Conditioned pain modulation and pain sensitivity in functional somatic disorders: The DanFunD study, 2021, Petersen, Fink et al

ABSTRACT

Disrupted pain regulation has been proposed as a component in functional somatic disorders (FSD). The objective of this study was to examine a general population sample, encompassing three delimitations of FSD while assessing pain sensitivity and conditioning pain modulation (CPM).

Pressure pain thresholds (PPTs) at the tibialis and trapezius muscles were recorded at baseline. During cold pressor stimulation of the hand, the tibialis PPTs were re-assessed and the difference from baseline measures defined the CPM effect. Participants (n=2,198, 53% females) were randomly selected from the adult Danish population. FSD was established by self-reported symptom questionnaires.

With a few exceptions, only weak associations were seen between PPTs and CPM in cases with FSD (p>0.1). A high PPT was associated with lower odds of having multi-organ bodily distress syndrome (ORPPT trapezius: 0.66, 95% CI: 0.49-0.88, p=0.005), with the symptom profile characterized by all symptoms (ORPPT trapezius: 0.72, 95% CI: 0.58-0.90, p=0.003 and ORPPT tibialis: 0.75, 95% CI: 0.62-0.91, p=0.004), and with multiple chemical sensitivity (ORPPT trapezius: 0.81, 95% CI: 0.67-0.97, p=0.022). High CPM was associated with high odds of having irritable bowel (ORCPM relative: 1.22, 95% CI: 1.04-1.43, p=0.013 and ORCPM absolute=2.66, 95% CI: 1.07-6.45, p=0.033). However, only PPT measured over the trapezius muscle were still significant after correction for multiple testing for the symptom profile characterized by all symptoms.

Findings from this study do not support altered pain regulation in questionnaire-based FSD which is in contrast with the existing presumption. Further epidemiological studies in this field are needed.

Paywall, https://onlinelibrary.wiley.com/doi/10.1002/ejp.1847

 

I have never understood why results from acute pain are thought to say anything about chronic pain.

Too many studies have been based on students putting a hand into iced water.

 

They are trying to measure sensitised pain pathways, (what they're really trying to say is the brain is overreacting to pain signals). But study results tend to be equivocal or inconsistent between studies.

There has been many attempts to state and or try and prove that all "functional somatic disorders" have common pathways, but studies like this suggest that is unlikely to be true.

 

How long do students put their hands in iced water for studies such as this? I'm just wondering what these researchers consider to be an accurate representation of chronic pain. Surely after a certain amount of time a hand in iced water would just go numb?

 

Obviously won't stop anyone in this cult from repeating the assumptions as fact. Because even though they admitted their assumption is wrong, this is not a scientific study and they never trust negative findings anyway. No idea why these people think there is any relation between acute pain perception and chronic pain other than believing in a circular belief system.

Given the description this would normally be considered CSS, so it's odd that they don't mention it, or at least in the abstract. Don't want to mix the concepts, I guess, even when identical.

Why do these BS studies keep getting funded? They obviously serve no purpose and there are dozens identical to this one already. Always the same process, always cherry-picked and barely reaching Mythbusters level of serious methodology.