What is the research about?
It is thought that a body-wide, low grade inflammation process may be present in common types of neck pain, such as pain after a whiplash injury. This is reflected by raised markers of inflammation on a blood test, like C-reactive protein (CRP).
This study aimed to determine if blood markers of inflammation are raised in people with neck pain.
What did the researchers do?
We searched scientific databases to identify all published studies that measured inflammation in the blood in people with neck pain. We then pooled the data reported in these papers to statistically compare levels of blood inflammatory markers in people with neck pain compared to people with no pain.
What did the researchers find?
Ten studies were included in the review, consisting of 706 participants. We found that people with neck pain had higher levels of inflammatory markers than people without pain. This was particularly evident for people with longer term neck pain (>3 months), however there was also some evidence of raised inflammatory markers early after a whiplash injury.
Higher levels of some inflammatory markers were associated with higher levels of pain, greater sensitivity to blunt pressure and thermal stimulations, and other clinical factors.
What you need to know:
These findings suggest that body-wide, low grade inflammation in the blood may contribute to symptoms in people with neck pain, as this inflammation can sensitise the nerves that carry information related to pain. This may also explain some of the clinical features of neck pain, such as increased senisitivity to thermal or blunt pressure stimulations.
It should be noted however that we do not know definitively if there is a causal relationship between neck pain iand inflammation (that is, does one cause the other?). It is also possible that the observed inflammation reflect other factors, such as poor sleep, stress or depression, which we know affect people with neck pain and are associated with inflammation.
How can you use this research?
We do not yet understand the clinical implications of raised blood inflammatory markers in individual patient management of people with neck pain. The findings of this study will inform future research on the biological pathways contributing to neck pain conditions. They may also be relevant for future research testing use of blood tests in clinical management of people with neck pain, such as guiding medication selection.
About the researchers
Dr Scott Farrell is a physiotherapist researcher at RECOVER Injury Research Centre. Professor Michele Sterling leads the ‘Improving health outcomes after musculoskeletal injury’ program at RECOVER. A/Prof Peter Cabot is a pharmacist at The University of Queensland and Dr Rutger de Zoete is a lecturer in physiotherapy at University of Adelaide.
Citation
Farrell SF, de Zoete RMJ, Cabot PJ & Sterling M. (2020). Systemic inflammatory markers in neck pain: a systematic review with meta-analysis. European Journal of Pain, 24 (9), pp1666-1686 https://doi.org/10.1002/ejp.1630
Keywords
Neck pain; inflammation; whiplash injuries; blood tests
Contact information, acknowledgements
Dr Scott Farrell
RECOVER Injury Research Centre, The University of Queensland
