The importance of paraoxonase 1 activity in chronic kidney disease.

Paraoxonase 1 (PON1) is one of the most significant antioxidative enzymes associated with high-density lipoprotein (HDL). It has been proved that is involved in the pathogenesis of many diseases including chronic kidney disease (CKD). The association between PON1 and CKD seems to be mutual, such that the disease produces a significant decrease in PON1 activity levels, while the genetics of PON1 may affect the risk of susceptibility to CKD. Recent studies reveal that the decrease in serum PON1 activity observed in non-dialyzed and dialyzed CKD patients as well as in renal transplant (RT) patients is linked to an increased vulnerability to atherosclerosis. We intend to summarize current literature concerning PON1 activity in CKD, highlighting on the main determinants of PON1 activity, its association with oxidative stress, the impact of its genetic polymorphism on the disease development, the effect of drugs and nutritional state. Furthermore, evidence supporting the implication of reduced PON1 activity in the incident of cardiovascular disease in CKD patients, is also examined. It appears that despite the lack of standardization of PON1 activity measurement, PON1 remains a valuable biomarker for the researchers through the last decades, which contributes to the assessment of the antioxidant status having prognostic benefit on adverse clinical outcomes at various stages and etiologies of kidney disease.

Association of lipid profile with serum PON1 concentration in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) are at high risk of atherosclerotic events; dyslipoproteinemia and the decrease of the HDL-linked enzyme paraoxonase 1 (PON1), might have a major role. This study intends to compare the association between lipid profile and serum PON1 levels in renal failure (RF) and hemodialysis (HD) patients. Serum lipids, HDL-subclasses and PON1 concentration were evaluated in 90 patients with CKD, divided into groups: RF (n = 46) and HD (n = 44), and in 30 normal individuals (control group). The results showed that PON1 was significantly lower in HD patients than in RF and controls (p < 0.001). In RF patients under statin therapy, PON1 did not differ from that of patients without statins. In HD patients without statins, PON1 was considerably low, whereas in HD with statins (30.42 ± 12.62 µg/mL) was lower than RF with statins (49.31 ± 14.94, p < 0.001). PON1 concentration was significantly and positively associated with HDL-C, HDL3-C and Apo A1 in all groups. Additionally, in HD patients PON1 was negatively associated with LDL-C. Multiple regression analysis revealed that LDL-C and statin treatment were independently related to PON1 concentration in HD patients (ß = -0.331, p = 0.026 and ß = 0.344, p = 0.020, respectively). In RF patients, HDL3-C and Apo A1 are strong determinants of PON1 levels. It is concluded that different parameters of lipid profile seem to affect serum PON1 concentration of RF and HD patients and probably contribute to the delay of atherosclerosis.