Author/Authors :
Reddy, Prabhakar E Departments of Biochemistry - Tirupati - Andhra Pradesh, India , Manohar, Suchitra M Departments of Biochemistry - Tirupati - Andhra Pradesh, India , Reddy, Seshadri V Departments of Biochemistry - Tirupati - Andhra Pradesh, India , Bitla, Aparna R Departments of Biochemistry - Tirupati - Andhra Pradesh, India , Vishnubhotla, Sivakumar Nephrology - Sri Venkateswara Institute of Medical Sciences - Tirupati - Andhra Pradesh, India , Lakshmi Narasimha, Srinivasa Rao P.V Departments of Biochemistry - Tirupati - Andhra Pradesh, India
Abstract :
Background and Aims: Patients on maintenance hemodialysis are at an increased risk of cardiovascular
disease. Oxidative stress has a negative impact on endothelial functions producing endothelial
dysfunction which contributes to cardiovascular risk. FRAP assay has been shown to be a simple cost
effective tool for estimating antioxidant capacity. Hence the present study was taken up to evaluate total
antioxidant capacity as ferric reducing ability of plasma (FRAP) and malondialdehyde (MDA), in patients
during hourly intervals of a single hemodialysis session. During hemodialysis, FRAP is subjected to
alterations, due to intradialytic changes in various molecules that contribute FRAP. This study was
aimed to assess the utility of FRAP as a measure of the antioxidant capacity during hemodialysis.
Methods: Twenty seven patients with end stage renal disease on maintenance hemodialysis were recruited
into the study. Time course changes in plasma MDA, FRAP, uric acid, total bilirubin, vitamin C and vitamin
E were evaluated. Statistical evaluation of changes in the biochemical parameters during the whole period
of dialysis was done using Friedman’s test. Linear regression using generalized estimating equations (GEE)
model for repeated measures was applied to study the association between parameters on intradialytic FRAP.
Results: Intradialytic increase in plasma MDA (p<0.01), decrease in FRAP (<0.01) and uric acid (p<0.001) levels
were found. Uric acid was found to have significant association with FRAP as found by GEE (p<0.001).
Conclusions: A single session of hemodialysis contributes substantially to oxidative stress. Decreased
intradialytic FRAP levels can be due to a decrease in uric acid levels. Assessment of antioxidant status in
hemodialysis patients by FRAP method may not truly represent the actual antioxidant status, as changes
in uric acid levels are reflected in FRAP levels. Hence measurement of individual antioxidants would give a
better picture of the antioxidant status during hemodialysis.
Keywords :
Oxidative stress , Hemodialysis , Malondialdehyde , Total Antioxidant Capacity
