The Association of Phytochemical Index and oxidative balance score with bone Mineral density: a case-control study

Phytochemical index (PI) and oxidative balance score (OBS) have not been previously evaluated in women with osteoporosis. The present study aimed to investigate their relationship with bone mineral density (BMD) in postmenopausal women.

The current case-control study included healthy postmenopausal women (n = 131) and postmenopausal women with abnormal BMD (osteopenia: T-score between - 1 and - 2.5; osteoporosis: T-score less than - 2.5) (n = 131). All participants were recruited from the Isfahan Bone Densitometry Center. Dual-energy X-ray absorptiometry (DXA) measured BMD at the lumbar vertebrae and femoral neck, expressed in grams per square centimeter. A validated semi-quantitative food frequency questionnaire was used to assessed PI and OBS. Binary logistic regression was performed to analyze the association between PI and OBS with BMD.

A positive association was observed between PI and both lumbar and femoral BMD (P < 0.001 for both of them). Similarly, a significant positive association was found between OBS and both lumbar and femoral BMD (P < 0.001 for both of them). Compared to the first tertile of PI, significantly higher odds of abnormal BMD were observed in the last tertile across all models (crude model: odds ratio (OR) = 0.25, 95% confidence interval (CI): 0.13-0.46, P < 0.001 - adjusted model 1: OR = 0.23, 95% CI: 0.12-0.44, P < 0.001 - adjusted model 2: OR = 0.28, 95% CI: 0.14-0.55, P < 0.001). Similarly, compared to the first tertile of OBS, higher odds of abnormal BMD were in the last tertile across all models (crude model: OR = 0.25, 95% CI: 0.13-0.47, P < 0.001 - adjusted model 1: OR = 0.24, 95% CI: 0.13-0.46, P < 0.001 - adjusted model 2: OR = 0.26, 95% CI: 0.13-0.52, P < 0.001).

Overall, the present study highlighted the important role of PI and OBS in abnormal BMD. The findings indicated that higher PI and OBS were inversely associated with the odds of abnormal BMD.