Spinal cord injury (SCI) has been associated with marked bone loss and an increased risk of fractures under the SCI level. The aim of the study was to analyze the effect of recent complete SCI on bone turnover and bone mineral density (BMD) evolution and factors related to bone loss.
Methods: Prospective study including patients with complete motor SCI (ASIA A or B) (<6 months). Bone turnover markers (bone formation: P1NP, bone ALP and resorption: sCTx) and BMD (lumbar spine and femur (DXA)) were assessed in all patients at baseline and at 6 and 12 months. Risk factors for osteoporosis, SCI level (paraplegia/tetraplegia), lesion type (spastic/flaccid), SCI severity (ASIA score) and fractures were evaluated, comparing results with a control group.
Results: 42 patients (40M:2F) (mean age 35±14 years) were included 100±33 days after SCI (ASIA A 39:B 3). 55% had paraplegia and 78% spasticity. 24 were followed-up at 6 months and 22 at 12 months. Compared to controls, bone turnover markers were markedly increased just after SCI (P1NP: 194±124 vs 50±19 ng/ml, P<0.001; bone ALP: 15±7 vs 12±4 ng/ml, P=0.04; and sCTx 1.48±0.52 vs 0.49±0.23 ng/ml, P<0.001), with maintained, although with less increased, values at 6 and 12 months. BMD decreased progressively at proximal femur (−13±5% at 6 months, P<0.001, −20±8% at 12 months, P<0.001), with no significant changes at lumbar BMD. At 12 months 59% of the SCI patients presented densitometric osteoporosis. Patients with higher sCTX values after SCI (third tertile) had the highest femur BMD loss at 12 months (−23%). No relationship was observed between BMD and bone marker changes, or SCI level or lesion type.
Conclusions: Patients with complete SCI have increased bone turnover after injury with marked bone loss under the injury level of ~−20% of BMD at the proximal femur at 1 year, being more marked in individuals with the highest sCTX levels. Awareness of this complication and its therapeutic approach are mandatory.
17 - 20 May 2014
European Calcified Tissue Society