High red blood cell distribution width associated with incident frailty in patients with cardiometabolic diseases: A longitudinal study

Frailty is an important health issue in older adults that leads to disability and increased mortality. Red blood cell distribution width (RDW), a measure of variability in red blood cell volume, is associated with inflammation, anemia, and cardiovascular diseases. This study examined whether high RDW (≥ 13.5%) predicts incident frailty over three years in 469 older adults with cardiometabolic disease but without baseline frailty, as defined by the modified Cardiovascular Health Study (mCHS) criteria or the Kihon Checklist (KCL). RDW was measured through a complete blood cell count. Multivariate Cox regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for high RDW and incident frailty, adjusting for age, sex, body mass index, eGFR, HbA1c, and basely ne mCHS or KCL score, with low RDW as the reference. During the follow-up period, 29.5% and 24.6% of the patients developed frailty, as defined by the mCHS and KCL, respectively. High RDW was significantly associated with incident mCHS- and KCL-defined frailty, with adjusted HRs of 1.62 (95% CI: 1.10-2.37) and 1.49 (95% CI: 1.02-2.34), respectively. Thus, elevated RDW levels (≥ 13.5%) were found to be an independent predictor of the incidence of two distinct types of frailty in older adults with cardiometabolic diseases.