Interactive association of the dietary oxidative balance score and cardiovascular disease with mortality in older adults: evidence from NHANES.

Objectives : We conducted an assessment to explore potential associations of the dietary oxidative balance score (DOBS), cardiovascular disease (CVD), with all-cause mortality among older adults, while also exploring the potential moderating effect of DOBS on the relationship between CVD and mortality. Methods : This study included 9059 older adults (≥60 years) from NHANES 2003-2014. Determination of DOBS involves scoring the combination of 16 nutrients, comprising 2 pro-oxidants and 14 anti-oxidants. Cox regression analysis was used to assess the individual associations of CVD and DOBS status with all-cause mortality. Additional evaluations were conducted to assess the combined impact of CVD and DOBS status on mortality, and the interaction were estimated. Sensitivity analyses were performed by excluding participants who died within two years. Results : The findings demonstrated a significant association between pro-oxidant diet (lower DOBS) or CVD and elevated mortality risk among older adults. It is also suggested that older adults with CVD and pro-oxidant diet exhibit the highest risk of all-cause mortality (HR = 1.96, 95% CI: 1.64-2.34), compared to individuals without CVD who follow an antioxidant-rich diet. Further stratified analysis based on CVD status revealed a different pattern in the correlation between pro-oxidant diet and all-cause mortality risk ( P for interaction = 0.015). The results of sensitivity analysis were consistent. Conclusions : The lower levels of DOBS and/or CVD were significantly associated with an increased risk of all-cause mortality in older adults. Notably, we also identified a significant interaction between DOBS and CVD affecting all-cause mortality.