Bone mass in individuals with chronic spinal cord injury: associations with activity-based therapy, neurologic and functional status, a retrospective study.

OBJECTIVE: To describe the prevalence of osteoporosis and its association with functional electrical stimulation (FES) use in individuals with spinal cord injury (SCI)-related paralysis.

DESIGN: Retrospective cross-sectional evaluation.

SETTING: Clinic.

PARTICIPANTS: Consecutive persons with SCI (N=364; 115 women, 249 men) aged between 18 and 80 years who underwent dual-energy x-ray absorptiometry (DXA) examinations.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURE: Prevalence of osteoporosis defined as DXA T score ≤-2.5.

RESULTS: The prevalence of osteoporosis was 34.9% (n=127). Use of FES was associated with 31.2% prevalence of osteoporosis compared with 39.5% among persons not using FES. In multivariate adjusted logistic regression analysis, FES use was associated with 42% decreased odds of osteoporosis after adjusting for sex, age, body mass index, type and duration of injury, Lower Extremity Motor Scores, ambulation, previous bone fractures, and use of calcium, vitamin D, and anticonvulsant; (adjusted odds ratio [OR]=.58; 95% confidence interval [CI], .35-.99; P=.039). Duration of injury >1 year was associated with a 3-fold increase in odds of osteoporosis compared with individuals with injury <1 year; (adjusted OR=3.02; 95% CI, 1.60-5.68; P=.001).

CONCLUSIONS: FES cycling ergometry may be associated with a decreased loss of bone mass after paralysis. Further prospective examination of the role of FES in preserving bone mass will improve our understanding of this association.