Dextrose injections into arthritic knees provided rapid and sustained pain relief over 9 months while significantly altering levels of pain-related neuropeptides substance P and neuropeptide Y in joint fluid.
65% drop in neuropeptide YSynovial fluid neuropeptide Y concentration decreased by 65% at three months after open-label dextrose injections, with high statistical significance (p < 0.001).
What the researchers found
Dextrose injections resulted in a 111% increase in synovial-fluid substance P at one week and a 65% decrease in neuropeptide Y at three months.
Why it matters
This research highlights a potential new treatment for chronic knee pain, which could improve quality of life for those suffering from osteoarthritis.
How the study worked
Participants underwent synovial-fluid aspiration followed by dextrose or placebo injections, with assessments of pain and neurocytokine levels over nine months.
What this study cannot tell us
The study had a small sample size and lacked a long-term follow-up beyond nine months.
How to read the evidence
This is a small pilot study with 20 participants. It included a brief crossover component but primarily relied on open-label treatment without a sustained control group. The neuropeptide findings are exploratory and the between-group comparison for substance P did not reach statistical significance (p = 0.07).
When this study was published
Published in 2022, this is recent research. Prolotherapy remains a topic of active investigation, and this study's focus on neuropeptide mechanisms adds a newer dimension to the evidence base.
The bigger picture
Understanding how treatments affect neuropeptide signaling in joints could open new avenues for osteoarthritis pain management. Substance P, neuropeptide Y, and CGRP are key players in pain transmission, and their modulation by a simple dextrose injection suggests that prolotherapy's mechanisms may be more complex than previously thought. This neuropeptide-focused approach to studying prolotherapy could help bridge the gap between clinical observations of pain relief and the biological mechanisms responsible.
Questions still open
- Would the neuropeptide changes and pain relief hold up in a larger, fully randomized controlled trial with a sustained sham-injection control group?
- Is the early rise in substance P a necessary part of the therapeutic mechanism, or is it an incidental finding?
- Could measuring neuropeptide Y in joint fluid serve as a biomarker for treatment response in osteoarthritis pain management?
Common questions
What is dextrose prolotherapy and how does it work?
What are substance P and neuropeptide Y, and why do they matter for pain?
Read the original research
Dextrose Prolotherapy for Symptomatic Grade IV Knee Osteoarthritis: A Pilot Study of Early and Longer-Term Analgesia and Pain-Specific Cytokine Concentrations.
Clinics and practice, 12(6), 926-938
Citation
Topol, Gastón Andrés; Pestalardo, Ines Guerrero; Reeves, Kenneth Dean; Elias, Fernando; Steinmetz, Neven J; Cheng, An-Lin; Rabago, David. (2022). Dextrose Prolotherapy for Symptomatic Grade IV Knee Osteoarthritis: A Pilot Study of Early and Longer-Term Analgesia and Pain-Specific Cytokine Concentrations.. Clinics and practice, 12(6), 926-938. https://doi.org/10.3390/clinpract12060097