Protein intake and injury outcomes among fallers in the Women's Health Initiative's Objective Physical Activity and Cardiovascular Health in Older Women Study

BACKGROUND: Falls among older adults are associated with increased morbidity, mortality, and healthcare costs; therefore, it is critical to assess modifiable risk factors. This study aimed to determine if low protein intake among older women was associated with injuries among fallers. METHODS: The Women's Health Initiative ancillary studies, Live Long Study (LLS), Food Intake (FI), and Objective Physical Activity and Cardiovascular Health in Older Women study (OPACH) were combined for analyses (n = 6,580; n = 1,285 fallers). Protein intake was assessed by food frequency questionnaires at LLS/FI/OPACH baseline. Participants completed fall calendars for 13 months and self-reported injuries in interviews. Logistic regression determined odds ratios (OR) and 95% confidence intervals (CI) for risk of injurious falls and falls with fracture. Diabetes medication use had a significant interaction between protein density and fall with any injury; thus, models were stratified. RESULTS: Of the participants who fell, 841 (65.4%) fell without injury, 444 (34.6%) fell with injury, and 70 (7.7%) fell with fracture. Lower protein density (<15% calories from protein) increased risk of fracture from falling (OR: 1.73; 95% CI: 1.02-2.92) compared to those with higher protein density (≥15% calories from protein). Among participants with diabetes medication use and lower protein density, the OR for any injury from falling was 5.54 (95% CI: 1.79-17.19) compared to those with higher protein density though based on a small subgroup. CONCLUSION: Lower protein density increased risk of injurious falls. Dietary and medication screening may facilitate selection and tailoring for behavioral falls prevention to reduce injurious falls and fractures.