence of TD was strongly associated with female sex (p<0.01) advancing age (p<0.01),the presence of goitre (p< 0.01) and a positive family history of thyroid disorder among 1st degree relatives (p=0.02).There was no association between the presence of TD and the duration of T2DM, presence of hypertension or chronic complications of DM, type of antidiabetic drugs used, current glycaemic control, body mass index (BMI) and total cholesterol level. Conclusion:The prevalence of TD was 21.1% and higher prevalence was seen in T2DM patients with female sex, advancing age, presence of goitre and positive family history of thyroid disorder among 1st degree relatives.