Increased oxidized-LDL levels and arylesterase activity/HDL ratio in ESRD patients treated with hemodialysis.
OBJECTIVE
Investigations, in which oxidized-low density lipoprotein (ox-LDL), serum paraoxonase (PON1) and homocysteine (Hcy) are considered together as important agents involved in the development of oxidative and atherogenic events in non-diabetic hemodialysis (HD) population, are limited. This case-control study was designed to evaluate these parameters in the patients and control subjects and to determine the correlations among the factors.


METHODS
Forty-nine age- and sex- matched subjects, including 28 non-diabetic HD patients (paired pre-and post-dialysis samples) and 21 control subjects, were enrolled. Ox-LDL and Hcy levels were measured with ELISA and EIA methods, respectively. Arylesterase activity of PON1 was measured by spectrophotometric assay.


RESULTS
Compared with the control group, ox-LDL levels were significantly increased both before (p=0.001) and after HD (p=0.036). Arylesterase activity-to-HDL ratio in HD patients was significantly higher than control subjects (p=0.003). Homocysteine levels in the ESRD patients were higher than control subjects both in pre-dialysis and post-dialysis. There was a significant positive correlation (r= 0.25, p= 0.026) between ox-LDL and homocysteine in samples obtained before HD. Logistic regression analysis revealed ox-LDL levels (OR=3.02, p < 0.001) and arylesterase activity/HDL ratio (OR=2.43, p=0.01) to be associated with the increased risk of ESRD.


CONCLUSIONS
Ox-LDL levels and arylesterase activity/HDL ratio indicated the strongest association with ESRD risk. These factors, especially ox-LDL as an indicator of oxidative stress, may be biomarkers in evaluating the status of non-diabetic ESRD patients. Because of the pathogenic relationship between ox-LDL and homocysteine as nontraditional risk factors of atherosclerosis, therapeutic strategies adopted to reduce them may be useful in decrease of high prevalence of cardiovascular mortality in dialysis patients. In addition, measurement of PON1 activity to HDL ratio is possibly a more valuable biomarker than arylesterase activity alone in non-diabetic ESRD.
Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. kmahrooz2@gmail.com
Abdolkarim
A
Mahrooz
Mehryar
M
Zargari
Omid
O
Sedighi
Hamed
H
Shaygani
Ghorban
G
Gohari
D043303:Aryldialkylphosphatase / Q000097:blood*; D002265:Carboxylic Ester Hydrolases / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008077:Lipoproteins, LDL / Q000097:blood*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects*; D018709:Statistics, Nonparametric
D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D006710:Homocysteine; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human