Impaired Hand Grip Strength Correlates with Greater Disability and Symptom Severity in Post-COVID Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. — CFSMEATLAS
Impaired Hand Grip Strength Correlates with Greater Disability and Symptom Severity in Post-COVID Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Paffrath, Anna, Kim, Laura, Kedor, Claudia et al. · Journal of clinical medicine · 2024 · DOI
Quick Summary
Researchers tested hand grip strength in 144 women with long-COVID symptoms, comparing those who met strict ME/CFS criteria (78 patients) with those who had other long-COVID symptoms. People with ME/CFS showed weaker grip strength and more severe disability, fatigue, and symptom worsening after activity compared to other long-COVID patients. Weak grip strength appeared to be connected to the core symptoms that define ME/CFS, suggesting muscle weakness in ME/CFS may share a common cause with other hallmark symptoms.
Why It Matters
This study provides objective biological evidence that ME/CFS after COVID differs mechanistically from other long-COVID presentations, validating the distinct clinical status of ME/CFS. The correlation between grip strength and ME/CFS-specific symptoms suggests researchers should investigate shared underlying mechanisms, potentially leading to targeted diagnostics and treatments for this severe subtype.
Observed Findings
Patients with ME/CFS had significantly lower hand grip strength and greater physical disability (p < 0.001) compared to other PCS patients.
Hand grip strength correlated with physical function across all PCS patients (p < 0.001).
In ME/CFS patients only, impaired grip strength was significantly associated with symptom severity, fatigue, postexertional malaise, and autonomic dysfunction.
ME/CFS patients reported significantly more severe symptoms overall, including greater fatigue and postexertional malaise than other PCS patients.
Inferred Conclusions
Hand grip strength is an objective marker of physical function impairment in post-COVID patients broadly.
The unique association between grip strength and hallmark ME/CFS symptoms in the ME/CFS subgroup suggests a distinct common pathophysiological mechanism underlying muscle dysfunction and symptom severity in ME/CFS, separate from other PCS manifestations.
ME/CFS represents a biologically distinct subtype of long-COVID rather than a milder variant.
Remaining Questions
What underlying pathophysiological mechanisms link muscle fatigue and ME/CFS-specific symptoms that do not apply to other PCS types?
Does grip strength impairment precede symptom development in ME/CFS, or do symptoms and weakness develop simultaneously?
What This Study Does Not Prove
This study does not prove that impaired grip strength causes ME/CFS symptoms or vice versa—it only shows they correlate. The cross-sectional design means we cannot determine temporal relationships or causality. The findings apply only to female patients with post-COVID ME/CFS and may not generalize to other ME/CFS populations or men with similar conditions.