ABNORMAL ANTIOXIDANT VITAMIN AND CAROTENOID STATUS IN CHRONIC-RENAL-FAILURE

Oxidative modification of plasma lipoproteins increases their atheroge nicity. Nutritive antioxidants, including carotenoids, can prevent suc h lipoperoxidation and may protect against atherosclerosis. Plasma ret inol, ascorbate, alpha-tocopherol and four carotenoids (lutein, lycope ne, alpha-carotene and beta-carotene) were measured using HPLC in 45 p atients with chronic renal failure (CRF) and in 21 controls. Plasma re tinol was significantly increased in patients with CRF (conservative t herapy m-ean of 3.7 mu mol/l vs. 1.9 mu mol/l; p<0.001). Plasma lycope ne was significantly lower in patients with CRF (healthy mean 0.44 mu mol/l vs. conservative therapy mean 0.27 mu mol/l and haemodialysis me an of 0.17 mu mol/l; p<0.001), a finding that persisted even after adj usting for plasma cholesterol. Low circulating antioxidant lycopene le vels may contribute to an already impaired antioxidant defence system in patients with CRF. The process of haemodialysis further compromises antioxidant defences, principally by removing water-soluble ascorbate and urate, but does not appear to affect circulating carotenoid conce ntrations.