TR06 Anti-TPO antibody titer as an independent correlate of insulin resistance and dyslipidemia: a cross-sectional study across euthyroid, hypothyroid, and healthy cohorts
Anti-thyroid peroxidase (anti-TPO) antibodies are established diagnostic markers of autoimmune thyroiditis. Emerging evidence suggests that thyroid autoimmunity may contribute to cardiometabolic risk independently of thyroid hormone status. To investigate the associations between anti-TPO antibody titers, insulin resistance, and lipid profile across euthyroid, hypothyroid, and healthy individuals. In this cross-sectional study, 111 adults were stratified into three groups: euthyroid anti-TPO-positive individuals (n = 34), patients with hypothyroidism due to Hashimoto thyroiditis (n = 60), and healthy controls (n = 17). Fasting plasma glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and lipid profile were assessed. Anti-TPO antibody titer was analysed as a continuous variable using Spearman correlation and multiple linear regression adjusted for age, body mass index (BMI), and sex. Anti-TPO antibody titer correlated positively with triglycerides (r = 0.221, P = 0.033), low-density lipoprotein cholesterol (r = 0.295, P = 0.004), and non-high-density lipoprotein cholesterol (r = 0.306, P = 0.003), but not with HOMA-IR (r = 0.090, P = 0.37). After adjustment for age, BMI, and sex, anti-TPO antibody titer remained an independent predictor of triglyceride concentrations (β = 0.059, 95% confidence interval 0.008–0.109; P = 0.023), whereas the associations with low-density lipoprotein and non-high-density lipoprotein cholesterol were no longer significant, suggesting mediation by age. HOMA-IR was not independently associated with anti-TPO antibody titer, while BMI was the strongest predictor (P = 0.004). Low-density lipoprotein cholesterol and BMI differed significantly among the three groups (P = 0.002 and P = 0.007, respectively). Anti-TPO antibody titer was independently associated with serum triglyceride concentrations regardless of thyroid functional status, supporting a potential role of thyroid autoimmunity itself in dyslipidaemia. No independent association between anti-TPO antibody titer and insulin resistance was observed. Larger longitudinal studies are needed to clarify the causal relationship.