C-Reactive Protein (CRP) is Associated With Chronic Pain Independently of Biopsychosocial Factors, 2023, Sterling et al

C-Reactive Protein (CRP) is Associated With Chronic Pain Independently of Biopsychosocial Factors
The Journal of Pain
Pre-print: https://pubmed.ncbi.nlm.nih.gov/37741522/

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Inflammation is linked with chronic pain but the extent to which this relationship is associated with biopsychosocial factors is not known. We investigated relationships between blood C-reactive protein (CRP) and regional chronic pain conditions adjusting for a large range and number of potential confounders.

We performed cross-sectional analyses using the UK Biobank (N = 415,567) comparing CRP in people reporting any of 9 types of regional chronic pain with pain-free controls. Using logistic regression modelling, we explored relationships between CRP and the presence of chronic pain, with demographic, socioeconomic, psychological/lifestyle factors, and medical comorbidities as covariates.

CRP was higher in chronic pain at any site compared with controls (Females: median [interquartile range] 1.60 mg/L [2.74] vs 1.17 mg/L [1.87], P < .001; Males: 1.44 mg/L [2.12] vs 1.15 mg/L [1.65], P < .001). In males, associations between CRP and all types of chronic pain were attenuated but remained significant after adjustment for biopsychosocial covariates (OR range 1.08-1.49, P ≤ .001). For females, adjusted associations between CRP and pain remained significant for most chronic pain types (OR range 1.07-1.34, P < .001) except for facial pain (OR 1.04, P = .17) and headache (OR 1.02, P = .07)-although these non-significant findings may reflect reduced sample size.

The significant association between CRP and chronic pain after adjustment for key biopsychosocial confounders implicates an independent underlying biological mechanism of inflammation in chronic pain. The presence of yet unknown or unmeasured confounding factors cannot be ruled out. Our findings may inform better-targeted treatments for chronic pain.

PERSPECTIVE: Using a large-scale dataset, this article investigates associations between chronic pain conditions and blood C-reactive protein (CRP), to evaluate the confounding effects of a range of biopsychosocial factors. CRP levels were higher in those with chronic pain versus controls after adjusting for confounders-suggesting a possible independent biological mechanism.

 

This has been previously studied and results have been ambiguous. Strength here is the large dataset coming from the UK biobank at nearly a half-million people. The obsession with psychosocial causes, rather than them being obvious consequences, remains one of the top own-goals in the history of humanity. It has made us all poorer and sicker.

Although reading this is both important and a bit cringe, considering it's basically been poo-pooed away for decades despite, you know, being the literal basis of scientific thinking:

I used to think that this is what scientists did all the time. It turns out to actually be a rare thing, most of all in medicine. That was very shocking to find out.