Telomere length and all-cause mortality risk among U.S. Adults: Examining the role of age and race/ethnicity

BACKGROUND: The relationship between telomere attrition and all-cause mortality among U.S. adults has been inconsistent. Additionally, the combined effect of age and race/ethnicity on this association has rarely been investigated. METHODS: We utilized two publicly available datasets, the National Health and Nutrition Examination Survey (1999-2002) and the 2019 Linked Mortality File, including data on adults aged 25 years or older (n = 6516 and 2163 deaths). Telomere length (TL) was measured as a standardized value expressed in kilobase pairs (kbp). We specified TL as continuous and categorical variables using quartile distribution (Q). Cox proportional hazards regression was used to quantify the association between TL and all-cause mortality using hazard ratios (HR) and 95% confidence intervals (CI). To test this association, we fitted three models: an unadjusted model, a model adjusted for sociodemographic variables, and a final model additionally adjusted for health risk factors and chronic diseases. We also tested for effect modification by age group and race/ethnicity. RESULTS: After adjusting for baseline sociodemographic characteristics, health risks, and chronic health conditions, a kbp decrease in TL was associated with 1.36 higher rate of all-cause mortality (95% CI: 1.17, 1.58). The rate of all-cause mortality was 1.57 times higher among adults with the shortest TL (Q1) relative to the longest TL (Q4) (95% CI: 1.25, 1.98). We did not find evidence of an effect modification by age and race/ethnicity. CONCLUSIONS: These findings highlight a significant association between TL and all-cause mortality, supporting telomere attrition as a predictor.