Association between Thyroid Function and Nonalcoholic Fatty Liver Disease in Euthyroid Type 2 Diabetes Patients

Area of Science:

• Endocrinology
• Hepatology
• Metabolic Diseases

Background:

• Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are linked to adverse clinical outcomes.
• Thyroid dysfunction is also a risk factor for poor health outcomes in patients with T2DM and NAFLD.
• Understanding the interplay between thyroid function, NAFLD, and T2DM is crucial for patient management.

Purpose of the Study:

• To evaluate the association between thyroid function and NAFLD in euthyroid T2DM patients.
• To analyze the potential effects of metformin on the pathological processes in T2DM patients with NAFLD.
• To investigate the relationship between thyroid hormones, metabolic parameters, and NAFLD in T2DM.

Main Methods:

• A cohort of 369 T2DM patients was stratified into NAFLD and non-NAFLD groups.
• Data collected included demographics, body mass index (BMI), metformin use, basal metabolic rate (BMR), and biochemical markers.
• Multivariate analyses and correlation studies were performed to assess associations between variables.

Main Results:

• Increased odds of NAFLD were associated with higher BMI, free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) in T2DM patients.
• Positive correlation between alanine aminotransferase (ALT) and FT3, and negative correlations between TSH and BMR, and BMR and FT3 were observed in T2DM with NAFLD.
• Obese T2DM patients with NAFLD showed significant differences in FT3 and TSH levels between metformin users and non-users.

Conclusions:

• The pathophysiology of T2DM with NAFLD in euthyroid patients may involve insulin resistance and thyroid hormone resistance.
• Metformin may mitigate this 'double-resistance' state, particularly in obese individuals.
• Further research is warranted to elucidate the precise mechanisms and therapeutic implications.