Gu Y, et al. - This cross-sectional study examined the association of serum thyroid hormones concentrations with the prevalence of elevated blood pressure (BP) levels in euthyroid adults (n=12,487) in Tianjin, China. Using chemiluminescence immunoassay, serum free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) levels were measured. JNC 8 criteria was used to define elevated BP. The links between FT3, FT4, and TSH quartiles and elevated BP levels were evaluated by performing analysis of covariance and using multiple logistic regression models. Findings demonstrated a positive association of FT3 and FT4 with the prevalence of elevated BP levels in euthyroid adults, but there was no significant link between TSH and elevated BP levels.