Subclinical Hypothyroidism in Type 2 Diabetes Mellitus Patients Attending In a Tertiary Care Hospital in Bangladesh

Background: Type 2 diabetes mellitus (DM) and subclinical hypothyroidism (SCH) are common endocrine disorders in general population.This study was conducted to observe the frequency of SCH in type 2 DM and to compare different demographic, anthropometric and laboratory data between the type 2 diabetic patients with SCH and euthyroidism. Materials and Methods:This cross sectional observational study was conducted among 100 (one hundred) previously diagnosed type 2 DM patients with unknown thyroid functional status which included equal number of male and female patients.Various demographic, anthropometric and clinical data were recorded and biochemical parameters like thyroid stimulating hormone (TSH), free thyroxine (FT 4 ) & HbA1c were measured.SCH was diagnosed when TSH ≥5.1 µIU/ml and Free T4 remained in reference range (0.83-1.8 ng/dl).Statistical analysis was done by IBM SPSS version 22.0.A P value <0.05 was considered as statistically significant.Results: Frequency of SCH in Type 2 DM was 18%.Frequency of SCH increased with age and highest frequency was found in 60-69 years age group (26.3%).Females were more affected with SCH than males (26% VS 10%, P value 0.037).Moreover females had higher mean TSH value than males (4.11 ± 3.84 µIU/ml VS 2.57 ± 2.49 µIU/ml, P value 0.001) where FT 4 were comparable between them (1.24 ± 0.19 ng/dl VS 1.33 ± 0.20 ng/dl, P value 0.961).Type 2 DM patients with SCH had significantly higher BMI and TSH compared to euthyroid subjects (26.53 ± 4.63 kg/m 2 VS 23.77 ± 3.33 kg/m 2 , P value 0.039 and 9.67 ± 2.80 µIU/ml VS 1.95 ± 0.96 µIU/ml, P value 0.000 respectively) where age, duration of DM, FT 4 and HbA1c were comparable between them (56.56 ± 11.27 years VS 53.51 ± 10.90 years, P value 0.582; 5.83 ± 3.28 years VS 4.99 ± 3.47 years, P value 0.890; 1.10 ± 0.21 ng/dl VS 1.32 ± 0.18 ng/dl, P value 0.573 and 8.77 ± 1.72% VS 8.45 ± 1.54%, P value 0.398 respectively).Conclusions: SCH is common in type 2 diabetic patients especially in elderly, female and obese subjects.