Oxidative stress, endothelial function, carotid artery intimal thickness and their correlates among chronic peritoneal dialysis patients

Abstract

We evaluated important nontraditional cardiovascular risk factors, endothelial function and oxidative stress (OS) among stable peritoneal dialysis (PD) patients. Their association with carotid intimal medial thickness (CIMT) was also assessed. Thirty-eight adult patients (13 diabetics, 20 males) on PD for >6 months and 15 age and sex-matched controls were studied. Duration of dialysis (DOD), residual urine output (UO), weekly Kt/V urea, detailed biochemical and lipid profile were noted. OS was measured by serum concentration of antioxidants; vitamin C and ferric reducing ability of plasma (FRAP) and pro-oxidant; thiobarbituric acid-reactive substances (TBARS). High-resolution ultrasonography was used to determine CIMT and flow-mediated dilatation of brachial artery [endothelium-dependent dilatation (EDD)] and dilatation subsequent to nitrate spray [endothelium-independent dilatation (EID)]. Mean age, DOD, UO and Kt/V of study population were 49.3 ± 11.6 years, 19.4 ± 11.8 months, 508.2 ± 422.9 ml/day and 1.73 ± 0.24, respectively. As compared to controls PD patients had higher CIMT (0.46 ± 0.05 vs 0.50 ± 0.07 mm, P = 0.003) and TBARS (1.5 ± 0.4 vs 5.1 ± 2.3 nM/ml, P < 0.001) but lower Vitamin C (1.7 ± 0.3 vs 0.6 ± 0.2 mg%, P < 0.001), FRAP (990.8 ± 78.1 vs 328.7 ± 183.5 μM/L, P < 0.001) and EDD (26.2 ± 5.4 vs 9.8 ± 4.6 %, P < 0.001). TBARS correlated positively with DOD and negatively with hemoglobin. Vitamin C and FRAP correlated positively with serum albumin. EDD correlated positively with UO, Kt/V and hemoglobin. CIMT correlated negatively with Kt/V and hemoglobin. Among themselves CIMT correlated negatively with EDD and vitamin C. EDD correlated positively with vitamin C, while FRAP correlated positively with vitamin C and negatively with TBARS. PD patients have higher OS, poorer endothelial function and higher structural atherosclerosis. These parameters are closely linked to each other, hemoglobin, DOD, residual UO, serum albumin and small solute clearances.

Influence of Malondialdehyde and Matrix Metalloproteinase‐9 on Progression of Carotid Atherosclerosis in Chronic Renal Disease with Cardiometabolic Syndrome

“…A few studies reported increased OS among PD patients, but other prooxidants (TBARS, TAC) were measured, associated with hypoalbuminemic state or loss of residual renal function (RRF), and without comparing it with nondialysis CKD patients [ 25 , 27 , 30 ]. Khaira et al [ 31 ] found that PD patients have markedly impaired endothelial function as documented by impaired flow mediated dilatation of brachial artery with higher serum concentration of OS markers. Furthermore, Raju et al [ 29 ] confirmed significant increase in serum MDA in hemodialysis patients, compared with the same patients before they had started the hemodialysis treatment, which could be attributed to a bioincompatibility of dialysis membrane and diffusion of hydrophilic compounds to the dialysate and influx of endotoxin from the dialysate.…”

Effect of vitamin C on endothelial function of children with chronic renal failure: An experimental study

“…IMT and FMD measurements are reliable, reproducible and noninvasive technique to assess endothelial function as well as detecting and monitoring progression of atherosclerosis. [ 25 ]…”

Impact of Peritoneal Dialysis Treatment on Arterial Stiffness and Vascular Changes in Diabetic Type 2 and Nondiabetic Patients with End-Stage Renal Disease

“…Hypercalcaemia and the increased product of CaxP in PD patients are linked to the development of CCA calcification, especially in diabetic patients, independent of parathormone values [18]. …”

“…Using multivariate analysis we found a statistically significant influence of CaxP product and the serum calcium on plaque score CCA. Hypercalcaemia and the increased product of CaxP in PD patients are linked to the development of CCA calcification, especially in diabetic patients, independent of parathormone values [ 18 ].…”