Association of APOE gene expression with thyroid dysfunction, inflammation, and nitrosative stress in cardiometabolic syndrome: a case–control study

OBJECTIVES: This study aimed to examine the association of thyroid-stimulating hormone (TSH), interleukin-6 (IL-6), and 3-nitrotyrosine (3-NT) with ApoE gene expression and to evaluate their diagnostic utility in CMS. METHODS: This case-control study compared hormonal, inflammatory, oxidative stress, and gene expression markers between CMS cases and healthy controls. Group differences were analyzed using non-parametric tests. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis, and relationships among variables were assessed using correlation and multivariable logistic regression models. RESULTS: CMS cases showed significantly higher levels of TSH, IL-6, 3-NT, and ApoE gene expression compared with controls. TSH demonstrated modest diagnostic accuracy (AUC=0.740), whereas 3-NT exhibited excellent discriminative performance (AUC=0.963). IL-6 also showed good diagnostic accuracy. ApoE gene expression demonstrated strong diagnostic performance and was positively correlated with TSH, 3-NT, and IL-6, with the strongest association observed for IL-6. Multivariable regression analysis confirmed that elevated TSH, IL-6, and 3-NT were independently associated with CMS status. CONCLUSIONS: CMS is characterized by the convergence of thyroid dysregulation, inflammation, oxidative stress, and increased ApoE gene expression. These findings highlight a coordinated molecular network underlying CMS and support the integration of molecular and inflammatory biomarkers into cardiometabolic risk assessment. Larger longitudinal studies are required to confirm these observations.