E2 ModerateModerate confidencePEM not requiredCross-SectionalPeer-reviewedMachine draft
Fatigue after COVID-19 in non-hospitalized patients according to sex.
Mazurkiewicz, Iwona, Chatys-Bogacka, Zaneta, Slowik, Joanna et al. · Brain and behavior · 2023 · DOI
Quick Summary
This study looked at whether men and women experience post-COVID fatigue differently after a mild COVID-19 infection. Researchers asked 303 people (mostly women) about fatigue symptoms before COVID-19 and at different time points afterward. Women reported more persistent tiredness that didn't improve with rest, sleep problems, and sore throats compared to men, especially in the weeks right after infection.
Why It Matters
Understanding sex-based differences in post-COVID fatigue is crucial for ME/CFS research, as many post-COVID cases meet ME/CFS criteria. This study provides evidence that women may be at higher risk for specific fatigue-related symptoms, which could inform clinical assessment, treatment approaches, and future investigations into biological mechanisms underlying sex-specific disease expression.
Observed Findings
- Women experienced persistent, non-effort-dependent fatigue at higher rates than men in the first 4 weeks (OR=2.31) and 4-12 weeks (OR=1.95) post-infection.
- Women reported non-restorative sleep more frequently at <4 weeks (OR=2.17) and >12 weeks (OR=1.95) post-infection.
- Sex differences in headache, joint pain, and post-exertional fatigue were statistically significant only in the first 4 weeks post-infection.
- No significant sex differences were found for myalgia or self-reported lymph node enlargement.
Inferred Conclusions
- Post-COVID fatigue presents differently in women compared to men, with women bearing a greater symptom burden in early recovery.
- Persistent fatigue, sleep disturbance, and sore throat show the most robust and sustained sex-specific differences.
- Sex should be considered a relevant variable in post-COVID fatigue assessment and management strategies.
Remaining Questions
- What biological mechanisms (hormonal, immunological, genetic) underlie the observed sex differences in post-COVID fatigue symptoms?
- Do these sex-specific patterns persist beyond 12 weeks, and do they differ in hospitalized versus severely ill COVID-19 patients?
- How do sociodemographic factors, pre-infection health status, and healthcare worker status specifically influence the observed sex differences?
What This Study Does Not Prove
This study does not establish causation or biological mechanisms for sex differences in post-COVID fatigue. The retrospective design and reliance on recalled symptoms (assessed a median of 30 weeks later) introduce significant recall bias. Additionally, the high proportion of healthcare workers and female participants limits generalizability to the broader COVID-19 population.
Tags
Symptom:Post-Exertional MalaiseUnrefreshing SleepFatigue
Phenotype:Infection-TriggeredLong COVID Overlap
Method Flag:PEM Not DefinedNo ControlsMixed CohortSex-Stratified
Metadata
- DOI
- 10.1002/brb3.2849
- PMID
- 36620918
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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