Association between oxidative balance score and cardiovascular diseases: mediating analysis of methylmalonic acid based on the NHANES database

AimTo explore the association between oxidative balance score (OBS) and cardiovascular diseases (CVD) in patients with hypertension, and further clarify the mediating role of methylmalonic acid (MMA) in the relationship between OBS and CVD risk.MethodsWe included 4,137 participants with hypertension from the 2011–2014 National Health and Nutrition Examination Survey cohort. The study endpoint was the incidence of CVD in patients with hypertension. OBS was calculated based on 16 dietary and 4 lifestyle components. Weighted multivariable logistic regression models were adopted to assess the associations between OBS and CVD risk, OBS and MMA levels, and MMA levels and CVD risk. Odds ratios (OR) and 95% confidence interval (CI) were estimated. We used distribution-of-product method to test for mediation effect, with a presence of mediation indicated by 95% CI that does not include 0 for the distribution-of-product method and 95% CI that does not include 1 for the indirect effect.ResultsTotally 812 developed CVD. In weighted multivariable logistic regression models, lower OBS category (OBS