Thyroid-stimulating hormone variation within the euthyroid range and the severity of fatty liver disease in patients with type 2 diabetes mellitus: A cross-sectional study

Abstract

Objective: To identify the relationship between thyroid-stimulating hormone levels within the euthyroid range and the severity of fatty liver disease in patients with type 2 diabetes mellitus.

Method: The cross-sectional study was conducted at the Department of Medicine, Pakistan Railways Hospital, Rawalpindi, Pakistan, from August 15, 2024, to February 15, 2025, and comprised euthyroid patients with type 2 diabetes mellitus of either gender, aged 35-65 years. Those with non-alcoholic fatty liver disease were placed in group A, while those with non-alcoholic steatohepatitis were placed in group B. The diagnosis was based on abdominal ultrasonography. Thyroid-stimulating hormone was classified as low-normal (0.5-2.5mIU/L) or high-normal (>2.5-5.0mIU/L). Alanine aminotransferase, body mass index, fasting blood sugar and duration of diabetes were recorded. Data was analysed using SPSS 27.

Results: Of the 670 patients with a median age of 48.0 years (interquartile range: 37.0-57.0 years), 520(77.6%) were female, and 150(22.4%) were male. There were 480 (71.6%) patients in group A and 190 (28.4%) in group B. Median thyroid-stimulating hormone was higher in group B than in group A (p=0.018). High-normal thyroid-stimulating hormone was more frequent in group B than group A (p=0.001). Fasting blood sugar was higher in group B (p<0.001), while body mass index was higher in group A (p = 0.001). The correlation between alanine aminotransferase and thyroid-stimulating hormone was weak overall (p=0.023). Multivariable regression showed high-normal thyroid-stimulating hormone was independently associated with non-alcoholic steatohepatitis (p<0.001).

Conclusion: Within the euthyroid range, higher thyroid-stimulating hormone levels in type 2 diabetes mellitus patients were associated with non-alcoholic steatohepatitis, which is a more severe fatty liver disease than non-alcoholic fatty liver disease. This was independent of confounders. Thyroid-stimulating hormone level within the normal range may help identify diabetic patients at higher risk of progressive liver disease.

Key Words: Non-alcoholic fatty liver disease, Metabolically-dysfunction-associated steatotic liver disease, Metabolically-dysfunction-associated steatohepatitis, Diabetes mellitus, Type 2, Thyrotropin.