Relationship Among Body Mass Index, Nutrient Intake and Antioxidant Enzyme Activity of Postmenopausal Women

To elucidate the relationship among body mass index, nutrient intake and blood antioxidant capacity in the postmenopausal period, 60 women residing in Iksan area were recruited. Body mass index (BMI) was calculated base on height and weight, and food and nutrient intakes were estimated by 24-hour recalls of 3 non-consecutive days. Parameters of antioxidant capacity including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA) were measured in fasting blood samples from the subjects. The average age, height, weight and BMI of the subjects were 65 years, 151.1cm, 59.5 kg and 26.0 m/kg$^2$, respectively. The macronutrient intake rate of carbohydrate : protein : fat were 65:17.5:17.5; the mean intakes of energy and protein were 1532.7 kcal (86.3% of RDA) and 67.1 g (122.0% of RDA) respectively. The mean intakes of phosphorus, vitamin A, niacin and vitamin C were higher than Recommended Daily Allowance (RDA) for Koreans. On the other hand, calcium and riboflavin intakes were only 84.6% and 70.4% of RDA. Among the parameters of antioxidant capacity, SOD activity was significantly lower in lean subjects (BMI<20) than in the normal or overweight subjects (BMI${\geq}$20) (p<0.05). TAs of the subjects with the highest intakes of vegetables and fruits were significantly higher than those of subjects with lower intakes (p<0.05). Antioxidant capacity was compared among subjects according to 3 different nutrient intake levels according percentage of RDA for Koreans for selected nutrients with the following results: The high protein and niacin groups exhibited significantly lower TA status than those of the other intake groups (p<0.05). In conclusion, the low BMI was associated with lower SOD activity in postmenopausal women. Higher consumption of fruits and vegetables was associated with higher TA. When protein and niacin intakes were excessive, SOD activity and TA tended to be low. SOD and TA, among antioxidant indexes, seemed to be mostly influenced by other factors. Therefore, more studies on the effects of nutritional intake and the activity of antioxidant enzyme should be conducted.