Red Blood Cell Distribution Width Is Associated With Functional Outcomes Following Surgery for Hip Fracture

Area of Science:

• Gerontology
• Clinical Medicine
• Biomarkers

Background:

• Elevated red blood cell distribution width (RDW) is linked to adverse health outcomes in older adults.
• The predictive role of RDW for musculoskeletal recovery after hip fracture is not well understood.
• This study investigates RDW as a biomarker in older adults post-hip fracture surgery.

Purpose of the Study:

• To evaluate the association between baseline RDW and musculoskeletal outcomes in older women after hip fracture.
• To determine if RDW can predict functional recovery in response to supervised exercise (EX) with or without testosterone (T).
• To explore the potential of RDW as a predictive biomarker within the framework of Precision Gerontology.

Main Methods:

• Ancillary analysis of 105 women (≥65 years) from the STEP-HI randomized clinical trial.
• Outcomes measured: muscle mass, hand grip strength, 1-RM leg press, 6-minute walk distance, 4-meter walk, and SPPB.
• Linear mixed-effects models analyzed outcomes at baseline, 3, and 6 months, considering baseline RDW and treatment group (EX or EX+T).

Main Results:

• In the EX+T group, lower RDW was inversely associated with the Short Physical Performance Battery (SPPB) at all time points (p=0.02).
• Lower RDW was also inversely associated with 1-RM leg press in the EX+T group at 3 and 6 months (p=0.002).
• No significant associations were found in the EX-only group.

Conclusions:

• Lower RDW may indicate greater functional improvement from combined exercise and testosterone therapy post-hip fracture.
• These findings support the use of RDW as a predictive biomarker in Precision Gerontology.
• Targeting inter-individual heterogeneity can improve outcomes for older adults following hip fracture surgery.