The Relationship between Exercise, Bone Mineral Density and Antioxidant Enzyme Activity of Postmenopausal Women

This study was carried out to elucidate the relationship among exercise, bone mineral density and antioxidant enzyme activity of postmenopausal women. 60 women residing in the Iksan, Korea area were recruited. The questionnaires were designed to find out exercise habits. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. Parameters of antioxidative capacity, including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA) were analyzed in fasting blood. The mean age, height, weight, and BMI of subjects were 65.0 years, 151.1 cm, 59.5 kg $26.0\;m/kg^2$, respectively. The mean BMDs of subjects were $0.85\;g/cm^2$ (lumbar spine), $0.6\;g/cm^2$ (Femoral neck), $0.49\;g/cm^2$ (trochanter), and $0.40\;g/cm^2$ (Ward's triangle). There was a significant difference in BMD among different age groups (50's, 60's and 70's) showing lower value with increasing age (p<0.05). The mean SOD, GPx, and CAT activities were 138.5 U/mL, 1,273.8 U/mL and 314.3 kU/L respectively, and TA was 1.16 mmol/L. TA of the group which exercised 3$\sim$4 times a week was significantly higher than those of the other exercise groups (p<0.05). The subjects with higher SOD activity also have a higher the T values in the lumbar spine, femoral neck, trochanter, and Ward's triangle. In conclusion, this study revealed that the levels of antioxidant enzyme activity were closely associated with the exercise status and bone mineral density in postmenopausal women.