Microparticle responses to aerobic exercise and meal consumption in healthy men

PURPOSE: Microparticles (MPs) are shed extracellular vesicles that express the pro-thrombotic tissue factor (TF). Aerobic exercise may reduce MP count and TF expression. This study investigated the impact of acute running or rest followed by standardised meal consumption on MP phenotypes and TF expression. METHODS: 15 males (age: 22.9 ± 3.3 years; body mass: 81.9 ± 11.4 kg; V[Combining Dot Above]O2 max 54.9 ± 6.5 mL·kg·min; mean ± SD) completed 1h of running (70% V[Combining Dot Above]O2max) or rest at 9am, and consumed a standardised meal (1170 kcal, 43% CHO, 17% PRO, 40% fat) at 10:45am. Venous blood samples were taken at 9am, 10am and 11:30am. MP concentration, diameter, phenotypes and TF-expression were assessed using nanoparticle tracking analysis (NTA) and flow cytometry. RESULTS: NTA identified no changes in MP concentration or diameter in response to time or trial. Flow cytometry revealed total MP count increased from 9am to 10am (1.62 ± 2.28 to 1.74 ± 2.61 x10/L, p = .016, effect size (η) = .105), but was unaffected by trial. TF platelet-derived MP % reduced from 9am to 10am (44.0 ± 21.2 to 21.5 ± 9.3%, p = .001, η = .582) after exercise only (control: 36.8 ± 18.2 to 34.9 ± 11.9%, p = .972). TF neutrophil-derived MP % reduced from 9am to 11:30am (42.3 ± 17.2 to 25.1 ± 14.9%, p = 0.048, η = .801) in the exercise trial only (control: 28.5 ± 15.7 to 32.2 ± 9.6%, p = .508). CONCLUSION: Running induced a significant reduction in %TF platelet and neutrophil MP, suggesting a transient reduction in cardiovascular risk via reduced TF-stimulated thrombosis. This requires further investigation over longer time periods in cardiovascular disease populations

The influence of acute moderate-to-high intensity aerobic exercise on markers of immune function and microparticles in renal transplant recipients.

Renal transplant recipients (RTRs) and non-dialysis chronic kidney disease (ND-CKD) patients display elevated circulating microparticle (MP) counts, whilst RTRs display immunosuppression-induced infection susceptibility. The impact of aerobic exercise on circulating immune cells and microparticles is unknown in RTRs. Fifteen RTRs (age 52.8±14.5 years, estimated glomerular filtration rate [eGFR] 51.7±19.8 ml/min/1.73m2 [mean ± SD]), 16 ND-CKD patients (54. ± 6.3 years, eGFR 61.9±21.0 ml/min/1.73m2, acting as a uremic control group), and 16 HCs (52.2±16.2 years, eGFR 85.6±6.1 ml/min/1.73m2) completed 20 minutes of walking at 60-70% VO2 peak. Venous blood samples were taken pre, post, and 1h post-exercise. Leukocytes and MPs were assessed using flow cytometry. Exercise increased classical (p = 0.001) and non-classical (p = 0.002) monocyte subset proportions but decreased the intermediate subset (p < 0.001) in all groups. Exercise also decreased the percentage of platelet-derived MPs that expressed tissue factor (TF+) in all groups (p = 0.01), though no other exercise-dependent effects were observed. The exercise-induced reduction in intermediate monocyte percentage suggests an anti-inflammatory effect, though this requires further investigation. The reduction in the percentage of TF+ platelet-derived MPs suggests reduced pro-thrombotic potential, though further functional assays are required. Exercise did not cause aberrant immune cell activation, suggesting its safety from an immunological standpoint (ISRCTN38935454)

A cost-effective analysis of the CYCLE-HD randomized controlled trial

Introduction: No formal cost-effectiveness analysis has been performed for programs of cycling exercise during dialysis (intradialytic cycling [IDC]). The objective of this analysis is to determine the effect of a 6-month program of IDC on health care costs. Methods: This is a retrospective formal cost-effectiveness analysis of adult participants with end-stage kidney disease undertaking in-center maintenance hemodialysis enrolled in the CYCLE-HD trial. Data on hospital utilization, primary care consultations, and prescribed medications were extracted from medical records for the 6 months before, during, and after a 6-month program of thrice-weekly IDC. The cost-effectiveness analysis was conducted from a health care service perspective and included the cost of implementing the IDC intervention. The base-case analyses included a 6-month “within trial” analysis and a 12-month “within and posttrial” analysis considering health care utilization and quality of life (QoL) outcomes. Results: Data from the base-case within trial analysis, based on 109 participants (n = 56 control subjects and n = 53 IDC subjects) showed a reduction in health care utilization costs between groups, favoring the IDC group, and a 73% chance of IDC being cost-effective compared with control subjects at a willingness to pay of £20,000 and £30,000 per quality-adjusted life year (QALY) gained. When QoL data points were extrapolated forward to 12 months, the probability of IDC being cost-effective was 93% and 94% at £20,000 and £30,000 per QALY gained. Sensitivity analysis broadly confirms these findings. Conclusion: A 6-month program of IDC is cost-effective and the implementation of these programs nationally should be a priority