High prevalence of low bone mineral density in wheelchair users regardless of sports participation: a cross-sectional analysis of the bonewheel study.

PURPOSE: Wheelchair users are at increased risk of low bone mineral density (BMD). While BMD varies by sport among Paralympic athletes, it remains unclear whether sports participation protects against low BMD in the impaired population. This study compared BMD at several skeletal sites between sports-active and non-sports-active wheelchair users.

METHODS

This study presents cross-sectional analyses of adult (18–60 years) wheelchair users with non-progressive impairments recruited for a subsequent multi-site intervention study. BMD and body composition were measured with dual-energy X-ray absorptiometry. Low BMD was defined as Z-score <–1.0. Multiple linear regression models assessed differences between sports-active (≥ 1 year organised; ≥3 training hours per week) and non-sports-active participants, and associations with impairment and exercise characteristics, and body composition.

RESULTS

Sixty-three wheelchair users (age 37 ± 11 years; 41% female; 48% sports-active; 49% with acquired impairments) were included. Low BMD was prevalent in 33%, 81% and 77% at the spine, hip and femoral neck, respectively. Low BMD at the hip was less prevalent in sports-active compared to non-sports-active (p = 0.013), without differences in any BMD Z-score models (all p > 0.05). Acquired impairments was positively associated with lumbar spine BMD (p = 0.034), while full-time wheelchair use was negatively associated with femoral neck BMD (p = 0.036). Impairments and SCIM scores were associated with hip BMD (both p < 0.05).

CONCLUSION

Notably high prevalences of low BMD was found in this study, particularly at the hip and regardless of sports participation. Impairments and ambulatory ability appear the most influential on BMD. Targeted exercise interventions for bone health are warranted in this population. TRIAL REGISTRATION: This study was registered in ClinicalTrials.gov (NCT05615402) on Nov 14, 2022, as well as Open Science Framework ( https://doi.org/10.17605/OSF.IO/SE2TB ) on Jan 04, 2023.