Serum paraoxonase activity in patients with low glomerular filtration rates

Abstract

Objective: Epidemiological and experimental studies indicate that kidney disease is associated with increased oxidative stress. Our aim was to determine whether paraoxonase 1 (PON1) activity is altered in patients with moderately decreased glomerular filtration rates (GFRs) compared to healthy controls. Material and methods: Forty-eight patients showing relatively low GFRs upon renal scintigraphy with 99mTc-DTPA were compared to 40 age-matched healthy subjects. Serum PON1 activity was measured spectrophotometrically. Lipid hydroperoxide levels were measured via iodometric assay. Results: The mean ages of the patient and control groups were 32.09 ± 6.10 (range 23–50) and 31.30 ± 5.30 (range 20–46) years, respectively. Serum PON1 (p= 0.949) and high-density lipoprotein (p= 0.473) levels did not differ between groups. Significant differences were detected between groups in terms of mean triglyceride (p= 0.009), very-low-density lipoprotein (p = 0.010), lipid hydroperoxide (p = 0.026), urea (p = 0.012), and creatinine (p = 0.001) levels, whereas total cholesterol (p = 0.520) and low-density lipoprotein (p = 0.161) were similar between groups. Mean GFR was significantly lower in the low GFR group compared to the control (p = 0.000). Conclusion: Our results indicate that PON1 activity and high-density lipoprotein levels may not be determining factors in premature vascular aging in patients with moderately decreased GFRs. Instead, some other undetermined factor(s) may be involved in modulating enzymatic activity.