Baseline oxysterols and other markers of oxidative stress, inflammation and malnutrition in the vitamin E and intima media tckness progression in end-stage renal disease (VIPER) cohort.

Background and Objectives: Oxysterols are markers of oxidative stress, levels of which have not yet been reported in hemodialysis (HD) patients. This study was designed to compare levels of the oxysterols 7-ketocholesterol (7KC) and 7 beta-hydroxycholesterol (7 beta OH) between a cohort of HD patients and healthy controls. Methods: This nested cross-sectional study reflects baseline (preintervention) values for markers of oxidative stress, inflammation and nutrition status in the 160-member vitamin E and carotid intima media thickness progression in end-stage renal disease (VIPER) cohort (age 64.1 +/- 8.8, 33.5% female). Age- and sex-matched healthy volunteers served as controls. Plasma oxysterols 7KC and 7 beta OH were determined by isotope dilution gas chromatography/mass spectrometry. Results: Despite higher plasma alpha-tocopherol levels in HD patients than controls (36.0 +/- 9.3 vs. 31.8 +/- 8.4 mu mol/l, p = 0.007), 7KC levels (9.8 +/- 6.9 vs. 5.9 +/- 2.8 nmol/mmol cholesterol, p < 0.0001) and 7 beta OH levels (8.7 +/- 4.3 vs. 2.7 +/- 1.6 nmol/mmol cholesterol, p ! 0.0001) were higher in HD patients. The oxysterol 7 beta OH was significantly, inversely associated with prealbumin (r = -0.18, p = 0.03), though neither oxysterol was significantly associated with any other marker of oxidative stress, inflammation or nutrition status and did not discriminate for CVD in HD patients. Conclusions: Elevated levels of the oxysterols 7KC and 7 beta OH indicate that HD patients are in a state of oxidative stress compared to healthy controls. However, oxysterols 7KC and 7 beta OH did not appear to contribute additional information about oxidative stress among HD patients.