title: Influence of repeated maximal exercise testing on biomarkers and fatigue in sarcoidosis.
abstract: Fatigue in the immune mediated inflammatory disease sarcoidosis is thought to be associated with impaired exercise tolerance. This prospective study assessed fatigue and recuperative capacity after repeated exercise, and examined whether changing concentrations in biomarkers upon exercise are associated with fatigue. Twenty sarcoidosis patients and 10 healthy volunteers performed maximal cardiopulmonary exercise tests on two successive days. Concentrations of cytokines, stress hormones, ACE and CK were assessed before and after the two exercise tests, and 3 days thereafter. All participants completed a sleep diary. Severely fatigued patients showed significant lower VO2 max (p=0.038, p=0.022) and maximal workload (p=0.034, p=0.028) on both exercise tests compared to healthy controls. No impairment of maximal exercise testing was demonstrated during the second cycling test in any group. Fatigue was not correlated with changes in concentrations of biomarkers upon exercise. Severely fatigued patients rated both tests as significantly more fatiguing, and reported significant lower mean subjective night sleeping time during the testing period. Fatigue in sarcoidosis patients cannot be objectified by reduction of exercise capacity after repeated maximal exercise testing, and is not correlated with significant changes in biomarkers. Severe fatigue is only and consistently featured by patient reported outcomes.
authors.affiliation: Rijnstate Hospital, Arnhem, The Netherlands; Beatrix Hospital, Gorinchem, The Netherlands.
authors.forename: A W E
authors.initials: AW
authors.lastname: Braam
authors.forename: S N
authors.initials: SN
authors.lastname: de Haan
authors.forename: A D M
authors.initials: AD
authors.lastname: Vorselaars
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
authors.forename: J C
authors.initials: JC
authors.lastname: Grutters
authors.forename: F J J
authors.initials: FJ
authors.lastname: van den Elshout
authors.forename: I H E
authors.initials: IH
authors.lastname: Korenromp
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D015331:Cohort Studies; D005080:Exercise Test / Q000009:adverse effects* / Q000379:methods*; D017079:Exercise Tolerance / Q000276:immunology; D005221:Fatigue / Q000175:diagnosis* / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000276:immunology; D020127:Recovery of Function / Q000276:immunology; D012129:Respiratory Function Tests / Q000009:adverse effects; D017565:Sarcoidosis, Pulmonary / Q000150:complications* / Q000276:immunology / Q000503:physiopathology; D055502:Secondary Prevention; D057566:Self Report; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Exercise testing; Fatigue; Immune parameters; Sarcoidosis; Stress hormones