Conjugated diene fatty acids in patients with chronic renal failure: evidence of increased lipid peroxidation?

Conjugated diene fatty acids (CDFA) were evaluated by second derivative spectrophotometry in the plasma and adipose tissue of 42 chronic renal failure (CFR) patients in conservative treatment, 40 patients treated by hemodialysis (HD) with cuprophane, cellulose acetate or hemophan, 29 treated by hemodiafiltration (HDF) with polysulfone, polyacrylonitrile or polyamide, and 28 healthy controls. Plasma CDFA were also evaluated at the beginning, at 30 min and at the end of the dialytic session. CDFA were unchanged in CRF patients with creatinine clearance (Ccr) > 10 ml/min respect to the controls, CRF patients with Ccr < 10 ml/min showed a higher level of CDFA both in plasma and adipose tissue (p < 0.02). HD patients showed values similar to those of the control group. The lowest level of CDFA was found in HDF patients (p < 0.01 for plasma, p < 0.05 for adipose tissue versus both control and any other group). A significant relationship between plasma and adipose tissue CDFA was found in all groups. In the group of CRF patients with Ccr < 10 ml/min, females exhibited a higher level of CDFA both in plasma and adipose tissue. No significant change was found during dialytic session, independently from the membrane used. CDFA are not only primary products of lipid peroxidation, but also have a dietary origin, primarily from dairy products. Taking into account the reduced dietary intake, the increase in end-stage CRF may be due to an enhanced oxidative stress and/or to abnormalities in CDFA metabolism. Uremic patients, particularly in the predialytic stage, should be considered at risk for increased oxidative stress. HDF treatment better corrects the abnormality compared to conventional HD.