Bone Abstracts

Introduction: A retrospective analysis we previously performed on post-menopausal women showed that the addition of inulin (3 g) and soy isoflavones (40 mg) to daily calcium (500 mg) and vitamin D₃ (300 UI) supplementation was able to increase calcium absorption by 60%, while reducing circulating parathormone and leaving vitamin D₃ levels unchanged. Therefore, we tested whether such a mixture could affect also bone metabolism.

Methods: Otherwise healthy post-menopausal women presenting to our ambulatory and that received the study mixture for at least 3 months were retrospectively analysed for the following markers of bone metabolism: IGF1, collagen-telopeptide (CTX) and osteocalcin.

Results: The retrospective analysis included 28 women. 3 months of supplementation induced an increase of IGF1 levels, from a mean value of 107.59 (S.D. 51.13) ng/ml at baseline to 124.86 (61.77) ng/ml; P=0.01, suggesting an increase in bone anabolism. On the other hand, CTX levels were significantly reduced, from 315.57 (211.11) pg/ml at baseline to 263.43 (154.60) pg/ml; P=0.04, pointing out a positive effect on bone resorption, too. A modest reduction of osteocalcin levels was observed, from 22.91 (10.25) ng/ml at baseline to 20.82 (8.34) ng/ml, although it did not reach statistical significance (P=0.07).

Conclusions: Taken together, these results suggest that the study mixture has an overall beneficial effect on bone metabolism, by improving the anabolism and in parallel reducing bone resorption. Given the relatively low amount of calcium and vitamin D₃ present in the mixture, the addition of inulin and soy isoflavones had likely contributed to the observed effects.