Characterizing Sjögren-Associated Fatigue: A Distinct Phenotype from ME/CFS, 2023, Scheibenbogen et al

Abstract:
Fatigue is the most commonly reported and debilitating extraglandular symptom of primary Sjögren′s syndrome (pSS). Fatigue and exertional intolerance are hallmark symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

We aimed to characterize fatigue and further symptoms among pSS patients and to determine whether there is a symptom overlap in pSS and ME/CFS. In 19 patients with pSS, we assessed pSS symptom severity and disease activity via questionnaires as well as the Canadian Consensus Criteria (CCC) for ME/CFS. Hand grip strength (HGS) and levels of α1-, α2-, β1-, β2-, M3- and M4-receptor-autoantibodies were measured. A subgroup of pSS patients exhibited severe fatigue and had higher severity of pain (p = 0.045), depression (p = 0.021) and sleep disturbances (p = 0.020) compared to those with less fatigue. Four of eighteen pSS patients fulfilled the CCC. HGS parameters strongly correlated with fatigue severity (p < 0.05), but strength fully recovered one hour after exertion in contrast to ME/CFS.

Levels of β1-, β2- and M4-receptor-autoantibodies were elevated and correlated significantly with disease activity assessed by the ESSDAI (p < 0.05), but not fatigue severity. Only a minor subgroup of pSS patients fulfills the CCC, and post exertional malaise (PEM) is atypical, as it is primarily triggered by mental/emotional but not physical exertion. HGS assessment is an objective measure to assess overall fatigue severity.

https://www.mdpi.com/2077-0383/12/15/4994

 

Great to see these comparison studies. We need more of those. The impression here is that ME/CFS in comparison to SD affects physical activity or muscles more.

It's also further evidence that PEM is also seen in other conditions.

 

"Out of 18 pSS patients that completed evaluation for the CCC (Figure A1 of the Appendix A), 13 patients fulfilled criterion 1, stating that they were experiencing significant fatigue. Eleven of those patients stated that they were experiencing PEM after mental or emotional exertion, with only five additionally agreeing that this lasted for 24 h or longer. Out of these five, four patients would have fulfilled the CCC if not for their pre-existing diagnosis of pSS. However, PEM was atypical in these four patients and only triggered by mental and emotional exertion but not physical activity.

Finally, despite scoring a median of 11 points in the ‘reduced activity’ domain of the MFI, as shown by the results of the IPAQ-SF, all but two patients managed to keep up with the WHO recommended level of physical activity. Fatigue severity in the MFI did not significantly correlate with the level of physical activity"

None of that convinces me that what the pSS experience as PEM is the same as my experience. Also I would love to be able to fulfil "at least 150 to 300 minutes of moderate aerobic activity per week (or the equivalent vigorous activity)", which Google tells me is the WHO recommended level of physical activity.