Autonomic Phenotypes in Chronic Fatigue Syndrome (CFS) are Associated with Illness Severity: A Cluster Analysis, 2020, Zalewski, Morten, Newton et al

Andy

Andy

Retired committee member
In this study we set out to define the characteristics of autonomic subgroups of patients with Chronic Fatigue Syndrome (CFS).

The study included 131 patients with CFS (Fukuda criteria). Participants completed the following screening symptom assessment tools: Chalder Fatigue Scale, Fatigue Impact Scale, Fatigue Severity Scale, Epworth Sleepiness Scales, the self-reported Composite Autonomic Symptom Scale. Autonomic parameters were measured at rest with a Task Force Monitor (CNS Systems) and arterial stiffness using an Arteriograph (TensioMed Kft.).

Principal axis factor analysis yielded four factors: fatigue, subjective and objective autonomic dysfunction and arterial stiffness. Using cluster analyses, these factors were grouped in four autonomic profiles: 34% of patients had sympathetic symptoms with dysautonomia, 5% sympathetic alone, 21% parasympathetic and 40% had issues with sympathovagal balance.

Those with a sympathetic-dysautonomia phenotype were associated with more severe disease, reported greater subjective autonomic symptoms with sympathetic over-modulation and had the lowest quality of life. The highest quality of life was observed in the balance subtype where subjects were the youngest, had lower levels of fatigue and the lowest values for arterial stiffness.

Future studies will aim to design autonomic profile-specific treatment interventions to determine links between autonomic phenotypes CFS and a specific treatment.
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Open access, https://www.mdpi.com/2077-0383/9/8/2531
 
This is a Fukuda criteria CFS study with no controls that started in 2013.

The results look confusing to me. Seems like just a random scatter. But then I'm only able to scan papers and not read the detail so hopefully it's me that's at fault. Some interesting ideas on measuring autonomic parameters to try and subgroup..........

I like to look at scatter plots and data tables. This is table A1. Can anyone explain to me why they didn't throw out so many lines items where the standard deviation is greater that the mean?

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wigglethemouse said:
This is a Fukuda criteria CFS study
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This may account for the fact that nearly 20% did not report PEM. At least this was recorded and it turns out that the non-PEM cases cluster in some of the subgroups. Which could possibly tell us something but what that might be isn't further analysed. Seems like a missed opportunity. I'd like to see more studies looking at Fukuda-with-PEM compared to Fukuda-without-PEM.

But as for using the CFQ! Admittedly just as one amongst other instruments but still, can we please please please just press delete on that thing!
wigglethemouse said:
The results look confusing to me. Seems like just a random scatter. But then I'm only able to scan papers and not read the detail so hopefully it's me that's at fault. Some interesting ideas on measuring autonomic parameters to try and subgroup..........
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Confusing all right. Those tables just make my brain go crosseyed.

Also confusing, they decided their results suggested the following subgroups (some of which are very small):
  • sympathetic with dysautonomia
  • sympathetic
  • parasympathetic
  • balanced
The names 'sympathetic' and 'sympathetic with dysautonomia' are confusing. The group called 'sympathetic with dysautonomia' has autonomic symptoms both subjectively and objectively. Whereas the (very small) group called just 'sympathetic' report few autonomic symptoms (subjectively) but they still have lots of objective markers of dysautonomia. So better names would have been 'sympathetic with symptomatic dysautonomia' and 'sympathetic with asymptomatic dysautonomia'.

Ignoring the problems of validity with the small numbers, this observation that some people experience subjective dysautonomia symptoms and others do not despite both groups having objective markers could maybe fit in with that recent study showing low brain perfusion even in patients not reporting OI?

polish subgroups graph.JPG
 
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