THYROID FUNCTION STATUS IN OVERWEIGHT AND OBESE PATIENTS WITH TYPE 2 DIABETES AT THE NATIONAL HOSPITAL OF ENDOCRINOLOGY

Objective: To assess the current status of thyroid function and investigate selected associated factors among overweight/obese patients with type 2 diabetes mellitus (T2DM) at the National Hospital of Endocrinology. Patients and Methods: An analytical cross-sectional study was conducted on 320 overweight/obese patients with T2DM. Results: The mean age of the study population was 60.6 ± 11.8 years; 59.7% were aged ≥60 years, and women accounted for 69.7%. The mean body mass index (BMI) was 25.4 ± 2.1 kg/m². The prevalence of thyroid dysfunction was 28.4% (91/320), including secondary hypothyroidism in 10.9%, subclinical hyperthyroidism in 7.2%, subclinical hypothyroidism in 5.9%, overt primary hyperthyroidism in 3.1%, and overt primary hypothyroidism in 1.3%. Age, sex, and BMI categories were not significantly associated with thyroid dysfunction. Patients with hypothyroidism had significantly higher total cholesterol levels. Free thyroxine (FT4) was inversely correlated with total cholesterol (r = −0.42; p = 0.001), whereas thyroid-stimulating hormone (TSH) showed a weak positive correlation with fasting plasma glucose (r = 0.14; p = 0.012). In multivariable logistic regression analysis, total cholesterol was the only factor independently associated with hypothyroidism (OR = 1.89; 95% CI: 1.45–2.46; p < 0.001). Conclusion: Thyroid dysfunction is common among overweight/obese patients with type 2 diabetes. Routine thyroid function assessment should be considered in this high-risk metabolic population, particularly when lipid control is suboptimal, as total cholesterol was identified as an independent factor associated with hypothyroidism in the multivariable analysis.