Oxidative stress and some antioxidant parameters in postmenopausal osteoporotic women with fractures a case control study

ABSTRACT

Osteoporosis is a major metabolic bone disease that occurs primarily in women over the age of 50 year because of the loss of estrogen during menopause. Oxidative stress plays an important role in the pathogenesis of postmenopausal osteoporosis [PMO]. Antioxidants, by virtue of their ability to mitigate the damaging effects of reactive oxygen species [ROS], have generated interest in their use as chemopreventive agents. The aim of this study was to evaluate the plasma levels of two selected antioxidant defenses [vit C and superoxide dismutase SOD] in addition to Malondialdehyde [MDA] levels, the byproduct of lipid peroxidation as an indicator of oxidative stress in postmenopausal osteoporotic women in comparison with non osteoporotic. Postmenopausal osteoporotic [n=40] and non osteoporotic [n=20] women as a control group aged from 45 years and above were included. All studied women were subjected to full history taking, clinical examination, and bone mineral density [BMD] measurements of the proximal femur using dual energy x-ray absorptiometry [DXA] scan and plasma levels of vit C, SOD and MDA were measured in all studied subjects. The study showed that women with PMO had significantly lower levels of plasma vit C and SOD and higher MDA levels in comparison to non osteoporotic control group [p < 0.05]. A significant positive correlation [p < 0.01] was found between plasma levels of vitamin C [r = 0.91], SOD [r =0.65] and Femoral neck BMD while a significant but negative correlation was found [r = -0.85, p <0.01] between MDA and femoral neck BMD among the studied subjects. It could be concluded that oxidative stress and decreased antioxidant defenses have an important role in the pathogenesis of postmenopausal osteoporosis and MDA, the oxidative stress marker may be an important indicator for bone loss in postmenopausal women. Further studies need to be carried out to investigate the exact rote of antioxidants in osteoporosis and their promising use as chemopreventive agents