Circulating FGF-21 as a Disease-Modifying Factor Associated with Distinct Symptoms and Cognitive Profiles in Myalgic...

Area of Science:

• Biochemistry
• Immunology
• Neurology

Background:

• Myalgic encephalomyelitis (ME) and fibromyalgia (FM) are complex syndromes lacking objective diagnostic biomarkers.
• Fibroblast growth factor 21 (FGF-21), a metabolic hormone, is being investigated for its potential role in these conditions.

Purpose of the Study:

• To investigate plasma FGF-21 levels as a potential biomarker for distinguishing subtypes within ME and FM patient populations.
• To explore the correlation between FGF-21 levels and symptom burden, cognitive function, and post-exertional malaise (PEM).

Main Methods:

• Cross-sectional study measuring plasma FGF-21 in 250 ME/FM patients and 54 healthy controls.
• Categorization of participants into low, normal, and high FGF-21 groups.
• Assessment of symptoms and cognition using validated questionnaires and a cognitive testing platform, with a mechanical maneuver to induce PEM.

Main Results:

• Elevated FGF-21 levels were common in ME and ME + FM groups but showed wide variation.
• Stratification by FGF-21 levels, not diagnosis alone, revealed distinct clinical profiles.
• Specific FGF-21 levels correlated with varied symptom severity, cognitive performance, and PEM perception across ME and FM subtypes.

Conclusions:

• FGF-21 shows promise as a biomarker for identifying clinically relevant ME and FM subtypes.
• Findings support the development of personalized treatment strategies (precision medicine) for ME and FM.
• Highlights the need for objective tools to assess post-exertional malaise (PEM).