Intradialytic cycling does not exacerbate microparticles or circulating markers of systemic inflammation in haemodialysis patients

Patrick J Highton,Hannah M L Young,Matthew P M Graham-Brown,Naomi Martin,Charlotte E Grantham,Nicolette C Bishop,Daniel S March,Alice C Smith,Nigel J Brunskill,James O Burton,Seila Estruel,Darren R Churchward

doi:10.1007/s00421-021-04846-7

Abstract

PurposePatients receiving haemodialysis (HD) display elevated circulating microparticle (MP) concentration, tissue factor (TF) expression and markers of systemic inflammation, though regular intradialytic cycling (IDC) may have a therapeutic effect. This study investigated the impact of regular, moderate-intensity IDC on circulating MPs and inflammatory markers in unit-based HD patients.MethodsPatients were cluster-randomised to intervention (n = 20, age: 51.4 ± 18.1 years, body mass: 77.6 ± 18.3 kg, mean ± SD) or no-exercise control (n = 20, 56.8 ± 14.0 years, 80.5 ± 26.5 kg). Intervention participants completed 30 min of moderate intensity (rating of perceived exertion [RPE] of 12–14) IDC, thrice weekly for 6 months. Pre-dialysis venous blood samples were obtained at 0, 3 and 6 months. Circulating MP phenotypes, cytokines, chemokine and MP TF expression were quantified using flow cytometry and cytometric bead array assays.ResultsDespite high exercise compliance (82%), no IDC-dependent effects were observed for any MP, cytokine or chemokine measure (p ≥ 0.051, ηρ2 ≤ 0.399) other than TNF-α (p = 0.001, ηρ2 = 0.186), though no significance was revealed upon post hoc analysis.ConclusionSix months of regular, moderate-intensity IDC had no effect on MPs, cytokines or chemokines. This suggests that the exercise did not exacerbate thrombotic or inflammatory status, though further functional assays are required to confirm this.Trial registrationISRCTN1129707, prospectively registered on 05/03/2015.

Highlights

People with end-stage kidney disease (ESKD) receiving regular haemodialysis (HD) display elevated cardiovascular mortality, and cardiovascular disease is the leading cause of death in this population (23.3%) (UK Renal Registry 2019)
Chronic leukocyte activation increases the chemokine secretion (e.g. monocyte chemotactic protein-1 (MCP-1)), which positively associates with systemic inflammation (Papayianni et al 2002) and may drive atherosclerosis in HD patients (Hu et al 2016)
There was no evidence for intradialytic cycling (IDC)-dependent effects observed in the circulating concentration of total platelet-derived MPs or T F+ platelet-derived MPs, or the % of total MPs that were platelet-derived or platelet-derived MPs that were tissue factor (TF)+ (p ≥ 0.279, ηρ2 ≤ 0.035)

Summary

Introduction

People with end-stage kidney disease (ESKD) receiving regular haemodialysis (HD) display elevated cardiovascular mortality, and cardiovascular disease is the leading cause of death in this population (23.3%) (UK Renal Registry 2019). This may be in part due to elevated circulating microparticle (MP) concentrations and altered MP characteristics. MPs are shed upon cellular activation or apoptosis and can act as biomarkers for inflammation and leukocyte dysfunction whilst promoting thrombosis through tissue factor (TF) expression (Piccin et al, 2007). Chronic leukocyte activation increases the chemokine secretion (e.g. monocyte chemotactic protein-1 (MCP-1)), which positively associates with systemic inflammation (Papayianni et al 2002) and may drive atherosclerosis in HD patients (Hu et al 2016)

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