The inflammatory response to a wheelchair half-marathon in people with a spinal cord injury - the role of autonomic function

Abstract

9 10 11 Running title: Autonomic function and the inflammatory response to a wheelchair half-12 marathon 13 The authors declare no conflicts of interest. 14 interleukin-6; heat shock protein 72; wheelchair racing; upper-body exercise; sympathetic 15 response; adrenaline 16 Word count: 4283 17 Abstract 32This study investigates the relationship between autonomic function and the inflammatory 33 response to a wheelchair half-marathon in people with a spinal cord injury (SCI). Seventeen 34 wheelchair athletes with a cervical SCI (CSCI, N=7) and without CSCI (NON-CSCI, N=10) 35 participated in a wheelchair half-marathon. Blood was taken prior, post and 1 h post-race to 36 determine the concentrations of adrenaline, noradrenaline, extracellular heat shock protein 72 37 (eHsp72) and interleukin-6 (IL-6). A sit-up tilt test was performed to assess autonomic 38 function at rest. CSCI showed a lower supine ratio of the low and high frequency power of 39 the variability in RR intervals (LF/HF RRI, p=0.038), total and low frequency power of the 40 systolic blood pressure variability (TP SBP, p<0.001; LF SBP, p=0.005) compared to NON-41 CSCI. Following the race, catecholamine concentrations increased only in NON-CSCI 42 (p<0.036). The increase in IL-6 post-race was larger in NON-CSCI (p=0.040). Post-race 43 catecholamine levels explained 60% of the variance in the IL-6 response (r=0.77, p=0.040), 44which was further increased when the resting autonomic function indices were added to the 45 regression model (R 2 >81%, p<0.012). In summary, the dampened acute inflammatory 46 response to a wheelchair half-marathon in CSCI was strongly associated with the autonomic 47 dysfunction present in this group.

The acute effect of dopamine infusion on lipid and cytokine concentrations in persons with a cervical spinal cord injury—a pilot study

“…The absence of an acute increase in IL-6 and IL-1ra concentration may be explained by the relatively low dopamine doses used in the present study. As the dampened cytokine response to exercise in people with CSCI is strongly associated with catecholamine concentration [17], it was hypothesised that catecholamine administration alone, activating β-adrenergic receptors on skeletal muscle, would increase circulating cytokine concentrations [14]. Indeed, in resting AB individuals, infusion of adrenaline at similar concentrations as observed during endurance exercise increases IL-6 concentration [14].…”

“…Indeed, the acute elevation of IL-6 concentration after acute exercise has been suggested key for the anti-inflammatory effects of regular exercise training [16]. Supporting the importance of sympathetic activation for IL-6 production, the absence of an acute elevation in catecholamine concentrations after exercise in persons with CSCI is accompanied by an attenuated IL-6 response compared with individuals with paraplegia or non-SCI impairments [17]. In keeping with markers of lipid metabolism, however, it is currently unknown whether catecholamine administration can independently increase circulating cytokine concentration in persons with CSCI.…”

Immunological Response to Exercise in Athletes with Disabilities: A Narrative Review of the Literature

“…Twelve studies [ 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ] investigating cytokines and chemokines in disabled athletes (ten [ 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ] in persons with spinal cord injuries, and two [ 68 , 69 ] in those with Down syndrome) could be retrieved and synthesized in the current review.…”

“…Hoekstra et al [ 63 ] investigated the relationship between autonomic function and the inflammatory response to a wheelchair half-marathon in seventeen wheelchair athletes with ( n = 7) and without cervical spinal cord injury ( n = 10). Catecholamine post-race levels increased only in the non-cervical spinal cord injury group ( p = 0.036), whilst the increase in IL-6 post-race concentrations was larger in wheelchair athletes without cervical spinal cord injury ( p = 0.040).…”

Inflammation and Oxidative Stress as Common Mechanisms of Pulmonary, Autonomic and Musculoskeletal Dysfunction after Spinal Cord Injury

“…Noller et al [59] point out that the management of chronic inflammation in persons with SCI is very relevant to improve their quality of life, and for that it is necessary to understand in a deeper way the role of the autonomic nervous system. Hoekstra et al [63] studied the systemic inflammatory response to exercise in subjects with SCI. Subjects with a non-cervical injury generated increased catecholamine release and concurrently increased plasma IL-6 after competing in a wheelchair half-marathon event.…”