A new study, published Wednesday in the journal Science Translational Medicine claims that the treatments often used to soothe pain in the lower back might cause it to last longer.
According to the study authors, chronic pain inflicts huge societal costs, in terms of management, loss of work productivity, and effects on quality of life. And chronic low back pain (LBP) is the most frequently reported chronic pain condition. LBP ranks the highest of all chronic conditions in terms of years lived with disability, with its prevalence and burden increasing with age.
Current treatments for LBP often target the immune system and include nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and corticosteroids, although all of these drug classes are minimally effective at best.
The transition from acute to chronic pain is critically important but not well understood. Despite advances in the understanding of social, psychological, and genetic factors, as well as brain processes associated with chronic LBP, scientists understand very little of the molecular mechanisms underlying the acute-to-chronic pain transition that might lead to more efficacious analgesic strategies.
Therefore the researchers investigated the pathophysiological mechanisms underlying the transition from acute to chronic low back pain (LBP) and performed transcriptome-wide analysis in peripheral immune cells of 98 participants with acute LBP, followed for 3 months.
Transcriptomic changes were compared between patients whose LBP was resolved at 3 months with those whose LBP persisted.
Clinical data showed that the use of anti-inflammatory drugs was associated with increased risk of persistent pain, suggesting that anti-inflammatory treatments might have negative effects on pain duration. Analysis of pain trajectories of human subjects reporting acute back pain in the UK Biobank identified elevated risk of pain persistence for subjects taking NSAIDs.
Thus, despite analgesic efficacy at early time points, the management of acute inflammation may be counterproductive for long-term outcomes of LBP sufferers.
Researchers then replicated their findings using a prospective cohort of similar design. The replication cohort comprised subjects with another musculoskeletal pain condition, temporomandibular disorders (TMD). Although the pathophysiology of TMD is likely not identical to LBP, they hypothesized that the active contribution of the immune system in the transition to chronic pain could be shared.
The authors say that these conclusions may have a substantial impact on medical treatment of the most common presenting complaints to health care professionals. Specifically, the data suggest that the long-term effects of anti-inflammatory drugs should be further investigated in the treatment of acute LBP and likely other pain conditions.