Abstract #1406850: Prevalence of Primary and Sub-clinical Hypothyroidism and Impact of Metformin on Thyroid Hormones in Patients with Type 2 Diabetes Mellitus in a Tertiary Care Hospital in Kashmir

Abstract

Diabetes mellitus and hypothyroidism are the commonest endocrine disorders worldwide and tend to coexist and mutually influence each other. We aim to determine the prevalence of overt (OH) and subclinical hypothyroidism (SCH) and impact of metformin on thyroid hormones in patients with type 2 diabetes mellitus (T2DM). In this cross-sectional observational study, 257 adult patients of T2DM enrolled were evaluated for thyroid dysfunctions by testing thyroid profile. The levels of fT3, fT4, serum TSH, and anti-TPO antibody were estimated by chemiluminescent micro-particle immunoassay (CMIA). The correlation analysis of prevalence of thyroid disorder with age distribution, gender distribution, BMI, duration of diabetes and glycated hemoglobin (HbA1C) was done. The mean age in our study was 56.3±7.82 (28-74) years with female to male ratio of 1.62:1(159 females vs. 98 Males). The mean (± SD) duration of diabetes HbA1c of the study cohort was 6.7±2.19years and 8.1±2.53% respectively. The prevalence of OH and SCH was 7.4% (Female vs. Male; 10.7% vs. 2%; p=0.013) and 12.1 % (Female vs. Male; 15.7% vs. 6.1%; p=0.021) respectively. The prevalence of anti-TPO positivity was 94.7%, 51.6%and 10.6% in OH, SCH and euthyroid patients respectively. The prevalence of hypothyroidism and subclinical hypothyroidism was higher in patients of female gender, age >60 years, long duration and uncontrolled diabetes. Among 257 patients, 63% (n=163) patients were on metformin. The mean TSH of patients who were on metformin was significantly lower (1.34±0.95 vs. 3.19±1.41; p < 0.001). However, the mean free T4 and free T3 levels were not significantly different between the two groups. There is high prevalence of hypothyroidism especially subclinical hypothyroidism in diabetic patients. Patients on metformin therapy had significantly lower TSH levels. Screening for thyroid dysfunction among patients with diabetes mellitus should be routinely considered for early diagnosis and effective management.