Prevalence and associated factors of low bone mineral density in young adults with spinal cord injury.

OBJECTIVE

To evaluate the prevalence of low bone mineral density (BMD) and its associated factors in young adults (18-50 years) with spinal cord injury (SCI), using real-world clinical data.

METHODS

We retrospectively analyzed 63 hospitalized SCI patients (21 women, 42 men) between January 2021 and December 2023. BMD was measured by dual-energy X-ray absorptiometry DXA at the lumbar spine, femoral neck, and total hip, and classified as normal or low (Z-score ≤ -2.0). Demographics, body mass index (BMI), spasticity, ambulation (FAC), biochemical parameters, and fracture history were compared between groups.

RESULTS

Low bone mass was detected in 38.1% of participants. BMD reduction was most pronounced at the femoral neck (0.6 ± 0.18 vs. 0.9 ± 0.15 g/cm2; p = 0.001) and total femur (0.6 ± 0.10 vs. 0.9 ± 0.17 g/cm2; p = 0.001), while lumbar spine values showed no significant difference (p = 0.62). Patients with low BMD had significantly lower BMI (23.8 ± 6.1 vs. 26.2 ± 5.0 kg/m2; p = 0.020). Notably, all fractures (n = 3) occurred in the normal BMD group, all with poor ambulation (FAC 0-1) and spasticity.

CONCLUSION

Low BMD is common in young adults with SCI, particularly in the femoral region, and is associated with lower BMI. The paradoxical finding of fractures in patients with normal BMD suggests that fracture risk is multifactorial and extends beyond densitometric parameters alone. These findings underscore the need for femur-focused DXA protocols and individualized risk-based management strategies.