Hemorheological responses to an acute bout of maximal exercise in Veterans with Gulf War Illness

Abstract

BackgroundAltered red blood cell (RBC) deformability has been reported in Veterans with Gulf War Illness (GWI) who endorse exercise-induced symptom exacerbation and fatigue. However, it is unknown whether altered RBC deformability is worsened secondary to exercise. ObjectiveTo evaluate RBC deformability in response to maximal exercise in individuals with and without GWI. MethodsSeventeen Veterans with GWI and 11 controls performed maximal exercise and provided blood samples (pre-, immediately post- and 60-min post-exercise). We calculated RBC deformation at infinite stress (EIMAX), shear stress for half-deformation (SS1/2) and their ratio (SS1/2/EIMAX) via repeated measures ANOVA with group and time as factors. ResultsA moderate interaction effect (p = 0.08, η2p = 0.10), large main effect for group (p = 0.02, η2p = 0.19) and moderate main effect for time (p = 0.20, η2p = 0.06) were observed for EIMAX, but only the main effect for group reached statistical significance. Changes in SS1/2 and SS1/2/EIMAX over time were similar between cases and controls as were main effects. ConclusionsVeterans with GWI had more deformable RBCs in comparison to controls that was unaffected by maximal exercise. Future studies to confirm our findings and identify associated mechanisms are warranted.