The association between red blood cell distribution width-to-albumin ratio and chest pain prevalence in US adults: A cross-sectional analysis of NHANES 2005-2018.

The red blood cell distribution width-to-albumin ratio (RAR), a novel marker reflecting both inflammation and nutritional status, has emerged as a potential clinical biomarker. However, its link to chest pain in general populations remains underexplored. This study is the first to assess the association between RAR and chest pain prevalence using data from the nationally representative National Health and Nutrition Examination Survey cohort. Data from 21,174 adults in the 2005-2018 National Health and Nutrition Examination Survey were analyzed. Chest pain was assessed via the Rose Angina Questionnaire. RAR was calculated by dividing red cell distribution width by serum albumin. Multivariable logistic regression models incorporating survey weights, restricted cubic spline analyses, and subgroup analyses were used to evaluate the association, adjusting for demographic, socioeconomic, lifestyle, and clinical factors. A nonlinear relationship was found between RAR and chest pain, with an inflection point at RAR = 3.59. Below this point, each unit increase in RAR was associated with a 32% higher likelihood of chest pain (odds ratio = 1.32, 95% confidence interval: 1.17-1.49, P < .0001). Above 3.59, the association weakened. Compared to the lowest quartile (Q1), individuals in the highest RAR quartile (Q4) had a 26% increased prevalence of chest pain (odds ratio = 1.26, 95% confidence interval 1.15-1.39, P < .0001). Subgroup analysis showed stronger associations in smokers (interaction P = .016), with consistent results across age and racial/ethnic groups. Higher RAR is independently associated with increased chest pain prevalence, especially below 3.59, suggesting its value in risk stratification, particularly among smokers.