Abstract
BACKGROUND: The Oxidative Balance Score (OBS) is a new measure for assessing systemic oxidative stress, where higher scores indicate increased exposure to antioxidants. However, the relationship between the OBS and mortality in individuals with hypertension remains unclear. METHODS: This study evaluated 8151 hypertensive individuals from the National Health and Nutrition Examination Survey (NHANES) (2001-2018), utilizing data from the National Death Index, tracked through December 31, 2019. The association between OBS and mortality (cardiovascular and all-cause) was examined using multivariable Cox regression models. RESULTS: During a median follow-up of 9.7 years, which included 1692 deaths (461 of which were cardiovascular), multivariable Cox regression showed the highest quartile of OBS had significantly lower rates of all-cause mortality (hazard ratio (HR) 0.761, 95% CI: 0.635-0.912) and cardiovascular mortality (HR 0.553, 95% CI: 0.388-0.788) compared to those in the lowest quartile. An increase of one unit in the OBS was associated with a 1.9% reduction in all-cause mortality risk and a 3.7% reduction in cardiovascular mortality risk. This relationship remained consistent across various subgroup analyses, and spline regression supported a linear inverse trend. CONCLUSIONS: For adults with hypertension, an elevated OBS is independently associated with a lower risk of mortality both from all-cause and cardiovascular diseases, suggesting that higher antioxidant levels may be protective.