The Relationship Between Autoimmune Thyroiditis and Metabolic Syndrome

Abstract

Hashimoto’s thyroiditis is the most common autoimmune thyroid disorder and represents a leading cause of hypothyroidism worldwide. In parallel, metabolic syndrome has emerged as a major global health problem, characterized by a cluster of metabolic abnormalities that substantially increase cardiovascular and metabolic risk. Growing evidence indicates that these two conditions are closely interconnected through shared pathophysiological mechanisms that extend beyond thyroid hormone deficiency alone. This review summarizes current epidemiological, clinical, and mechanistic data on the association between Hashimoto’s thyroiditis and metabolic syndrome. Available studies demonstrate a higher prevalence of metabolic syndrome and its components among patients with Hashimoto’s thyroiditis, including those in the euthyroid state, while thyroid autoimmunity is also more frequently observed in individuals with metabolic syndrome. Chronic low-grade inflammation, immune–metabolic crosstalk, adipokine imbalance, oxidative stress, and endothelial dysfunction appear to play central roles in linking autoimmune thyroid disease with metabolic dysregulation. Thyroid hormone replacement therapy improves certain metabolic parameters in hypothyroid patients but does not fully eliminate cardiometabolic risk, highlighting the importance of integrated management strategies. Understanding the bidirectional relationship between Hashimoto’s thyroiditis and metabolic syndrome has important implications for early detection, risk stratification, and comprehensive preventive and therapeutic approaches aimed at reducing long-term cardiovascular morbidity.