Pilot study to investigate differences in middle molecules, oxidative stress and markers of peripheral vascular disease in patients treated by high flux haemodialysis and haemodiafiltration.

Arkom Nongnuch,Pin Zhang,Supawadee Sappadungsuk,Chagriya Kitiyakara,Andrew Davenport,Nathan Davies,Nuankanya Sathirapongsasuti,Kotcharat Vipattawat,Abduzhappar Gaipov

doi:10.1371/journal.pone.0258223

Abstract

BackgroundDialysis patients have an increased risk of mortality. Recently treatment with haemodiafiltration (HDF) has been reported to reduce mortality, particularly cardiovascular mortality, compared to standard high-flux haemodialysis (HD). However, why HDF may offer a survival advantage remains to be determined. So, we conducted a pilot study to explore differences in middle-molecules, inflammation and markers of vascular disease in patients treated by HD and HDF.MethodsObservational cross-sectional study measuring serum β2-microglobulin (β2M), Advanced Glycosylation End Products (AGEs) by skin autofluorescence (SAF), oxidative stress with ischaemia modified albumin ratio (IMAR) and peripheral vascular disease assessment using Ankle-Brachial Index (ABI), and arterial stiffness using Cardio-Ankle Vascular Index (CAVI).ResultsWe studied 196 patients, mean age 69.1 ± 12.4 years, 172 (87.8%) treated by HD and 24 (12.2%) by HDF. Age, body mass index, co-morbidity and dialysis vintage were not different between HD and HDF groups. Middle molecules; β2M (31±9.9 vs 31.2±10 ug/mL) and SAF (2.99±0.72 vs 3.0±0.84 AU), ABI (1.06±0.05 vs 1.07±0.10) and CAVI (9.34±1.55 vs 9.35±1.23) were not different, but IMAR was higher in the HD patients (38.4±14.8 vs 31.3 ± 17.4, P = 0.035)ConclusionsIn this pilot observational study, we found patients treated by HDF had lower oxidative stress as measured by IMAR, with no differences in middle molecules. Lower oxidative stress would be expected to have diverse protective effects on the cardiovascular system Although we found no differences in ABI and CAVI, future studies are required to determine whether reduced oxidative stress translates into clinically relevant differences over time.

Highlights

Haemodialysis (HD) is life-sustaining for patients with chronic kidney disease (CKD) stage 5, mortality remains high, with an increased risk of cardiovascular disease (CVD) [1]
Middle molecules; β2M (31±9.9 vs 31.2±10 ug/mL) and skin autofluorescence (SAF) (2.99±0.72 vs 3.0±0.84 arbitrary units (AU)), ankle-brachial index (ABI) (1.06±0.05 vs 1.07±0.10) and cardio ankle vascular index (CAVI) (9.34±1.55 vs 9.35 ±1.23) were not different, but ischaemia modified albumin ratio (IMAR) was higher in the HD patients (38.4±14.8 vs 31.3 ± 17.4, P = 0.035)
In this pilot observational study, we found patients treated by HDF had lower oxidative stress as measured by IMAR, with no differences in middle molecules

Summary

Introduction

Haemodialysis (HD) is life-sustaining for patients with chronic kidney disease (CKD) stage 5, mortality remains high, with an increased risk of cardiovascular disease (CVD) [1]. Patients are at risk of atheromatous coronary artery disease, and arteriosclerosis, and as such HD patients have an increased risk for developing peripheral vascular disease (PVD) [2]. In clinical practice PVD can be assessed by measuring the ankle-brachial index (ABI) and arterial stiffness can be measured using the cardio ankle vascular index (CAVI). The ABI is the ratio of systolic blood pressure (SBP) between the ankle and brachial arteries, and the lower the ABI the greater the reduction in peripheral blood supply and risk of mortality [3]. We conducted a pilot study to explore differences in middle-molecules, inflammation and markers of vascular disease in patients treated by HD and HDF

Methods

Results

Conclusion