Metabolic, Inflammatory and Oxidative Alterations in Patients with Steatotic Liver Disease: Role of Subclinical Hypothyroidism

Background: Subclinical hypothyroidism has emerged as a potential contributor to the metabolic dysfunction-associated steatotic liver disease, particularly in individuals with coexisting hypertension. Aims: To evaluate metabolic profiles, inflammatory markers, and oxidative stress parameters in hypertensive patients with metabolic dysfunction-associated steatotic liver disease, depending on the presence of concomitant subclinical hypothyroidism. Methods: A total of 126 patients examined from 2019 to 2022 were divided into four groups: Group 1 – controls (n = 30); Group 2 – hypertensive patients with steatotic liver disease (n = 26); Group 3 – patients with hypertension and subclinical hypothyroidism (n = 18); and Group 4 – patients with all three conditions (n = 52). In Groups 3 and 4, thyroid-stimulating hormone (TSH) levels ranged from 4 to 10 mU/L. Anthropometric parameters, biochemical profile, inflammatory (C-reactive protein, CRP, tumor necrosis factor α, TNF-α), and oxidative stress markers (total hydroperoxide content, THP, total antioxidant activity, TAA) were assessed. Results: The presence of subclinical hypothyroidism (in either Group 3 or 4) was associated with significantly higher hip circumference (p < 0.05), lower waist-to-hip ratio (p < 0.001), elevated levels of glycated hemoglobin (p < 0.05), CRP (p < 0.05), and TNF-α (p < 0.001). Significantly higher levels of non-high-density lipoprotein cholesterol (non-HDL-C) (p = 0.005) and low-density lipoprotein cholesterol (p = 0.028), total cholesterol (p = 0.021), aspartate aminotransferase (p = 0.01), alkaline phosphatase (p = 0.034), THP (p = 0.014), and lower levels of HDL-C (p = 0.027) and glomerular filtration rate (p = 0.048) were observed in Group 4 compared to Group 2. In Group 4, TSH levels were positively associated with glucose (p = 0.008), TNF-α (p < 0.001), and inversely associated with HDL-C (p < 0.001), glomerular filtration rate (p < 0.001), and TAA (p = 0.012). A significantly higher proportion had a high cardiovascular risk according to SCORE2 in Group 4 compared to Group 2 (p = 0.023). Conclusion: Subclinical hypothyroidism significantly contributes to the cardiometabolic burden in hypertensive patients with metabolic dysfunction-associated steatotic liver disease. Even among patients with mild subclinical hypothyroidism, higher systemic inflammation, oxidative stress, impaired glucose control, and lipid dysregulation are observed.