Inflamed, but not psychosocially

A new UK study has shown that chronic pain patients are inflamed, as measured by high C-reactive protein, the best known biomarker for systemic inflammation. That isn’t much of a news flash — chronic pain and inflammation? Who would have guessed?!

This is the cool part, and the reason I picked this one to write about today: the study showed that chronic pain patients aren’t just inflamed… they are inflamed even without any of the traditional psychosocial bogeymen. That is a surprise.

Farrell et al went mining for data about hundreds of thousands of patients, identifying a strong link between pain and CRP compared to people without pain… and that link remained robust even when a great variety of other common correlates with pain were factored out: income, demographics, mental health, and so on. The authors reckon this means there is “a possible independent biological mechanism” for pain.

This is the opposite of what many experts would predict. Supposedly people get more inflamed precisely because of those influences: that is, we get unfit and unhealthy because of things like eating junk food, sitting all day, or getting really stressed trying to raise a kid alone. But this study shows that chronic pain patients are inflamed even without such things.

That flies in the face of the (fashionable?) attempt to explain pain with a lot of psychosocial stuff — things that probably do matter, but these results strongly suggest there’s much more to the story, namely the “bio” in “biopsychosocial.” Relatively subtle pathology is probably the broad explanation for the inflammation in these chronic pain patients.

I do not think this is a surprise to the millions of people who felt like they had good, healthy lives *right up until the pain started.