Unveiling the Link: Hypothyroidism's Role in the Prevalence and Severity of Non-Alcoholic Fatty Liver Disease

Aim: This study aims to investigate the prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with subclinical and overt hypothyroidism at a tertiary care center in Northern India. Additionally, it seeks to establish the correlation between NAFLD and hypothyroidism, focusing on the different grades of fatty liver and the degree of hepatic stiffness. Methods: A cross-sectional study conducted on patients presenting with hypothyroidism. The sample included individuals diagnosed with subclinical or overt hypothyroidism. NAFLD was assessed using ultrasonography, and hepatic stiffness was measured using transient elastography. Patients were categorized based on the severity of NAFLD and the extent of liver stiffness. Statistical analyses were performed to determine the correlation between hypothyroidism severity, fatty liver grades, and hepatic stiffness. Results: The study found a high prevalence of NAFLD among patients with hypothyroidism. The prevalence was significantly higher in patients with overt hypothyroidism compared to those with subclinical hypothyroidism. There was a positive correlation between the severity of hypothyroidism and the grades of fatty liver. Increased hepatic stiffness was observed in patients with higher levels of TSH, indicating a progression toward more severe liver conditions. Serum free thyroxine (FT4) levels were inversely related to the prevalence and severity of NAFLD. Discussion: The findings suggest that hypothyroidism, particularly in its overt form, is a significant risk factor for NAFLD. The correlation between decreased FT4 levels and increased NAFLD prevalence underscores the importance of thyroid function in lipid metabolism and liver health. These results highlight the need for routine screening for NAFLD in patients with hypothyroidism and suggest that managing thyroid dysfunction could be crucial in preventing and treating NAFLD. Further research is needed to elucidate the underlying mechanisms linking these conditions and to develop targeted therapeutic strategies.