Exploring the Prevalence of Thyroid Dysfunction in Type 2 Diabetes Mellitus in Central India

Background: Thyroid dysfunction is a commonly reported endocrine abnormality among patients with type 2 diabetes mellitus (T2DM) and may adversely influence glycaemic control and cardiovascular risk. However, the prevalence of thyroid dysfunction varies across populations and geographical regions. Data from Central India are relatively limited. This study aimed to determine the prevalence of thyroid dysfunction among patients with T2DM and assess its distribution according to age and sex. Material and Methods: A prospective longitudinal study was conducted among patients with T2DM attending the Medicine Outpatient Department in Central India from 1 May 2024 to 30 April 2025. Patients providing informed consent were included, while those with known autoimmune diseases or unwilling to participate were excluded. Demographic and clinical details were recorded, and thyroid function was assessed using serum thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4). Thyroid dysfunction was categorized as hypothyroid or hyperthyroid pattern based on biochemical parameters and laboratory reference ranges. The prevalence of thyroid dysfunction was evaluated overall and according to sex and age groups. Results: Among 161 participants with available thyroid-function results, 53 (32.9%) had thyroid dysfunction, while 108 (67.1%) were euthyroid. Hypothyroid-pattern abnormalities were predominant, occurring in 50 (31.1%) participants, whereas hyperthyroid-pattern abnormalities were present in 3 (1.9%). Thyroid dysfunction was observed in 37 (34.9%) males and 16 (29.1%) females; this difference was not statistically significant (p=0.570). Prevalence according to age was 25.0% in participants aged <40 years, 23.1% in those aged 40–59 years, 39.8% in those aged 60–79 years, and 40.0% in those aged ≥80 years, with no statistically significant association (p=0.193). Conclusion: Thyroid dysfunction was common among patients with T2DM, with hypothyroid-pattern abnormalities predominating. Although no statistically significant association with sex or age was observed, the higher prevalence among older participants highlights the importance of considering thyroid dysfunction during routine evaluation of patients with T2DM.

Keywords: Type 2 diabetes mellitus; thyroid dysfunction; hypothyroidism; hyperthyroidism; TSH; prevalence; Central India.