Joint and Independent Associations of Dietary Antioxidant Intakes With Advanced Stages in Older Patients With...

This study explored the association between the composite dietary antioxidant index (CDAI) and cardiovascular-kidney-metabolic (CKM) progression in an older population. Using data from NHANES 2001-2020, we analyzed 4974 adults aged ≥ 60 years with CKM syndrome. The CDAI was calculated from the intake of six dietary antioxidants. Associations between the CDAI and its components and advanced CKM syndrome (Stages 3-4) were assessed using multivariable logistic regression, restricted cubic splines, piecewise logistic regression, and weighted quantile sum (WQS) regression. Participants in the highest CDAI quartile had lower odds of advanced CKM syndrome than those in the lowest quartile (OR = 0.728, 95% CI: 0.594-0.893). Restricted cubic spline analysis showed an L-shaped association between CDAI and odds of advanced CKM syndrome, with an inflection point at 5.857; the inverse association was evident below this threshold and plateaued above it. Furthermore, the WQS regression model identified a protective combined effect of the six dietary antioxidants against advanced CKM syndrome, with vitamin A and vitamin C contributing the largest weights. Higher CDAI levels were associated with a lower risk of advanced CKM syndrome in older adults, with vitamins A and C emerging as the most influential components.