Association between the oxidative balance score and all-cause and cardiovascular mortality in patients with diabetes and prediabetes

Background: Few studies have examined the link between systemic oxidative stress and mortality risk in diabetes and prediabetes patients. The Oxidative Balance Score (OBS) is a novel measure of systemic oxidative stress, with higher scores indicating greater antioxidant exposure. This study investigates the relationship between OBS and all-cause and cardiovascular mortality in these patients.

Methods: This study analyzed 10,591 diabetes and prediabetes patients from the 1999-2018 National Health and Nutrition Examination Survey (NHANES). The endpoints were all-cause and cardiovascular mortality, determined from the National Death Index (NDI). OBS was calculated using 20 dietary and lifestyle factors. Kaplan-Meier survival analysis, multivariable Cox regression models, restricted cubic splines (RCS), and subgroup analyses were used to assess the relationship between OBS and mortality risks.

Results: Over an average follow-up of 99.8 months, 2900 (26.4 %) participants died, including 765 (8.9 %) from cardiovascular diseases. Kaplan-Meier analysis showed the lowest all-cause and cardiovascular mortality in the highest OBS quartile (Q4) and the highest mortality in the lowest quartile (Q1) (p < 0.001). In the fully adjusted model, multivariable Cox regression revealed that each unit increase in OBS was linked to a 1.8 % decrease in all-cause mortality risk (HR 0.982, 95 % CI 0.976-0.987, p < 0.0001) and a 4 % decrease in cardiovascular mortality risk (HR 0.960, 95 % CI 0.949-0.970, p < 0.0001). Compared to Q1, those in Q4 had significantly lower all-cause mortality (HR 0.719, 95 % CI 0.643-0.804, p < 0.0001, p for trend <0.0001) and cardiovascular mortality (HR 0.567, 95 % CI 0.455-0.705, p < 0.0001, p for trend <0.0001). These findings were consistent across subgroups. RCS curves showed a negative correlation between OBS and both mortality types.

Conclusion: Higher OBS is linked to reduced all-cause and cardiovascular mortality in diabetes and prediabetes patients.