Comparison Of The Long-Term Effects Of Liraglutide And Glimepiride Monotherapy On Bone Mineral Density In Patients With Type 2 Diabetes

Objective: Patients with type 2 diabetes have an increased risk of fragility fractures; the cause is unclear but is likely multifactorial. Some diabetes treatments induce bone loss, accentuating underlying skeletal fragility and increasing fracture risk. This subgroup analysis aimed to compare long-term effects of liraglutide and glimepiride on bone mineral density (BMD) in patients with type 2 diabetes.Methods: LEAD-3, a 52-week, double-blind, activecontrol, phase III, multicenter trial, investigated the efficacy of liraglutide (1.2 and 1.8 mg/day) versus glimepiride monotherapy in type 2 diabetes. A 52-week, open-label extension followed, in which participants remained on randomized therapy. A subgroup of participants underwent BMD measurement by dual-energy X-ray absorptiometry at baseline, 52, and 104 weeks. The main outcome measure was change from baseline in total body BMD at 52 and 104 weeks, assessed by analysis of covariance.Results: A total of 746 patients with type 2 diabetes aged 19 to 79 years were randomized into the main trial. Of these, 61 patients (20 assigned to liraglutide 1.8 mg/day, 23 to liraglutide 1.2 mg/day, 18 to glimepiride 8 mg/day) had BMD measurements. Baseline age, body mass index, diabetes duration, glycated hemoglobin, and total BMD were similar across treatment groups. There was no apparent difference in mean total BMD change from baseline in patients receiving liraglutide 1.8 or 1.2 mg/day or glimepiride 8 mg/day at 52 or 104 weeks.Conclusion: In this small subgroup analysis, liraglutide monotherapy did not negatively affect total BMD in a 2-year prospective study, suggesting it may not exacerbate the consequences of bone fragility.Abbreviations:BMD = bone mineral densityBMI = body mass indexDPP-4 = dipeptidyl peptidase-4DXA = dual-energy X-ray absorptiometryGLP-1RA = glucagon-like peptide 1 receptor agonistLEAD = Liraglutide Effect and Action in DiabetesTZD = thiazolidinedione     

Does Baseline PTH Influence Recovery of Bone Mineral Density,Trabecular Bone Score and Bone Turnover Markers? A Prospective Study Following Curative PArathyroidectomy in Primary Hyperparathyroidism

Objective: This prospective study was carried out to assess trabecular bone score, bone mineral density (BMD), and bone biochemistry in Indian subjects with symptomatic primary hyperparathyroidism (PHPT), and to study the influence of baseline parathyroid hormone (PTH) on recovery of these parameters following curative surgery.Methods: This was a 2-year prospective study conducted at a tertiary care centre in southern India. Baseline assessment included demographic details, mode of presentation, bone mineral biochemistry, BMD, trabecular bone score (TBS), and bone turnover markers (BTMs). These parameters were reassessed at the end of the first and second years following curative parathyroid surgery.Results: Fifty-one subjects (32 men and 19 women) with PHPT who had undergone curative parathyroidectomy were included in this study. The mean (SD) age was 44.6 (13.7) years. The TBS, BTMs, and BMD at lumbar spine and forearm were significantly worse at baseline in subjects with higher baseline PTH (≥250 pg/mL) when compared to the group with lower baseline PTH (<250 pg/mL). At the end of 2 years, the difference between high versus low PTH groups (mean ± SD) persisted only for forearm BMD (0.638 ± 0.093 versus 0.698 ± 0.041 g/cm²; P =.01). However, on follow-up visits in the first and second year after curative parathyroidectomy, there was no significant difference in BTMs, BMD at the femoral neck, lumbar spine, and TBS between the 2 groups stratified by baseline PTH.Conclusion: The BMD at the forearm remained significantly worse in individuals with high baseline PTH even at 2 years after surgery, while other parameters including TBS improved significantly from baseline.Abbreviations: 25(OH)D = 25-hydroxyvitamin D; BMD = bone mineral density; BMI = body mass index; BTMs = Bone turnover markers; CTX = C-terminal telopeptide of type 1 collagen; DXA = dual energy X-ray absorptiometry; P1NP = N-terminal propeptide of type 1 procollagen; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; TBS = trabecular bone score     

Opportunistic Evaluation of Bone Mineral Density By Pet-Ct in Hodgkin Lymphoma Patients

Objective: Bone density loss and increased risk for osteoporosis are of concern in Hodgkin lymphoma (HL) patients. Routinely performed positron emission tomography–computed tomography (PET-CT) scans could be informative in assessing bone mineral density (BMD).Methods: This retrospective study included 80 adults with newly diagnosed HL treated with standard first-line chemotherapy regimens. PET-CT scans performed at diagnosis (PET-CT₁), at the end of chemotherapy (PET-CT₂), and at follow-up after remission (PET-CT₃) were used to assess BMD changes by measuring lumbar vertebrae CT attenuation. A CT attenuation threshold of 160 Hounsfield units was used to define abnormal BMD.Results: Following chemotherapy, comparison of PET-CT₂ with PET-CT₁ revealed a mean (standard deviation) 14.2% (10.4%) BMD reduction (P<.001). On PET-CT₃ performed at 14.6 (3.25) months after the last course of chemotherapy, a slight improvement (4.6% &lsqb;10.4%]) in comparison to PET-CT₂ was noted. Twelve patients (15%) converted from normal baseline BMD on PET-CT₁ to abnormal BMD after chemotherapy on PET-CT₂. Age, baseline BMD, and steroid cumulative dose were associated with BMD decline and risk for abnormal BMD after chemotherapy. No clinical fractures were reported, and only one rib fracture was incidentally captured (1.25%).Conclusion: HL patients treated with common first-line chemotherapies demonstrate a significant decline in bone density on routine PET-CT scans. Opportunistic use of PET-CT scan has the potential to detect HL patients at high risk for developing osteoporosis and to guide clinicians regarding monitoring and intervention.Abbreviations: BMD = bone mineral density; CT = computed tomography; DXA = dual-energy X-ray absorptiometry; HL = Hodgkin lymphoma; HU = Hounsfield units; L = lumbarvertebra; PET-CT = positron emission tomography-computed tomography; T = thoracic vertebra     

Transient Osteoporosis: Clinical Spectrum in Adults and Associated Risk Factors

Objective: We aimed to describe the natural history of the rare clinical syndrome of transient osteoporosis (TO) and ascertain potential risk factors.Methods: Retrospective cohort study of adults with TO at Mayo Clinic, Rochester, Minnesota, over 15 years. Adults with acute-onset joint pain worsened by weight bearing and bone marrow edema on magnetic resonance imaging were included; exclusion criteria were trauma, tumors, rheumatic diseases, avascular necrosis, infection, and hyperesthesia.Results: Thirty-three patients with TO were identified: 20 males, median age at diagnosis 47 years, and median body mass index 28 kg/m². Median time to diagnosis was 2 months, and time to symptom resolution was 4 months. All cases involved the lower extremity, with the majority affecting the hip. Most patients (79%) had at least one possible identified risk factor. The most frequent risk factor was low bone mineral density (BMD) in 13 patients (39% of cohort). Of the 16 patients with BMD measure, 8 had low BMD at a site other than TO. The next most frequent risk factors were sudden limb overuse and more than one episode of TO, observed in 30%, followed by a disorder of bone and mineral metabolism in 27%.Conclusion: TO affects middle-age men more than women, primarily involves weight-bearing joints, and usually resolves with conservative management. Its etiology remains unclear; however, the common presence of risk factors, abnormalities in bone and mineral laboratories, and decrease in BMD suggest that systemic factors may be important in its development.Abbreviations: AVN = avascular necrosis; BMD = bone mineral density; DXA = dual-energy X-ray absorptiometry; MRI = magnetic resonance imaging; TO = transient osteoporosis     

The Associations Between Hypovitaminosis D,Higher Pth Levels With Bone Mineral Densities,And Risk Of The 10-Year Probability Of Major Osteoporotic Fractures In Chinese Patients With T2Dm

Objective: In the current study, we investigated the vitamin D status, and its relationships with parathyroid hormone (PTH) levels, bone mineral density (BMD), and the 10-year probability of fractures in Chinese patients with type 2 diabetes mellitus (T2DM).Methods: This was a cross-sectional study of 785 patients. BMDs at the lumbar spine (L2-4), femoral neck (FN), and total hip (TH) were measured by dual-energy X-ray absorptiometry (DXA). Serum levels of 25-hydroxyvitamin D (25(OH)D) and intact PTH were also quantified. The 10-year probability of fracture risk (major osteoporotic fracture &lsqb;MOF] and hip fracture &lsqb;HF]) was assessed using the fracture risk assessment tool (FRAX).Results: The prevalence of vitamin D deficiency was 82.3%, and the mean 25(OH)D level was 36.9 ± 15.2 nmol/L. The adequate group had higher BMDs at the FN and TH and lower MOF risk than the inadequate groups. Lower 25(OH)D was associated with higher PTH (r = -0.126, P<.001). PTH was negatively correlated with BMDs at 3 sites and positively correlated with MOF and HF, but this relationship disappeared in the adequate subgroup. Multivariate stepwise regression analysis revealed that PTH was the determinant of MOF (standard β = 0.073, P = .010) and HF (standard β = 0.094, P = .004).Conclusion: Our results identified a significantly high rate of vitamin D deficiency among Chinese patients with T2DM. PTH is an important risk factor responsible for the higher 10-year probability of osteoporotic fractures in diabetic patients, especially in those with lower vitamin D levels.Abbreviations: AKP = alkaline phosphatase; ALB = serum albumin; BMD = bone mineral density; BMI = body mass index; Ca = calcium; CKD = chronic kidney disease; Cr = creatinine; FN = femoral neck; FRAX = fracture risk assessment tool; HbA1c = glycated hemoglobin A1c; HF = hip fracture; L2-4 = lumbar spine; MOF = major osteoporotic fracture; 25(OH)D = 25-hydroxyvitamin D; P = phosphorus; PTH = parathyroid hormone; T2DM = type 2 diabetes mellitus; TH = total hip; UA = uric acid     

Adding VFA to DXA Identifies Fracture Risk in a Way Not Duplicated by Other Measures

Objective: Published studies have demonstrated that adding vertebral fracture assessment (VFA) to dual-energy X-ray absorptiometry (DXA) identifies more patients with increased fracture risk than DXA alone. But who needs VFA? This study attempts to determine if some test other than VFA could duplicate the additional information obtained by performing VFA on all first-time patients. This study looked at the Fracture Risk Assessment Tool (FRAX), height loss, age, documented back pain, and nonvertebral fragility fractures.Methods: VFA was performed on 1,259 (all) DXA patients at their first visit from March 2010 through September 2013. All DXA and VFA results were read by the same International Society for Clinical Densitometry–certified clinician.Results: By DXA alone, 44% were osteoporosis. Adding VFA increased clinical osteoporosis by 36% of the original total patients. Eighty-three “normal bone mineral density” patients were changed to clinical osteoporosis. FRAX identified 53% of the patients with diagnosis changes. Historical height loss was not reliable. Increasing age correlated only weakly with clinical osteoporosis.Conclusion: These are modest numbers from a nonacademic referral practice and may not be typical of other populations. Thirty-six percent of our patients were misclassified by DXA alone, with fragility fractures already taken into account for T-scores of -1.5 and lower. FRAX, height loss, age, back pain, and fragility fractures all failed to identify many of the patients identified by VFA. Seeing the lateral spine images obtained by VFA influenced patients and families. VFA on all first-time patients should be reconsidered.Abbreviations:BMD = bone mineral density; DXA = dual-energy X-ray absorptiometry; FRAX = Fracture Risk Assessment Tool; HL = height loss; ISCD = International Society for Clinical Densitometry; VF = vertebral fracture; VFA = vertebral fracture assessment     

Bone Analysis Using Trabecular Bone Score and Dual-Energy X-Ray Absorptiometry-Based 3-Dimensional Modeling in Postmenopausal Women With Primary Hyperparathyroidism

ObjectivePredominance of bone loss in cortical sites with relative preservation of trabecular bone, even in postmenopausal women, has been described in primary hyperparathyroidism (PHPT). The aim of this study was to evaluate bone microarchitectural differences using dual-energy x-ray absorptiometry (DXA), trabecular bone score (TBS), and DXA-based 3-dimensional (3D) modeling (3D-DXA) between postmenopausal women diagnosed with PHPT (PM-PHPT) and healthy postmenopausal controls.MethodsThis retrospective study included 44 women with PM-PHPT (9 of whom had fractures) and 48 healthy women matched by age, body mass index, and years since menopause treated at Hospital Universitario Fundación Jiménez Díaz between 2008 and 2017. The bone mineral density (BMD) of the lumbar spine (LS), femoral neck, total hip (TH), and 1/3 radius was assessed using DXA, and trabecular volumetric BMD (vBMD), cortical vBMD, integral vBMD, cortical thickness, and cortical surface BMD at TH were assessed using a 3D-DXA software and TBS at LS.ResultsThe mean adjusted BMD values at LS, the femoral neck, and TH; TBS at LS; and TH 3D-DXA parameters (trabecular vBMD, integral vBMD, cortical thickness, and cortical surface BMD) were significantly reduced in women with PM-PHPT compared with those in the controls. However, differences in mean cortical vBMD were not statistically significant (P = .078). There were no significant differences in mean BMD, TBS, or the 3D-DXA parameters between patients with fractures and those without fractures. The 25-hydroxyvitamin D level appeared to be associated with TBS but not with DXA and 3D-DXA measurements.ConclusionPM-PHPT has significant involvement of the trabecular and cortical compartments of the bone, as determined by DXA, TBS, and 3D-DXA.     

Influence of cardiovascular disease risk factors on the relationship between low bone mineral density and type 2 diabetes mellitus in a multiethnic us population of women and men: A cross-sectional study

Introduction: Higher bone mineral density (BMD) has been reported among white women and men with type 2 diabetes mellitus (DM) compared with nondiabetic white individuals, but there is scant evidence for nonwhite persons. It is also not known whether cardiovascular disease (CVD) risk factors may confound any association between BMD and type 2 DM.Objective: The present study examined the relationship between low BMD and type 2 DM in a multiethnic population of women and men while controlling for the influence of osteoporosis and CVD risk factors including body mass index (BMI), cigarette smoking, physical inactivity, total cholesterol and its components, blood pressure, and C-reactive protein.Methods: Data collected from 4929 African American, Mexican American, and white women and men aged 50 to 79 years who participated in the household interview and clinical examinations during the Third National Health and Nutrition Examination Survey were analyzed. CVD risk factors associated with type 2 DM in this study population were included as covariates in gender-specific multiple logistic regression models assessing the relationship between type 2 DM and low BMD while controlling for osteoporosis risk factors. Gender- and race/ethnicity-specific mean BMD values at the total hip for young adults aged 20 to 29 years were used to establish race/ethnicity and gender-specific low BMD T-scores.Results: The final study population included 2505 women and 2424 men. More women and men with type 2 DM than women and men without type 2 DM were nonwhite and had high BMI. Osteoporosis risk factors but not CVD risk factors were associated with low BMD in both women and men. Type 2 DM was not associated with low BMD among women (odds ratio [OR] = 0.77; 95% CI, 0.56-1.08). Based on a statistically significant interaction between type 2 DM status and race/ethnicity, white men with type 2 DM were less likely to have low BMD than were white men without type 2 DM (OR = 0.56; 95% CI, 0.37-0.86; P = 0.01). There was no significant BMD difference between diabetic and nondiabetic nonwhite men.Conclusion: CVD risk factors did not appear to influence the relationship between low BMD and type 2 DM in this study     

Hormone replacement therapy improves distal radius bone structure by endocortical mineral deposition

Hormone replacement therapy (HRT) produces a small increase in bone mineral density (BMD) when measured by dual energy X-ray absorptiometry (DXA). The corresponding decrease in fracture risk is more impressive, implying that other factors that contribute to bone strength are favourably modified by HRT. We investigated, using peripheral quantitated computed tomography (pQCT), the changes produced by HRT in both the distribution of mineral between cortical and trabecular bone and the changes produced by HRT in the apparent structure of trabecular bone, expressed as average hole area and apparent connectivity. Twenty-one postmenopausal women starting HRT and 32 control women were followed for 2 years, with distal radius pQCT measurements every 6 months. HRT prevented the loss of total bone mass seen in controls (p < 0.02). HRT also produced an apparent rapid loss of trabecular bone mass within the first 6 months of the study (p < 0.02), with an associated rapid loss in the apparent connectivity (p = 0.034). Average hole area also increased but not to a statistically significant extent. Exogenous estrogen apparently fills small marrow pores close to the endocortical surface, such that the pQCT-defined boundary between trabecular and cortical bone is shifted in favour of cortical bone. Trabecular bone structure indices are adversely affected, as the central, poorly interconnected trabecular bone with greater than average marrow spaces constitutes a greater fraction of the remaining trabecular bone. This study suggests that the improvements in fracture risk resulting from HRT are explained by a reversal of net endocortical resorption of bone.     

Consensus Statement by the American Association of Clinical Endocrinologists and American College of Endocrinology on the Quality of DXA Scans and Reports

Objective: High-quality dual-energy X-ray absorptiometry (DXA) scans are necessary for accurate diagnosis of osteoporosis and monitoring of therapy; however, DXA scan reports may contain errors that cause confusion about diagnosis and treatment. This American Association of Clinical Endocrinologists/American College of Endocrinology consensus statement was generated to draw attention to many common technical problems affecting DXA report conclusions and provide guidance on how to address them to ensure that patients receive appropriate osteoporosis care.Methods: The DXA Writing Committee developed a consensus based on discussion and evaluation of available literature related to osteoporosis and osteodensitometry.Results: Technical errors may include errors in scan acquisition and/or analysis, leading to incorrect diagnosis and reporting of change over time. Although the International Society for Clinical Densitometry advocates training for technologists and medical interpreters to help eliminate these problems, many lack skill in this technology. Suspicion that reports are wrong arises when clinical history is not compatible with scan interpretation (e.g., dramatic increase/decrease in a short period of time; declines in previously stable bone density after years of treatment), when different scanners are used, or when inconsistent anatomic sites are used for monitoring the response to therapy. Understanding the concept of least significant change will minimize erroneous conclusions about changes in bone density.Conclusion: Clinicians must develop the skills to differentiate technical problems, which confound reports, from real biological changes. We recommend that clinicians review actual scan images and data, instead of relying solely on the impression of the report, to pinpoint errors and accurately interpret DXA scan images.Abbreviations: AACE = American Association of Clinical Endocrinologists; BMC = bone mineral content; BMD = bone mineral density; DXA = dual-energy X-ray absorptiometry; ISCD = International Society for Clinical Densitometry; LSC = least significant change; TBS = trabecular bone score; WHO = World Health Organization     

Zoledronic Acid Versus Alendronate In The Treatment of Children With Osteogenesis Imperfecta: A 2-Year Clinical Study

Objective: Bisphosphonates have been demonstrated to increase the bone mineral density (BMD) of osteogenesis imperfecta (OI) patients. We aimed to compare the efficacy and safety of intravenous zoledronic acid and oral alendronate in patients with OI.Methods: A total of 161 patients with OI ranging from 2 to 16 years old were included and randomized at a 2:1 ratio to receive either weekly oral alendronate (ALN) 70 mg or a once-yearly infusion of zoledronic acid (ZOL) for 2 years. The primary endpoints were percentage change from baseline in lumbar spine (LS) BMD and change in Z-scores of LS BMD.Results: A total of 136 patients with OI completed the 2-year clinical study, 90 of whom were assigned to receive ALN, while 46 received ZOL treatment. The percentage change in LS BMD was 60.01 ± 7.08% in the ALN group and 62.04 ± 5.9% in the ZOL group (P = .721). The corresponding BMD Z-score increased by 0.50 ± 0.05 in the ALN group and 0.71 ± 0.06 in the ZOL group (P = .013). ZOL was superior to ALN in reducing the clinical fracture rate (hazard ratio, 0.23; 95% confidence interval, 0.118 to 0.431). There was no difference in the incidence of severe side effects between the two groups.Conclusion: A once-yearly 5 mg infusion of ZOL and weekly oral ALN had similar effects in increasing BMD and reducing bone resorption in children and adolescents with OI. ZOL was superior to ALN in reducing the clinical fracture rate.Abbreviations: 25OHD = 25-hydroxyvitamin D; ALN = alendronate; ALP = alkaline phosphatase; β-CTX = cross-linked C-telopeptide of type I collagen; BMD = bone mineral density; BP = bisphosphonate; FN = femoral neck; LS = lumbar spine; OI = osteogenesis imperfecta; SAE = severe adverse event; ZOL = zoledronic acid     

The Clinical Characteristics and Efficacy of Bisphosphonates in Audlt Patients with Osteogenesis Impergecta

Objective: Osteogenesis imperfecta (OI) is characterized by low bone mass and recurrent fractures. Adults with OI are often treated with oral or intravenous bisphosphonates (BPs). We investigated the clinical phenotypes of adult OI patients and prospectively compared the efficacy of oral alendronate (ALN) with intravenous zoledronic acid (ZOL) in OI patients.Methods: This 24-month, observational, randomized clinical study included 60 adult patients with OI. We compared the differences in bone mineral density (BMD) and bone turnover biomarkers between OI adults and healthy subjects. Thereafter, OI patients were randomized at a 2:1 ratio to receive either weekly oral ALN 70 mg or once-yearly infusion of ZOL 5 mg. The efficacy outcomes were changes in BMD, bone turnover biomarkers, and fracture incidence.Results: Adult OI patients had significantly lower BMD and significantly higher cross-linked C-telopeptide of type I collagen (β-CTX) levels than age-/sex-/BMI-matched healthy subjects. A total of 52 patients completed the 24-month clinical study. BMD at lumbar spine, femoral neck, and total hip were equivalently elevated in the ALN (10.5, 13.2, and 14.7%, respectively) and ZOL (11.3, 13.7, and 11.7%, respectively; all P>.05) groups. Serum alkaline phosphatase decreased by 30.3% in the ALN group and 37.3% in the ZOL group (P =.12), and β-CTX decreased by 58.0% in the ALN group and 63.6% in the ZOL group (P =.48). Compared to the prior fracture rates, clinical fracture incidences were decreased in the ALN and ZOL groups (both P<.05).Conclusion: Adults with OI present significantly lower bone mass and higher bone resorption biomarkers than healthy populations. Oral ALN and intravenous ZOL are equally effective at increasing BMD and inhibiting bone turnover in adults with OI. The treatment may reduce fractures in this study, but further efforts are still needed to demonstrate the anti-fracture efficacy of BPs.Abbreviations:25OHD = 25-hydroxyvitamin DALN = alendronateALP = alkaline phosphataseBMD = bone mineral densityBMI = body mass indexBP = bisphosphonateβ-CTX = cross-linked C-telopeptide of type I collagenFN = femoral neckLS = lumbar spineOI = osteogenesis imperfectaRCT = randomized controlled trialTH = total hipZOL = zoledronic acid     

Dual-Energy X-Ray Absorptiometry And Calculated Frax Risk Scores May Underestimate Osteoporotic Fracture Risk In Vitamin D-Deficient Veterans With Hiv Infection

Objective: We evaluated the utility of the Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency.Methods: This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures.Results: We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between -1 and -2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant.Conclusion: We found a high prevalence of subclinical vertebral fractures among vitamin D–deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population.Abbreviations:25(OH)D = 25-hydroxyvitamin DBMD = bone mineral densityBMI = body mass indexDEXA = dual-energy X-ray absorptiometryFRAX = Fracture Risk Assessment ToolHIV = human immunodeficiency virusIQR = interquartile rangePTH = parathyroid hormoneVA = Veterans AffairsWHO = World Health Organization     

Trabecular Bone Score in Patients with Normocalcemic Hyperparathyroidism

Objective: The effects of normocalcemic hyperparathyroidism (NHPT) on bone remain unclear. The objective of this study was to evaluate differences in the trabecular bone score (TBS) of NHPT patients and asymptomatic hypercalcemic hyperparathyroidism (HHPT) patients.Methods: We performed a prospective study that enrolled consecutive patients with asymptomatic hyperparathyroidism (NHPT and HHPT) with a follow-up ≥1 year at the University Hospital of Valladolid, Spain. Metabolic phosphocalcium plasma and urine parameters were evaluated in ≥2 determinations during follow-up to classify patients as NHPT patients or asymptomatic HHPT patients. A control group was enrolled during the same period. TBS and bone mineral density (BMD) were evaluated.Results: Thirty-nine patients with asymptomatic HPT (24 with NHPT and 15 with HHPT) and 24 controls were recruited. NHPT patients and HHPT patients had a similar mean age, vitamin D level, TBS, and areal BMD (all sites). Compared to controls, symptomatic HPT patients had significantly higher parathyroid hormone (PTH) and calcium levels and significantly lower TBS and areal BMD at all sites (all P<.05). A significant negative relationship between TBS and PTH was found in asymptomatic HPT patients (r = -0.320, P = .043), which remained significant after adjustment for age, sex, and body mass index.Conclusion: There was no difference in the TBS between NHPT and HHPT patients. However, there was a reduction in the TBS of patients with asymptomatic HPT that was related to PTH levels but had no repercussion on bone mass. Higher levels of PTH seem to be responsible for this alteration in microarchitecture texture.Abbreviations:aBMD = areal bone mineral densityBMD = bone mineral densityBMI = body mass indexDXA = dual-energy X-ray absorptiometryHHPT = hypercalcemic hyperparathyroidismHPT = hyperparathyroidismHR-MRI = high-resolution magnetic resonanceHR-pQcT = high-resolution peripheral quantitative computed tomographyNHPT = normocalcemic hyper-parathyroidismPTH = parathyroid hormoneTBS = trabecular bone score25vitD = 25-hydroxyvitamin D     

Laser-Supported Dual Energy X-Ray Absorptiometry (DXL) Compared to Conventional Absorptiometry (DXA) and to FRAX as Tools for Fracture Risk Assessments

Dual X-ray and Laser (DXL) adds a measure of the external thickness of the heel, measured by laser, to a conventional measurement of bone mineral density (BMD) of the calcaneus, using Dual energy X-ray Absorptiometry (DXA). The addition of heel thickness aims at a better separation of fatty tissue from bone than the standard method of DXA, which may mistake fatty tissue for bone and vice versa. The primary aim of this study was to evaluate whether DXL of the calcaneus can be used to assess the 10-year risk of fractures. Secondary aims were to compare the predictive ability of DXL with the two most established methods, Dual energy X-ray Absorptiometry (DXA) of the hip and spine and the WHO fracture risk assessment tool, FRAX. In 1999 a cohort of 388 elderly Swedish women (mean age 73.2 years) was examined with all three methods. Prospective fracture data was collected in 2010 from health care registers. One SD decrease in BMD of the heel resulted in an age-adjusted Hazard Ratio (HR) of 1.47 for a hip fracture (95% CI 1.09–1.98). Harrell’s C is the Cox regression counterpart of the Area Under Curve (AUC) of the Receiver Operating Characteristic (ROC) as a measure of predictive accuracy. Harrell’s C for BMD of the calcaneus was 0.65 for prediction of hip fractures. These results were not significantly different from those for BMD of the femoral neck or for FRAX. The HR for a hip fracture, for one SD decrease in BMD at the femoral neck, was 1.72 (95% CI 1.21–2.44. Harrell’s C was 0.67 for BMD at the femoral neck and 0.59 for FRAX. We conclude that DXL of the calcaneus could be a useful tool for fracture risk assessments.     

Effects of Long-Term Alendronate Treatment on a Large Sample of Pediatric Patients with Osteogenesis Imperfecta

Objective: Osteogenesis imperfecta (OI) is a group of inherited diseases characterized by reduced bone mass, recurrent bone fractures, and progressive bone deformities. Here, we evaluate the efficacy and safety of long-term treatment with alendronate in a large sample of Chinese children and adolescents with OI.Methods: In this prospective study, a total of 91 children and adolescents with OI were included. The patients received 3 years' treatment with 70 mg alendronate weekly and 500 mg calcium daily. During the treatment, fracture incidence, bone mineral density (BMD), and serum levels of the bone turnover biomarkers (alkaline phosphatase [ALP] and cross-linked C-telopeptide of type I collagen [β-CTX]) were evaluated. Linear growth speed and parameters of safety were also measured.Results: After 3 years of treatment, the mean annual fracture incidence decreased from 1.2 ± 0.8 to 0.2 ± 0.3 (P<.01). BMD at the lumbar spine and femoral neck significantly increased by 74.6% and 39.5%, with their BMD Z-score increasing from -3.0 to 0.1 and from -4.2 to -1.3, respectively (both P<.01 vs. baseline). In addition, serum ALP and β-CTX levels decreased by 35.6% and 44.3%, respectively (both P<.05 vs. baseline). Height significantly increased, but without an obvious increase in its Z-score. Patient tolerance of alendronate was good.Conclusion: Three years' treatment with alendronate was demonstrated for the first time to significantly reduce fracture incidence, increase lumbar spine and femoral neck BMD, and decrease bone turnover biomarkers in Chinese children and adolescents with OI.Abbreviations:ALP = alkaline phosphataseβ-CTX = cross-linked C-telopeptide of type I collagenBMD = bone mineral densityBP = bisphosphonateDXA = dual-energy X-ray absorptiometry25OHD = 25-hydroxyvitamin DOI = osteogenesis imperfectaPTH = parathyroid hormone     

Osteoporotic Fractures During Bisphosphonate Drug Holiday

Objective: Bisphosphonate (BP) drug holidays are recommended to lower the risk of rare adverse events, such as atypical femoral fractures and osteonecrosis of the jaw. However, there are minimal data on the optimal duration of these holidays. Our aim was to determine the clinical and laboratory parameters associated with increased fracture risk in patients on BP drug holiday.Methods: A retrospective chart review was conducted of 401 patients with osteopenia or osteoporosis who began a BP drug holiday from 2004 to 2013. Collected parameters included demographics, prior therapy, bone mineral density (BMD), bone turnover markers, parathyroid hormone, calcium & vitamin D status, and clinical reports of fractures.Results: Sixty-two (15.4%) patients developed a fracture during follow-up. The yearly incidence of fractures ranged from 3.7 to 9.9%, peaking at 9.9% and 9.8% during years 4 and 5, respectively. The mean age of the fracture group was higher than the nonfracture group, though not significantly different (69.24 ± 12.26 years vs. 66.42 ± 10.18 years; P = .09). Compared to the nonfracture group, the fracture group had lower femoral neck BMD (0.75 ± 0.12 g/cm² vs. 0.79 ± 0.10 g/cm²; P = .03) and T-scores (-2.13 ± 0.99 vs. -1.78 ± 0.79; P = .01) at baseline.Conclusion: Patients who begin BP drug holidays at high risk of fracture based on BMD, age, or other clinical risk factors warrant close follow-up, especially as its duration lengthens. Fracture risk analysis needs to be regularly assessed during the drug holiday and treatment resumed accordingly.Abbreviations:25-OHD = 25-hydroxyvitamin DAACE = American Association of Clinical EndocrinologistsACE = American College of EndocrinologyBMD = bone mineral densityBP = bisphosphonateBSAP = bone-specific alkaline phosphataseBTM = bone turnover markerFN = femoral neckLS = lumbar spinePTH = parathyroid hormone     

Densitometric, morphometric and mechanical distributions in the human proximal femur

With the prevalent use of DXA-measured BMD to assess pathologic hip fractures and its recently reported lack of reliability to predict fracture or account for efficacy of anti-resorptive therapy, it is reasonable to assess whether variations in the primary and secondary tensile and compressive trabecular microstructure can account for variations in proximal femur strength in comparison to DXA-measured BMD. To that end, microstructural and densitometric measures of trabecular bone specimens, from discrete sites within the proximal femur, were correlated with their mechanical properties. We hypothesize that accounting for regional variations in trabecular microstructure will improve predictions of proximal femur strength and stiffness compared to bone density measured by DXA. Forty-seven samples (seven donors) from seven distinct sites of human proximal femur underwent DXA and muCT imaging and mechanical testing. The results revealed significant variations in BMC, morphometric indices and mechanical properties within the proximal femur. This work has demonstrated that the mechanical performance of each sub-region is highly dependent on the corresponding trabecular microstructure. BMD measured by DXA at standard regions of interest cannot resolve the variations in trabecular density and microstructure that govern the mechanical behavior of the proximal femur. This work suggests that a quantitative Singh index that uses high resolution QCT to monitor the trabecular microstructure at specific sub-regions of the proximal femur may allow better predictions of hip fracture risk in individual patients and an improved assessment of changing bone structure in response to pharmacological interventions.     

Cortical Hand Bone Porosity and Its Association with Distal Radius Fracture in Middle Aged and Elderly Women

Objective

Reduced bone mineral density (BMD), assessed by Dual Energy X-ray absorptiometry (DXA), is a well-known risk factor for fragility fracture. A large proportion of patients with fracture have only slightly reduced BMD. Assessment of other bone structure features than BMD may improve identification of individuals at increased fracture risk. Digital X-ray radiogrammetry (DXR), which is a feasible tool for measurement of metacarpal cortical bone density, also gives an estimate of cortical bone porosity. Our primary aim was to explore the association between cortical porosity in the hand assessed by DXR and distal radius fracture.

Methods

This case-control study included 123 women >50 years with distal radius fracture, and 170 controls. DXR was used to measure metacarpal BMD (DXR-BMD), cortical porosity (DXR-porosity), thickness (DXR-CT) and bone width (DXR-W) of the hand. Femoral neck BMD was measured by DXA.

Results

The fracture group had a statistically significant lower DXR-BMD (0.492 vs. 0.524 g/cm² p<0.001), higher cortical DXR-porosity (0.01256 vs. 0.01093, p<0.001), less DXR-CT (0.148 vs. 0.161cm, p<0.001) and lower femoral neck DXA-BMD (0.789 vs. 0.844 g/cm², p = 0.001) than the controls. In logistic regression analysis adjusted for age, a significant association with distal radius fracture (OR, 95% CI) was found for body mass index (0.930, 0.880–0.983), DXA-BMD (0.996, 0.995–0.999), DXR-BMD (0.990, 0.985–0.998), DXR-porosity (1.468, 1.278–1.687) and DXR-CT (0.997, 0.996–0.999). In an adjusted model, DXR-porosity remained the only variable associated with distal radius fracture (1.415, 1.194–1.677).

Conclusion

DXR derived porosity is associated with fracture at distal radius and might be a sensitive marker for skeletal fragility.     

Estimation of 3D shape, internal density and mechanics of proximal femur by combining bone mineral density images with shape and density templates

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) alone is only a moderate predictor of fracture risk. Finite element analysis (FEA) of bone mechanics, based on DXA images, may improve the prediction of fracture risk. We developed a method to estimate the 3D shape and density distribution of the proximal femur, using a 2D BMD image and a femur shape template. Proximal femurs of eighteen human cadavers were imaged using computed tomography and divided into two sets (N = 9 + 9). The template was created from the samples in first set by using 3D generalized Procrustes analysis and thin-plate splines. Subsequently, the template and 2D BMD image were utilized to estimate the shape and internal density distribution of the femurs in the second set. Finally, FEA was conducted based on the original and the estimated bone models to evaluate the effect of geometrical and density distributional errors on the mechanical strength. The volumetric errors induced by the estimation itself were low (<1.4%). In the estimation of bones in the second set, the mean distance difference between the estimated and the original bone surfaces was 0.80 ± 0.19 mm, suggesting feasible estimation of the femoral shape. The mean absolute error in voxel-by-voxel BMD was 120±8 mg cm?3. In FEA, the stiffness of the proximal femur differed by -7±16% between the original and estimated bones. The present method, in comparison with methods used in previous studies, improved the prediction of the geometry, the BMD distribution and the mechanical characteristics of the proximal femur. Potentially, the proposed method could ultimately improve the determination of bone fracture risk.