Reconstruction of Remodeling units reveals positive effects after 2 and 12 months of Romosozumab treatment.

Romosozumab treatment results in a transient early increase in bone formation and sustained decrease in bone resorption. Histomorphometric analyses revealed that the primary bone-forming effect of romosozumab is transient early stimulation of modeling-based bone formation on cancellous and endocortical surfaces; preclinical studies have demonstrated that romosozumab may affect changes in the remodeling unit resulting in positive bone balance. To further investigate the effects of romosozumab on bone balance, month 12 (M12) and M2 (to analyze early effects) unpaired bone biopsies from the FRAME clinical trial were analyzed using remodeling site reconstruction to assess whether positive changes in bone balance on cancellous/endocortical surfaces may contribute to the progressive improvement in bone mass/structure and reduced fracture risk in osteoporotic women at high fracture risk. At M12, bone balance was higher with romosozumab vs placebo on cancellous (+6.1 µm vs +1.5 µm; p = 0.012) and endocortical (+5.2 µm vs -1.7 µm; p = 0.02) surfaces; higher bone balance was due to lower final erosion depth (40.7 µm vs 43.7 µm; p = 0.05) on cancellous surfaces and higher completed wall thickness (50.8 µm vs 47.5 µm; p = 0.037) on endocortical surfaces. At M2, final erosion depth was lower on the endocortical surfaces (42.7 µm vs 50.7 µm; p = 0.021) and slightly lower on the cancellous surfaces (38.5 µm vs 44.6 µm; p = 0.11) with romosozumab vs placebo. Sector analysis of early endocortical formative sites revealed higher osteoid thickness (29.9 µm vs 19.2 µm; p = 0.005) and mineralized wall thickness (18.3 µm vs 11.9 µm; p = 0.004) with romosozumab vs placebo. These evolving bone packets may reflect early stimulation of bone formation that contributes to the increase in completed wall thickness at M12. These data suggest that romosozumab induces a positive bone balance due to its effects on bone resorption and formation at the level of the remodeling unit, contributing to the positive effects on bone mass, structure, and fracture risk.

Romosozumab treatment has a dual effect on bone, adding new bone and reducing bone loss. In the FRAME clinical trial, romosozumab increased bone mass and strength, and reduced fracture risk in postmenopausal women with osteoporosis. Addition of new bone occurs early in treatment and rapidly on cancellous and endocortical bone surfaces where bone resorption is not ongoing. However, it remains unclear if romosozumab affects bone loss or gain in areas where bone resorption is ongoing (remodeling units), contributing to a further positive bone balance. Here, we examined whether changes at the remodeling unit occur early (2 months) and/or late (12 months) in treatment, using bone biopsies from patients treated with romosozumab or placebo in FRAME. At month 2, a combination of lower bone resorption and higher bone gain on endocortical surfaces resulted in a positive bone balance with romosozumab versus placebo. At month 12, bone balance was positive with romosozumab versus placebo due to lower bone resorption on cancellous surfaces and greater bone gain on endocortical surfaces. This demonstrates that romosozumab induces a positive bone balance at remodeling units early in treatment leading to overall gains observed later, contributing to the positive effects of romosozumab on bone mass and structure.

Postfracture survival in a population-based study of adults aged ≥66 yr: a call to action at hospital discharge.

Postfracture survival rates provide prognostic information but are rarely reported along with other mortality outcomes in adults aged ≥50 yr. The timing of survival change following a fracture also needs to be further elucidated. This population-based, matched-cohort, retrospective database study examined 98 474 patients (73% women) aged ≥66 yr with an index fracture occurring at an osteoporotic site (hip, clinical vertebral, proximal non-hip non-vertebral [pNHNV], and distal non-hip non-vertebral [dNHNV]) from 2011 to 2015, who were matched (1:1) to nonfracture individuals based on sex, age, and comorbidities. All-cause 1- and 5-yr overall survival and relative survival ratios (RSRs) were assessed, and time trends in survival changes were characterized starting immediately after a fracture. In both sexes, overall survival was markedly decreased over 6 yr of follow-up after hip, vertebral, and pNHNV fractures, and as expected, worse survival rates were observed in older patients and males. The lowest 5-yr RSRs were observed after hip fractures in males (66-85 yr, 51.9%-63.9%; ≥86 yr, 34.5%), followed by vertebral fractures in males (66-85 yr, 53.2%-69.4%; ≥86 yr, 35.5%), and hip fractures in females (66-85 yr, 69.8%-79.0%; ≥86 yr, 52.8%). Although RSRs did not decrease as markedly after dNHNV fractures in younger patients, relatively low 5-yr RSRs were observed in females (75.9%) and males (69.5%) aged ≥86 yr. The greatest reduction in survival occurred within the initial month after hip, vertebral, and pNHNV fractures, indicating a high relative impact of short-term factors, with survival-reduction effects persisting over time. Therefore, the most critical period for implementing interventions aimed at improving post-fracture prognosis appears to be immediately after a fracture; however, considering the immediate need for introducing such interventions, primary fracture prevention is also crucial to prevent the occurrence of the initial fracture in high-risk patients.

Proceedings of the 2023 Santa Fe Bone Symposium: Progress and Controversies in the Management of Patients with Skeletal Diseases.

The Santa Fe Bone Symposium (SFBS) held its 23rd annual event on August 5-6, 2023, in Santa Fe, New Mexico, USA. Attendees participated in-person and remotely, representing many states and countries. The program included plenary presentations, panel discussions, satellite symposia, a Project ECHO workshop, and a session on healthcare policy and reimbursement for fracture liaison programs. A broad range of topics were addressed, including transitions of osteoporosis treatments over a lifetime; controversies in vitamin D; update on Official Positions of the International Society for Clinical Densitometry; spine surgery and bone health; clinical applications of bone turnover markers; basic bone biology for clinicians; premenopausal-, pregnancy-, and lactation-associated osteoporosis; cancer treatment induced bone loss in patients with breast cancer and prostate cancer; genetic testing for skeletal diseases; and an update on nutrition and bone health. There were also sessions on rare bone diseases, including managing patients with hypophosphatasia; treatment of X-linked hypophosphatemia; and assessment and treatment of patients with hypoparathyroidism. There were oral presentations of abstracts by endocrinology fellows selected from those who participated in the Santa Fe Fellows Workshop on Metabolic Bone Diseases, held the 2 days prior to the SFBS. These proceedings of the 2023 SFBS present the clinical highlights and insights generated from many formal and informal discussions in Santa Fe.

Prevalence and incidence of Paget's disease of bone: Temporal trend over 20 years in the province of Quebec, Canada.

BACKGROUND: Paget's disease of bone (PDB) is a focal bone disorder characterized by an increased bone remodeling and an anarchic bone structure. A decline of prevalence and incidence of PDB has been observed in some countries. No epidemiological data are available on PDB in Canada. AIMS: We aimed at examining the evolution of the prevalence and incidence of PDB in Quebec (Canada) by analyzing health administrative databases. METHODS: PDB case definition relied on one or more hospitalizations, or one or more physician-billing claims with a diagnosis code of PDB. To identify incident cases, a 'run-in' period of four years (1996-1999) was used to exclude prevalent cases. For each fiscal year from 2000 to 2001 to 2019-2020 (population size 2,914,480), crude age and sex-specific prevalence and incidence rates of PDB among individuals aged ≥55 years were determined, and sex-specific rates were also standardized to the 2011 age structure of the Quebec population. Generalized linear regressions were used to test for linear changes in standardized prevalence and incidence rates. RESULTS: Over the study period, standardized prevalence of PDB has remained stable in Quebec, from 0.44 % in 2000/2001 to 0.43 % in 2019/2020 (mean change -0.002, p-value = 0.0935). For the 2019-2020 fiscal year, 13,165 men and women had been diagnosed with PDB and prevalence of PDB increased with age. Standardized incidence of PDB has decreased over time from 0.77/1000 in 2000/2001 to 0.28/1000 in 2019-2020 (mean change -0.228/year, p-value<0.0001), the incidence decreasing from 0.82/1000 to 0.37/1000 in men and from 0.76/1000 to 0.22/1000 in women, respectively. This decrease was observed in all age categories. CONCLUSION: With the exception of a slight increase in PDB prevalence up to 0.55 % in years 2005 to 2007, the prevalence of PDB has remained stable in Quebec over the past 20 years, 13,160 men and women being currently diagnosed with PDB. The incidence has decreased over time. Our results support the epidemiological changes of PDB reported in other countries.

Decline in clinical severity of Paget's disease of bone: Comparison between a contemporary cohort and a historical cohort.

BACKGROUND: European and Australian studies have reported a decrease in the prevalence, incidence and clinical severity of Paget's disease of bone (PDB). There are no studies on the current clinical characteristics of PDB in Quebec, Canada. AIMS: The purpose of this study was to describe the characteristics of unrelated patients with PDB diagnosed after the year 2000 in our region and to compare them to a historical cohort diagnosed before 2000. METHODS: In this retrospective descriptive cohort study, socio-demographic data and clinical characteristics for the contemporary cohort were collected from electronic medical records of patients with PDB followed at our university hospital. For the historical cohort, the same data were collected from the research files of PDB participants in our research program. Inclusion criteria were: age > 18 years, having PDB diagnosed by a rheumatologist, and being followed in our hospital. Exclusion criteria were: having a relative with PDB participating in this study. Variables were reported as mean, standard deviation, frequency and percentage. Chi-square tests were used to compare categorical variables. Continuous values were compared with Wilcoxon-Mann-Whitney tests. Unadjusted p-values and adjusted p-values with the Bonferroni correction method were calculated. A p-value <0.05 was considered statistically significant. RESULTS: Among the 195 patients with PDB in the contemporary cohort, 53.3 % were men, 60.5 % had monostotic involvement, 14.2 % were symptomatic at diagnosis. In comparison to the historical cohort of 173 patients, patients in the contemporary cohort were older at diagnosis (68.7  10.7 vs. 58.5  10.1; p < 0.0001) and had less family history of PDB (13.8 % vs. 33.6 %; p = 0.0024). They also had lower total alkaline phosphatase levels at diagnosis (118.0 (85.0-184.0)) vs. 184.0 (115.0-312.0)); p = 0.0006), a lower pagetic bone number (1.0 (1.0-3.0) vs. 2.0 (1.0-5.0); p < 0.0001), lower pagetic bone fractures (6.7 % vs. 36.7 %; p = 0.0078) and lower bone deformities (13.0 % vs. 54.0 %; p < 0.0001). There was no significant difference for pagetic bone pain (52.0 % vs. 52.6 %; p = 1.0000), percentage of patients who had orthopedic surgery related to PDB complications (8.8 % vs. 28.6 %; p = 1.0000), secondary osteoarthritis (43.0 % vs. 51.6 %; p = 1.0000), and hearing impairment (51.9 % vs. 61.1 %; p = 0.1000). CONCLUSION: The contemporary cohort is characterized by an older age at diagnosis, a majority of monostotic disease and fewer complications of PDB. This decline in clinical severity of PDB in Quebec is consistent with studies reported in other countries.

Molecular test of Paget's disease of bone in families not linked to SQSTM1 gene mutations.

Purpose: Paget's disease of bone (PDB) is a focal metabolic bone disorder characterized by an increased bone remodeling. Fifteen to 40 % of PDB patients have a familial form with an autosomal dominant inheritance. Disease-causing mutations of the SQSTM1 gene have been linked to PDB in about 40 % of families whereas genes linked to the remaining families are unknown. Several single nucleotide polymorphisms (SNPs) have been associated with PDB in unrelated patient non-carriers of a SQSTM1 mutation. The current clinical practice guidelines still recommend the measure of serum total alkaline phosphatase (sALP) for PDB screening. In unrelated individual non-carriers of SQSTM1 mutations, we previously developed a genetic test combining male sex with five genetic markers (rs499345, rs5742915, rs2458413, rs3018362, rs2234968), giving rise to an area under the curve (AUC) for PDB phenotype of 0.73 (0.69; 0.77). A combination of male sex with total calcium corrected for albumin and Procollagen type I N-terminal propeptide (P1NP), had an AUC of 0.82 (0.73; 0.92). Combining both genetic and biochemical tests increased the AUC to 0.89 (0.83; 0.95). Objective: This study aimed at estimating the performance of our previous test of PDB, in families not linked to SQSTM1 mutations with disease-causing genes yet unknown, and at developing a new algorithm if the performance is not satisfactory. Methods: We genotyped the five SNPs cited above, and measured calcium corrected for albumin and P1NP in 181 relatives, with PDB or not, from 19 PDB families not linked to SQSTM1 mutations. Bivariate and multivariate logistic regression models including male sex were fitted to search for a molecular test that could best detect PDB in these families. A receiving operating characteristics analysis was done to establish a cut-off point for continuous variables. Results: Logistic regression estimates of our previous molecular test gave rise to a high sensitivity of 78 %, 97 % and 88 % for the genetic, biochemical, and combined test but the specificity was very low, 35 %, 11 % and 21 %, respectively. This poor specificity persisted even when the cut-off point was changed. We then generated in these families, new logistic regression estimates but on the same parameters as mentioned above, giving rise to an AUC of 0.65 (0.55; 0.75) for the genetic test, of 0.84 (0.74; 0.94) for the biochemical test, and 0.89 (0.82; 0.96) for the combination test, the latter having a sensitivity of 96 % and specificity of 57 %. By comparison serum P1NP alone gave rise to an AUC of 0.84 (0.73; 0.94), with a sensitivity of 71 % and a specificity of 79 %. Conclusion: In PDB families not linked to SQSTM1 mutations, the estimates of our previous molecular test gave rise to a poor specificity. Using new estimates, the biochemical and combined tests have similar predictive abilities than our former test. Serum P1NP is a bone marker of interest for the screening for PDB in families not linked to SQSTM1 mutations.

Current use of bone turnover markers in the management of osteoporosis.

The adult bone is continuously being remodelled to repair microdamage, preserve bone strength and mechanical competence as well as maintain calcium homeostasis. Bone turnover markers are products of osteoblasts (bone formation markers) and osteoclasts (bone resorption markers) providing a dynamic assessment of remodelling (turnover). Resorption-specific bone turnover markers are typically degradation products of bone collagen molecules (N- [NTX] and C-telopeptide cross-linked type 1 collagen [CTX]), which are released into the circulation and excreted in urine; or enzymatic activities reflecting osteoclastic resorption, tartrate-resistant acid phosphatase [TRACP]. Formation-specific bone turnover markers embrace different osteoblastic activities: type 1 collagen synthesis (Procollagen type I N- propeptide [PINP]), osteoblast enzymes (bone-specific alkaline phosphatase [BALP]), or bone matrix proteins [osteocalcin]. Among individuals not receiving osteoporosis treatment, resorption and formation markers are tightly linked and highly correlated (r = 0.6-0.8). Significant biological variability was reported in the past, but these issues have been greatly improved with automated assays and attention to pre-analytical and analytical factors that are known to influence bone turnover marker levels. Bone turnover markers are not useful in the diagnosis of osteoporosis, the individual prediction of bone loss, fracture, or rare complications, or in the selection of pharmacological treatment. Despite remaining issues with reference intervals and assays harmonization, bone turnover markers have proven to be useful in elucidating the pharmacodynamics and effectiveness of osteoporosis medications in clinical trials. As an alternative to BMD testing, BTMs may be useful to monitor osteoporosis therapies.

Cost-effectiveness of romosozumab for the treatment of postmenopausal women at very high risk of fracture in Canada.

This study evaluated the cost-effectiveness of 1 year of romosozumab followed by alendronate versus oral bisphosphonates alone in women with postmenopausal osteoporosis at very high risk for fracture in Canada. Results showed that romosozumab sequenced to alendronate is a cost-effective treatment option, dominating both alendronate and risedronate alone. PURPOSE: To demonstrate the value of romosozumab sequenced to alendronate compared to alendronate or risedronate alone, for the treatment of osteoporosis in postmenopausal women with a history of osteoporotic fracture and who are at very high risk for future fracture in Canada. METHODS: A Markov model followed a hypothetical cohort of postmenopausal osteoporotic women at very high risk for future fractures, to estimate the cost-effectiveness of romosozumab and alendronate compared to oral bisphosphonates alone. A total treatment period of 5 years was assumed. Quality-adjusted life years and costs were estimated for each comparator across health states defined by different types of fragility fractures. RESULTS: Romosozumab/alendronate was associated with a lifetime gain of 0.103 and 0.127 QALYs and a cost reduction of $343 and $3805, relative to alendronate and risedronate, respectively. These results were driven by a reduction of the number of fractures (2561 per 1000 patients, versus 2700 for alendronate and 2724 for risedronate over lifetime). Romosozumab/alendronate had the highest probability of being cost-effective, relative to alendronate and risedronate, at any willingness to pay threshold value. CONCLUSION: Romosozumab/alendronate was associated with reduced costs and greater benefit relative to other comparators. Probabilistic, deterministic, and scenario analyses indicate that romosozumab/alendronate represents the best value for money; the uncertainty analyses are robust, and therefore romosozumab should be considered for reimbursement by public drug plans in Canada .

Attenuated clinical and osteoclastic phenotypes of Paget's disease of bone linked to the p.Pro392Leu/SQSTM1 mutation by a rare variant in the DOCK6 gene.

BACKGROUND: We identified two families with Paget's disease of bone (PDB) linked to the p.Pro392Leu mutation within the SQSTM1 gene displaying a possible digenism. This study aimed at identifying this second genetic variant cosegregating with the p.Pro392Leu mutation and at characterizing its impact on the clinical and cellular phenotypes of PDB. METHODS: Whole exome sequencing was performed in one patient per family and two healthy controls. We compared clinical characteristics of PDB in 14 relatives from the two families. The osteoclastic phenotype was compared in in vitro differentiated osteoclasts from 31 participants carrying the DOCK6 and/or SQSTM1 variants. Tridimensional models of SQSTM1 and DOCK6 proteins were generated to evaluate the impact of these variants on their stability and flexibility. Statistical analyses were performed with Graphpad prism. RESULTS: Whole-exome sequencing allowed us to identify the p.Val45Ile missense variant in the DOCK6 gene in patients. In both families, the mean age at PDB diagnosis was delayed in pagetic patients carrier of the p.Val45Ile variant alone compared to those carrying the p.Pro392Leu mutation alone (67 vs. 44 years, P = 0.03). Although both p.Val45Ile and p.Pro392Leu variants gave rise to a pagetic phenotype of osteoclast versus healthy controls, the p.Val45Ile variant was found to attenuate the severity of the osteoclastic phenotype of PDB caused by the p.Pro392Leu mutation when both variants were present. The DOCK6 mRNA expression was higher in carriers of the p.Val45Ile variant than in pagetic patients without any mutations and healthy controls. Structural bioinformatics analyses suggested that the p.Pro392Leu mutation might rigidify the UBA domain and thus decrease its possible intramolecular interaction with a novel domain, the serum response factor-transcription factor (SRF-TF)-like domain, whereas the p.Val45Ile variant may decrease SRF-TF-like activity. CONCLUSION: The p.Val45Ile variant may attenuate the severity of the clinical phenotype of PDB in patient carriers of both variants. In vitro, the rare variant of the DOCK6 may have a modifier effect on the p.Pro392Leu mutation, possibly via its effect on the SRF-TF-like.

Bone Mineral and Organic Properties in Postmenopausal Women Treated With Denosumab for Up to 10 years.

In postmenopausal women with osteoporosis, denosumab (DMAb) therapy through 10 years resulted in significantly higher degree of mineralization of bone, with a subsequent increase from years 2-3 to year 5 and no further difference between years 5 and 10. Our aim was to assess the variables reflecting the quality of bone mineral and organic matrix (Fourier transform infrared microspectroscopy), and the microhardness of bone (Vickers microindentation). Cross-sectional assessments were performed in blinded fashion on iliac bone biopsies from osteoporotic women (72 from FREEDOM trial, 49 from FREEDOM Extension trial), separately in cortical and cancellous compartments. After 2-3 years of DMAb, mineral/matrix ratio and microhardness of cortical bone were significantly higher compared with placebo, whereas mineral maturity, mineral crystallinity, mineral carbonation, and collagen maturity were not different in both bone compartments. Through 5 years of DMAb, mineral carbonation was significantly lower and mineral/matrix ratio, mineral maturity, and crystallinity were significantly higher versus 2-3 years and were not different between 5 and 10 years, with the exception of mineral maturity in cancellous bone. These data support a transition of mineral to more mature crystals (within physiological range) and the completeness of secondary mineralization within 5 years of DMAb treatment. Microhardness in cortical and cancellous compartments was significantly lower at 5 years of DMAb versus 2-3 years and was not different from years 5 to 10. The lower microhardness at years 5 and 10 is likely the result of maturation of the organic matrix in a persistently low state of bone remodeling over 5 and 10 years. © 2022 American Society for Bone and Mineral Research (ASBMR).

Modeling-Based Bone Formation After 2 Months of Romosozumab Treatment: Results From the FRAME Clinical Trial.

The bone-forming agent romosozumab is a monoclonal antibody that inhibits sclerostin, leading to increased bone formation and decreased resorption. The highest levels of bone formation markers in human patients are observed in the first 2 months of treatment. Histomorphometric analysis of bone biopsies from the phase 3 FRAME trial (NCT01575834) showed an early significant increase in bone formation with concomitant decreased resorption. Preclinical studies demonstrated that most new bone formation after romosozumab treatment was modeling-based bone formation (MBBF). Here we analyzed bone biopsies from FRAME to assess the effect of 2 months of romosozumab versus placebo on the surface extent of MBBF and remodeling-based bone formation (RBBF). In FRAME, postmenopausal women aged ≥55 years with osteoporosis were randomized 1:1 to 210 mg romosozumab or placebo sc every month for 12 months, followed by 60 mg denosumab sc every 6 months for 12 months. Participants in the bone biopsy substudy received quadruple tetracycline labeling and underwent transiliac biopsies at month 2. A total of 29 biopsies were suitable for histomorphometry. Using fluorescence microscopy, bone formation at cancellous, endocortical, and periosteal envelopes was classified based on the appearance of underlying cement lines as modeling (smooth) or remodeling (scalloped). Data were compared using the Wilcoxon rank-sum test, without multiplicity adjustment. After 2 months, the median percentage of MBBF referent to the total bone surface was significantly increased with romosozumab versus placebo on cancellous (18.0% versus 3.8%; p = 0.005) and endocortical (36.7% versus 3.0%; p = 0.001), but not on periosteal (5.0% versus 2.0%; p = 0.37) surfaces, with no significant difference in the surface extent of RBBF on all three bone surfaces. These data show that stimulation of bone formation in the first 2 months of romosozumab treatment in postmenopausal women with osteoporosis is predominately due to increased MBBF on endocortical and cancellous surfaces. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Hip fracture predicts subsequent hip fracture: a retrospective observational study to support a call to early hip fracture prevention efforts in post-fracture patients.

In this real-world retrospective cohort, subsequent hip fracture occurred in one in four patients with any initial fracture, most often after hip fracture, on average within 1.5 years. These data support the need for early post-fracture interventions to help reduce imminent hip fracture risk and high societal and humanistic costs. PURPOSE: This large retrospective cohort study aimed to provide hip fracture data, in the context of other fractures, to help inform efforts related to hip fracture prevention focusing on post-fracture patients. METHODS: A cohort of 115,776 patients (72.3% female) aged > 65 (median age 81) with an index fracture occurring at skeletal sites related to age-related bone loss between January 1, 2011, and March 31, 2015, was identified using health services data from Ontario, Canada, and followed until March 31, 2017. RESULTS: Hip fracture was the most common second fracture (27.8%), occurring in ≥ 19% of cases after each index fracture site and most frequently (33.0%) after hip index fracture. Median time to a second fracture of the hip was ~ 1.5 years post-index event. Patients with index hip fracture contributed the most to fracture-related initial surgeries (64.1%) and post-surgery complications (71.9%) and had the second-highest total mean healthcare cost per patient in the first year after index fracture ($62,793 ± 44,438). One-year mortality (any cause) after index hip fracture was 26.2% vs. 15.9% in the entire cohort, and 25.9% after second hip fracture. CONCLUSION: A second fracture at the hip was observed in one in four patients after any index fracture and in one in three patients with an index hip fracture, on average within 1.5 years. Index hip fracture was associated with high mortality and post-surgery complication rates and healthcare costs relative to other fractures. These data support focusing on early hip fracture prevention efforts in post-fracture patients.

Romosozumab Enhances Vertebral Bone Structure in Women With Low Bone Density.

Romosozumab monoclonal antibody treatment works by binding sclerostin and causing rapid stimulation of bone formation while decreasing bone resorption. The location and local magnitude of vertebral bone accrual by romosozumab and how it compares to teriparatide remains to be investigated. Here we analyzed the data from a study collecting lumbar computed tomography (CT) spine scans at enrollment and 12 months post-treatment with romosozumab (210 mg sc monthly, n = 17), open-label daily teriparatide (20 µg sc, n = 19), or placebo (sc monthly, n = 20). For each of the 56 women, cortical thickness (Ct.Th), endocortical thickness (Ec.Th), cortical bone mineral density (Ct.bone mineral density (BMD)), cancellous BMD (Cn.BMD), and cortical mass surface density (CMSD) were measured across the first lumbar vertebral surface. In addition, color maps of the changes in the lumbar vertebrae structure were statistically analyzed and then visualized on the bone surface. At 12 months, romosozumab improved all parameters significantly over placebo and resulted in a mean vertebral Ct.Th increase of 10.3% versus 4.3% for teriparatide, an Ec.Th increase of 137.6% versus 47.5% for teriparatide, a Ct.BMD increase of 2.1% versus a -0.1% decrease for teriparatide, and a CMSD increase of 12.4% versus 3.8% for teriparatide. For all these measurements, the differences between romosozumab and teriparatide were statistically significant (p < 0.05). There was no significant difference between the romosozumab-associated Cn.BMD gains of 22.2% versus 18.1% for teriparatide, but both were significantly greater compared with the change in the placebo group (-4.6%, p < 0.05). Cortical maps showed the topographical locations of the increase in bone in fracture-prone areas of the vertebral shell, walls, and endplates. This study confirms widespread vertebral bone accrual with romosozumab or teriparatide treatment and provides new insights into how the rapid prevention of vertebral fractures is achieved in women with osteoporosis using these anabolic agents. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Prediction of Osteoporotic Fractures in Elderly Individuals: A Derivation and Internal Validation Study Using Healthcare Administrative Data.

In Canada and other countries, osteoporosis is monitored as part of chronic disease population surveillance programs. Although fractures are the principal manifestation of osteoporosis, very few algorithms are available to identify individuals at high risk of osteoporotic fractures in current surveillance systems. The objective of this study was to derive and validate predictive models to accurately identify individuals at high risk of osteoporotic fracture using information available in healthcare administrative data. More than 270,000 men and women aged ≥66 years were randomly selected from the Quebec Integrated Chronic Disease Surveillance System. Selected individuals were followed between fiscal years 2006-2007 and 2015-2016. Models were constructed for prediction of hip/femur and major osteoporotic fractures for follow-up periods of 5 and 10 years. A total of 62 potential predictors measurable in healthcare administrative databases were identified. Predictor selection was performed using a manual backward algorithm. The predictive performance of the final models was assessed using measures of discrimination, calibration, and overall performance. Between 20 and 25 predictors were retained in the final prediction models (eg, age, sex, social deprivation index, most of the major and minor risk factors for osteoporosis, diabetes, Parkinson's disease, cognitive impairment, anemia, anxio-depressive disorders). Discrimination of the final models was higher for the prediction of hip/femur fracture than major osteoporotic fracture and higher for prediction for a 5-year than a 10-year period (hip/femur fracture for 5 years: c-index = 0.77; major osteoporotic fracture for 5 years: c-index = 0.71; hip/femur fracture for 10 years: c-index = 0.73; major osteoporotic fracture for 10 years: c-index = 0.68). The predicted probabilities globally agreed with the observed probabilities. In conclusion, the derived models had adequate predictive performance in internal validation. As a final step, these models should be validated in an external cohort and used to develop indicators for surveillance of osteoporosis. © 2021 American Society for Bone and Mineral Research (ASBMR).

Skeletal responses to romosozumab after 12 months of denosumab.

Romosozumab, a monoclonal anti-sclerostin antibody that has the dual effect of increasing bone formation and decreasing bone resorption, reduces fracture risk within 12 months. In a post hoc, exploratory analysis, we evaluated the effects of romosozumab after 12 months of denosumab in postmenopausal women with low bone mass who had not received previous osteoporosis therapy. This phase 2 trial (NCT00896532) enrolled postmenopausal women with a lumbar spine, total hip, or femoral neck T-score ≤ -2.0 and ≥ -3.5. Individuals were randomized to placebo or various romosozumab dosing regimens from baseline to month 24, were re-randomized to 12 months of denosumab or placebo (months 24-36), and then all received romosozumab 210 mg monthly for 12 months (months 36-48). Results for the overall population have been previously published. Here, we present results for changes in bone mineral density (BMD) and levels of procollagen type I N-terminal propeptide (P1NP) and ß-isomer of the C-terminal telopeptide of type I collagen (ß-CTX) from a subset of women who were randomized to placebo for 24 months, were re-randomized to receive denosumab (n = 16) or placebo (n = 12) for 12 months, and then received romosozumab for 12 months. In women who were randomized to placebo followed by denosumab, romosozumab treatment for 12 months maintained BMD gained during denosumab treatment at the total hip (mean change from end of denosumab treatment of 0.9%) and further increased BMD gains at the lumbar spine (mean change from end of denosumab treatment of 5.3%). Upon transition to romosozumab (months 36-48), P1NP and ß-CTX levels gradually returned to baseline from their reduced values during denosumab administration. Transitioning to romosozumab after 12 months of denosumab appears to improve lumbar spine BMD and maintain total hip BMD while possibly preventing the rapid increase in levels of bone turnover markers above baseline expected upon denosumab discontinuation. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Romosozumab improves lumbar spine bone mass and bone strength parameters relative to alendronate in postmenopausal women: results from the Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial.

The Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial (NCT01631214; https://clinicaltrials.gov/ct2/show/NCT01631214) showed that romosozumab for 1 year followed by alendronate led to larger areal bone mineral density (aBMD) gains and superior fracture risk reduction versus alendronate alone. aBMD correlates with bone strength but does not capture all determinants of bone strength that might be differentially affected by various osteoporosis therapeutic agents. We therefore used quantitative computed tomography (QCT) and finite element analysis (FEA) to assess changes in lumbar spine volumetric bone mineral density (vBMD), bone volume, bone mineral content (BMC), and bone strength with romosozumab versus alendronate in a subset of ARCH patients. In ARCH, 4093 postmenopausal women with severe osteoporosis received monthly romosozumab 210 mg sc or weekly oral alendronate 70 mg for 12 months, followed by open-label weekly oral alendronate 70 mg for ≥12 months. Of these, 90 (49 romosozumab, 41 alendronate) enrolled in the QCT/FEA imaging substudy. QCT scans at baseline and at months 6, 12, and 24 were assessed to determine changes in integral (total), cortical, and trabecular lumbar spine vBMD and corresponding bone strength by FEA. Additional outcomes assessed include changes in aBMD, bone volume, and BMC. Romosozumab caused greater gains in lumbar spine integral, cortical, and trabecular vBMD and BMC than alendronate at months 6 and 12, with the greater gains maintained upon transition to alendronate through month 24. These improvements were accompanied by significantly greater increases in FEA bone strength (p < 0.001 at all time points). Most newly formed bone was accrued in the cortical compartment, with romosozumab showing larger absolute BMC gains than alendronate (p < 0.001 at all time points). In conclusion, romosozumab significantly improved bone mass and bone strength parameters at the lumbar spine compared with alendronate. These results are consistent with greater vertebral fracture risk reduction observed with romosozumab versus alendronate in ARCH and provide insights into structural determinants of this differential treatment effect. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Long-Term Treatment of Postmenopausal Osteoporosis.

Osteoporosis is an incurable chronic condition, like heart disease, diabetes, or hypertension. A large gap currently exists in the primary prevention of fractures, and studies show that an estimated 80% to 90% of adults do not receive appropriate osteoporosis management even in the secondary prevention setting. Case finding strategies have been developed and effective pharmacological interventions are available. This publication addresses how best to use the pharmacological options available for postmenopausal osteoporosis to provide lifelong fracture protection in patients at high and very high risk of fracture. The benefit of osteoporosis therapies far outweighs the rare risks.

Fragility fracture identifies patients at imminent risk for subsequent fracture: real-world retrospective database study in Ontario, Canada.

BACKGROUND: The secondary fracture prevention gap in the osteoporosis field has been previously described as a 'crisis'. Closing this gap is increasingly important in the context of accumulating evidence showing that an incident fragility fracture is associated with an increased risk of subsequent fracture within 1-2 years, known as imminent fracture risk. The objective of this study was to use health services data to characterize the time between index fragility fractures occurring at different osteoporotic sites and subsequent fractures. METHODS: This retrospective observational study used de-identified health services data from the publicly funded healthcare system in Ontario, the largest province of Canada. Patients aged > 65 with an index fragility fracture occurring between 2011 and 2015 were identified from the ICES Data Repository using International Classification of Diseases (ICD)-10 codes. We examined median time to subsequent fragility fractures for osteoporotic fracture sites until the end of follow-up (2017). BMD assessment and use of osteoporosis therapies following index fracture were also characterized. RESULTS: Among 115,776 patients with an index fragility fracture, 17.8% incurred a second fragility fracture. Median time between index and second fracture occurring at any site was 555 days (interquartile range: 236-955). For each index fracture site examined, median time from index to second fracture was < 2 years. The proportion of patients with BMD assessment was 10.3% ≤1 year prior to and 16.4% ≤1 year post index fracture. The proportion of patients receiving osteoporosis therapy was 29.8% ≤1 year prior, 34.6% ≤1 year post, and 25.9% > 3 years post index fracture. CONCLUSIONS: This cohort of Canadian patients aged > 65 years who experienced a fragility fracture at any site are at imminent risk of experiencing subsequent fracture within the next 2 years and should be proactively assessed and treated.

Duration-Dependent Increase of Human Bone Matrix Mineralization in Long-Term Bisphosphonate Users with Atypical Femur Fracture.

Bisphosphonates (BPs) are the most widely used drugs for the treatment of osteoporosis but prolonged use of BPs might increase the risk of atypical femur fracture (AFF). There are only a few studies that address the bone material quality in patients on long-term BP treatment with or without AFFs. We analyzed 52 trans-iliac bone biopsies from patients on long-term BP therapy with (n = 26) and without (n = 26) AFF. At the microscopic level, the degree of mineralization of bone (DMB) was assessed on whole bone by X-ray digitized microradiography while microhardness by Vickers microindentation, and bone matrix characteristics by Fourier transform infrared microspectroscopy (FTIRM) (mineral/organic ratio, mineral maturity and crystallinity, and collagen maturity) were measured at random focal areas. The AFF patients were treated longer than non-AFF patients (9.7 ± 3.3 years versus 7.9 ± 2.7 years). As expected, bone remodeling was low in both groups, without difference between them. The AFF group had significantly higher DMB in cortical bone (+2.9%, p = .001), which remained so after adjusting for treatment duration (p = .007), and showed a trend in cancellous bone (+1.6%, p = .05). Consistent with higher DMB, heterogeneity index (HI) was lower in the AFF than in the non-AFF group, illustrating lower heterogeneity of mineralization in the AFF group. A significant positive correlation between the duration of treatment and DMB in cortical bone was found in AFF, and not in the non-AFF group. Microhardness and bone matrix characteristics were similar between groups. We conclude that the AFF group had a duration-dependent increase in DMB leading to a significantly higher DMB than the non-AFF. Because BPs have high affinity to bone mineral and lining the walls of the osteocyte lacunae, the accumulation of matrix-bound BPs in AFF could lead to inhibition of the osteocyte cytoskeleton blunting their response to mechanical strains, a hypothesis to be further investigated. © 2021 American Society for Bone and Mineral Research (ASBMR).

Mortality in older adults following a fragility fracture: real-world retrospective matched-cohort study in Ontario.

BACKGROUND: Recent studies are lacking reports on mortality after non-hip fractures in adults aged > 65. METHODS: This retrospective, matched-cohort study used de-identified health services data from the publicly funded healthcare system in Ontario, Canada, contained in the ICES Data Repository. Patients aged 66 years and older with an index fragility fracture occurring at any osteoporotic site between 2011 and 2015 were identified from acute hospital admissions, emergency and ambulatory care using International Classification of Diseases (ICD)-10 codes and data were analyzed until 2017. Thus, follow-up ranged from 2 years to 6 years. Patients were excluded if they presented with an index fracture occurring at a non-osteoporotic fracture site, their index fracture was associated with a trauma code, or they experienced a previous fracture within 5 years prior to their index fracture. This fracture cohort was matched 1:1 to controls within a non-fracture cohort by date, sex, age, geography and comorbidities. All-cause mortality risk was assessed. RESULTS: The survival probability for up to 6 years post-fracture was significantly reduced for the fracture cohort vs matched non-fracture controls (p < 0.0001; n = 101,773 per cohort), with the sharpest decline occurring within the first-year post-fracture. Crude relative risk of mortality (95% confidence interval) within 1-year post-fracture was 2.47 (2.38-2.56) in women and 3.22 (3.06-3.40) in men. In the fracture vs non-fracture cohort, the absolute mortality risk within one year after a fragility fracture occurring at any site was 12.5% vs 5.1% in women and 19.5% vs 6.0% in men. The absolute mortality risk within one year after a fragility fracture occurring at a non-hip vs hip site was 9.4% vs 21.5% in women and 14.4% vs 32.3% in men. CONCLUSIONS: In this real-world cohort aged > 65 years, a fragility fracture occurring at any site was associated with reduced survival for up to 6 years post-fracture. The greatest reduction in survival occurred within the first-year post-fracture, where mortality risk more than doubled and deaths were observed in 1 in 11 women and 1 in 7 men following a non-hip fracture and in 1 in 5 women and 1 in 3 men following a hip fracture.