Antioxidant Status and its Relationship to Plasma Cytokine Levels in Korean Elderly Women Living in Seoul

Body antioxidant status is an important factor for the prevention of many chronic diseases in the elderly. This study was done to investigate antioxidant status and its relationship to immune response by measuring plasma cytokine (IL-2 and IL-6) levels in elderly women. Subjects were 76 elderly women aged over 60 years, visiting Jangwhi Social Welfare Center of Seongbook-Gu in Seoul. Subjects were divided into 3 groups according to age (< 65, 65 - 74, > 75). Dietary intakes were assessed by semi-quantitative food frequency questionnaires (SFFQ). Plasma vitamin C level was measured by 2,4-dinitrophenylhydrazine method and plasma levels of vitamin E, A and ${\beta}$-carotene were measured by HPLC. Plasma levels of IL-2 and IL-6 were determined with a solid phase sandwich enzyme linked-immuno-sorbent assay (ELISA) using commercial kits. The average intakes of antioxidant vitamins were 96.3mg (137.5% of RDA) for vitamin C and 523.3 ${\mu}$gRE (74.8% of RDA) for vitamin A in elderly women. All of the average plasma levels of antioxidant vitamins were within normal range. However the percentage of the elderly women with deficiency plus marginal values were 7.9% in vitamin C, 9.2% in vitamin A and 7.9% in vitamin E. Plasma levels of IL-2 and IL-6 were 27.1${\pm}$7.1pg/ml and 5.9${\pm}$5.3pg/ml in elderly women. Correlation data showed that plasma IL-2 level was negatively correlated with plasma vitamin C level. In addition, IL-6 level was also negatively correlated with plasma vitamin C, A and E levels, respectively. There was a significant positive correlation between erythrocyte thiobarbituric acid-reactive substance(TB-ARS) level and plasma IL-2 or IL-6 levels. In addition, erythrocyte TBARS level showed a significant positive correlation with plasma total antioxidant status (TAS) level and a significant negative correlation with plasma vitamin C level. Overall results might imply that the decreased levels of antioxidant vitamins result in an increase in oxidative stress and thereby increase cytokine production such as IL-2 and IL-6. However further research is required to elucidate these relationships.