Background Spinal cord injury (SCI) has been associated with a marked increase in bone loss.
Objectives To analyse the effect of Wnt signalling antagonists (sclerostin and DKK-1) and their relationship with bone turnover markers and BMD evolution in patients with a recent SCI.
Methods Patients with a recent complete motor SCI (AIS A or B)(<6 months) were prospectively included. Bone turnover markers (Bone formation: P1NP, bone AP; Bone resorption: sCTx), Wnt antagonists (serum sclerostin and Dkk-1, determined by ELISA, Biomedica Gruppe, Austria) and bone mineral density (BMD) were assessed in all patients at baseline and at 6 months. The results were compared with 23 healthy individuals of similar age and sex.
Results 25 men with a mean age of 37±15 years were included at 101±33 days of SCI onset (AIS 24A;1B). 56% had paraplegia. 13 patients were assessed at 6 months of follow-up. Patients with SCI showed a significant increase in bone turnover markers compared to controls (P1NP 194±87 ng/ml vs. 49±15, p<0.001; sCTx 1.39 ± 0.47 ng/ml vs. 0.48±0.21, p<0.001) and decreased levels of Dkk-1 (63.5±32.8 vs. 39.9±15.7 pmol/L, p=0.003). No differences in sclerostin levels were observed versus controls (39.7±15.4 vs. 35.9±20.5 pmol/L, p=ns). 60% had a low BMD. At 6 months, sclerostin levels increased significantly (40%, p=0.013), bone turnover markers decreased (P1NP -37%, p=0.003 and sCTx -32%, p=0.007) and BMD decreased about 11% at total femur (p=0.002) compared to baseline. Dkk-1 levels also significantly decreased (-35%, p=0.041). Changes in Dkk-1 levels were positively correlated with changes in total femur BMD (r=0.6, p=0.05), while changes in sclerostin were negatively correlated with bone AP change (r=-0.668, p=0.025).
Conclusions Patients with complete SCI have a marked increase in bone turnover markers and early bone loss over 10% at femur. Wnt signalling antagonists seem to be related to bone loss in acute SCI.
Acknowledgements Work funded by a grant from Fundació La Marató de TV3.
Disclosure of Interest None Declared