Baseline oxysterols and other markers of oxidative stress, inflammation and malnutrition in the vitamin e and intima media thickness 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 7beta-hydroxycholesterol (7betaOH) between a cohort of HD patients and healthy controls.

METHODS

This nested cross-sectional study reflects baseline (pre-intervention) 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 7betaOH 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 micromol/l, p = 0.007), 7KC levels (9.8 +/- 6.9 vs. 5.9 +/- 2.8 nmol/mmol cholesterol, p < 0.0001) and 7betaOH levels (8.7 +/- 4.3 vs. 2.7 +/- 1.6 nmol/mmol cholesterol, p < 0.0001) were higher in HD patients. The oxysterol 7betaOH 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 7betaOH indicate that HD patients are in a state of oxidative stress compared to healthy controls. However, oxysterols 7KC and 7betaOH did not appear to contribute additional information about oxidative stress among HD patients.