Several studies in animals and humans have shown positive effects of nondigestible oligosaccharides (NDO) on mineral absorption and metabolism and bone composition and architecture. These include inulin, oligofructose, fructooligosaccharides, galactooligosaccharides, soybean oligosaccharide, and also resistant starches, sugar alcohols, and difructose anhydride. A positive outcome of dietary prebiotics is promoted by a high dietary calcium content up to a threshold level and an optimum amount and composition of supplemented prebiotics. There might be an optimum composition of fructooligosaccharides with different chain lengths (synergy products). The efficacy of dietary prebiotics depends on chronological age, physiological age, menopausal status, and calcium absorption capacity. There is evidence for an independent probiotic effect on facilitating mineral absorption. Synbiotics, i.e., a combination of probiotics and prebiotics, can induce additional effects. Whether a low content of habitual NDO would augment the effect of dietary prebiotics or synbiotics remains to be studied. The underlying mechanisms are manifold: increased solubility of minerals because of increased bacterial production of short-chain fatty acids, which is promoted by the greater supply of substrate; an enlargement of the absorption surface by promoting proliferation of enterocytes mediated by bacterial fermentation products, predominantly lactate and butyrate; increased expression of calcium-binding proteins; improvement of gut health; degradation of mineral complexing phytic acid; release of bone-modulating factors such as phytoestrogens from foods; stabilization of the intestinal flora and ecology, also in the presence of antibiotics; stabilization of the intestinal mucus; and impact of modulating growth factors such as polyamines. In conclusion, prebiotics are the most promising but also best investigated substances with respect to a bone-health-promoting potential, compared with probiotics and synbiotics. The results are more prominent in animal models, where more studies have been performed, than in human studies, where experimental conditions are more difficult to control.

In conclusion, all five QUS devices tested showed significant age-adjusted differences between subjects with and without vertebral fracture. When selecting the strongest variable, QUS of the calcaneus worked as well as central DXA for identification of women at high risk for prevalent osteoporotic vertebral fractures. QUS-based case-finding strategies would allow halving the number of radiographs in high-risk populations, and this strategy works increasingly well for women with more severe vertebral fractures. It is likely that the good performance of QUS was in part achieved by rigorous quality assurance measures that should also be used in clinical practice.

We introduce a method for microstructural analysis of vertebral trabecular bone in vivo based on HRCT. When applied to monitor teriparatide treatment, changes in structural variables exceeded and were partially independent of changes in volumetric BMD.Introduction: Monitoring of osteoporosis therapy based solely on bone densitometry is insufficient to assess anti-fracture efficacy. Assessing bone microstructure in vivo is therefore of importance. We studied whether it is possible to monitor effects of teriparatide on vertebral trabecular microstructure independent of BMD by high-resolution CT (HRCT). Materials and Methods:In a subset of 65 postmenopausal women with established osteoporosis who participated in the EUROFORS study, HRCT scans of T 12 , quantitative CT of L 1 -L 3 , and DXA of L 1 -L 4 were performed after 0, 6, and 12 mo of teriparatide treatment (20 g/d). We compared BMD and 3D microstructural variables in three groups of women, based on prior antiresorptive treatment: treatment-naïve; pretreated; and pretreated women showing inadequate response to treatment. Results: We found statistically highly significant increases in most microstructural variables and BMD 6 mo after starting teriparatide. After 12 mo, apparent bone volume fraction (app. BV/TV) increased by 30.6 ± 4.4% (SE), and apparent trabecular number (app. Tb.N.) increased by 19.0 ± 3.2% compared with 6.4 ± 0.7% for areal and 19.3 ± 2.6% for volumetric BMD. The structural changes were partially independent of BMD as shown by a significantly larger standardized increase and a standardized long-term precision at least as good as DXA. Patients who had shown inadequate response to prior osteoporosis treatment did show improvements in BMD and structural measures comparable to treatment-naïve patients. Conclusions: HRCT is a feasible method for longitudinal microstructural analysis of human vertebrae in vivo, offers information beyond BMD, and is sufficiently precise to show profound effects of teriparatide after 12 mo.

BMD precision errors were lower than those for trabecular architecture and cortical porosity. Motion artifacts remain a challenge, particularly at the forearm. Quality grading remains subjective, and more objective evaluation methods are needed. Precision in the context of a multicenter clinical trial, with centralized training and scan analysis, was comparable to single-center results previously reported.

The effect of season on bone turnover is controversial. No information is available on seasonality of new serum markers of bone resorption. In this study, we have been unable to confirm findings of a marked wintertime increase in bone formation and resorption within the general population. Seasonality was assessed by cosinor analysis. Introduction:We investigated the effect of season on seven markers of bone turnover in a longitudinal study (six men and six premenopausal women; age, 24 -44 years) and a separate large population-based multicenter European study (n ϭ 2780 women, Osteoporosis and Ultrasound Study [OPUS]). Materials and Methods: Measurements included serum Crosslaps, procollagen type I N-terminal propeptide (PINP), osteocalcin (OC), and the N-telopeptide fragment of type I collagen in urine (NTX). Seasonality was assessed by cosinor analysis with Hotelling's T 2 test. Results: Serum 25(OH) vitamin D showed a marked seasonal rhythm. There was no significant seasonal component for any marker of bone turnover in the longitudinal analysis (cosinor analysis, p Ͼ 0.05). The percentage of within subject variance accounted for by any seasonal trend was very small for all markers (less than 2.5%). Less than 1% of the between-person variance was accounted for by seasonality in the cross-sectional analysis for all markers (n ϭ 2780). There was a small but statistically significant summertime increase in OC and PINP in the healthy postmenopausal population after exclusions based on disease or medication use (remaining n ϭ 1226, amplitudes 5.6% and 5.4%, respectively, p Ͻ 0.001). Conclusions:We have been unable to confirm findings of a marked wintertime increase in bone formation and resorption within the general population. The absence of marked seasonality was irrespective of age, menopausal status, reported supplemental Vitamin D intake, age or geographical location. The small but statistically significant summertime increase in bone formation in this and other studies is unlikely to confound clinical interpretation of these measurements.