Fatigue and physical activity patterns in children with Inflammatory Bowel Disease, 2023, Bevers et al

Objectives:

Fatigue is a common symptom in children with inflammatory bowel disease (IBD). Diagnostic tests to evaluate biological causes of fatigue commonly include markers of inflammation and haemoglobin (Hb), yet functional parameters have been inadequately studied in paediatric IBD. In this study we compared fatigued and non-fatigued children with IBD from both a biological and functional point of view.

Methods:
A cross-sectional study of 104 paediatric IBD patients with mild to moderately active IBD was conducted. Fatigued children were defined as those with a Pediatric Quality of Life Inventory (PedsQL TM) Multidimensional Fatigue Scale Z-score <-2.0. Non-fatigued children had a Z-score ≥ -2.0. Disease-specific quality of life (measured with IMPACT-III score), C-reactive protein (CRP), faecal calprotectin (FC), haemoglobin Z-score (Hb Z-score) and physical activity tests including 6-minute walking distance Z-score (6MWD Z-score) and triaxial accelerometry (TA) were evaluated.

Results:
Fatigued children (n=24) had a significant lower IMPACT-III score than non-fatigued children (n=80). Hb Z-scores, CRP, FC and 6 MWD Z-scores were not significantly different between groups. TA was performed in 71 patients. Wear time validation requirements were met in only 31 patients. Fatigued patients spent significant shorter median time in moderate-to-vigorous activity than non-fatigued patients (18.3 versus 37.3 minutes per day, P=0.008).

Conclusion:
Biological parameters did not discriminate fatigued from non-fatigued patients. TA possibly distinguishes fatigued from non-fatigued patients; the potential association may provide a target for interventions to combat fatigue and improve quality of life.

Paywall, https://journals.lww.com/jpgn/Abstr...ysical_activity_patterns_in_children.445.aspx

 

It's quite possible that there is no way to assess fatigue biologically simply because it is not one thing, in the same vein as "this very complex machine is not performing adequately" can have multiple reasons and generally requires a more precise explanation as to exactly what is not performing adequately, all even more complicated by the fact that we are capable of doing almost anything, accounting for the laws of physics.

A cutting machine only cuts, it's easy to tell how it's not performing, it means it's not performing at the one thing it is built to do. A human can do millions of different things thanks to our general intelligence and impressive dexterity. The more complex the machine the more reasons there could be, and biology is massively more complex than any engineered system we have ever built.

It seems to me to be more of a meta property, an end state of ability to perform that can have almost as many causes as there are systems that can be affected. And in biology, every single system can be affected in numerous ways given how many common factors there are to all of them, from entire organ systems down to individual cells.

It probably only can be assessed subjectively. Which would require medicine to massively transform its culture and attitudes. Not ideal.

 

What do the authors mean by "functional" parameters? Are they results from questionnaires?

If I (someone with zero medical training) was looking for biological causes of fatigue in anyone with IBD it would seem sensible to test for iron deficiency and B12 deficiency as an absolute minimum. It is perfectly possible to be iron deficient or B12 deficient and still have high enough haemoglobin to not be considered anaemic. And iron/b12 being low causes dreadful fatigue.