Effects of vitamin D3, omega-3 s and a simple strength training exercise program on bone health: the DO-HEALTH randomized controlled trial.

INTRODUCTION: Evidence on the effects of Vitamin D, omega-3 s and exercise on aBMD in healthy older adults is limited. We examined whether vitamin D3, omega-3 s, or a simple home-based exercise program (SHEP), alone or in combination, over three years, improve lumbar spine (LS), femoral neck (FN) or total hip (TH) aBMD assessed by DXA. METHODS: aBMD was a secondary outcome in DO-HEALTH, a 3-year, multicenter, double-blind, randomized 2 × 2 × 2 factorial design trial in generally healthy older adults age ≥ 70 years. The study interventions were vitamin D3 (2000IU/d), omega-3 s (1 g/d), and SHEP (3 × 30 min/wk), applied alone or in combination in 8 treatment arms. Mixed effect models were used adjusting for age, sex, BMI, prior fall, study site and baseline level of the outcome. Main effects were assessed in the absence of an interaction between the interventions. Subgroup analyses by sex, physical activity level, dietary calcium intake, serum 25(OH)D levels, and fracture history were conducted. RESULTS: DXA scans were available for 1493 participants (mean age 75 years; 80.4% were physically active, 44% had 25(OH)D levels <20 ng/ml). At the LS and FN sites, none of the treatments showed a benefit. At the TH, vitamin D vs. no vitamin D treatment showed a significant benefit across 3 years (difference in adjusted means [AM]: 0.0035 [95% CI 0.0011, 0.0059] g/cm2). Furthermore, there was a benefit for vitamin D vs. no vitamin D treatment on LS aBMD in the male subgroup of (interaction P = 0.003; ∆AM: 0.0070 [95% CI 0.0007, 0.0132] g/cm2). CONCLUSIONS: Omega-3 and SHEP had no benefit on aBMD in healthy, active and largely vitamin D replete older adults. Our study suggests a small benefit of 2000 IU vitamin D daily on TH aBMD overall and LS aBMD among men, however, effect sizes were very modest and the clinical impact of these findings is unclear.

Vitamin D, omega-3 fatty acids (omega-3 s) and strength training are simple but promising strategies to improve bone health, however, their effect in healthy older adults over a period of three years was unclear. In this study, we examined whether daily vitamin D supplementation (2000 IU/d), daily omega-3 s supplementation (1 g/d) or a simple strength training program performed three times per week, either applied alone (e.g., only vitamin D supplements) or in combination (e.g., vitamin D and omega-3 s supplements) could improve bone density at the spine, hip or femoral neck. We included 1493 healthy older adults from Switzerland, Germany, France and Portugal who were at least 70 years of age and who had not experienced any major health events in the five years before study start. Taking omega-3 s supplements showed no benefit for bone density. Similarly, the simple strength exercise program showed no benefit. In contrast, participants receiving daily vitamin D supplements experienced a benefit at the hip. However, it should be noted that the effect across three years was very small.

Transferrin receptor 2 deficiency promotes macrophage polarization and inflammatory arthritis.

OBJECTIVE: Rheumatoid arthritis is an inflammatory joint disease in which synovial iron deposition has been described. Transferrin receptor 2 (Tfr2) represents a critical regulator of systemic iron levels. Loss of Tfr2 function in humans and mice results in iron overload. As iron contributes to inflammatory processes, we investigated whether Tfr2-deletion affects the pathogenesis of inflammatory arthritis in an iron-dependent manner. METHODS: Using a global and conditional genetic disruption of Tfr2, we assessed the relevance of Tfr2 in K/BxN serum-transfer arthritis (STA) and macrophage polarization. RESULTS: Male Tfr2-/- mice subjected to STA developed pronounced joint swelling, and bone erosion as compared to Tfr2+/+ littermate-controls (P < 0.01). Furthermore, an increase of neutrophils and macrophages/monocytes was observed in the inflammatory infiltrate within the paws of Tfr2-/- mice. To elucidate whether Tfr2 in myeloid cells has a direct role in the pathogenesis of arthritis or whether the effects were mediated via the systemic iron overload, we induced STA in Tfr2fl/fl-LysMCre + mice, which showed normal iron-loading. Cre + female mice displayed increased disease development compared to Cre-controls. As macrophages regulate iron availability and innate immunity, we hypothesized that Tfr2-deficiency would polarize macrophages toward a pro-inflammatory state (M1) that contributes to arthritis progression. In response to IFN-γ stimulation, Tfr2-/- macrophages showed increased expression of M1-like cytokines, IFN-γ-target genes, nitric-oxide production, and prolonged STAT1 activation compared to Tfr2+/+ macrophages (P < 0.01), while pre-treatment with ruxolitinib abolished Tfr2-driven M1-like polarization. CONCLUSION: Taken together, these findings suggest a protective role of Tfr2 in macrophages on the progression of arthritis via suppression of M1-like polarization.

The Impact of COVID-19 in Bone Metabolism: Basic and Clinical Aspects.

The use of standard procedures for the diagnosis of osteoporosis and assessment of fracture risk significantly decreased during the COVID-19 pandemic, while the incidence of fragility fractures was mostly unaltered. Both COVID-19 per se and its treatments are associated with a negative impact on bone health. Preclinical models show that mice infected with SARS-CoV2 even without symptoms display loss of trabecular bone mass two weeks post infection, due to increased numbers of osteoclasts. Osteoporosis medications do not aggravate the clinical course of COVID-19, while preclinical data suggests possible beneficial effects of some therapies. While vitamin D deficiency is clearly associated with a worse clinical course of COVID-19, evidence of improved patient outcome with vitamin D supplementation is lacking. Osteoporosis treatment should not be generally discontinued, and recommendations for substituting therapies are available. Osteoporosis therapies do not interfere with the efficacy or side-effect profiles of COVID-19 vaccines and should not be stopped or indefinitely delayed because of vaccination.

Effects of vitamin D, omega-3 fatty acids, and a simple home strength exercise program on fall prevention: the DO-HEALTH randomized clinical trial.

BACKGROUND: The roles of vitamin D, omega-3 fatty acids, and home exercise on fall prevention among generally healthy and active older adults are unclear. OBJECTIVES: We tested the effects of daily supplemental vitamin D, daily supplemental marine omega-3s fatty acids, and a simple home exercise program (SHEP), alone or in combination, on the incidences of total and injurious falls among generally healthy older adults. METHODS: We performed a 2 × 2 × 2 factorial-design randomized controlled trial among 2157 community-dwelling adults aged 70 years and older, who had no major health events in the 5 years prior to enrolment, recruited from Switzerland, Germany, Austria, France, and Portugal between December 2012 and November 2014. Participants were randomly assigned to supplementation with 2000 international units/day of vitamin D3 and/or 1 g/day of marine omega-3s, and/or a SHEP compared with placebo and/or control exercise over 3 years. The primary endpoint for the present fall analysis was the incidence rate of total falls. Falls were recorded prospectively throughout the trial. Since there were no interactions between treatments, the main effects are reported based on a modified intent-to-treat analysis. RESULTS: Of 2157 randomized participants, 1900 (88%) completed the study. The mean age was 74.9 years, 61.7% were women, 40.7% had a serum 25-hydroxyvitamin D concentration < 20 ng/ml, and 83% were at least moderately physically active. In total, 3333 falls were recorded over a median follow-up of 2.99 years. Overall, vitamin D and the SHEP had no benefit on total falls, whilst supplementation with omega-3s compared to no omega-3 supplementation reduced total falls by 10% (incidence rate ratio = 0.90; 95% CI, 0.81-1.00; P = 0.04). CONCLUSIONS: Among generally healthy, active, and vitamin D-replete older adults, omega-3 supplementation may have a modest benefit on the incidence of total falls, whilst a daily high dose of vitamin D or a SHEP had no benefit.

Exosomal miRNAs from Prostate Cancer Impair Osteoblast Function in Mice.

Prostate cancer (PCa) is the most frequent malignancy in older men with a high propensity for bone metastases. Characteristically, PCa causes osteosclerotic lesions as a result of disrupted bone remodeling. Extracellular vesicles (EVs) participate in PCa progression by conditioning the pre-metastatic niche. However, how EVs mediate the cross-talk between PCa cells and osteoprogenitors in the bone microenvironment remains poorly understood. We found that EVs derived from murine PCa cell line RM1-BM increased metabolic activity, vitality, and cell proliferation of osteoblast precursors by >60%, while significantly impairing mineral deposition (-37%). The latter was further confirmed in two complementary in vivo models of ossification. Accordingly, gene and protein set enrichments of osteoprogenitors exposed to EVs displayed significant downregulation of osteogenic markers and upregulation of proinflammatory factors. Additionally, transcriptomic profiling of PCa-EVs revealed the abundance of three microRNAs, miR-26a-5p, miR-27a-3p, and miR-30e-5p involved in the suppression of BMP-2-induced osteogenesis in vivo, suggesting the critical role of these EV-derived miRNAs in PCa-mediated suppression of osteoblast activity. Taken together, our results indicate the importance of EV cargo in cancer-bone cross-talk in vitro and in vivo and suggest that exosomal miRNAs may contribute to the onset of osteosclerotic bone lesions in PCa.

PaTH Forward: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial of TransCon PTH in Adult Hypoparathyroidism.

CONTEXT: Hypoparathyroidism is characterized by insufficient levels of parathyroid hormone (PTH). TransCon PTH is an investigational long-acting prodrug of PTH(1-34) for the treatment of hypoparathyroidism. OBJECTIVE: This work aimed to investigate the safety, tolerability, and efficacy of daily TransCon PTH in adults with hypoparathyroidism. METHODS: This phase 2, randomized, double-blind, placebo-controlled 4-week trial with open-label extension enrolled 59 individuals with hypoparathyroidism. Interventions included TransCon PTH 15, 18, or 21 µg PTH(1-34)/day or placebo for 4 weeks, followed by a 22-week extension during which TransCon PTH dose was titrated (6-60 µg PTH[1-34]/day). RESULTS: By Week 26, 91% of participants treated with TransCon PTH achieved independence from standard of care (SoC, defined as active vitamin D = 0 µg/day and calcium [Ca] ≤ 500 mg/day). Mean 24-hour urine Ca (uCa) decreased from a baseline mean of 415 mg/24h to 178 mg/24h by Week 26 (n = 44) while normal serum Ca (sCa) was maintained and serum phosphate and serum calcium-phosphate product fell within the normal range. By Week 26, mean scores on the generic 36-Item Short Form Health Survey domains increased from below normal at baseline to within the normal range. The Hypoparathyroidism Patient Experience Scale symptom and impact scores improved through 26 weeks. TransCon PTH was well tolerated with no treatment-related serious or severe adverse events. CONCLUSION: TransCon PTH enabled independence from oral active vitamin D and reduced Ca supplements (≤ 500 mg/day) for most participants, achieving normal sCa, serum phosphate, uCa, serum calcium-phosphate product, and demonstrating improved health-related quality of life. These results support TransCon PTH as a potential hormone replacement therapy for adults with hypoparathyroidism.

Effect of Vitamin D Supplementation, Omega-3 Fatty Acid Supplementation, or a Strength-Training Exercise Program on Clinical Outcomes in Older Adults: The DO-HEALTH Randomized Clinical Trial.

Importance: The benefits of vitamin D, omega-3 fatty acids, and exercise in disease prevention remain unclear. Objective: To test whether vitamin D, omega-3s, and a strength-training exercise program, alone or in combination, improved 6 health outcomes among older adults. Design, Setting, and Participants: Double-blind, placebo-controlled, 2 × 2 × 2 factorial randomized clinical trial among 2157 adults aged 70 years or older who had no major health events in the 5 years prior to enrollment and had sufficient mobility and good cognitive status. Patients were recruited between December 2012 and November 2014, and final follow-up was in November 2017. Interventions: Participants were randomized to 3 years of intervention in 1 of the following 8 groups: 2000 IU/d of vitamin D3, 1 g/d of omega-3s, and a strength-training exercise program (n = 264); vitamin D3 and omega-3s (n = 265); vitamin D3 and exercise (n = 275); vitamin D3 alone (n = 272); omega-3s and exercise (n = 275); omega-3s alone (n = 269); exercise alone (n = 267); or placebo (n = 270). Main Outcomes and Measures: The 6 primary outcomes were change in systolic and diastolic blood pressure (BP), Short Physical Performance Battery (SPPB), Montreal Cognitive Assessment (MoCA), and incidence rates (IRs) of nonvertebral fractures and infections over 3 years. Based on multiple comparisons of 6 primary end points, 99% confidence intervals are presented and P < .01 was required for statistical significance. Results: Among 2157 randomized participants (mean age, 74.9 years; 61.7% women), 1900 (88%) completed the study. Median follow-up was 2.99 years. Overall, there were no statistically significant benefits of any intervention individually or in combination for the 6 end points at 3 years. For instance, the differences in mean change in systolic BP with vitamin D vs no vitamin D and with omega-3s vs no omega-3s were both -0.8 (99% CI, -2.1 to 0.5) mm Hg, with P < .13 and P < .11, respectively; the difference in mean change in diastolic BP with omega-3s vs no omega-3s was -0.5 (99% CI, -1.2 to 0.2) mm Hg; P = .06); and the difference in mean change in IR of infections with omega-3s vs no omega-3s was -0.13 (99% CI, -0.23 to -0.03), with an IR ratio of 0.89 (99% CI, 0.78-1.01; P = .02). No effects were found on the outcomes of SPPB, MoCA, and incidence of nonvertebral fractures). A total of 25 deaths were reported, with similar numbers in all treatment groups. Conclusions and Relevance: Among adults without major comorbidities aged 70 years or older, treatment with vitamin D3, omega-3s, or a strength-training exercise program did not result in statistically significant differences in improvement in systolic or diastolic blood pressure, nonvertebral fractures, physical performance, infection rates, or cognitive function. These findings do not support the effectiveness of these 3 interventions for these clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT01745263.

Challenges in Preventing Bone Loss Induced by Aromatase Inhibitors.

CONTEXT: Aromatase inhibitors have become a mainstay in the adjuvant treatment regimen in postmenopausal women with hormone receptor-positive breast cancer. While many of these patients have an excellent long-term prognosis, adverse effects on bone represent an emerging complication of aromatase inhibitor treatment, resulting in substantial bone loss and fragility fractures. Treatment approaches to prevent aromatase inhibitor-induced bone loss typically consist of an antiresorptive approach with bisphosphonates or the RANKL antibody denosumab. However, different guidelines vary with respect to treatment thresholds, duration, and dosing. The choice of antiresorptive regime is further complicated by comorbidities and potential disease-modifying effects of individual agents. OBJECTIVE: This review summarizes the evidence of how aromatase inhibitors affect bone health and provides an update of clinical approaches to preserve bone strength in affected women. (J Clin Endocrinol Metab XX: 0-0, 2020).

Bone health during endocrine therapy for cancer.

Preservation of bone health remains a long-term clinical challenge in patients with breast and prostate cancer. Osteoporosis, defined by a loss of bone mass and microarchitecture, often results in fragility fractures that are typically associated with a high socioeconomic burden. Endocrine therapy, a mainstay treatment in the management of patients with hormone-sensitive breast and prostate cancer in the adjuvant setting, commonly exerts adverse effects on the musculoskeletal system and is associated with an increased risk of osteoporosis and fractures. Adjuvant use of gonadotropin-releasing hormone analogues, which can also be used in metastatic disease, in combination with tamoxifen in premenopausal women, and aromatase inhibitors in postmenopausal women with hormone-sensitive breast cancer, causes rapid bone loss and fragility fractures. By contrast, selective oestrogen receptor modulators, such as tamoxifen, have bone-protective effects in postmenopausal women. In men with castration-sensitive prostate cancer, androgen deprivation is achieved with drugs that lower gonadotropin levels, and these drugs can be combined with androgen receptor antagonists. These therapies induce a high bone turnover with rapid bone loss that is reminiscent of the changes occurring in early menopause and result in an increased risk of fracture. In this Review, we describe how adjuvant endocrine therapies of breast and prostate cancer impair bone health and outline evidence from randomised controlled trials of strategies to reduce risk of fracture.

Crystallizing nanoparticles derived from vascular smooth muscle cells contain the calcification inhibitor osteoprotegerin.

Osteoprotegerin (OPG), a member of the TNF receptor superfamily, was initially found to modulate bone mass by blocking osteoclast maturation and function. Rodent models have also revealed a role for OPG as an inhibitor of vascular calcification. However, the precise mode of how OPG blocks mineralization is unclear. In this study, OPG was found in an in vitro assay to significantly inhibit calcification of vascular smooth muscle cells (VSMC) induced by high calcium/phosphate (Ca/P) treatment (p=0.0063), although this effect was blunted at high OPG concentrations. By confocal microscopy, OPG was detected in VSMC in the Golgi, the same localization seen in osteoblasts, which express OPG in bone. Treatment of VSMC by minerals (Ca, P, or both) induced OPG mRNA expression as assessed by real-time quantitative PCR, and VSMC derived from atherosclerotic plaque material also exhibited higher OPG expression as compared to control cells (p<0.05). Furthermore, OPG was detected by Western blotting in matrix vesicles (MV), nanoparticles that are released by VSMC with the capacity to nucleate mineral. In atherosclerotic arteries, OPG colocalized immunohistochemically with annexin VI, a calcium-dependent membrane and phospholipid binding protein found in MV. Thus, the calcification inhibitor OPG is contained in crystallizing MV and has a biphasic effect on VSMC: physiologic concentrations inhibit calcification, whereas high concentrations commonly seen in patients with vascular disease have no effect. Like other calcification inhibitors, OPG may be specifically loaded into these nanoparticles to be deposited at remote sites, where it acts to inhibit calcification.

An anti-inflammatory selective glucocorticoid receptor modulator preserves osteoblast differentiation.

Glucocorticoids (GCs) are in widespread use to treat inflammatory bone diseases, such as rheumatoid arthritis (RA). Their anti-inflammatory efficacy, however, is accompanied by deleterious effects on bone, leading to GC-induced osteoporosis (GIO). These effects include up-regulation of the receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratio to promote bone-resorbing osteoclasts and include inhibition of bone-forming osteoblasts. We previously identified suppression of osteoblast differentiation by the monomer glucocorticoid receptor (GR) via the inhibition of Il11 expression as a crucial mechanism for GIO. Here we show that the GR-modulating substance compound A (CpdA), which does not induce GR dimerization, still suppresses proinflammatory cytokines in fibroblast-like synovial cells from patients with RA and in osteoblasts. In contrast to the full GR agonist dexamethasone, it does not unfavorably alter the RANKL/OPG ratio and does not affect Il11 expression and subsequent STAT3 phosphorylation in these cells. Notably, while dexamethasone inhibits osteoblast differentiation, CpdA does not affect osteoblast differentiation in vitro and in vivo. We describe here for the first time that selective GR modulators can act against inflammation, while not impairing osteoblast differentiation.

Approach to the patient with secondary osteoporosis.

Secondary osteoporosis is characterized by low bone mass with microarchitectural alterations in bone leading to fragility fractures in the presence of an underlying disease or medication. Scenarios that are highly suspicious for secondary osteoporosis include fragility fractures in younger men or premenopausal women, very low bone mineral density (BMD) values, and fractures despite anti-osteoporotic therapy. An open-minded approach with a detailed history and physical examination combined with first-line laboratory tests are aimed at identifying clinical risk factors for fractures, osteoporosis-inducing drugs, and underlying endocrine, gastrointestinal, hematologic, or rheumatic diseases, which then need to be confirmed by specific and/or more invasive tests. BMD should be assessed with bone densitometry at the hip and spine. Lateral X-rays of the thoracic and lumbar spine should be performed to identify or exclude prevalent vertebral fractures which may be clinically silent. Management of secondary osteoporosis includes treatment of the underlying disease, modification of medications known to affect the skeleton, and specific anti-osteoporotic therapy. Calcium and vitamin D supplementation should be initiated with doses that result in normocalcemia and serum 25-hydroxyvitamin D concentrations of at least 30 ng/ml. Oral and i.v. bisphosphonates are effective and safe drugs for most forms of secondary osteoporosis. Severe osteoporosis may require the use of teriparatide.

Paneling human thyroid cancer cell lines for candidate proteins for targeted anti-angiogenic therapy.

Tumor angiogenesis is believed to result from an imbalance of pro- and anti-angiogenic factors, some of which are candidates for targeted therapy. Such therapy has raised hopes for patients with undifferentiated thyroid carcinomas, who are facing a grave prognosis with a survival of only months. In this study, in vivo growth of xenografted human thyroid carcinomas unexpectedly responded quite differently to neutralizing anti-vascular endothelial growth factor (VEGF) antibody. In particular, lasting inhibition as well as accelerated growth occurred after treatment. Consequently, a panel of anti-angiogenic factors was addressed in a representative sample of thyroid carcinoma lines. VEGF, fibroblast growth factor (FGF-2), and endostatin were demonstrated by Western blotting and EIA, whereas PDGF-A, PDGF-B, and IL-6 were negative. Quantification of VEGF, FGF-2, and endostatin revealed a wide range of concentrations from 500 to 4,200 pg/ml VEGF, 5 to 60 pg/ml FGF-2, and 50 to 300 pg/ml endostatin, not related to a particular histologic thyroid carcinoma background. Angiostatin (kringles 1-3) was detected in all, but one of the cell lines. Finally, aaATIII was confirmed in FTC133 cells. These data highlight the complex regulation of angiogenesis in thyroid carcinoma cell lines and suggest that the array of angiogenic factors differs markedly between individual cell lines. For the first time, angiostatin, endostatin, and possibly also aaATIII are identified as novel candidate regulators of angiogenesis in thyroid carcinoma cells.

Isopropanolic extract of black cohosh stimulates osteoprotegerin production by human osteoblasts.

UNLABELLED: An isopropanolic extract (iCR) from the rhizomes of Cimicifuga racemosa (black cohosh) is used an alternative in the treatment of menopausal symptoms, and animal studies suggest positive skeletal effects. iCR stimulated osteoblastic OPG protein secretion by 3- to 5-fold as early as 12 h without affecting RANKL expression. The iCR effect, abrogated by the pure estrogen receptor antagonist ICI 182,780, also enhanced ALP activity (4-fold) and osteocalcin expression (3-fold), possibly contributing to the skeletal effects of black cohosh. INTRODUCTION: Despite its positive effects on the skeleton, estrogen replacement therapy is no longer recommended as first-line therapy for the prevention and treatment of postmenopausal osteoporosis because it increases cardiovascular, thromboembolic, and breast cancer risk. Recently, herbal therapeutics such as an isopropanolic extract (iCR) from the rhizomes of Cimicifuga (=Actaea) racemosa (black cohosh) are gaining interest as an alternative in the treatment of menopausal symptoms. Whereas animal studies in rats suggest positive skeletal effects, the mechanism of its actions on bone cells remain unclear. RANKL is essential for osteoclast formation and activation, while osteoprotegerin (OPG) neutralizes RANKL. MATERIALS AND METHODS: In this study, we assessed the effects of iCR on OPG and RANKL mRNA steady-state levels by semiquantitative RT-PCR and on protein production by an ELISA system in human osteoblasts (hOBs). RESULTS: Under serum-free conditions, treatment with iCR increased OPG mRNA levels and protein secretion of hOBs by 2- to 3-fold in a dose-dependent manner, with a maximum effect at a 10(6)-fold dilution of iCR (p < 0.001) after 24-48 h. Time-course experiments indicated a stimulatory effect of iCR on osteoblastic OPG protein secretion by 3- to 5-fold (p < 0.001) as early as 12 h, whereas RANKL expression was very low and was not found to be modulated by iCR. Of note, the stimulatory effect of iCR on OPG production was abrogated by the pure estrogen receptor antagonist ICI 182,780. Moreover, iCR enhanced two osteoblastic differentiation markers, bone-specific alkaline phosphatase activity and osteocalcin expression, by up to 4- and 3-fold, respectively (p < 0.001). CONCLUSIONS: Our data suggest that iCR enhances differentiation and increases the OPG-to-RANKL ratio of normal human osteoblasts. These effects may contribute to the positive skeletal effects of black cohosh.

Effect of systemic glucocorticoid therapy on bone metabolism and the osteoprotegerin system in patients with active Crohn's disease.

BACKGROUND AND AIMS: Osteoporosis may occur in 25-30% of patients with Crohn's disease. Its pathogenesis is not completely understood. Both systemic inflammation in acute disease and treatment with systemic glucocorticoids have been implicated. The aim of the present study was to investigate changes in bone density and biochemical markers of bone metabolism before and during a 3-month period of high-dose glucocorticoid treatment for acute flare-up of Crohn's disease. METHODS: Twenty-five patients with active Crohn's disease requiring systemic glucocorticoid treatment (prednisolone, 60 mg/day) were investigated. Lumbar spine and femoral neck bone mineral densitometry was performed at baseline and again after 3 months. Clinical examinations including evaluation of the Crohn's disease activity index and measurement of the biochemical markers osteocalcin, deoxypyridinoline, osteoprotegerin and the soluble receptor activator of NF-kappaB ligand were performed prior to, and at 1, 2 and 12 weeks following steroid administration. RESULTS Median lumbar bone mineral density decreased significantly during the observation period by 1.04% from -0.84 (t score; range, -2.8 to +0.57) to -0.95 (range, -3.1 to +0.40; P = 0.022), while bone density of the total femur decreased by 2.9% from -0.83 (range, -2.61 to +1.86) to -0.90 (range, -2.65 to +0.19; P = 0.01). Serum levels of osteocalcin, a bone formation marker, and osteoprotegerin, an anti-resorptive cytokine produced by osteoblasts, decreased after the first 2 weeks of treatment and reached baseline levels after 3 months. No significant change was found for the bone resorption marker deoxypyridinoline, while soluble receptor activator of NF-kappaB ligand, a cytokine promoting bone resorption, tended to increase during steroid treatment. CONCLUSION: A decrease in bone mineral density in patients with Crohn's disease appears to result, at least in part, from a short-term effect of systemic glucocorticoid. Modulation of osteoclastogenesis by the receptor activator of NF-kappaB ligand/osteoprotegerin cytokine system and decreased osteoblastic function may be the underlying molecular basis.