Serum paraoxonase activity in patients with low glomerular filtration rates

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.

Forty-eight patients showing relatively low GFRs upon renal scintigraphy with (99m)Tc-DTPA were compared to 40 age-matched healthy subjects. Serum PON1 activity was measured spectrophotometrically. Lipid hydroperoxide levels were measured via iodometric assay.

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).

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.