Lower hair cortisol concentration in adolescent and young adult patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Q-Fever Fatigue Syndrome compared to controls. — CFSMEATLAS
Lower hair cortisol concentration in adolescent and young adult patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Q-Fever Fatigue Syndrome compared to controls.
Vroegindeweij, Anouk, Eijkelkamp, Niels, van den Berg, Sjoerd A A et al. · Psychoneuroendocrinology · 2024 · DOI
Quick Summary
This study looked at cortisol (a stress hormone) levels in hair samples from young people with ME/CFS and other fatigue conditions. Researchers found that people with ME/CFS and Q-Fever Fatigue Syndrome had lower cortisol levels in their hair compared to healthy people, suggesting a long-term difference in how their bodies handle this hormone. Interestingly, baseline cortisol levels did not predict whether patients would improve with lifestyle and dietary changes.
Why It Matters
This research confirms that abnormal cortisol regulation in ME/CFS extends beyond acute measurements to long-term patterns, providing biological evidence supporting the physiological basis of this condition. The finding that lower cortisol also appears in QFS suggests this may be a marker of a broader class of post-infectious fatigue disorders. Understanding cortisol dysfunction may eventually help develop targeted treatments.
Observed Findings
Adolescents and young adults with ME/CFS had significantly lower hair cortisol concentration compared to healthy controls (p=.009)
Patients with Q-Fever Fatigue Syndrome also showed significantly lower hair cortisol than controls (p=.047)
Lower hair cortisol was negatively associated with fatigue-related symptoms like sleep issues and cognitive difficulties (β=-0.018, p=.035)
Baseline hair cortisol levels did not predict whether patients would experience clinically relevant fatigue improvement during the intervention trial (p=.449)
Hair cortisol concentrations increased during the trial regardless of whether patients showed meaningful fatigue improvement (p=.658)
Inferred Conclusions
Long-term cortisol dysregulation (not just acute elevations) characterizes ME/CFS and extends to other post-infectious fatigue syndromes like QFS
Cortisol abnormalities may play different biological roles across different fatigue diagnoses rather than being a universal driver of fatigue severity
Cortisol regulation appears mechanistically distinct from the fatigue response itself and may not be a primary therapeutic target for symptom improvement
Remaining Questions
Does the mechanism underlying cortisol dysregulation differ between ME/CFS and QFS, and if so, what explains these differences?
What This Study Does Not Prove
This study does not establish that low cortisol causes ME/CFS or explains fatigue severity—the association may reflect a consequence rather than a cause. It cannot determine whether cortisol abnormalities would respond to direct hormonal interventions, nor does it prove that normalizing cortisol would improve symptoms. The lack of relationship between baseline cortisol and treatment response suggests cortisol may not be the primary driver of fatigue in these conditions.