Is the Red Blood Cell Distribution Widthto- Albumin Ratio Sufficient to Predict Cardiovascular Risk?

To the Editor,We read with interest the study by Li et al 1 demonstrating associations between red cell distribution width (RDW), RDW-to-albumin ratio (RAR), and cardiovascular disease (CVD) in 7619 postmenopausal women from NHANES 2003 to 2016. 1 The large sample and rigorous analysis are commendable, but several limitations constrain interpretation.Key biomarkers were not included in the study.Low-density lipoprotein cholesterol (LDL-C), the primary lipid target in CVD prevention, was omitted despite adjustment for total cholesterol and high-density lipoprotein cholesterol (HDL-C). 2 The authors propose inflammation as the mechanistic link between RDW and CVD, yet no inflammatory markers such as C-reactive protein (CRP) or interleukin-6 were measured.Prior studies have shown RDW correlates strongly with CRP and other inflammatory indices, making these essential to validate the proposed pathway. 3Without them, the inference that RDW serves as an "inflammatory surrogate" remains speculative.Medication use, particularly statins and anticoagulants, was also unaccounted for.Statins lower inflammation and affect albumin metabolism, while both drug classes are commonly used among older adults with CVD risk factors.Their omission may lead to residual confounding and overstate the independent effect of RDW and RAR.