Exploring cardiovascular risk in subclinical hypothyroidism: The impact of TSHR gene expression and systemic biomarkers

Introduction: Subclinical hypothyroidism (SCH), defined by elevated thyroid-stimulating hormone (TSH) with normal thyroid hormone levels, affects approximately 3-8% of the population. Growing evidence indicates that thyroid-stimulating hormone receptor (TSHR) expression in cardiovascular tissues, together with systemic inflammation (IL-6) and oxidative stress (3-nitrotyrosine), may contribute to cardiovascular dysfunction in SCH. This study aimed to evaluate the association between TSHR gene expression and systemic biomarkers-hormonal, inflammatory, and oxidative-and to assess their predictive value for cardiovascular risk in SCH patients. Methods: A case-control design was adopted involving 150 SCH subjects and 150 age- and sex-matched healthy controls. Demographic and clinical data were collected using structured interviews. Fasting blood samples were analyzed for TSH (CLIA), IL-6, and 3-nitrotyrosine (ELISA), while TSHR gene expression was quantified using real-time PCR with GAPDH as an internal control. Statistical analyses were performed using Stata version 17.0. Results: