Plasma levels of lipophilic antioxidants in very old patients with Type 2 diabetes

Background. Experimental research indicates that oxidative stress is implicated in aging and in the pathogenesis of diabetes and its complications. This evidence is limited in elderly patients with non-insulin dependent diabetes, in which age- and disease-related production of reactive oxygen species might exert synergistic damaging effects on tissues and organs. Methods. Plasma levels of lipid-soluble compounds with antioxidant properties including vitamin A, vitamin E and carotenoids (lutein, zeaxanthin, β-cryptoxanthin, lycopene, α- and β-carotene) were measured by HPLC in 72 elderly patients with non-insulin dependent diabetes (75.7 ± 0.8 years, 40 F, 32 M) and in 75 age-matched controls (77.2 ± 1.2 years, 48 F, 27 M). Results. All compounds measured were significantly lower in plasma from diabetic patients as compared to controls (p <0.0001). Plasma levels of vitamins A and E and of carotenoids did not significantly correlate with dietary intake and lipid profile in both groups. In patients, significant inverse correlations were found between age and levels of vitamin E, β-cryptoxanthin, lycopene and β-carotene. Conclusions. We conclude that patients of very old age with Type 2 diabetes show a poor plasma status of vitamins A and E and carotenoids, which negatively correlates with age. Further studies are needed to explore the possible therapeutic role of lipid-soluble vitamin supplements in elderly diabetic subjects. Copyright (C) 2000 John Wiley and Sons, Ltd.