Biochemical Changes of Bone Metabolism in Spinal Cord Injured Patients

Kim, Yun Hee

Abstract

Spinal cord injury causes a decrease in bone mass, an osteopenia and an increased risk of fractures. In this condition, previous histomorphologic and biochemical reports have shown an uncoupling between bone formations and resorptions, however the exact sequence of events resulting in bone loss is still not fully understood. Since accurate and sensitive techniques have become available recently to assess bone metabolism, more informations are now available regarding the bone loss in paralysed or immobilized individuals. The purpose of this study is to clarify the changes of biochemical markers and bone densities. Ten complete and 10 incomplete spinal cord injury patients were enrolled for this study. The bone density of femur and lumbar vertebra, and the biochemical markers such as serum osteocalcin and urine deoxypyridinoline were measured. Results were analyzed by Mann-Whitney method and Pearson's correlation of SPSS PC program. Comparing with normal values, in the spinal cord injury groups, the values of serum osteocalcin were elevated (p>0.05), and also the values of urine deoxypyridinoline were significantly elevated(p<0.05). The duration after spinal cord injury and the bone density of femur and lumbar vertebra showed a moderate negative correlation (Pearson's R: +/-0.47, +/-0.43, respectively)(p<0.05). In conclusion, the results of increased values of biochemical markers in bone metabolism support that the bone turn-over rate increases after the spinal cord injury.