Zoledronic acid for hip fracture during initial hospitalization.

Inpatient zoledronic acid (IP-ZA) administered during the initial fracture hospitalization significantly improves the osteoporosis treatment rate. Clinical outcomes of IP-ZA after hip fracture remains uncertain. Here we report a new-user active comparator cohort study that emulated a randomized controlled trial using real-world data and evaluated the risk of death of any cause and radiologically confirmed subsequent new fractures among patients hospitalized for a hip fracture who had received IP-ZA as compared with propensity-matched controls who were not treated with anti-osteoporosis medication within the first-year post fracture. 654 patients who had received IP-ZA and 6877 controls (for whom antiosteoporosis treatment was indicated but no IP-ZA started during index hospitalization) were included in the study. The primary cohort comprised 652 IP-ZA patients (IP-ZA group) and 1926 matched controls (Untreated group) with 71.7% female, 92.1% White, and mean age of 80.9 years. Cumulative all-cause-mortality over the 24 months follow-up for the IP-ZA group was 12.3%, and 20.7% for Untreated group [hazard ratio (HR), 0.62; 95% confidence interval (CI), 0.49-0.78, p < 0.001)]. 585 (89.7%) patients in IP-ZA group received only a single dose of ZA during the 24 months, and the death rate of this single dose group was 13.3%, which was significantly lower than that of the Untreated group (HR, 0.70; 95% CI, 0.55-0.89, p = 0.003). Rates of radiologically confirmed cumulative subsequent new vertebral fractures were 2.0% in IP-ZA group and 5.4% in Untreated group (HR, 0.40; 95% CI, 0.22-0.71, P = 0.001). A similarly lower rate of new vertebral fractures was seen in the single dose subgroup (1.9% vs. 5.4%. HR, 0.44; 95% 0.24-0.82, p = 0.008). IP-ZA, administered during the initial hospitalization for hip fracture, was associated with lower all-cause-mortality and risk of radiologically confirmed subsequent new vertebral fractures, and thus offers a mechanism to narrow the treatment gap in patients having sustained a hip fragility fracture.

Hip fracture is a serious complication of osteoporosis affecting approximately 300 000 Americans per year and is associated with a 20-30% one-year mortality rate. Most patients with hip fracture are elderly (average age 80-81 years), with multiple underlying medical conditions and are often unable to timely attend post-hospitalization outpatient follow-up to initiate anti-osteoporosis treatment. As a result, only ~10% of post-hip fracture patients receive treatment for underlying osteoporosis. We have previously reported that zoledronic acid (ZA) administered during initial fracture hospitalization (IP-ZA) is safe and can effectively improve the osteoporosis treatment rate to 70%. The present study analyzed the clinical outcomes of 652 patients who had sustained hip fractures and were treated with IP-ZA and 1926 matched controls and revealed significantly reduced rates of all-cause mortality and vertebral compression fracture (VCF) during a 2-year follow-up period. Of note, nearly 90% of the treated patients received only a single dose of ZA (namely, IP-ZA), suggesting that, for most patients, the only opportunity to receive anti-osteoporosis treatment was during the index fracture hospitalization. Importantly, reduced mortality and VCF rates were readily seen in this single-dose group of patients. Our data suggests that IP-ZA is beneficial for osteoporotic hip fracture.

A Fracture Liaison Service to Address Vitamin D Deficiency for Patients Hospitalized for Osteoporotic Fracture.

Context: Addressing vitamin D deficiency (VDD) is important for fracture secondary prevention. Objectives: To explore the function of a fracture liaison service (FLS) to address VDD. Design Setting and Patients: An observational study of patients admitted to the Massachusetts General Hospital with fractures between January 1, 2016, and October 31, 2023, cared for by the FLS. Intervention: Ergocalciferol 50 000 international units (50ku-D2) oral daily for 3 to 7 days. Main Outcomes Measures: VDD prevalence. Efficacy of inpatient daily 50ku-D2 in raising serum 25-hydroxyvitamin D (25OHD) levels. Results: Of the 2951 consecutive patients, 724 (24.53%) had VDD (defined by 25OHD ≤ 19 ng/mL). Men (252/897, or 28.09%) were more likely than women (472/2054, or 22.98%) to have VDD (P = .003). VDD was seen in 41.79% (117/280), 24.41% (332/1360), and 20.98% (275/1311) of patients of aged ≤59, 60 to 79, and ≥80 years, respectively (P < .00001). Of the 1303 patients with hip fractures, 327 (25.09%) had VDD, which was associated with a longer length of stay (8.37 ± 7.35 vs 7.23 ± 4.78 days, P = .009) and higher trend of 30-day-readmission rate (13.63% vs 18.35%, P = .037). In a cohort of 32 patients with complete data, each dose of 50ku-D2 increased serum 25OHD by 3.62 ± 2.35 ng/mL without affecting serum calcium or creatinine levels. Conclusion: VDD was seen in nearly 25% of Massachusetts General Hospital FLS patients and more prevalent in male and younger patients. VDD was associated with longer length of stay and higher 30-day-readmission risk in patients with hip fracture. Daily 50ku-D2 appeared to be a practical way to quickly replete vitamin D in the inpatient setting.

Treatment Sequence for Osteoporosis.

BACKGROUND: Osteoporosis is a chronic progressive disease that requires lifelong monitoring and treatment. Sequencing from one treatment to another at different ages and stages of disease is an approach that can maximize benefits and avoid potential risks from long-term treatment with a single agent. OBJECTIVE: This article reviews clinical trial data in postmenopausal women that evaluate the effects of antiresorptive agents followed by other antiresorptives, osteoanabolic agents followed by antiresorptives, and antiresorptives followed by osteoanabolic medications. METHODS: Literature review and discussion. RESULTS: When medications are discontinued, in the absence of sequential therapy, bone turnover rates return to baseline or above baseline, and bone loss occurs. The rate of bone loss differs for different treatments, with a very slow decline after stopping bisphosphonates and a particularly rapid decline after stopping denosumab. Careful attention to osteoporosis medication transitions can mitigate bone density loss and its consequences. For women who remain at high risk, switching from bisphosphonates to the more potent antiresorptive, denosumab, will result in further improvement in bone mineral density (BMD). When indicated, stopping denosumab can be accomplished safely by transition to an adequate bisphosphonate regimen. For high- and very-high-risk patients, treating with osteoanabolic agents first, followed by antiresorptive agents, produces substantially larger BMD gains than the reverse treatment sequence, with the biggest differences seen for BMD of the hip. CONCLUSION: Awareness of the importance of treatment sequences can help improve osteoporosis care across the postmenopausal lifespan.

The comparison of alendronate and raloxifene after denosumab (CARD) study: A comparative efficacy trial.

Denosumab discontinuation results in accelerated bone remodeling, decreased bone mineral density (BMD), and an increased risk of multiple vertebral fractures. Bisphosphonates are at least partially effective at inhibiting these consequences but there have been no randomized clinical trials assessing the efficacy of alternative antiresorptives. PURPOSE: The aim of this study was to evaluate the comparative efficacy of alendronate and the SERM, raloxifene, in preventing the post-denosumab high-turnover bone loss. METHODS: We conducted an open-label randomized controlled trial in which 51 postmenopausal women at increased risk of fracture were randomized with equal probability to receive 12-months of denosumab 60-mg 6-monthly followed by 12-months of either alendronate 70-mg weekly or raloxifene 60-mg daily. Serum bone remodeling markers were measured at 0,6,12,15,18, and 24 and areal BMD of the distal radius, spine, and hip were measured at 0,12,18 and 24 months. RESULTS: After denosumab discontinuation, serum markers of bone remodeling remained suppressed when followed by alendronate, but gradually increased to baseline when followed by raloxifene. In the denosumab-to-alendronate group, denosumab-induced BMD gains were maintained at all sites whereas in the denosumab-to-raloxifene group, BMD decreased at the spine by 2.0% (95% CI -3.2 to -0.8, P = 0.003) and at the total hip by 1.2% (-2.1 to -0.4%, P = 0.008), but remained stable at the femoral neck and distal radius and above the original baseline at all sites. The decreases in spine and total hip BMD in the denosumab-to-raloxifene group (but not the femoral neck or distal radius) were significant when compared to the denosumab-to-alendronate group. CONCLUSIONS: These results suggest that after one year of denosumab, one year of alendronate is better able to maintain the inhibition of bone remodeling and BMD gains than raloxifene.

Sequential Therapy for the Long-Term Treatment of Postmenopausal Osteoporosis.

Osteoporosis is a chronic condition characterized by decreased bone mass, loss of skeletal integrity, and increased susceptibility to fracture. Drugs used to treat osteoporosis can be classified as those that block bone resorption (antiresorptive), stimulate bone formation (anabolic), or do both. While all currently approved medications reduce the risk of fragility fractures in high-risk populations, they are generally unable to fully restore bone strength in most patients with established disease. Thus, the majority of patients require disease management over many years. Unfortunately, the continuous use of a single drug has limitations, both in terms of efficacy and safety, and so sequential therapy is commonly required. Given the expanding list of pharmacological agents currently available, careful consideration needs to be given as to which drugs to use and in what sequence. This review will evaluate the differential effects of antiresorptive, bone-forming, and dual-acting drugs when used in specific sequences and will explore the current evidence favoring the initial use of bone-forming/dual-acting drugs followed by antiresorptive medications. This review will also examine the notion that long-term treatment with an antiresorptive drug may diminish the efficacy of subsequent treatment with a bone-forming/dual-acting drug. Finally, this review will explore the current evidence pertaining to the specific issue of how to best prevent the clinical ramifications of denosumab cessation.

Safety of Inpatient Zoledronic Acid in the Immediate Postfracture Setting.

CONTEXT: Zoledronic acid (ZA) administered during the initial hospitalization for a fragility fracture improves the osteoporosis pharmacotherapy rate. Distinguishing the safety profile of inpatient ZA (IP-ZA) in this context is crucial if this approach is to be widely adopted. OBJECTIVE: To study the acute safety profile of IP-ZA. METHODS: An observational study of patients admitted to the Massachusetts General Hospital with fragility fractures who were eligible to receive IP-ZA. Patients were treated with or without IP-ZA. Acetaminophen, either as a single pre-ZA dose or standing multiple-doses-per-day regimen for 48 hours or longer after ZA infusion, was also administered along with protocolized vitamin D and calcium supplementation. Changes in body temperature, serum creatinine, and serum calcium were measured. RESULTS: A total of 285 consecutive patients, meeting inclusion and exclusion criteria, are included in this analysis; 204 patients received IP-ZA. IP-ZA treatment was associated with a transient mean rise of body temperature of 0.31 °C on the day following its administration. Temperatures above 38 °C were seen in 15% of patients in the IP-ZA group and 4% in the nontreated group. Standing multiple-doses-per-day but not a single pre-ZA dose of acetaminophen effectively prevented this temperature increase. IP-ZA did not affect serum creatinine levels. Mean levels of serum total calcium and albumin-corrected calcium decreased by 0.54 mg/dL and 0.40 mg/dL, respectively, at their nadirs (Day 5). No patient experienced symptomatic hypocalcemia. CONCLUSION: IP-ZA along with standing multiple-doses-per-day acetaminophen, administered to patients in the immediate postfracture period, is not associated with significant acute adverse effects.

The Effect of Zoledronic Acid on Bone Microarchitecture and Strength after Denosumab and Teriparatide Administration: DATA-HD Study Extension.

The combination of denosumab and teriparatide is an effective treatment strategy in postmenopausal osteoporosis, though skeletal gains are promptly lost when these agents are discontinued. In the DATA-HD study, we reported that a single dose of zoledronic acid (ZOL) maintains the increases in areal spine and hip bone mineral density (BMD) achieved with this combination for at least 12 months. The capacity of ZOL to maintain corresponding improvements in peripheral volumetric BMD and microarchitecture, however, has not been reported. In the 15-month DATA-HD study, 76 postmenopausal osteoporotic women were randomized to receive 9 months of teriparatide (20-µg or 40-µg daily) overlapped with denosumab (60 mg at months 3 and 9). In the Extension study, 53 participants received a single dose of ZOL (5 mg intravenously) 24-35 weeks after the last denosumab dose. We measured volumetric BMD and microarchitecture at the distal radius and tibia using high-resolution peripheral quantitative computed tomography at months 27 and 42. Despite ZOL administration, total and cortical BMD gradually decreased over 27 months resulting in values similar to baseline at the radius but still significantly above baseline at the tibia. At both sites, cortical porosity decreased to values below pretreatment baseline at month 27 but then increased from month 27 to 42. There were no significant changes in trabecular parameters throughout the 27-month post-ZOL observation period. Stiffness and failure load, at both sites, decreased progressively from month 15 42 though remained above baseline at the tibia. These findings suggest that in contrast to the largely maintained gains in dual-energy X-ray absorptiometry (DXA)-derived spine and hip BMD, a single dose of ZOL was not as effective in maintaining the gains in volumetric peripheral bone density and microarchitecture produced by 15 months of overlapping treatment with denosumab and teriparatide. Alternative therapeutic approaches that can fully maintain improvements in peripheral bone parameters require further study. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Inpatient Zoledronic Acid and Integrated Orthopedic and Fracture Liaison Services Improve Osteoporosis Treatment Rates.

CONTEXT: Fragility fractures increase risks for future fractures, morbidity, and mortality. Available pharmacotherapy for underlying osteoporosis is safe and effective but underused. OBJECTIVE: To improve pharmacotherapy rate representing secondary prevention of osteoporotic fractures. METHODS: This single-center, observational, follow-up study included patients with fragility fractures admitted to the Massachusetts General Hospital between February 2016 and December 2019. For patients admitted to the orthopedics service with fragility fracture, the Massachusetts General Hospital Fracture Liaison Service (FLS) was systematically consulted. Initial outpatient follow-up with FLS was established in conjunction with the orthopedic postoperative follow-up visit. Patients at risk for failing timely outpatient follow-up were administered zoledronic acid (ZA) during the index fracture hospitalization. The main outcome measures were percentage of patients with fragility fracture(s) started on pharmacotherapy for osteoporosis and average length of stay and 30-day readmission rate of patients treated with ZA. RESULTS: Compared with baseline (8-11%) and reference (5-20%) rates, integration of FLS to the orthopedics service, along with appropriate inpatient administration of ZA, increased the pharmacotherapy rate to 70% (412/589) among eligible patients with verified treatment status. Inpatient ZA administration neither affected the average length of stay nor 30-day readmission rate. Treatment status of 37.9% (471/1240) of the study patients remained unknown due to lack of or unknown follow-up. CONCLUSION: Integration of a FLS and orthopedics services along with inpatient ZA administration improved the osteoporosis pharmacotherapy rate among patients with fragility fracture(s) who often had obstacles for outpatient follow-up.

Romosozumab and antiresorptive treatment: the importance of treatment sequence.

To evaluate whether treatment sequence affects romosozumab response, this analysis reviewed studies where romosozumab was administered before or following an antiresorptive (alendronate or denosumab). Initial treatment with romosozumab followed by an antiresorptive resulted in larger increases in bone mineral density of both hip and spine compared with the reverse sequence. INTRODUCTION: Teriparatide followed by an antiresorptive increases bone mineral density (BMD) more than using an antiresorptive first. To evaluate whether treatment sequence affects romosozumab response, we reviewed randomized clinical trials where romosozumab was administered before (ARCH, FRAME) or following (STRUCTURE, Phase 2 extension) an antiresorptive (alendronate or denosumab, respectively). METHODS: We evaluated BMD percentage change for total hip (TH) and lumbar spine (LS) and response rates (BMD gains ≥ 3% and ≥ 6%) at years 1 and 2 (except STRUCTURE with only 1-year data available). RESULTS: With 1-year romosozumab initial therapy in ARCH and FRAME, TH BMD increased 6.2% and 6.0%, and LS BMD increased 13.7% and 13.1%, respectively. When romosozumab was administered for 1 year after alendronate (STRUCTURE) or denosumab (Phase 2 extension), TH BMD increased 2.9% and 0.9%, respectively, and LS BMD increased 9.8% and 5.3%, respectively. Over 2 years, TH and LS BMD increased 7.1% and 15.2% with romosozumab/alendronate, 8.5% and 16.6% with romosozumab/denosumab, and 3.8% and 11.5% with denosumab/romosozumab, respectively. A greater proportion of patients achieved BMD gains ≥ 6% when romosozumab was used first, particularly for TH, versus the reverse sequence (69% after romosozumab/denosumab; 15% after denosumab/romosozumab). CONCLUSION: In this study, larger mean BMD increases and greater BMD responder rates were achieved when romosozumab was used before, versus after, an antiresorptive agent. Since BMD on treatment is a strong surrogate for bone strength and fracture risk, this analysis supports the thesis that initial treatment with romosozumab followed by an antiresorptive will result in greater efficacy versus the reverse sequence.

Efficacy of Zoledronic Acid in Maintaining Areal and Volumetric Bone Density After Combined Denosumab and Teriparatide Administration: DATA-HD Study Extension.

Combined teriparatide and denosumab rapidly and substantially increases bone mineral density (BMD) at all anatomic sites. Discontinuation of denosumab however, results in high-turnover bone loss and increased fracture risk. The optimal way to prevent this bone loss remains undefined. This study is a preplanned extension of the DATA-HD study, where postmenopausal women with osteoporosis were randomized to receive 9 months of either 20 µg or 40 µg of teriparatide daily overlapping with denosumab (60 mg administered at months 3 and 9). At the completion of this 15-month study, women were invited to enroll in the DATA-HD Extension where they received a single dose of zoledronic acid (5 mg) 24 to 35 weeks after the last denosumab dose. Areal BMD and bone turnover markers were measured at month 27 and 42 (12 and 27 months after zoledronic acid, respectively) and spine and hip volumetric bone density by quantitative CT was measured at month 42. Fifty-three women enrolled in the DATA-HD Extension. At the femoral neck and total hip, the mean 5.6% and 5.1% gains in BMD achieved from month 0 to 15 were maintained both 12 and 27 months after zoledronic acid administration. At the spine, the mean 13.6% gain in BMD achieved from month 0 to 15 was maintained for the first 12 months but modestly decreased thereafter, resulting in a 3.0% reduction (95% CI, -4.0% to -2.0%, p < .0001) 27 months after zoledronic acid. The pattern of BMD changes between months 15 and 42 were qualitatively similar in the 20-µg and 40-µg groups. A single dose of zoledronic acid effectively maintains the large and rapid total hip and femoral neck BMD increases achieved with combination teriparatide/denosumab therapy for at least 27 months following the transition. Spine BMD was also largely, though not fully, maintained during this period. These data suggest that the DATA-HD Extension regimen may be an effective strategy in the long-term management of patients at high risk of fragility fracture. © 2021 American Society for Bone and Mineral Research (ASBMR).

Early Effects of Abaloparatide on Bone Formation and Resorption Indices in Postmenopausal Women With Osteoporosis.

Anabolic osteoporosis drugs improve bone mineral density by increasing bone formation. The objective of this study was to evaluate the early effects of abaloparatide on indices of bone formation and to assess the effect of abaloparatide on modeling-based formation (MBF), remodeling-based formation (RBF), and overflow MBF (oMBF) in transiliac bone biopsies. In this open-label, single-arm study, 23 postmenopausal women with osteoporosis were treated with 80 µg abaloparatide daily. Subjects received double fluorochrome labels before treatment and before biopsy collection at 3 months. Change in dynamic histomorphometry indices in four bone envelopes were assessed. Median mineralizing surface per unit of bone surface (MS/BS) increased to 24.7%, 48.7%, 21.4%, and 16.3% of total surface after 3 months of abaloparatide treatment, representing 5.5-, 5.2-, 2.8-, and 12.9-fold changes, on cancellous, endocortical, intracortical, and periosteal surfaces (p < .001 versus baseline for all). Mineral apposition rate (MAR) was significantly increased only on intracortical surfaces. Bone formation rate (BFR/BS) was significantly increased on all four bone envelopes. Significant increases versus baseline were observed in MBF on cancellous, endocortical, and periosteal surfaces, for oMBF on cancellous and endocortical surfaces, and for RBF on cancellous, endocortical, and intracortical surfaces. Overall, modeling-based formation (MBF + oMBF) accounted for 37% and 23% of the increase in bone-forming surface on the endocortical and cancellous surfaces, respectively. Changes from baseline in serum biomarkers of bone turnover at either month 1 or month 3 were generally good surrogates for changes in histomorphometric endpoints. In conclusion, treatment with abaloparatide for 3 months stimulated bone formation on cancellous, endocortical, intracortical, and periosteal envelopes in transiliac bone biopsies obtained from postmenopausal women with osteoporosis. These increases reflected stimulation of both remodeling- and modeling-based bone formation, further elucidating the mechanisms by which abaloparatide improves bone mass and lowers fracture risk. © 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).

Widespread disturbance in extracellular matrix collagen biomarker responses to teriparatide therapy in osteogenesis imperfecta.

Osteogenesis imperfecta (OI), a heritable disorder caused by abnormalities in synthesis or processing of type I collagen, is characterized by skeletal fragility. Type I collagen interacts with multiple components of the extracellular matrix (ECM) including other collagens types. Thus, alterations in structure or quantity may broadly affect ECM homeostasis. In fact, while OI is clinically categorized by severity of bone disease, patients can also present with extra-skeletal manifestations, including the pulmonary, muscle and cardiovascular systems. Parathyroid hormone (PTH) is a regulator of skeletal homeostasis but the receptor for PTH/PTH1R is expressed in a variety of other tissues. Given interactions between type I collagen with other collagens in the ECM and the potential for PTH action on tissues beyond the skeleton, we explored whether serum levels of non-type I collagens are altered in response to teriparatide (human parathyroid hormone 1-34). We measured biomarkers of collagens II, III, IV, V, and VI in serum from individuals with type I and types III/IV OI in response to an 18 month course of teriparatide or placebo. These results were compared to similar biomarker measures in postmenopausal (PM) women without OI treated with teriparatide. In type I OI, teriparatide therapy increased concentrations of biomarkers of collagens II, III, IV, V, and VI. In individuals with types III/IV OI these biomarker changes in response to teriparatide were blunted, as we previously reported with collagen I biomarkers during teriparatide therapy. In contrast to OI, in PM women there were no effects of teriparatide on the collagen biomarkers we assessed (II, V, and VI). These findings suggest that in OI teriparatide therapy has abnormal effects on the homeostasis of many ECM collagens likely derived from skeletal as well as extra-skeletal tissues.

Effects of Combination Denosumab and High-Dose Teriparatide Administration on Bone Microarchitecture and Estimated Strength: The DATA-HD HR-pQCT Study.

In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 µg) teriparatide increased spine and hip bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 µg). To assess the effects of these combinations on bone microarchitecture and estimated bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 µg (n = 39) or 40 µg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of bone density, microstructure, and estimated strength, with greater gains in total bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

Delayed Denosumab Injections and Fracture Risk Among Patients With Osteoporosis : A Population-Based Cohort Study.

BACKGROUND: Denosumab is effective for osteoporosis, but discontinuation leads to rapid reversal of its therapeutic effect. OBJECTIVE: To estimate the risk for fracture among users of denosumab who delayed subsequent doses compared with users who received doses on time. DESIGN: Population-based cohort study. SETTING: The Health Improvement Network U.K. primary care database, 2010 to 2019. PATIENTS: Persons aged 45 years or older who initiated denosumab therapy for osteoporosis. MEASUREMENTS: Observational data were used to emulate an analysis of a hypothetical trial with 3 dosing intervals: subsequent denosumab injection given within 4 weeks after the recommended date ("on time"), delay by 4 to 16 weeks ("short delay"), and delay by more than 16 weeks ("long delay"). The primary outcome was a composite of all fracture types at 6 months after the recommended date. Secondary outcomes were major osteoporotic fracture, vertebral fracture, hip fracture, and nonvertebral fracture. RESULTS: Investigators identified 2594 patients initiating denosumab therapy. The risk for composite fracture over 6 months was 27.3 in 1000 for on-time dosing, 32.2 in 1000 for short delay, and 42.4 in 1000 for long delay. Compared with on-time injections, short delay had a hazard ratio (HR) for composite fracture of 1.03 (95% CI, 0.63 to 1.69) and long delay an HR of 1.44 (CI, 0.96 to 2.17) (P for trend = 0.093). For vertebral fractures, short delay had an HR of 1.48 (CI, 0.58 to 3.79) and long delay an HR of 3.91 (CI, 1.62 to 9.45). LIMITATION: Dosing schedules were not randomly assigned. CONCLUSION: Although delayed administration of subsequent denosumab doses by more than 16 weeks is associated with increased risk for vertebral fracture compared with on-time dosing, evidence is insufficient to conclude that fracture risk is increased at other anatomical sites with long delay. PRIMARY FUNDING SOURCE: National Clinical Research Center for Orthopedics, Sports Medicine & Rehabilitation.

Dose-Response Relationships Between Gonadal Steroids and Bone, Body Composition, and Sexual Function in Aging Men.

CONTEXT: Most labs set the lower limit of normal for testosterone at the 2.5th percentile of values in young or age-matched men, an approach that does not consider the physiologic changes associated with various testosterone concentrations. OBJECTIVE: To characterize the dose-response relationships between gonadal steroid concentrations and measures regulated by gonadal steroids in older men. DESIGN, PARTICIPANTS, AND INTERVENTION: 177 men aged 60 to 80 were randomly assigned to receive goserelin acetate plus either 0 (placebo), 1.25, 2.5, 5, or 10 grams of a 1% testosterone gel daily for 16 weeks or placebos for both medications (controls). PRIMARY OUTCOMES: Changes in serum C-telopeptide (CTX), total body fat by dual energy X-ray absorptiometry, and self-reported sexual desire. RESULTS: Clear relationships between the testosterone dosage (or the resulting testosterone levels) and a variety of outcome measures were observed. Changes in serum CTX exceeded changes in the controls in men whose testosterone levels were 0 to 99, 100 to 199, 200 to 299, or 300 to 499 ng/dL, whereas increases in total body fat, subcutaneous fat, and thigh fat exceeded controls when testosterone levels were 0 to 99 or 100 to 199 ng/dL. Sexual desire and erectile function were indistinguishable from controls until testosterone levels were <100 ng/dL. CONCLUSION: Changes in measures of bone resorption, body fat, and sexual function begin at a variety of testosterone concentrations with many outcome measures remaining stable until testosterone levels are well below the stated normal ranges. In light of this variation, novel approaches for establishing the normal range for testosterone are needed.

Delayed Denosumab Injections and Bone Mineral Density Response: An Electronic Health Record-based Study.

CONTEXT: Discontinuation of denosumab leads to a rapid reversal of its therapeutic effect. However, there are no data regarding how unintended delays or missed injections of denosumab impact bone mineral density (BMD) response. OBJECTIVE: We examined the association of delays in injections of denosumab with BMD change. DESIGN: We used electronic medical records from two academic hospitals from 2010 to 2017. PARTICIPANTS: Patients older than 45 years of age and used at least 2 doses of 60 mg denosumab. Denosumab adherence was evaluated by the medication coverage ratio (MCR). Good adherence corresponds to a dosing interval ≤7 months (defined by MCR ≥93%), moderate adherence corresponds to an interval of 7 to 10 months (MCR 75%-93%), and poor adherence corresponds to an interval ≥10 months (MCR ≤75%). OUTCOME MEASURES: Annualized percent BMD change from baseline at the lumbar spine, total hip, and femoral neck. RESULTS: We identified 938 denosumab injections among 151 patients; the mean (SD) age was 69 (10) years, and 95% were female. Patients with good adherence had an annualized BMD increase of 3.9% at the lumbar spine, compared with patients with moderate (3.0%) or poor adherence (1.4%, P for trend .002). Patients with good adherence had an annualized BMD increase of 2.1% at the total hip, compared with patients with moderate (1.3%) or poor adherence (0.6%, P for trend .002). CONCLUSIONS: A longer interval between denosumab injections is associated with suboptimal BMD response at both spine and total hip. Strategies to improve the timely administration of denosumab in real-world settings are needed.