Cardiopulmonary and metabolic responses during a 2-day CPET in myalgic encephalomyelitis/chronic fatigue syndrome: translating reduced oxygen consumption to impairment status to treatment considerations.
| Publication Type | Academic Article |
| Authors | Keller B, Receno C, Franconi C, Harenberg S, Stevens J, Mao X, Stevens S, Moore G, Levine S, Chia J, Shungu D, Hanson M |
| Journal | J Transl Med |
| Volume | 22 |
| Issue | 1 |
| Pagination | 627 |
| Date Published | 07/05/2024 |
| ISSN | 1479-5876 |
| Keywords | Fatigue Syndrome, Chronic, Oxygen Consumption, Exercise Test |
| Abstract | BACKGROUND: Post-exertional malaise (PEM), the hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), represents a constellation of abnormal responses to physical, cognitive, and/or emotional exertion including profound fatigue, cognitive dysfunction, and exertion intolerance, among numerous other maladies. Two sequential cardiopulmonary exercise tests (2-d CPET) provide objective evidence of abnormal responses to exertion in ME/CFS but validated only in studies with small sample sizes. Further, translation of results to impairment status and approaches to symptom reduction are lacking. METHODS: Participants with ME/CFS (Canadian Criteria; n = 84) and sedentary controls (CTL; n = 71) completed two CPETs on a cycle ergometer separated by 24 h. Two-way repeated measures ANOVA compared CPET measures at rest, ventilatory/anaerobic threshold (VAT), and peak effort between phenotypes and CPETs. Intraclass correlations described stability of CPET measures across tests, and relevant objective CPET data indicated impairment status. A subset of case-control pairs (n = 55) matched for aerobic capacity, age, and sex, were also analyzed. RESULTS: V CONCLUSIONS: Presently, this is the largest 2-d CPET study of ME/CFS to substantiate impaired recovery in ME/CFS following an exertional stressor. Abnormal post-exertional CPET responses persisted compared to CTL matched for aerobic capacity, indicating that fitness level does not predispose to exertion intolerance in ME/CFS. Moreover, contributions to exertion intolerance in ME/CFS by disrupted cardiac, pulmonary, and metabolic factors implicates autonomic nervous system dysregulation of blood flow and oxygen delivery for energy metabolism. The observable declines in post-exertional energy metabolism translate notably to a worsening of impairment status. Treatment considerations to address tangible reductions in physiological function are proffered. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, retrospectively registered, ID# NCT04026425, date of registration: 2019-07-17. |
| DOI | 10.1186/s12967-024-05410-5 |
| PubMed ID | 38965566 |
| PubMed Central ID | PMC11229500 |