Association between mortality and the ratio of red blood cell distribution width to albumin concentration in pre-hypertension and hypertension: A population-based cohort study

Objectives

The ratio of red blood cell distribution width to albumin concentration (RAR) is a novel indicator of systemic inflammation and nutritional status. Its association with mortality in pre-hypertensive and hypertensive individuals remains unexplored.

Methods

This study investigates the relationship between RAR and all-cause as well as cause-specific mortality in a pre-hypertensive and hypertensive population using data from the National Health and Nutrition Examination Survey. Cox proportional hazard models assessed the relationship between RAR and mortality, with results reported as hazard ratios (HRs) and corresponding confidence intervals (CIs). Kaplan-Meier survival curves illustrated survival probabilities across quartiles, while restricted cubic spline (RCS) analysis examined potential non-linear associations.

Results

Elevated RAR was significantly associated with an increased risk of mortality. Each one-unit increase in RAR corresponded to an adjusted HR of 2.03 (95 % CI: 1.85–2.23) for all-cause mortality, 2.21 (95 % CI: 1.99–2.45) for heart disease, 1.86 (95 % CI: 1.65–2.10) for cancer, and 2.03 (95 % CI: 1.83–2.24) for other-cause mortality (P < 0.001). Participants in the highest RAR quartile had a 178 % increased risk of all-cause mortality (HR = 2.78, 95 % CI: 2.51–3.08). Kaplan-Meier curves depicting the survival probabilities of pre-hypertensive and hypertensive participants across RAR quartiles substantiated these associations. RCS analysis also confirmed a positive association, demonstrating distinct linear or non-linear patterns in the associations with all-cause and cause-specific mortality.

Conclusions

RAR is independently associated with all-cause and cause-specific mortality in adults with pre-hypertension and hypertension, warranting its consideration for clinical risk stratification.