J Cardiothorac Surg. 2026 Jul 19. doi: 10.1186/s13019-026-04589-6. Online ahead of print.
ABSTRACT
BACKGROUND: Fluctuations in thyroid function among euthyroid individuals have been linked to cardiovascular disease (CVD). We investigated whether central thyroid hormone sensitivity correlates with CVD risk, CVD-related death, and overall mortality in subjects with normal thyroid function, particularly examining how age modifies these associations.
METHODS: We analyzed data from 6,374 euthyroid adults enrolled in NHANES 2007-2012. Central thyroid hormone sensitivity was quantified using three indices: the thyroid feedback quantile-based index (TFQI), the thyrotropin-thyroxine resistance index (TT4RI) and the TSH index (TSHI). The Framingham Risk Score (FRS) estimated each participant's 10-year probability of developing CVD. CVD mortality and all-cause mortality were ascertained by linkage to the National Death Index through December 31, 2015. Associations were evaluated using logistic regression (10-year CVD risk) and Cox proportional hazards models (mortality), adjusted for sex and race, with analyses stratified by age (< 40 and ≥ 40 years).
RESULTS: Of the 6,374 participants (mean age 48.24 ± 17.59 years; 52.0% male), 18.5% had a 10-year CVD risk > 10%; during follow-up. In sex- and race-adjusted models, all three indices were positively associated with an elevated 10-year CVD risk (> 10%): TFQI (OR 1.40, 95% CI 1.15-1.71), TSHI (OR 1.27, 95% CI 1.11-1.45), and TT4RI (OR 1.01, 95% CI 1.01-1.02). Each index was also significantly associated with higher CVD mortality and all-cause mortality, with TFQI showing the strongest associations (CVD mortality: HR 3.30, 95% CI 2.24-4.85; all-cause mortality: HR 2.19, 95% CI 1.83-2.62). These associations remained significant in participants aged ≥ 40 years (p < 0.001) but not in those aged < 40 years.
CONCLUSION: Impaired central thyroid hormone sensitivity shows association with elevated CVD risk, CVD mortality, and all-cause mortality in euthyroid individuals aged 40 years and older.
PMID:42472843 | DOI:10.1186/s13019-026-04589-6