Abstract
Cardiac troponins are prognostic biomarkers for cardiovascular disease (CVD) and mortality, but their significance in individuals with early kidney disease, defined as preserved estimated glomerular filtration rate but albuminuria, remains unclear. This study evaluated the association between high-sensitivity troponin I (hs-TnI) and troponin T (hs-TnT) with all-cause and cardiovascular mortality in this population. This retrospective cohort study used data from the 1999 to 2004 National Health and Nutrition Examination Survey. We included 1296 adults (≥18 years) with estimated glomerular filtration rate ≥ 60 mL/min/1.73 m² and urinary albumin-creatinine ratio ≥ 30 mg/g. Serum hs-TnI and hs-TnT levels were categorized into quintiles. The primary outcomes were all-cause and cardiovascular mortality, determined via National Health and Nutrition Examination Survey-linked National Death Index data through December 31, 2019. The mean age of participants was 51.4 ± 0.7 years, and 45.9% were male. Over a median follow-up of 219 months, 601 participants died, including 185 from CVD. Higher hs-Tn levels were associated with older age, hypertension, diabetes, and greater urinary albumin-creatinine ratio. Each one-quintile increase in hs-TnI was associated with a 26% higher risk of all-cause mortality (hazard ratios [HR]: 1.26; 95% CI: 1.13-1.41; P-trend < .001) and a 33% higher risk of CVD mortality (HR: 1.33; 95% CI: 1.04-1.71; P-trend < .05). Similar associations were observed for hs-TnT (HR: 1.56 for all-cause mortality; 95% CI: 1.37-1.77; P < .001; HR: 1.64 for CVD mortality; 95% CI: 1.33-2.03; P < .001). Sensitivity analyses excluding individuals with preexisting CVD and early deaths confirmed the robustness of these findings. Elevated hs-TnI and hs-TnT independently predict all-cause and cardiovascular mortality in individuals with early kidney disease. These findings highlight the potential role of hs-Tn measurement in enhancing cardiovascular risk stratification. Incorporating hs-Tn testing into routine assessments may help identify individuals who could benefit from earlier preventive interventions to reduce long-term cardiovascular risk; however, further research is needed to validate its clinical utility.