Serum glycolipids mediate the link between dietary antioxidants and mortality in metabolic syndrome

While dietary modifications are increasingly recognized as a strategy to intervene in metabolic syndrome (MetS), the relationship between the composite dietary antioxidant index (CDAI) and long-term health outcomes in MetS populations remains unclear.

We analyzed data from 2074 adults with MetS in the NHANES (1999-2020). Weighted Cox proportional hazard regression models assessed hazard ratios (HRs) with 95% confidence intervals (CIs). Restricted cubic spline (RCS) curves were used to examine non-linear relationships, and stratified and mediation effect analyses were performed.

During a median follow-up of 76.24 months, 225 deaths occurred, including 65 from cardiovascular causes. After adjusting for confounders, participants in the third CDAI quartile had HRs of 0.63 (95% CI: 0.45-0.90, p = 0.025) for all-cause mortality and 0.54 (95% CI: 0.32-0.93, p = 0.023) for cardiovascular mortality, compared to those in the lowest quartile. RCS analysis showed a linear negative association between CDAI and mortality. Stratified analyses supported these findings, with no significant interactions. Mediation analysis revealed that serum glucose and HDL-C cholesterol mediated the relationship between CDAI and mortality.

Higher CDAI is associated with lower all-cause and cardiovascular mortality in MetS patients, potentially mediated through the regulation of glycolipid metabolism.