Oxidative balance score and risk of osteoporosis among postmenopausal Iranian women.

UNLABELLED: To our knowledge, this is the first study to examine the association of oxidative balance score (OBS) and risk of osteoporosis. Findings suggest that a predominance of anti- over pro-oxidant exposures, as reflected by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.

PURPOSE: The oxidative balance score (OBS) is a combined measure of pro- and anti-oxidant exposure status, with a higher OBS indicating a predominance of anti- over pro-oxidant exposures. We aimed to examine the potential association of OBS and risk of osteoporosis among postmenopausal Iranian women, hypothesizing that a higher OBS is associated with lower risk of postmenopausal osteoporosis.

METHODS

This cross-sectional study was conducted among 151 postmenopausal Iranian women aged 50-85 y. Bone mineral density (BMD) at lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry, and osteoporosis was defined using the WHO criteria as a BMD T-score of ≤ - 2.5 standard deviations. The OBS was calculated by combining information from 17 a-priori selected pro- and anti-oxidant components classified in the following four categories: non-dietary pro-oxidants (i.e., obesity and smoking); non-dietary anti-oxidants (i.e., physical activity); dietary pro-oxidants (i.e., saturated fatty acid, poly-unsaturated fatty acid, and iron); and dietary anti-oxidants (i.e., fiber, vitamin E, folate, vitamin C, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, zinc, and selenium).

RESULTS

After controlling for several potential covariates in the multivariable-adjusted binary logistic regression analysis, subjects in the highest tertile of OBS had a lower risk of lumbar spine osteoporosis than those in the lowest tertile (odds ratio = 0.14; 95% confidence interval, 0.04-0.45; p = 0.001). The OBS was not associated with risk of femoral neck osteoporosis.

CONCLUSION

Findings suggest that a predominance of anti- over pro-oxidant exposures, as indicated by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.