Thyroid function and Liver Fibrosis: Study unveils Link Between Liver Fibrosis and Hypothyroid Spectrum

Metabolic dysfunction n-associated steatotic liver disease (MASLD) or non-alcoholic fatty liver disease (NAFLD) is a common disease affecting globally. Studies have shown that hypothyroidism, even in the low-normal level, can progress the severity of MASLD. Even though previous literature assessed the prevalence of MASLD in hypothyroidism, there is uncertainty about the incidence of liver fibrosis. Some studies evaluated the liver fibrotic burden using serum markers, but there are no studies that evaluated liver fibrosis using vibration-controlled transient elastography (VCTE) in hypothyroid individuals. Hence, researchers conducted a study to evaluate the prevalence of liver fibrotic burden across the spectrum of hypothyroidism assessed by VCTE.

A cross-sectional analysis of about 30,091 individuals who attended a Health management Centre between 2019 and 2021 was carried out. Based on thyroid levels, participants were categorized as having strict-normal thyroid function, low-normal thyroid function, subclinical hypothyroidism, and overt hypothyroidism. Using vibration-controlled transient elastography (VCTE), liver fibrosis was assessed. Significant and advanced fibrosis was defined as liver stiffness measurements in VCTE of 8.1–9.6 and 9.7–13.5 kPa, respectively.

Findings:

• Liver fibrosis was found to be more common in the low-normal thyroid function group, subclinical hypothyroidism group, and overt hypothyroidism group than in the strict-normal thyroid function group.
• The fibrosis ranged from mild fibrosis, significant fibrosis, advanced fibrosis, and cirrhosis.
• Liver fibrosis was similar between the low-normal thyroid function group and the subclinical hypothyroidism group.
• The highest liver fibrosis was seen in the overt hypothyroidism group.
• A significant association was found between both significant and advanced liver fibrosis and low-normal thyroid function, subclinical hypothyroidism, and overt hypothyroidism in both men and women.

Thus, the study concluded that Liver fibrotic burden is highly prevalent in subjects with overt hypothyroidism. The pattern of fibrosis was also increased across the spectrum of hypothyroidism even within the low normal thyroid function. Hence, researchers suggested that screening for liver fibrosis should be carried out in patients with hypothyroidism to rule out fibrosis.

Further reading: Du, T., Huang, Y., Lv, Y. et al. Liver fibrotic burden across the spectrum of hypothyroidism. J Gastroenterol (2024). https://doi.org/10.1007/s00535-024-02184-x