Longitudinal associations between serum 25-hydroxyvitamin D physical activity knee pain and dysfunction and physiological falls risk in community-dwelling older adults — ASN Events
  1. Schedule
  2. Poster Viewing I (odd numbers)
  3. Longitudinal associations between serum 25-hydroxyvitamin D physical activity knee pain and dysfunction and physiological falls risk in community-dwelling older adults

Longitudinal associations between serum 25-hydroxyvitamin D physical activity knee pain and dysfunction and physiological falls risk in community-dwelling older adults (#235)

Saliu Balogun 1 , Tania Winzenberg 1 , Karen Wills 1 , David Scott 2 3 , Graeme Jones 1 , Michele L Callisaya 1 2 , Dawn Aitken 1
  1. Menzies Institute for Medical Research, University of Tasmania, Hobart, TASMANIA, Australia
  2. Department of Medicine, , School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, , Clayton, Victoria, Australia
  3. Melbourne Medical School (Western Campus) and Australian Institute for Musculoskeletal Science, The University of Melbourne and Western Health,, St Albans, Victoria, Australia

Objective: Traditionally, analysis has focused on examining how risk factors for falls differ between individuals (between-person comparison). Less well recognized is how variability in risk factors over time within the same individual (within-person comparison) is associated with falls risk. This study aims to describe the associations between falls risk, and between-person and within-person variability in 25-hydroxyvitamin D (25OHD), physical activity (PA), knee pain and dysfunction in community-dwelling older people.

Methods: Data for 1053 participants (51% women; mean age 63±7.4 years) studied at baseline, 2.5, 5, and 10 years were analysed. Falls risk (Z-score) was measured using the Physiological Profile Assessment. Knee pain and dysfunction were assessed using the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Moderate-to-vigorous PA (MVPA) was measured using accelerometer. Linear mixed-effect regression models, with adjustment for confounders, were used to estimate the association between physiological falls risk and between-person and within-person variability in PA, 25OHD and WOMAC score.

Results: Between-person effects showed that 10-year average physiological falls risk was lower in participants who had a higher 10-year average 25OHD (β= -0.005 per nmol/l, 95% CI: -0.008, -0.002), log-MVPA (β= -0.16 per minute, 95% CI: -0.22, -0.10) and lower mean WOMAC score (β=0.005 per-unit score, 95% CI: 0.003, 0.01). Within-person effects showed that a higher physiological falls risk at any time-point was associated with higher than average WOMAC score (β=0.002 per-unit score, 95% CI: 0.0003, 0.004) and lower than average log-MVPA (β= -0.15 per minute, 95% CI: -0.24, -0.06), but not 25OHD, at the same time-point.

Conclusion: Having knee pain and dysfunction above an individual’s average increases the risk of falling, whereas, increasing one’s own MVPA level further reduces their risk of falling. The presence of between-person but not within-person associations for 25OHD suggests the former may be confounded by other factors.