Oxidative stress is closely associated with hypertensive outcomes. The oxidative balance score (OBS) measures oxidative stress exposure from dietary and lifestyle elements. The objective of this study was to investigate the association between OBS and mortality in hypertensive patients.

This study included 7823 hypertensive patients from the National Health and Nutrition Examination Survey (NHANES) 1999–2014. Several models, including Cox regression, restricted cubic splines (RCS), Kaplan‒Meier survival analysis, subgroup, and sensitivity analyses, were exploited to investigate the relationship between OBS and the risk of mortality.

Controlling for all potential confounders, a significantly inverse association was observed between elevated OBS and all-cause [hazard ratio (HR) = 0.90, 95% CI: 0.85–0.95] and cardiovascular mortality (HR = 0.85, 95% CI: 0.75–0.95). With adjustment for covariates, significant associations between lifestyle OBS and mortality risks diminished, whereas associations between dietary OBS and these mortality risks remained robust (all-cause mortality: HR = 0.91, 95% CI: 0.86–0.96; cardiovascular mortality: HR = 0.85, 95% CI: 0.76–0.96). RCS demonstrated a linear relationship between OBS and all-cause and cardiovascular mortality risk (P_nonlinear = 0.088 and P_nonlinear = 0.447, respectively). Kaplan‒Meier curves demonstrated that the mortality rate was lower with a high OBS (P < 0.001). The consistency of the association was demonstrated in subgroup and sensitivity analyses. RCS after stratification showed that among current drinkers, those with higher OBS had a lower risk of mortality compared with former or never drinkers.

In hypertensive individuals, there was a negative association between OBS and all-cause and cardiovascular mortality. Encouraging hypertensive individuals, especially those currently drinking, to maintain high levels of OBS may be beneficial in improving their prognosis.