Chronic back pain may be eased by an existing parathyroid hormone treatment

A new animal study found that parathyroid hormone (PTH) reduced abnormal nerve growth and improved spinal tissue in mice, and researchers say human trials are needed before it can be used for chronic lower back pain.

Researchers report a study in mice that found parathyroid hormone (PTH) may ease chronic lower back pain by limiting abnormal nerve growth in damaged spinal tissue. PTH is a hormone used in synthetic form to treat osteoporosis and helps regulate bone remodeling. In the experiments, mice given daily PTH showed stronger spinal tissue and fewer pain-sensing nerve fibers. The authors say human trials are needed before PTH can be prescribed for chronic lower back pain. Key findings: - In three mouse models of spinal degeneration (aging, surgical instability and genetic susceptibility), daily PTH injections for weeks to months produced stronger, less porous disc-bone interfaces. - Treated mice showed reduced sensitivity to pressure and heat and increased activity compared with control animals. - PTH treatment was associated with fewer abnormal pain-sensing nerve fibers; researchers report this occurs because bone-forming cells make Slit3, a protein that appears to guide nerves away from sensitive areas. - The team notes these results may help explain reports of less back pain in some osteoporosis patients on PTH, but they emphasize that human clinical testing is required. Summary: The study reports that PTH reduced abnormal nerve growth and improved spinal tissue integrity in mice, with associated reductions in sensitivity. Researchers link the effect to PTH prompting production of Slit3, which guides nerves away from damaged regions. Human clinical trials are needed before PTH can be used for chronic lower back pain, and the timeline for such testing is undetermined at this time.