Age and recurrent infections are linked to worse PEM in ME/CFS
Post-exertional malaise (PEM) – the worsening of symptoms after even minor physical or mental exertion – is one of the hallmark symptoms of ME/CFS. Its severity, and how long people take to recover, can vary between individuals, so researchers in France recently attempted to identify factors which are associated with more severe PEM. (This study was not funded by ME Research UK.)
Read the full paper by Ghali and colleagues in the Journal of Translational Medicine.
Three factors were found to be associated with increased PEM severity, and may help to identify patients who would benefit from pacing strategies:
- Developing ME/CFS at the age of 32 years or older.
- Being susceptible to recurrent viral infections.
- Developing ME/CFS after a gastrointestinal infection.
What did they do?
The researchers identified 197 patients who were all diagnosed with ME/CFS by the same physician using the International Consensus Criteria. The group was made up of 51 males and 146 females, and, in nearly half of them, their illness appeared to have been triggered by an infectious event.
Information was collected about the onset of ME/CFS – including age and symptoms – and the participants’ current fatigue levels were assessed using validated questionnaires. PEM severity was assessed for the previous month, with patients asked to score how often they had experienced PEM as well as the intensity, resulting in a PEM severity score for each individual.
What did they find?
High PEM severity scores were more likely in individuals aged 32 years or older at the onset of ME/CFS, and also more likely in those who reported being susceptible to viral infections over the course of their illness. Suffering from a gastrointestinal infection prior to the onset of ME/CFS was also identified as a risk factor for worse PEM, although the researchers note that this accounted for only a small number of patients in this group, so the association is less clear.
Nevertheless, the authors have identified three key risk factors all linked to increased PEM severity, in terms of both frequency and intensity of symptoms.
What does this mean?
As there are not yet any treatments for ME/CFS, many patients have to employ pacing techniques to try and manage their symptoms. The researchers hope that these risk factors will help to identify patients at a higher risk of severe PEM who may therefore particularly benefit from following pacing strategies.