The Association of Red Cell Distribution Width with All-cause and Cardiovascular Mortality in American Adults with Hypertension: Population-Based Prospective Cohort Study (Preprint)

Abstract

The progression of hypertension is highly heterogeneous among populations and cost-effective biomarkers assessing the prognosis of hypertension have been rarely investigated. Recent studies have highlighted the diagnostic and prognostic potential of red cell distribution width (RDW) beyond hematologic disorders. The relationship between RDW and the prognosis of hypertension has been rarely investigated.

This study aimed to clarify the association of RDW with all-cause and cardiovascular disease (CVD) mortality in hypertensive adults.

This prospective cohort study included 20968 adults with hypertension from the National Health and Nutritional Examination Surveys (NHANES) 1999-2018 with mortality follow-up through December 31, 2019. The participants were grouped based on the RDW quartiles as follows: Q1(≤12.5%), Q2(12.6%–13.1%), Q3(13.2%–13.9%), and Q4(≥14.0%). Kaplan-Meier curves and Cox regressions were performed to assess the relationship between RDW and mortality risk due to all-cause and CVD. The restricted cubic spline regressions were used to profile the dose-response relationship between RDW and mortality risk. The receiver operating characteristic curves were used to examine the predictive performance of RDW for mortality risk.

During a median follow-up of 96 months, 5475 deaths were documented including 1890 due to CVD. Multivariate analysis revealed that mortality risk increased step-wise by RDW quartiles, in which the HRs (95% CIs) from Q1 to Q4 were 1.00 (reference), 1.18 (1.06-1.31), 1.41 (1.27-1.56), and 2.19 (1.94-2.48) for all-cause mortality (P for trend <.001), and those were 1.00 (reference), 1.12 (0.94-1.33), 1.35 (1.12-1.63), and 2.20 (1.75-2.75) for CVD mortality (P for trend <.001). The RCS analysis revealed S-shaped associations between RDW and all-cause and CVD mortality risk. The ROC curves demonstrated acceptable predictive performance of RDW for all-cause and CVD mortality in hypertensive adults.

In American adults with hypertension, higher RDW was significantly associated with higher risks of all-cause and CVD mortality. RDW might be a promising cost-effective prognostic biomarker in the management of hypertension. Further studies are warranted to explore the potential pathophysiological mechanisms underlying the association between RDW and mortality.