Dietary antioxidants and mortality in early-stage CKM syndrome: insights from NHANES
Lincheng Duan, Hong Yang, Zong-Ming Chen, Junxin Zhao, H. J. Yang, Dingjun Cai
Abstract
PURPOSE: Cardiovascular-kidney-metabolic (CKM) syndrome is a newly recognized multisystem disorder, with over 90% of cases occurring in the early stages (0–3). However, there is a lack of evidence for dietary interventions during this phase. This study is the first to examine the connection between the composite dietary antioxidant index (CDAI) and mortality risk in early-stage CKM patients, aiming to support early intervention strategies based on nutrition. METHODS: We analyzed data from 7,642 CKM 0–3 stage patients from the NHANES 2007–2018 cohort. Multivariable weighted Cox regression was used to assess the association between CDAI and all-cause/cardiovascular disease (CVD) mortality. A restricted cubic spline was applied to explore dose-response relationships, with subgroup analyses to explore population heterogeneity. RESULTS: During a median follow-up of 94 months, 594 all-cause deaths and 151 CVD deaths were recorded. Each unit increase in CDAI was substantially linked to a 6% decrease in all-cause mortality after controlling for covariates (HR = 0.94, 95% CI 0.91–0.98). Mortality risk was 40% lower in the highest CDAI quartile than in the lowest quartile (HR = 0.60, 95% CI 0.44–0.83). Dose-response analysis revealed a linear decreasing trend (p < 0.001). Subgroup analyses further supported these findings. Carotenoids and vitamin E were also substantially linked to a decreased all-cause mortality rate in CKM patients. For CVD mortality, a significant association was observed in unadjusted models (HR = 0.92, 95% CI 0.86–0.98, P < 0.05), but no significant association was found between CDAI and CVD mortality in the fully adjusted model (HR = 0.98, 95% CI 0.92–1.05, P = 0.62), suggesting potential mediation by covariates such as comorbidities and lifestyle factors. CONCLUSION: Enhanced dietary antioxidant capacity significantly reduces all-cause mortality risk in early-stage CKM patients (stages 0–3), with vitamin E and carotenoids potentially playing key protective roles. These findings provide dose-response evidence for early nutritional interventions in CKM syndrome, suggesting that multi-nutrient strategies targeting oxidative stress pathways may offer new directions for prevention and management.