The relationship between Oxidation Balance Score and all-cause mortality in patients with hypertension: An observational study

The Oxidation Balance Score (OBS), which integrates prooxidant and antioxidant exposures from diet and lifestyle, serves as an indicator of systemic oxidative stress. This study examined the association between OBS and all-cause mortality among U.S. adults with hypertension. OBS was derived from 16 dietary nutrients and 3 lifestyle factors. The nonlinear relationship between OBS and mortality was assessed using smoothing splines. Kaplan-Meier curves, multivariable Cox regression, competing risk models, and subgroup analyses were employed to evaluate mortality risks. The results from the smoothing spline plots and Kaplan-Meier curves suggested that higher OBS levels were associated with lower all-cause mortality. After full adjustment, the Cox regression model revealed that higher OBS levels were associated with a 13% reduction in the risk of all-cause mortality among patients with hypertension compared to those with lower OBS levels (hazard ratios = 0.87, 95% confidence interval: 0.78-0.96, P = .004; P for trend = .003). Sensitivity analysis confirmed a protective association between higher OBS and 10-year mortality, indicating a 13% reduction in risk (hazard ratios = 0.87, 95% confidence interval: 0.78-0.98, P = .019; P for trend = .017). Competing risk models further confirmed that higher OBS reduced hypertension-related mortality. A nonlinear relationship exists between OBS and all-cause mortality in patients with hypertension. Higher OBS is linked to lower mortality, suggesting its potential utility in the prognostic risk assessment for hypertension.