Abstract: Context Type 2 diabetes mellitus (DM) is associated with higher bone mineral density (BMD) and paradoxically with increased fracture risk. It is not known if low BMD, central to fracture prediction in older adults, identifies fracture risk in patients with DM. Objective To determine if femoral neck BMD T score and the World Health Organization Fracture Risk Algorithm (FRAX) score are associated with hip and nonspine fracture risk in older adults with type 2 DM. Design, Setting, and Participants Data from 3 prospective observational studies with adjudicated fracture outcomes (Study of Osteoporotic Fractures [December 1998-July 2008]; Osteoporotic Fractures in Men Study [March 2000-March 2009]; and Health, Aging, and Body Composition study [April 1997-June 2007]) were analyzed in older community-dwelling adults (9449 women and 7436 men) in the United States. Main Outcome Measure Self-reported incident fractures, which were verified by radiology reports. Results Of 770 women with DM, 84 experienced a hip fracture and 262 a nonspine fracture during a mean (SD) follow-up of 12.6 (5.3) years. Of 1199 men with DM, 32 experienced a hip fracture and 133 a nonspine fracture during a mean (SD) follow-up of 7.5 (2.0) years. Age-adjusted hazard ratios (HRs) for 1-unit decrease in femoral neck BMD T score in women with DM were 1.88 (95% confidence interval [CI], 1.43-2.48) for hip fracture and 1.52 (95% CI, 1.31-1.75) for nonspine fracture, and in men with DM were 5.71 (95% CI, 3.42-9.53) for hip fracture and 2.17 (95% CI, 1.75-2.69) for nonspine fracture. The FRAX score was also associated with fracture risk in participants with DM (HRs for 1-unit increase in FRAX hip fracture score, 1.05; 95% CI, 1.03-1.07, for women with DM and 1.16; 95% CI, 1.07-1.27, for men with DM; HRs for 1-unit increase in FRAX osteoporotic fracture score, 1.04; 95% CI, 1.02-1.05, for women with DM and 1.09; 95% CI, 1.04-1.14, for men with DM). However, for a given T score and age or for a given FRAX score, participants with DM had a higher fracture risk than those without DM. For a similar fracture risk, participants with DM had a higher T score than participants without DM. For hip fracture, the estimated mean difference in T score for women was 0.59 (95% CI, 0.31-0.87) and for men was 0.38 (95% CI, 0.09-0.66). Conclusions Among older adults with type 2 DM, femoral neck BMD T score and FRAX score were associated with hip and nonspine fracture risk; however, in these patients compared with participants without DM, the fracture risk was higher for a given T score and age or for a given FRAX score.

Abstract: This article reviews the risks of osteoporosis and osteonecrosis associated with glucocorticoid use, which are present even in the absence of low bone mineral density, and discusses strategies to reduce the risk of fractures and the data to support the strategies.

Abstract: The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the "gold standard" for diagnosing osteoporosis but does not directly reflect deterioration in bone microarchitecture. The trabecular bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of bone microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women.

Abstract: Background Progress in the diagnosis and prediction of fragility fractures depends on improvements to the understating of the compositional contributors of bone quality to mechanical competence. Raman spectroscopy has been used to evaluate alterations to bone composition associated with aging, disease, or injury.

Abstract: (See the editorial commentary by Yin and Overton, on pages 1705–7.) Background. Long-term effects of abacavir (ABC)–lamivudine (3TC), compared with tenofovir (TDF)–emtricitabine (FTC) with efavirenz (EFV) or atazanavir plus ritonavir (ATV/r), on bone mineral density (BMD) have not been analyzed. Methods. A5224s was a substudy of A5202, in which HIV-infected treatment-naive participants were randomized and blinded to receive ABC-3TC or TDF-FTC with open-label EFV or ATV/r. Primary bone end points included Dual-emission X-ray absorbtiometry (DXA)-measured percent changes in spine and hip BMD at week 96. Primary analyses were intentto-treat. Statistical tests used the factorial design and included linear regression, 2-samplet, log-rank, and Fisher’s exact tests. Results. Two hundred sixty-nine persons randomized to 4 arms of ABC-3TC or TDF-FTC with EFV or ATV/r. At baseline, 85% were male, and 47% were white non-Hispanic; the median HIV-1 RNA load was 4.6 log10 copies/ mL, the median age was 38 years, the median weight was 76 kg, and the median CD4 cell count was 233 cells/lL. At week 96, the mean percentage changes from baseline in spine and hip BMD for ABC-3TC versus TDF-FTC were -1.3% and -3.3% (P 5 .004) and -2.6% and -4.0% (P 5 .024), respectively; and for EFV versus ATV/r were -1.7% and -3.1% (P 5 .035) and -3.1% and -3.4% (P 5 .61), respectively. Bone fracture was observed in 5.6% of participants. The probability of bone fractures and time to first fracture were not different across components. Conclusions. Compared with ABC-3TC, TDF-FTC–treated participants had significantly greater decreases in spine and hip BMD, whereas ATV/r led to more significant losses in spine, but not hip, BMD than EFV. Clinical Trials Registration. NCT00118898.

Abstract: The human skeleton is affected by mutations in low-density lipoprotein receptor-related protein 5 (LRP5). To understand how LRP5 influences bone properties, we generated mice with osteocyte-specific expression of inducible Lrp5 mutations that cause high and low bone mass phenotypes in humans. We found that bone properties in these mice were comparable to bone properties in mice with inherited mutations. We also induced an Lrp5 mutation in cells that form the appendicular skeleton but not in cells that form the axial skeleton; we observed that bone properties were altered in the limb but not in the spine. These data indicate that Lrp5 signaling functions locally, and they suggest that increasing LRP5 signaling in mature bone cells may be a strategy for treating human disorders associated with low bone mass, such as osteoporosis.

Abstract: Context: Deficits in bone acquisition during growth may increase fracture risk. Assessment of bone health during childhood requires appropriate reference values relative to age, sex, and population ancestry to identify bone deficits. Objective: The objective of this study was to provide revised and extended reference curves for bone mineral content (BMC) and areal bone mineral density (aBMD) in children. Design: The Bone Mineral Density in Childhood Study was a multicenter longitudinal study with annual assessments for up to 7 yr. Setting: The study was conducted at five clinical centers in the United States. Participants: Two thousand fourteen healthy children (992 males, 22% African-Americans) aged 5–23 yr participated in the study. Intervention: There were no interventions. Main Outcome Measures: Reference percentiles for BMC and aBMD of the total body, lumbar spine, hip, and forearm were obtained using dual-energy x-ray absorptiometry for Black and non-Black children. Adjustment factors for height sta...

Abstract: Description Update of the 2002 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for osteoporosis. Methods The USPSTF evaluated evidence on the diagnostic accuracy of risk assessment instruments for osteoporosis and fractures, the performance of dual-energy x-ray absorptiometry and peripheral bone measurement tests in predicting fractures, the harms of screening for osteoporosis, and the benefits and harms of drug therapy for osteoporosis in women and men. Recommendations The USPSTF recommends screening for osteoporosis in women aged 65 years or older and in younger women whose fracture risk is equal to or greater than that of a 65-year-old white woman who has no additional risk factors. (Grade B recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for osteoporosis in men. (I statement).

Abstract: Sclerostin is a potent inhibitor of Wnt signaling and bone formation. However, there is currently no information on the relation of circulating sclerostin levels to age, gender, or bone mass in humans. Thus we measured serum sclerostin levels in a population-based sample of 362 women [123 premenopausal, 152 postmenopausal not on estrogen treatment (ET), and 87 postmenopausal on ET] and 318 men, aged 21 to 97 years. Sclerostin levels (mean ± SEM) were significantly higher in men than women (33.3 ± 1.0 pmol/L versus 23.7 ± 0.6 pmol/L, p < .001). In pre- and postmenopausal women not on ET combined (n = 275) as well as in men, sclerostin levels were positively associated with age (r = 0.52 and r = 0.64, respectively, p < .001 for both). Over life, serum sclerostin levels increased by 2.4- and 4.6-fold in the women and men, respectively. Moreover, for a given total-body bone mineral content, elderly subjects (age ≥ 60 years) had higher serum sclerostin levels than younger subjects (ages 20 to 39 years). Our data thus demonstrate that (1) men have higher serum sclerostin levels than women, (2) serum sclerostin levels increase markedly with age, and (3) compared with younger subjects, elderly individuals have higher serum sclerostin levels for a given amount of bone mass. Further studies are needed to define the cause of the age-related increase in serum sclerostin levels in humans as well as the potential role of this increase in mediating the known age-related impairment in bone formation. © 2011 American Society for Bone and Mineral Research.

Abstract: Clinical data suggest concomitant therapy with bisphosphonates and parathyroid hormone (PTH) may blunt the anabolic effect of PTH; rodent models suggest that infrequently administered bisphosphonates may interact differently. To evaluate the effects of combination therapy with an intravenous infusion of zoledronic acid 5 mg and daily subcutaneous recombinant human (rh)PTH(1-34) (teriparatide) 20 µg versus either agent alone on bone mineral density (BMD) and bone turnover markers, we conducted a 1-year multicenter, multinational, randomized, partial double-blinded, controlled trial. 412 postmenopausal women with osteoporosis (mean age 65 ± 9 years) were randomized to a single infusion of zoledronic acid 5 mg plus daily subcutaneous teriparatide 20 µg (n = 137), zoledronic acid alone (n = 137), or teriparatide alone (n = 138). The primary endpoint was percentage increase in lumbar spine BMD (assessed by dual-energy X-ray absorptiometry [DXA]) at 52 weeks versus baseline. Secondary endpoints included change in BMD at the spine at earlier time points and at the total hip, trochanter, and femoral neck at all time points. At week 52, lumbar spine BMD had increased 7.5%, 7.0%, and 4.4% in the combination, teriparatide, and zoledronic acid groups, respectively (p < .001 for combination and teriparatide versus zoledronic acid). In the combination group, spine BMD increased more rapidly than with either agent alone (p < .001 versus both teriparatide and zoledronic acid at 13 and 26 weeks). Combination therapy increased total-hip BMD more than teriparatide alone at all times (all p < .01) and more than zoledronic acid at 13 weeks (p < .05), with final 52-week increments of 2.3%, 1.1%, and 2.2% in the combination, teriparatide, and zoledronic acid groups, respectively. With combination therapy, bone formation (assessed by serum N-terminal propeptide of type I collagen [PINP]) increased from 0 to 4 weeks, declined minimally from 4 to 8 weeks, and then rose throughout the trial, with levels above baseline from 6 to 12 months. Bone resorption (assessed by serum β-C-telopeptide of type I collagen [β-CTX]) was markedly reduced with combination therapy from 0 to 8 weeks (a reduction of similar magnitude to that seen with zoledronic acid alone), followed by a gradual increase after week 8, with levels remaining above baseline for the latter half of the year. Levels for both markers were significantly lower with combination therapy versus teriparatide alone (p < .002). Limitations of the study included its short duration, lack of endpoints beyond DXA-based BMD (e.g., quantitative computed tomography and finite-element modeling for bone strength), lack of teriparatide placebo, and insufficient power for fracture outcomes. We conclude that while teriparatide increases spine BMD more than zoledronic acid and zoledronic acid increases hip BMD more than teriparatide, combination therapy provides the largest, most rapid increments when both spine and hip sites are considered.

Abstract: Background: Parathyroid hormone (PTH) has been shown to increase bone mineral density and to reduce the rate of fractures in patients with osteoporosis and also to improve fracture-healing. The purpose of the present prospective, randomized, controlled study was to evaluate the effect of PTH 1-84 on the course of pelvic fracture-healing and functional outcome in postmenopausal women. Methods: Sixty-five patients had a dual x-ray absorptiometry scan, radiographs, and a computed tomography scan to document pelvic fractures. Twenty-one patients received a once-daily injection of 100 μg of PTH 1-84 starting within two days after admission to the hospital, and forty-four patients served as the control group. All patients received 1000 mg of calcium and 800 IU of vitamin D. Computed tomography scans were repeated every fourth week until radiographic evidence of cortical bridging at the fracture site was confirmed. Functional outcome was assessed with use of a visual analog scale for pain and a Timed “Up and Go” test. Results: The mean time to fracture healing was 7.8 weeks for the treatment group, compared with 12.6 weeks for the control group (p < 0.001). At eight weeks, all fractures in the treatment group were healed and four fractures in the control group were healed (healing rate, 100% compared with 9.1%; p < 0.001). Both the visual analog scale score for pain and the result of the Timed “Up and Go” test improved in the study group as compared with the control group (p < 0.001). Conclusions: In elderly patients with osteoporosis, PTH 1-84 accelerates fracture-healing in pelvic fractures and improves functional outcome. Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Abstract: Recent studies have demonstrated an important physiologic link between bone and fat. Bone and fat cells arise from the same mesenchymal precursor cell within bone marrow, capable of differentiation into adipocytes or osteoblasts. Increased BMI appears to protect against osteoporosis. However, recent studies have suggested detrimental effects of visceral fat on bone health. Increased visceral fat may also be associated with decreased growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels which are important for maintenance of bone homeostasis. The purpose of our study was to assess the relationship between vertebral bone marrow fat and trabecular bone mineral density (BMD), abdominal fat depots, GH and IGF-1 in premenopausal women with obesity. We studied 47 premenopausal women of various BMI (range: 18–41 kg/m2, mean 30 ± 7 kg/m2) who underwent vertebral bone marrow fat measurement with proton magnetic resonance spectroscopy (1H-MRS), body composition, and trabecular BMD measurement with computed tomography (CT), and GH and IGF-1 levels. Women with high visceral fat had higher bone marrow fat than women with low visceral fat. There was a positive correlation between bone marrow fat and visceral fat, independent of BMD. There was an inverse association between vertebral bone marrow fat and trabecular BMD. Vertebral bone marrow fat was also inversely associated with IGF-1, independent of visceral fat. Our study showed that vertebral bone marrow fat is positively associated with visceral fat and inversely associated with IGF-1 and BMD. This suggests that the detrimental effect of visceral fat on bone health may be mediated in part by IGF-1 as an important regulator of the fat and bone lineage.

Abstract: Background Anorexia nervosa (AN) is prevalent in adolescents and is associated with decreased bone mineral accrual at a time critical for optimizing bone mass. Low bone mineral density (BMD) in AN is a consequence of nutritional and hormonal alterations, including hypogonadism and low estradiol levels. Effective therapeutic strategies to improve BMD in adolescents with AN have not been identified. Specifically, high estrogen doses given as an oral contraceptive do not improve BMD. The impact of physiological estrogen doses that mimic puberty on BMD has not been examined.

Abstract: Background Bone mass, geometry, and tissue material properties contribute to bone structural integrity. Thus, bone strength arises from both bone quantity and quality. Bone quality encompasses the geometric and material factors that contribute to fracture resistance.

Abstract: Summary It is unclear whether optimal levels of 25-hydroxyvitamin D (25(OH)D) in whites are the same as in minorities. In adult participants of NHANES, the relationships between 25(OH)D, bone mineral density (BMD), and parathyroid hormone (PTH) differed in blacks as compared to whites and Mexican-Americans, suggesting that optimal 25(OH)D levels for bone and mineral metabolism may differ by race.

Abstract: The purpose of this study was to evaluate the utility of lumbar spine attenuation measurement for bone mineral density (BMD) assessment at screening computed tomographic colonography (CTC) using central dual-energy X-ray absorptiometry (DXA) as the reference standard. Two-hundred and fifty-two adults (240 women and 12 men; mean age 58.9 years) underwent CTC screening and central DXA BMD measurement within 2 months (mean interval 25.0 days). The lowest DXA T-score between the spine and hip served as the reference standard, with low BMD defined per World Health Organization as osteoporosis (DXA T-score ≤ −2.5) or osteopenia (DXA T-score between −1.0 and −2.4). Both phantomless quantitative computed tomography (QCT) and simple nonangled region-of-interest (ROI) multi-detector CT (MDCT) attenuation measurements were applied to the T12–L5 levels. The ability to predict osteoporosis and low BMD (osteoporosis or osteopenia) by DXA was assessed. A BMD cut-off of 90 mg/mL at phantomless QCT yielded 100% sensitivity for osteoporosis (29 of 29) and a specificity of 63.8% (143 of 224); 87.2% (96 of 110) below this threshold had low BMD and 49.6% (69 of 139) above this threshold had normal BMD at DXA. At L1, a trabecular ROI attenuation cut-off of 160 HU was 100% sensitive for osteoporosis (29 of 29), with a specificity of 46.4% (104 of 224); 83.9% (125 of 149) below this threshold had low BMD and 57.5% (59/103) above had normal BMD at DXA. ROI performance was similar at all individual T12–L5 levels. At ROC analysis, AUC for osteoporosis was 0.888 for phantomless QCT [95% confidence interval (CI) 0.780–0.946] and ranged from 0.825 to 0.853 using trabecular ROIs at single lumbar levels (0.864; 95% CI 0.752–0.930 at multivariate analysis). Supine-prone reproducibility was better with the simple ROI method compared with QCT. It is concluded that both phantomless QCT and simple ROI attenuation measurements of the lumbar spine are effective for BMD screening at CTC with high sensitivity for osteoporosis, as defined by the DXA T-score. © 2011 American Society for Bone and Mineral Research

Abstract: Therapeutic enhancement of fracture healing would help to prevent the occurrence of orthopedic complications such as nonunion and revision surgery. Sclerostin is a negative regulator of bone formation, and treatment with a sclerostin monoclonal antibody (Scl-Ab) results in increased bone formation and bone mass in animal models. Our objective was to investigate the effects of systemic administration of Scl-Ab in two models of fracture healing. In both a closed femoral fracture model in rats and a fibular osteotomy model in cynomolgus monkeys, Scl-Ab significantly increased bone mass and bone strength at the site of fracture. After 10 weeks of healing in nonhuman primates, the fractures in the Scl-Ab group had less callus cartilage and smaller fracture gaps containing more bone and less fibrovascular tissue. These improvements at the fracture site corresponded with improvements in bone formation, bone mass, and bone strength at nonfractured cortical and trabecular sites in both studies. Thus the potent anabolic activity of Scl-Ab throughout the skeleton also was associated with an anabolic effect at the site of fracture. These results support the potential for systemic Scl-Ab administration to enhance fracture healing in patients.

Abstract: Low body mass index (BMI) is a risk factor for fracture, but little is known about the association between high BMI and fracture risk. We evaluated the association between BMI and fracture in the Osteoporotic Fractures in Men Study (MrOS), a cohort of 5995 US men 65 years of age and older. Standardized measures included weight, height, and hip bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA); medical history; lifestyle; and physical performance. Only 6 men (0.1%) were underweight (<18.5 kg/m2); therefore, men in this category were excluded. Also, 27% of men had normal BMI (18.5 to 24.9 kg/m2), 52% were overweight (25 to 29.9 kg/m2), 18% were obese I (30 to 34.9 kg/m2), and 3% were obese II (35 to 39.9 kg/m2). Overall, nonspine fracture incidence was 16.1 per 1000 person-years, and hip fracture incidence was 3.1 per 1000 person-years. In age-, race-, and BMD-adjusted models, compared with normal weight, the hazard ratio (HR) for nonspine fracture was 1.04 [95% confidence interval (CI) 0.87–1.25] for overweight, 1.29 (95% CI 1.00–1.67) for obese I, and 1.94 (95% CI 1.25–3.02) for obese II. Associations were weaker and not statistically significant after adjustment for mobility limitations and walking pace (HR = 1.02, 95% CI 0.84–1.23, for overweight; HR = 1.12, 95% CI 0.86–1.46, for obese I, and HR = 1.44, 95% CI 0.90–2.28, for obese II). Obesity is common among older men, and when BMD is held constant, it is associated with an increased risk of fracture. This association is at least partially explained by worse physical function in obese men. © 2011 American Society for Bone and Mineral Research.

Abstract: Peak bone mass is attained during the second and third decades of life. Sports participation during the years that peak bone mass is being acquired may lead to adaptive changes that improve bone architecture through increased density and enhanced geometric properties. A review of the literature evaluating sports participation in young athletes, ages 10-30 years, revealed that sports that involve high-impact loading (eg, gymnastics, hurdling, judo, karate, volleyball, and other jumping sports) or odd-impact loading (eg, soccer, basketball, racquet games, step-aerobics, and speed skating) are associated with higher bone mineral composition, bone mineral density (BMD), and enhanced bone geometry in anatomic regions specific to the loading patterns of each sport. Repetitive low-impact sports (such as distance running) are associated with favorable changes in bone geometry. Nonimpact sports such as swimming, water polo, and cycling are not associated with improvements in bone mineral composition or BMD, and swimming may negatively influence hip geometry. Participating in sports during early puberty may enhance bone mass. Continued participation in sports appears to maintain the full benefits of increased peak bone mass, although former athletes who do not maintain participation in sports may retain some benefits of increased BMD. Long-term elite male cycling was reported to negatively influence bone health, and female adolescent distance running was associated with suppressed bone mineral accrual; confounding factors associated with participation in endurance sports may have contributed to those findings. In summary, young men and women who participate in sports that involve high-impact or odd-impact loading exhibit the greatest associated gains in bone health. Participation in nonimpact sports, such as swimming and cycling, is not associated with an improvement in bone health.

Abstract: Objective To determine the effectiveness of vitamin D supplementation for improving bone mineral density in children and adolescents and if effects vary with factors such as vitamin D dose and vitamin D status. Design Systematic review and meta-analysis. Data sources Cochrane Central Register of Controlled Trials, Medline (1966 to present), Embase (1980 to present), CINAHL (1982 to present), AMED (1985 to present), and ISI Web of Science (1945 to present), last updated on 9 August 2009, and hand searching of conference abstracts from key journals. Study selection Placebo controlled randomised controlled trials of vitamin D supplementation for at least three months in healthy children and adolescents (aged 1 month to Data synthesis Standardised mean differences of the percentage change from baseline in bone mineral density of the forearm, hip, and lumbar spine and total body bone mineral content in treatment and control groups. Subgroup analyses were carried out by sex, pubertal stage, dose of vitamin D, and baseline serum vitamin D concentration. Compliance and allocation concealment were also considered as possible sources of heterogeneity. Results From 1653 potential references, six studies, totalling 343 participants receiving placebo and 541 receiving vitamin D, contributed data to meta-analyses. Vitamin D supplementation had no statistically significant effects on total body bone mineral content or on bone mineral density of the hip or forearm. There was a trend to a small effect on lumbar spine bone mineral density (standardised mean difference 0.15, 95% confidence interval −0.01 to 0.31; P=0.07). Effects were similar in studies of participants with high compared with low serum vitamin D levels, although there was a trend towards a larger effect with low vitamin D for total body bone mineral content (P=0.09 for difference). In studies with low serum vitamin D, significant effects on total body bone mineral content and lumbar spine bone mineral density were roughly equivalent to a 2.6% and 1.7% percentage point greater change from baseline in the supplemented group. Conclusions It is unlikely that vitamin D supplements are beneficial in children and adolescents with normal vitamin D levels. The planned subgroup analyses by baseline serum vitamin D level suggest that vitamin D supplementation of deficient children and adolescents could result in clinically useful improvements, particularly in lumbar spine bone mineral density and total body bone mineral content, but this requires confirmation.

Abstract: OBJECTIVE Thiazolidinediones and insulin are associated with a higher risk of fractures in type 2 diabetic patients. Incretin hormones increase bone density in experimental models, but the effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on bone fractures has not been reported so far. RESEARCH DESIGN AND METHODS A meta-analysis was performed including all randomized clinical trials with a duration of at least 24 weeks, enrolling patients with type 2 diabetes, comparing DPP-4 inhibitors with placebo or active drugs. RESULTS Twenty-eight trials enrolling 11,880 and 9,175 patients for DPP-4 inhibitors and comparators, respectively, were included, reporting 63 fractures. DPP-4 inhibitors, compared with placebo or other treatments, were associated with a reduced risk of fractures (Mantel–Haenszel odds ratio [MH-OR] 0.60, 95% CI 0.37–0.99, P = 0.045), even after the exclusion of comparisons with thiazolidinediones or sulfonylureas (MH-OR 0.56, 0.33–0.93, P = 0.026). CONCLUSIONS The present meta-analysis suggests that treatment with DPP-4 inhibitors could be associated with a reduced risk of bone fractures.

Abstract: Denosumab, a fully human monoclonal antibody to RANKL, decreases bone remodeling, increases bone density, and reduces fracture risk. This study evaluates the time course and determinants of bone turnover marker (BTM) response during denosumab treatment, the percentage of denosumab-treated women with BTMs below the premenopausal reference interval, and the correlations between changes in BTMs and bone mineral density (BMD). The BTM substudy of the Fracture REduction Evaulation of Denosumab in Osteoporosis every 6 Months (FREEDOM) Trial included 160 women randomized to subcutaneous denosumab (60 mg) or placebo injections every 6 months for 3 years. Biochemical markers of bone resorption (serum C-telopeptide of type I collagen [CTX] and tartrate-resistant acid phosphatise [TRACP-5b]) and bone formation (serum procollagen type I N-terminal propeptide [PINP] and bone alkaline phosphatase [BALP]) were measured at baseline and at 1, 6, 12, 24, and 36 months. Decreases in CTX were more rapid and greater than decreases in PINP and BALP. One month after injection, CTX levels in all denosumab-treated subjects decreased to levels below the premenopausal reference interval. CTX values at the end of the dosing period were influenced by baseline CTX values and the dosing interval. The percentage of subjects with CTX below the premenopausal reference interval before each subsequent injection decreased from 79% to 51% during the study. CTX and PINP remained below the premenopausal reference interval at all time points in 46% and 31% denosumab-treated subjects, respectively. With denosumab, but not placebo, there were significant correlations between CTX reduction and BMD increase (r = −0.24 to −0.44). The BTM response pattern with denosumab is unique and should be appreciated by physicians to monitor this treatment effectively. © 2011 American Society for Bone and Mineral Research.

Abstract: Targeted exercise training could reduce risk factors for fracture and obesity-related diseases that increase from breast cancer treatment, but has not been sufficiently tested We hypothesized that progressive, moderate-intensity resistance + impact training would increase or maintain hip and spine bone mass, lean mass and fat mass and reduce bone turnover compared to controls who participated in a low-intensity, non-weight bearing stretching program We conducted a randomized, controlled trial in 106 women with early stage breast cancer who were >1 year post-radiation and/or chemotherapy, ≥50 years of age at diagnosis and postmenopausal, free from osteoporosis and medications for bone loss, resistance and impact exercise naive, and cleared to exercise by a physician Women were randomly assigned to participate in 1 year of thrice-weekly progressive, moderate-intensity resistance + impact (jump) exercise or in a similar frequency and length control program of progressive, low-intensity stretching Primary endpoints were bone mineral density (BMD; g/cm2) of the hip and spine and whole body bone-free lean and fat mass (kg) determined by DXA and biomarkers of bone turnover—serum osteocalcin (ng/ml) and urinary deoxypyrodiniline cross-links (nmol/mmolCr) Women in the resistance + impact training program preserved BMD at the lumbar spine (047 vs −213%; P = 0001) compared to controls The resistance + impact group had a smaller increase in osteocalcin (70 vs 27%, P = 003) and a larger decrease in deoxypyrodinoline (−499 vs −326%, P = 006) than controls Increases in lean mass from resistance + impact training were greatest among women currently taking aromatase inhibitors compared to controls not on this therapy (P = 001) Our combined program of resistance + impact exercise reduced risk factors for fracture among postmenopausal breast cancer survivors (BCS) and may be particularly relevant for BCS on aromatase inhibitors (AIs) because of the additional benefit of exercise on muscle mass that could reduce falls

Abstract: Oral alendronate (5 or 10 mg daily) for 2 years in children with osteogenesis imperfecta was well-tolerated, significantly increased spine bone mineral density, and decreased bone turnover.

Abstract: Background Bone strength depends on both bone quantity and quality. The former is routinely estimated in clinical settings through bone mineral density measurements but not the latter. Bone quality encompasses the structural and material properties of bone. Although its importance is appreciated, its contribution in determining bone strength has been difficult to precisely quantify partly because it is multifactorial and requires investigation of all bone hierarchical levels. Fourier transform infrared spectroscopy provides one way to explore these levels.

Abstract: Copyright © 2011 Massachusetts Medical Society. A 72-year-old woman presents with a 2-month history of increasing pain in her lower back, which has not improved with ibuprofen and is causing difficulty with walking and dressing. On questioning, she reports having lost about 5 cm (2 in.) of height since she was a young woman. On examination, there is mild kyphosis in her lower thoracic spine but no point tenderness. A lateral spine radiograph reveals that the L2 vertebra is biconcave in appearance, a finding that is consistent with a vertebral fracture (Fig. 1). How should this case be managed?

Abstract: Sirt1, the mammalian ortholog of the yeast Sir2 (silent information regulator 2), was shown to play an important role in metabolism and in age-associated diseases, but its role in skeletal homeostasis and osteoporosis has yet not been studied. Using 129/Sv mice with a germline mutation in the Sirt1 gene, we demonstrate that Sirt1 haplo-insufficient (Sirt1(+/-)) female mice exhibit a significant reduction in bone mass characterized by decreased bone formation and increased marrow adipogenesis. Importantly, we identify Sost, encoding for sclerostin, a critical inhibitor of bone formation, as a novel target of Sirt1. Using chromatin immunoprecipitation analysis, we reveal that Sirt1 directly and negatively regulates Sost gene expression by deacetylating histone 3 at lysine 9 at the Sost promoter. Sost down-regulation by small interfering RNA and the administration of a sclerostin-neutralizing antibody restore gene expression of osteocalcin and bone sialoprotein as well as mineralized nodule formation in Sirt1(+/-) marrow-derived mesenchymal stem cells induced to osteogenesis. These findings reveal a novel role for Sirt1 in bone as a regulator of bone mass and a repressor of sclerostin, and have potential implications suggesting that Sirt1 is a target for promoting bone formation as an anabolic approach for treatment of osteoporosis.

Abstract: In hypoparathyroidism, plasma parathyroid hormone (PTH) levels are inadequate to maintain plasma calcium concentration within the reference range. On conventional treatment with calcium supplements and active vitamin D analogues, bone turnover is abnormally low, and BMD is markedly increased. We aimed to study the effects of PTH-replacement therapy (PTH-RT) on calcium-phosphate homeostasis and BMD. In a double-blind design, we randomized 62 patients with hypoparathyroidism to daily treatment with PTH(1–84) 100 µg or similar placebo for 24 weeks as add-on therapy to conventional treatment. Compared with placebo, patients on PTH(1–84) reduced their daily dose of calcium and active vitamin D significantly by 75% and 73%, respectively, without developing hypocalcemia. However, hypercalcemia occurred frequently during the downtitration of calcium and active vitamin D. Plasma phosphate and renal calcium and phosphate excretion did not change. Compared with placebo, PTH(1–84) treatment significantly increased plasma levels of bone-specific alkaline phosphatase (+226% ± 36%), osteocalcin (+807% ± 186%), N-terminal propeptide of procollagen 1 (P1NP; +1315% ± 330%), cross-linked C-telopeptide of type 1 collagen (CTX; +1209% ± 459%), and urinary cross-linked N-telopeptide of type 1 collagen (NTX; (+830% ± 165%), whereas BMD decreased at the hip (−1.59% ± 0.57%), lumbar spine (−1.76% ± 1.03%), and whole body (−1.26% ± 0.49%) but not at the forearm. In conclusion, the need for calcium and active vitamin D is reduced significantly during PTH-RT, whereas plasma calcium and phosphate levels are maintained within the physiologic range. In contrast to the effect of PTH(1–84) treatment in patients with osteoporosis, PTH-RT in hypoparathyroidism causes a decrease in BMD. This is most likely due to the marked increased bone turnover. Accordingly, PTH-RT counteracts the state of overmineralized bone and, during long-term treatment, may cause a more physiologic bone metabolism. © 2011 American Society for Bone and Mineral Research