Metabolomics: Impact of comorbidities and inflammation on sickness behaviors for individuals with chronic wounds, 2020, Kim et al

[Andy]

Significance: Approximately 6.5 million people in the United States suffer from chronic wounds. The chronic wound population is typically older and is characterized by a number of comorbidities associated with inflammation. In addition to experiencing wound-related pain, individuals with chronic wounds commonly experience multiple concurrent psychoneurological symptoms such as fatigue and depression, which delay wound healing. However, these distressing symptoms have been relatively overlooked in this population, although their adverse effects on morbidity are well-established in other chronic disease populations.

Recent Advances: Inflammation is involved in multiple pathways which activate brain endothelial and innate immune cells that release pro-inflammatory cytokines, which have been produce multiple symptoms known as sickness behaviors. Inflammation-based activation of the kynurenine pathway and its metabolites is a mechanism associated with chronic illnesses.

Critical Issues: Although putative humoral and neuronal routes have been identified, the specific metabolic variations involved in sickness behaviors in chronic wound patients remains unclear. To improve health outcomes in the chronic wound population, clinicians need to have better understanding of the mechanisms underlying sickness behaviors to provide appropriate treatments.

Future Directions: This paper presents a synthesis of studies investigating associations between inflammation, metabolic pathways, and sickness behaviors in multiple chronic diseases. The presentation of a theoretical framework proposes a mechanism underlying sickness behaviors in the chronic wound population. By mediating the immune system response, dysregulated metabolites in the kynurenine pathway may play an important role in sickness behaviors in chronic inflammatory conditions. This framework may guide researchers in developing new treatments to reduce the disease burden in the chronic wound population.

Paywall, https://www.liebertpub.com/doi/10.1089/wound.2020.1215
Not available via Sci hub at time of posting

 

[Trish]

From the first paragraph:

individuals with chronic wounds commonly experience multiple concurrent psychoneurological symptoms such as fatigue and depression, which delay wound healing.

I have only read the abstract - my question may be answered in the paper.

How can a symptom delay wound healing? A symptom is a subjectively experienced outcome of a biological process reported by the patient. How can that then feedback into the biological process of wound healing.

Do they mean there is some underlying biological process that both delays wound healing and causes depression and fatigue, or are they hinting at some sort of psychotherapeutic treatment that will act on the wound as well as the psyche?

 

[rvallee]

From the first paragraph:


I have only read the abstract - my question may be answered in the paper.

How can a symptom delay wound healing? A symptom is a subjectively experienced outcome of a biological process reported by the patient. How can that then feedback into the biological process of wound healing.

Do they mean there is some underlying biological process that both delays wound healing and causes depression and fatigue, or are they hinting at some sort of psychotherapeutic treatment that will act on the wound as well as the psyche?

Must be all that black bile, or something.

 

[Hutan]

How can a symptom delay wound healing? A symptom is a subjectively experienced outcome of a biological process reported by the patient. How can that then feedback into the biological process of wound healing.

I haven't read the paper. But perhaps fatigue limits the regularity of bathing, or the resulting reduction in exercise reduces blood flow that might remove waste products from the site and bring nutrients for wound healing. Fatigue might reduce the amount of time spent outside in the sun, so reducing vitamin D levels, or it might increase the likelihood that someone isn't eating well, because they can't get to the shops often for fresh vegetables. Depression might do a lot of those things too.

 

[Mithriel]

In addition to experiencing wound-related pain, individuals with chronic wounds commonly experience multiple concurrent psychoneurological symptoms such as fatigue and depression, which delay wound healing

I doubt there have been proper studies done on this to prove the direction of causality. It is more like the MUS dogma where conversion of emotional problems gives the "benefit" of being sick.

Constant pain and the distress of an unhealed wound will be very fatiguing and the immune system must be switched on to try to prevent infection. That is the common sense direction of cause and what is seen in patients with broken limbs where depression and distress lift as healing progresses.

Survival rates in the past would have been better for anyone with an open wound staying hidden so it makes perfect sense for evolution to have gone in this direction.

Therefore any evidence that it is the mental state which determines the rate of healing must be strong and powerful to convince and should be stated clearly and prominently in any paper.