Bone mineral density and fracture risk in older individuals with CKD

Dual-Energy X-Ray Absorptiometry-Derived Advanced Hip Analysis and the Trabecular Bone Score Are Associated With the Diagnosis of Fracture Following Kidney and Simultaneous Pancreas-Kidney Transplantation

BACKGROUND

Patients with kidney failure have elevated fracture risk that remains high following kidney transplantation. This study aimed to assess whether dual-energy x-ray absorptiometry-derived advanced hip analysis (AHA) and the trabecular bone score (TBS) improve bone mineral density (BMD)-based post-transplant fracture prediction.

METHODS

Patients receiving kidney-only or simultaneous pancreas-kidney (SPK) transplants underwent immediate post-transplant dual-energy x-ray absorptiometry to provide BMD, the TBS, and AHA parameters; femoral neck, calcar, and shaft cortical thickness (CTh), and femoral neck buckling ratio (BR), an index of structural instability. Patients received treatment to reduce post-transplant BMD loss, using an established risk algorithm. Hazard ratios were determined using Kaplan-Meier and Cox proportional hazard models.

RESULTS

Of 357 transplant recipients, 289 (83%) received a kidney-only transplant. There were 83 incident fractures over a median of 4.4 years (IQR: 2.5-5.5). Fracture was associated with type 1 diabetes mellitus (p < 0.001), former smoking (p = 0.006), lower 25-hydroxyvitamin D (p = 0.003), BMD at total proximal femur and neck of femur (p < 0.001) and spine (p = 0.008), lower CTh at the calcar (p = 0.005) and shaft (p = 0.023), higher BR (p = 0.016) and lower TBS (p = 0.047). Following multivariable adjustment, type 1 diabetes mellitus, 25-hydroxyvitamin D, smoking, and femoral neck BMD remained significant. Using the BMD-based risk algorithm, inclusion of the BR improved the model fit.

CONCLUSION

BMD, the TBS, and AHA parameters are associated with incident fracture in kidney-only and SPK transplant recipients. Pre-transplant smoking, lower 25-hydroxyvitamin D and BMD are potentially modifiable factors that could reduce post-transplant fracture risk.

The Challenge of Fractures in Patients With Chronic Kidney Disease

OBJECTIVE

People with chronic kidney disease (CKD) are at increased risk of fractures in comparison to the non-CKD population, and fractures are associated with high mortality and worsening quality of life. However, the approach for evaluation of bone disease and fracture risk in CKD is different from the approach in the general population.

METHODS

The authors conducted a literature review of PubMed to include studies on pathophysiology of CKD mineral bone disorder, fracture risk assessment, and therapeutic options in the setting of CKD.

RESULTS

The higher risk observed in the CKD population is related to the complex interplay of changes in bone turnover (T), mineralization (M), and volume (V), along with other risk factors accumulated as glomerular filtration rate declines. The diagnosis of the type of renal osteodystrophy is not based only on assessment of bone density and traditional risk factors for osteoporosis. There are limitations of currently available fracture risk tools in the CKD population. Treatment choice should take into consideration the 3 components of the TMV classification along with the stage of kidney disease and comorbidities, but the assessment of these components has not been well established.

CONCLUSIONS

Current data are limited on efficacy and safety of treatments for fracture prevention in CKD. As new medications for the treatment of osteoporosis become available, there is an urgency to establish more clear guidelines for the diagnosis, fracture risk stratification, and treatment of bone disease in CKD.

Trabecular bone score to assess bone microarchitecture in end-stage renal disease patients

RATIONALE

This study evaluates TBS for estimating bone microarchitecture in ESRD patients using HR-pQCT as the reference technique.

MAIN RESULTS

TBS correlates significantly with vBMD and bone microarchitecture, unlike aBMD.

SIGNIFICANCE

TBS may complement bone health assessment in ESRD patients by offering additional information alongside aBMD.

PURPOSE

Given the high fracture risk, non-invasive techniques for assessing bone fragility in chronic kidney disease (CKD) remain important. Trabecular bone score (TBS) may provide additional information that could help guide treatment and follow-up decisions. The aim of this study is to investigate whether TBS reflects bone microarchitecture in end-stage renal disease (ESRD) patients, using high-resolution peripheral quantitative computed tomography (HR-pQCT) as the reference technique. Additionally, we aim to identify parameters associated with a low TBS.

METHODS

Seventy-five ESRD patients were included at the time of kidney transplantation (KTx). Areal bone mineral density (aBMD) was analyzed using dual-energy X-ray absorptiometry (DXA). TBS was assessed from the L1-L4 area during DXA. Volumetric BMD (vBMD) and bone microarchitecture at tibia and radius sites were analyzed using HR-pQCT.

RESULTS

In ESRD patients, those with TBS < 1.370 were older and had a higher body mass index (BMI). In contrast to T-score-based classification (≤ -2.5 or > -2.5), low TBS was linked to significantly lower trabecular and cortical vBMD, reduced trabecular bone volume fraction (BV/TV) and trabecular number (Tb.N), and increased trabecular separation (Tb.Sp). In multivariate analysis, older age, higher BMI, and lower Tb.N remained independently associated with low TBS, while no HR-pQCT parameters were linked to low aBMD (T-score ≤ -2.5).

CONCLUSION

TBS correlates with both trabecular and cortical parameters measured by HR-pQCT, potentially offering a complementary perspective on bone microstructure compared to aBMD. At the time of KTx, a low TBS appears to better discriminate patients with significantly lower vBMD than aBMD alone.

Pathophysiology and therapies of CKD-associated secondary hyperparathyroidism

Uremic secondary hyperparathyroidism (SHP) refers to the biochemical abnormalities that characterize CKD-MBD. However, historically parathyroid hormone (PTH) is identified as the key culprit hormone and the essential biomarker of secondary hyperparathyroidism. SHP represents the adaptive response to several mineral abnormalities that initiate and maintain increased PTH secretion through classical mineral derangements and more recently elucidated hormonal dysregulations. Among classic factors involved in the pathogenesis of SHP, phosphate, calcium, and calcitriol have a prominent role. The discovery of new pathogenetic factors involved in the development of SHP (and the eventual CKD-MBD) including fibroblast growth factor-23 (FGF23) and klotho provides new hypothesis and perspectives to our understanding of this complex metabolic disturbance. Recently more than serum phosphate a critical role in regulating FGF23 synthesis and the progression of CKD is ascribed to phosphate pool, reflected by production of glycerol-3-phosphate and the formation of excessive CPP-2. Finally, also skeletal resistance to PTH action, due to dysregulation of the Wnt-β-catenin system and intestinal dysbiosis, affecting the PTH actions on bone are causal factor of SHP. Identifying all the actors at play is mandatory to allow the most precise therapeutic prescription in the individual patient. This paper aims to review, in particular, the pathophysiology of SHP, which is essential to envisage the eventual therapeutic options for the associated MBD.

Chronic kidney disease-mineral and bone disorder: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

In 2017, Kidney Disease: Improving Global Outcomes (KDIGO) published a Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Since then, new lines of evidence have been published related to evaluating disordered mineral metabolism and bone quality and turnover, identifying and inhibiting vascular calcification, targeting vitamin D levels, and regulating parathyroid hormone. For an in-depth consideration of the new insights, in October 2023, KDIGO held a Controversies Conference on CKD-MBD: Progress and Knowledge Gaps Toward Personalizing Care. Participants concluded that the recommendations in the 2017 CKD-MBD guideline remained largely consistent with the available evidence. However, the framework of the 2017 Guideline, with 3 major sections-biochemical abnormalities in mineral metabolism; bone disease; and vascular calcification-may no longer best reflect currently available evidence related to diagnosis and treatment. Instead, future guideline efforts could consider mineral homeostasis and deranged endocrine systems in adults within a context of 2 clinical syndromes: CKD-associated osteoporosis, encompassing increased fracture risk in patients with CKD; and CKD-associated cardiovascular disease, including vascular calcification and structural abnormalities, such as valvular calcification and left ventricular hypertrophy. Participants emphasized that the complexity of bone and cardiovascular manifestations of CKD-MBD necessitates personalized approaches to management.

Use of 3D-DXA in the assessment of bone structure among patients with chronic kidney disease

Introduction

Patients in later stages of chronic kidney disease (CKD) have a 2- to 14-fold increase in fracture risk. Bone mineral density (BMD) assessment is limited due to the inability to measure trabecular and cortical bone characteristics and the interference of aortic calcifications.

Study objective

This study aimed to assess the trabecular bone score (TBS) and three-dimensional dual-energy X-ray absorptiometry (3D-DXA) in participants across all CKD stages.

Patients and methods

In total, 64 CKD patients (consisting of 28 female participants and 36 male participants, with an average age of 69.5 years) were included. There were 9, 12, 8, 9, 11, and 15 participants in stages G1, G2, G3a, G3b, G4, and G5 of CKD, respectively. BMD at the lumbar spine (LS) and proximal femur, as well as the LS TBS, were analyzed. The proximal femur parameters such as cortical and trabecular volumetric (v)BMD, cortical thickness (CTh), and surface (s)BMD at the total hip (TH) and femoral neck (FN) were analyzed using 3D-Shaper software.

Results

Comparison between the earlier stages (G1-G3a) and the later CKD stages (G3b-G5) showed significant differences in carboxy terminal collagen crosslinks (CTx) (386 vs.1053 ng/L), TH areal bone mineral density (aBMD; 0.991 vs. 0.859 g/cm2), cortical TH vBMD (831 vs. 795 mg/cm3), FN (837 vs. 788 mg/cm3), TH cortical sBMD (170 mg/cm2), and TH Cth (2.03 vs. 1.92 mm; all p < 0.05). Cross-sectional comparisons between each CKD stage showed a gradual decrease in the LS BMD, TH cortical vBMD, sBMD (FN and TH), and TH Cth. Strong positive associations between the glomerular filtration rate (GFR) and cortical parameters (FN/TH vBMD and TH Cth) were observed (p < 0.01).

Conclusion

In conclusion, advanced stages of CKD (G3b-G5) were associated with lower cortical bone parameters. The majority of the cortical parameters were correlated with the GFR, demonstrating a direct relationship between the kidney function and bone structure.

Static histomorphometry parameters can identify bone turnover status in children and adults with chronic kidney disease

INTRODUCTION

Tetracycline labeling for bone biopsy facilitates quantification of the pace of new bone production. As tetracycline labeling needs to be done prior to biopsy, it cannot be used to assess bone turnover in patients presenting with fractures, yet knowing turnover rate in patients experiencing fractures - especially in those with chronic kidney disease (CKD) - may guide appropriate medical therapy after surgical repair. Therefore, we sought to determine the diagnostic accuracy of static markers of bone turnover relative to tetracycline labeling in a pediatric and adult cohort of patients with chronic kidney disease (CKD) undergoing iliac crest biopsy with histomorphometry.

METHODS

We evaluated two cohorts, one of 147 children and young adults ages 18±10 and another of 151 adults ages 49±13 who had undergone iliac crest biopsy with tetracycline labeling for clinical indications of CKD-mineral and bone disorders. We used bone formation rate relative to bone surface (BFR/BS) based on double tetracycline labeling as our gold standard marker of bone turnover. A blinded investigator used light microscopy without fluorescence to measure static bone turnover parameters. We compared the area under the ROC curve (AUC), sensitivity, and specificity of each static parameter with low and high bone turnover based on BFR/BS.

RESULTS

In the pediatric and adult cohorts, 35 (24 %) and 70 (46 %) had low bone turnover, respectively, and 18 (12 %) and 30 (20 %) had high bone turnover, respectively. The static parameters with the greatest AUCs for low and high turnover were osteoblast surface/bone surface (Ob.S/BS), osteoclast surface/bone surface (Oc.S/BS), eroded surface/bone surface (ES/BS), osteoid surface/bone surface (OS/BS), osteoid volume/bone volume (OV/BV), and osteoid thickness (O.Th.) in both cohorts. Ob.S/BS had the highest AUC for low and high turnover in the pediatric cohort (0.8204 and 0.8678, respectively) whereas Oc.S/BS had the highest AUC for low turnover (0.8325) and ES/BS had the highest AUC for high turnover (0.7360) in the adult cohort.

DISCUSSION

Static measures of histomorphometry that do not rely on tetracycline bone labeling can identify low and high bone turnover in children and adults with CKD with moderate to high accuracy. This approach may allow assessment of bone turnover in the setting of clinical fractures where clinicians may have access to bone tissue but where tetracycline labeling is not available.

Kidney function and bone mineral density in chronic kidney disease patients

Background

Bone mineral density (BMD) predicts fracture risk in patients with chronic kidney disease (CKD) and in the general population. However, few studies have investigated risk factors for bone loss in patients with CKD. The aim of this study was to investigate whether renal function is associated with the rate of BMD decline.

Methods

A prospective cohort study included 1006 patients with CKD stages 2-4 between 2011 and 2016. BMD was measured using dual-energy X-ray absorptiometry at baseline and 4 years. The eGFR was measured 2-6 times during the 4-year follow-up. We analyzed the decline in bone mineral density according to CKD stage and further compared the rate of BMD decline according to eGFR trajectories at each stage.

Results

Advanced CKD stage was associated with a faster rate of decline in total hip BMD [stage 2 -0.23, stage 3A -0.39, stage 3B -0.80, stage 4 -1.23% change/year in men (P < .001); stage 2 -0.86, stage 3A -1.19, stage 3B -1.20, stage 4 -1.58% change/year in women (P < .03)]. Two distinct eGFR trajectories (Class 1 stable group; Class 2 rapid decline group) were observed. The rapid decline group showed a trend toward an increased rate of decline in total hip BMD. Subgroup analysis according to eGFR trajectories revealed a significant difference in BMD decline rate between stable and rapid decline groups.

Conclusions

Advanced CKD stage and accelerated decline in renal function were associated with rapid BMD decline in non-dialysis patients with CKD.

Systemic immune-inflammatory indicators and bone mineral density in chronic kidney disease patients: A cross-sectional research from NHANES 2011 to 2018

BACKGROUND

The purpose of this study was to look at the relationship between the Systemic Immune Inflammatory Index (SII) and bone mineral density (BMD) in the pelvis, left upper and lower limbs, lumbar spine, thoracic spine, and trunk in a chronic kidney disease (CKD) population in the United States.

METHODS

The National Health and Nutrition Examination Survey (2011-2016) yielded 2302 people with CKD aged >18 years. CKD was defined as eGFR less than 90 ml/min/1.73 m2 or eGFR greater than 90 ml/min/1.73 m2 with urine ACR greater than 30 mg/L.SII was calculated as PC * (NC / LC) from platelet count (PC), neutrophil count (NC), and lymphocyte count (LC). Multiple logistic regression was used to examine the relationship between BMD and SII at different sites in CKD patients, smoothed curve-fitting and generalized weighting models were used to investigate non-linear relationships, and a two-tailed linear regression model was used to find potential inflection points in the model.

RESULTS

We discovered a negative correlation between SII and pelvic BMD among 2302 participants after controlling for gender, age, and race [β = -0.008; 95% confidence value -0.008; 95% confidence interval (CI) -0.014, -0.002]. Lower PEBMD was related to increasing SII (trend p = 0.01125). After additional correction, only pelvic BMD remained adversely linked with SII [value -0.006; 95% CI -0.012, -0.000, p = 0.03368]. Smoothed curve fitting revealed a consistent inverse relationship between SII and pelvic BMD. Further stratified analyses revealed a substantial positive negative connection between SII and pelvic BMD in individuals who did not have hypertension, diabetes, a BMI of more than 30 kg/m2, or stage 2 CKD. The connection between SII and PEBMD in people without diabetes revealed a strong inverted U-shaped curve.

CONCLUSION

In individuals with CKD in the United States, there was a negative connection between the systemic immunoinflammatory index (SII) and pelvic BMD. The SII might be a low-cost and simple test for CKD-related BMD loss.

Predicting Osteoporotic Fracture in Patients With Early-Stage Diabetic Kidney Disease Using a Radiomic Model: A Longitudinal Cohort Study

OBJECTIVE

There is an urgent need for effective predictive strategies to accurately evaluate the risk of fragility fractures in elderly patients in the early stages of diabetic kidney disease (DKD).

METHODS

This longitudinal cohort study included 715 older patients in the early stages of DKD diagnosed between January 2015 and August 2019. Patients were randomly allocated to a training cohort (n = 499) and a validation cohort (n = 216). The least absolute shrinkage and selection operator method was used to select key features for dual-energy x-ray absorptiometry-based radiomic analysis. A radiomic model was constructed using Cox proportional hazards regression. The performance of the radiomic model was compared with that of traditional fracture assessment tools through a receiver operating characteristic curve, calibration curve, and decision curve analysis.

RESULTS

Over a mean follow-up period of 4.72 ± 1.60 years, 65 participants (9.09%) experienced incident fragility fractures. Seventeen features were ultimately selected to create the radiomic model. The calibration plots of this model demonstrated satisfactory agreement between the observed and predicted outcomes. Moreover, the radiomic model outperformed traditional fracture assessment tools in both the training and validation cohorts according to the area under the receiver operating characteristic curve and decision curve analysis.

CONCLUSIONS

The novel radiomic model has demonstrated a more effective prediction of fragility fracture in elderly patients in the early stages of DKDcompared to traditional fracture assessment tools.

Osteoporosis management in patients with chronic kidney disease (ERCOS Study): A challenge in nephrological care

Fracture risk assessment in patients with chronic kidney disease (CKD) has been included in the CKD-MBD ("Chronic Kidney Disease-Mineral and Bone Disorders") complex in international and national nephrology guidelines, suggesting for the first time the assessment of bone mineral density (BMD) if the results can influence therapeutic decision-making. However, there is very little information on actual clinical practice in this population. The main objective of the ERCOS (ERC-Osteoporosis) study is to describe the profile of patients with CKD G3-5D with osteoporosis (OP) and/or fragility fractures treated in specialized nephrology, rheumatology and internal medicine clinics in Spain. Fifteen centers participated and 162 patients (mostly women [71.2%] postmenopausal [98.3%]) with a median age of 77 years were included. Mean estimated glomerular filtration rate (eGFR) was 36 mL/min/1.73 m2 and 38% of the included patients were on dialysis. We highlight the high frequency of prevalent fragility fractures [37.7%), mainly vertebral (52.5%) and hip (24.6%)], the disproportionate history of patients with glomerular disease compared to purely nephrological series (corticosteroids) and undertreatment for fracture prevention, especially in nephrology consultations. This study is an immediate call to action with the dissemination of the new, more proactive, clinical guidelines, and underlines the need to standardize a coordinated and multidisciplinary care/therapeutic approach to these patients in an efficient way to avoid current discrepancies and therapeutic nihilism.

Evaluating Osteoporosis in Chronic Kidney Disease: Both Bone Quantity and Quality Matter

Bone strength is determined not only by bone quantity [bone mineral density (BMD)] but also by bone quality, including matrix composition, collagen fiber arrangement, microarchitecture, geometry, mineralization, and bone turnover, among others. These aspects influence elasticity, the load-bearing and repair capacity of bone, and microcrack propagation and are thus key to fractures and their avoidance. In chronic kidney disease (CKD)-associated osteoporosis, factors traditionally associated with a lower bone mass (advanced age or hypogonadism) often coexist with non-traditional factors specific to CKD (uremic toxins or renal osteodystrophy, among others), which will have an impact on bone quality. The gold standard for measuring BMD is dual-energy X-ray absorptiometry, which is widely accepted in the general population and is also capable of predicting fracture risk in CKD. Nevertheless, a significant number of fractures occur in the absence of densitometric World Health Organization (WHO) criteria for osteoporosis, suggesting that methods that also evaluate bone quality need to be considered in order to achieve a comprehensive assessment of fracture risk. The techniques for measuring bone quality are limited by their high cost or invasive nature, which has prevented their implementation in clinical practice. A bone biopsy, high-resolution peripheral quantitative computed tomography, and impact microindentation are some of the methods established to assess bone quality. Herein, we review the current evidence in the literature with the aim of exploring the factors that affect both bone quality and bone quantity in CKD and describing available techniques to assess them.

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

[Diagnosis and treatment of osteoporosis in patients with chronic kidney disease : Joint guidelines of the Austrian Society for Bone and Mineral Research (ÖGKM), the Austrian Society of Physical and Rehabilitation Medicine (ÖGPMR) and the Austrian Society of Nephrology (ÖGN)]

DEFINITION AND EPIDEMIOLOGY

Chronic kidney disease (CKD): abnormalities of kidney structure or function, present for over 3 months. Staging of CKD is based on GFR and albuminuria (not graded). Osteoporosis: compromised bone strength (low bone mass, disturbance of microarchitecture) predisposing to fracture. By definition, osteoporosis is diagnosed if the bone mineral density T‑score is ≤ -2.5. Furthermore, osteoporosis is diagnosed if a low-trauma (inadequate trauma) fracture occurs, irrespective of the measured T‑score (not graded). The prevalence of osteoporosis, osteoporotic fractures and CKD is increasing worldwide (not graded). PATHOPHYSIOLOGY, DIAGNOSIS AND TREATMENT OF CHRONIC KIDNEY DISEASE-MINERAL AND BONE DISORDER (CKD-MBD): Definition of CKD-MBD: a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following: abnormalities of calcium, phosphorus, PTH, or vitamin D metabolism; renal osteodystrophy; vascular calcification (not graded). Increased, normal or decreased bone turnover can be found in renal osteodystrophy (not graded). Depending on CKD stage, routine monitoring of calcium, phosphorus, alkaline phosphatase, PTH and 25-OH-vitamin D is recommended (2C). Recommendations for treatment of CKD-MBD: Avoid hypercalcemia (1C). In cases of hyperphosphatemia, lower phosphorus towards normal range (2C). Keep PTH within or slightly above normal range (2D). Vitamin D deficiency should be avoided and treated when diagnosed (1C).

DIAGNOSIS AND RISK STRATIFICATION OF OSTEOPOROSIS IN CKD

Densitometry (using dual X‑ray absorptiometry, DXA): low T‑score correlates with increased fracture risk across all stages of CKD (not graded). A decrease of the T‑score by 1 unit approximately doubles the risk for osteoporotic fracture (not graded). A T-score ≥ -2.5 does not exclude osteoporosis (not graded). Bone mineral density of the lumbar spine measured by DXA can be increased and therefore should not be used for the diagnosis or monitoring of osteoporosis in the presence of aortic calcification, osteophytes or vertebral fracture (not graded). FRAX can be used to aid fracture risk estimation in all stages of CKD (1C). Bone turnover markers can be measured in individual cases to monitor treatment (2D). Bone biopsy may be considered in individual cases, especially in patients with CKD G5 (eGFR < 15 ml/min/1.73 m2) or CKD 5D (dialysis).

SPECIFIC TREATMENT OF OSTEOPOROSIS IN PATIENTS WITH CKD

Hypocalcemia should be treated and serum calcium normalized before initiating osteoporosis therapy (1C). CKD G1-G2 (eGFR ≥ 60 ml/min/1.73 m2): treat osteoporosis as recommended for the general population (1A). CKD G3-G5D (eGFR < 60 ml/min/1.73 m2 to dialysis): treat CKD-MBD first before initiating osteoporosis treatment (2C). CKD G3 (eGFR 30-59 ml/min/1.73 m2) with PTH within normal limits and osteoporotic fracture and/or high fracture risk according to FRAX: treat osteoporosis as recommended for the general population (2B). CKD G4-5 (eGFR < 30 ml/min/1.73 m2) with osteoporotic fracture (secondary prevention): Individualized treatment of osteoporosis is recommended (2C). CKD G4-5 (eGFR < 30 ml/min/1.73 m2) and high fracture risk (e.g. FRAX score > 20% for a major osteoporotic fracture or > 5% for hip fracture) but without prevalent osteoporotic fracture (primary prevention): treatment of osteoporosis may be considered and initiated individually (2D). CKD G4-5D (eGFR < 30 ml/min/1.73 m2 to dialysis): Calcium should be measured 1-2 weeks after initiation of antiresorptive therapy (1C).

PHYSICAL MEDICINE AND REHABILITATION

Resistance training prioritizing major muscle groups thrice weekly (1B). Aerobic exercise training for 40 min four times per week (1B). Coordination and balance exercises thrice weekly (1B). Flexibility exercise 3-7 times per week (1B).

Assessing cortical bone porosity with MRI in an animal model of chronic kidney disease

Chronic kidney disease (CKD) is characterized by secondary hyperparathyroidism and an increased risk of hip fractures predominantly related to cortical porosity. Unfortunately, bone mineral density measurements and high-resolution peripheral computed tomography (HR-pQCT) imaging have shortcomings that limit their utility in these patients. Ultrashort echo time magnetic resonance imaging (UTE-MRI) has the potential to overcome these limitations by providing an alternative assessment of cortical porosity. The goal of the current study was to determine if UTE-MRI could detect changes in porosity in an established rat model of CKD. Cy/+ rats (n = 11), an established animal model of CKD-MBD, and their normal littermates (n = 12) were imaged using microcomputed tomography (microCT) and UTE-MRI at 30 and 35 weeks of age (which approximates late-stage kidney disease in humans). Images were obtained at the distal tibia and the proximal femur. Cortical porosity was assessed using the percent porosity (Pore%) calculated from microCT imaging and the porosity index (PI) calculated from UTE-MRI. Correlations between Pore% and PI were also calculated. Cy/+ rats had higher Pore% than normal rats at both skeletal sites at 35 weeks (tibia = 7.13 % +/- 5.59 % vs. 0.51 % +/- 0.09 %, femur = 19.99 % +/- 7.72 % vs. 2.72 % +/- 0.32 %). They also had greater PI at the distal tibia at 30 weeks of age (0.47 +/- 0.06 vs. 0.40 +/- 0.08). However, Pore% and PI were only correlated in the proximal femur at 35 weeks of age (ρ = 0.929, Spearman). These microCT results are consistent with prior studies in this animal model utilizing microCT imaging. The UTE-MRI results were inconsistent, resulting in variable correlations with microCT imaging, which may be related to suboptimal bound and pore water discrimination at higher magnetic field strengths. Nevertheless, UTE-MRI may still provide an additional clinical tool to assess fracture risk without using ionizing radiation in CKD patients.

Bone and Chronic Kidney Disease

Chronic kidney disease (CKD) induces mineral and bone disorders (CKD-MBD) that affect calcium and phosphate metabolism. This review links pathophysiology, histologic aspects, and radiologic signs. CKD leads to bone lesions, namely renal osteodystrophy, which may combine low or high bone remodeling, impaired mineralization, and bone loss. CKD-MBD also comprises vascular calcifications, which, together with bone disease, lead to a high risk of cardiovascular events and osteoporotic fractures that increase both morbidity and mortality. Osteoporosis assessment is based on screening for classic risk factors and CKD-related factors (disease duration/severity, transplantation history, dialysis vintage). Treatment of mineral disorders may combine serum phosphate lowering drugs, natural vitamin D or its 1-α derivatives, or calcium-sensing receptor agonists. Treatment of osteoporosis is conventional in mild to moderate stages but more complex in severe CKD because evidence about the efficacy and safety of anti-osteoporosis drugs is scant.

Recommendations of the Spanish Society of Nephrology for the management of mineral and bone metabolism disorders in patients with chronic kidney disease: 2021 (SEN-MM)

As in 2011, when the Spanish Society of Nephrology (SEN) published the Spanish adaptation to the Kidney Disease: Improving Global Outcomes (KDIGO) universal Guideline on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD), this document contains an update and an adaptation of the 2017 KDIGO guidelines to our setting. In this field, as in many other areas of nephrology, it has been impossible to irrefutably answer many questions, which remain pending. However, there is no doubt that the close relationship between the CKD-MBD/cardiovascular disease/morbidity and mortality complex and new randomised clinical trials in some areas and the development of new drugs have yielded significant advances in this field and created the need for this update. We would therefore highlight the slight divergences that we propose in the ideal objectives for biochemical abnormalities in the CKD-MBD complex compared to the KDIGO suggestions (for example, in relation to parathyroid hormone or phosphate), the role of native vitamin D and analogues in the control of secondary hyperparathyroidism and the contribution of new phosphate binders and calcimimetics. Attention should also be drawn to the adoption of important new developments in the diagnosis of bone abnormalities in patients with kidney disease and to the need to be more proactive in treating them. In any event, the current speed at which innovations are taking place, while perhaps slower than we might like, globally drives the need for more frequent updates (for example, through Nefrología al día).

Serum calcification propensity and its association with biochemical parameters and bone mineral density in hemodialysis patients

BACKGROUND

T50 is a novel serum-based marker that assesses the propensity for calcification in serum. A shorter T50 indicates a greater propensity to calcify and has been associated with cardiovascular disease and mortality among patients with chronic kidney disease. The factors associated with T50 and the correlation between T50 and bone mineral density (BMD) are unknown in hemodialysis (HD) patients.

METHODS

This cross-sectional study included 184 patients undergoing HD. Individuals were grouped into tertiles of T50 to compare the demographic and disease indicators of the tertiles. Linear regression was used to evaluate the association between T50 and hip and spinal BMD in a multivariate model.

RESULTS

Mineral and inflammatory parameters, including serum phosphate (r = -0.156, p = 0.04), albumin (r = 0.289, p < 0.001), and high-sensitivity C-reactive protein (r = -0.224, p = 0.003) levels, were associated with T50. We found a weak association between T50 and BMD in the total hip area in the unadjusted model (β = 0.030, p = 0.04) but did not find a statistically significant association with the total hip (β = 0.017, p = 0.12), femoral neck (β = -0.001, p = 0.96), or spinal BMD (β = 0.019, p = 0.33) in multivariable-adjusted models.

CONCLUSION

T50 was moderately associated with mineral and inflammatory parameters but did not conclusively establish an association with BMD in HD patients. Broad-scale future studies should determine whether T50 can provide insights into BMD beyond traditional risk factors in this population.

Prevalence of low bone mineral density (T-score ≤ - 2.5) in the whole spectrum of chronic kidney disease: a systematic review and meta-analysis

The prevalence of low bone mineral density (LBMD) in people with chronic kidney disease (CKD) remains unknown. We identified a high prevalence of LBMD in CKD population. Thus, public health strategies should include efforts to prevent, early detect, and manage LBMD in CKD patients, especially in patients undergoing kidney replacement therapy. Mineral and bone disorders are common among patients with CKD, which affects bone mineral density. We conducted a systematic review and meta-analysis to estimate the prevalence of low bone mineral density (LBMD) in adults with CKD. We searched MEDLINE, EMBASE, Web of Science, CINAHL, and LILACS databases from inception to February 2021. Observational studies that reported the prevalence of LBMD in adults with CKD stages 3a-5D were included. The LBMD was defined according to the World Health Organization criterion (T-score ≤  - 2.5). Random-effect model meta-analyses were used to estimate the pooled prevalence of LBMD. Meta-regressions and subgroup analyses were conducted for stages of CKD, dialysis modality, gender, bone sites and morphology, and geographical region. This study was registered in PROSPERO, number CRD42020211077. One-hundred and fifty-three studies with 78,092 patients were included. The pooled global prevalence of LBMD in CKD was 24.5% (95% CI, 21.3 - 27.8%). Subgroup analyses indicated a higher prevalence of LBMD in dialysis patients (30%, 95% CI 25 - 35%) compared with non-dialysis CKD patients (12%, 95% CI 8 - 16%), cortical bone sites (28%, 95% CI 23 - 35%) relative to trabecular sites (19%, 95% CI 14 - 24%), while similar estimates in the European and the Asiatic continents (26%, 95% CI 21 - 30% vs 25%, 95% CI 21 - 29). The prevalence of LBMD in CKD patients is high, particularly in those undergoing dialysis and in cortical bone sites. Therefore, efforts to early diagnosis and management strategies should be implemented in clinical routine for an epidemiological control of LBMD in CKD patients.

Bone Mineral Density and All-Cause Mortality in Patients with Nondialysis Chronic Kidney Disease: Results from KNOW-CKD Study

Despite the clear association between low BMD and all-cause mortality in the general population, the association has not been validated in patients with nondialysis CKD. To investigate the association of low BMD with all-cause mortality in this population, a total of 2089 patients with nondialysis CKD at stages 1 to predialysis 5 were categorized into normal BMD (T-score ≥ -1.0), osteopenia (-2.5 < T-score < -1.0), and osteoporosis (T-score ≤ - 2.5) by the BMD at femoral neck. The study outcome was all-cause mortality. Kaplan-Meier curve depicted a significantly increased number of all-cause death events in the subjects with osteopenia or osteoporosis during the follow-up period compared with subjects with normal BMD. Cox regression models demonstrated that osteoporosis, but not osteopenia, was significantly associated with an increased risk of all-cause mortality (adjusted hazard ratio 2.963, 95% confidence interval 1.655 to 5.307). Smoothing curve fitting model visualized a clear inverse correlation between BMD T-score and the risk of all-cause mortality. Even after recategorizing the subjects by BMD T-scores at total hip or lumbar spine, the result was similar to the primary analyses. Subgroup analyses revealed that the association was not significantly modified by clinical contexts, such as age, gender, body mass index, estimated glomerular filtration rate, and albuminuria. In conclusion, low BMD is associated with an increased risk of all-cause mortality in patients with nondialysis CKD. This emphasizes that the routine measurement of BMD by DXA may confer an additional benefit beyond the prediction of fracture risk in this population.

Bone Disease in Chronic Kidney Disease and Kidney Transplant

Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) comprises alterations in calcium, phosphorus, parathyroid hormone (PTH), Vitamin D, and fibroblast growth factor-23 (FGF-23) metabolism, abnormalities in bone turnover, mineralization, volume, linear growth or strength, and vascular calcification leading to an increase in bone fractures and vascular disease, which ultimately result in high morbidity and mortality. The bone component of CKD-MBD, referred to as renal osteodystrophy, starts early during the course of CKD as a result of the effects of progressive reduction in kidney function which modify the tight interaction between mineral, hormonal, and other biochemical mediators of cell function that ultimately lead to bone disease. In addition, other factors, such as osteoporosis not apparently dependent on the typical pathophysiologic abnormalities resulting from altered kidney function, may accompany the different varieties of renal osteodystrophy leading to an increment in the risk of bone fracture. After kidney transplantation, these bone alterations and others directly associated or not with changes in kidney function may persist, progress or transform into a different entity due to new pathogenetic mechanisms. With time, these alterations may improve or worsen depending to a large extent on the restoration of kidney function and correction of the metabolic abnormalities developed during the course of CKD. In this paper, we review the bone lesions that occur during both CKD progression and after kidney transplant and analyze the factors involved in their pathogenesis as a means to raise awareness of their complexity and interrelationship.

Osteoporosis Risk in Hemodialysis Patients: The Roles of Gender, Comorbidities, Biochemical Parameters, Health and Diet Literacy

Osteoporosis is a common bone health disorder in hemodialysis patients that is linked with a higher morbidity and mortality rate. While previous studies have explored the associated factors of osteoporosis, there is a lack of studies investigating the impacts of health literacy (HL) and digital healthy diet literacy (DDL) on osteoporosis. Therefore, we aimed to investigate the associations of HL, DDL, and other factors with osteoporosis among hemodialysis patients. From July 2020 to March 2021, a cross-sectional study was conducted on 675 hemodialysis patients in eight hospitals in Vietnam. The data were collected by using the osteoporosis self-assessment tool for Asians (OSTA) and the 12-item short form of the health literacy questionnaire (HLS-SF12) on digital healthy diet literacy (DDL) and hemodialysis dietary knowledge (HDK). In addition, we also collected information about the socio-demographics, the clinical parameters, the biochemical parameters, and physical activity. Unadjusted and adjusted multinomial logistic regression models were utilized in order to investigate the associations. The proportion of patients at low, medium, and high levels of osteoporosis risk was 39.6%, 40.6%, and 19.8%, respectively. In the adjusted models, women had a higher likelihood of osteoporosis risk than men (odds ratio, OR, 3.46; 95% confidence interval, 95% CI, 1.86, 6.44; p < 0.001; and OR, 6.86; 95% CI, 2.96, 15.88; p < 0.001). The patients with rheumatoid arthritis (OR, 4.37; 95% CI, 1.67, 11.52; p = 0.003) and stomach ulcers (OR, 1.95; 95% CI, 1.01, 3.77; p = 0.048) were more likely to have a higher likelihood of osteoporosis risk than those without. The patients who had a higher waist circumference (WC), HL, and DDL were less likely to have a medium level of osteoporosis risk (OR, 0.95; 95% CI, 0.92, 0.98; p = 0.004; OR, 0.92; 95% CI, 0.88, 0.96; p < 0.001; OR, 0.96; 95% CI, 0.93, 0.99; p = 0.017, respectively) and a high level of osteoporosis risk (OR, 0.93; 95% CI, 0.89, 0.97; p = 0.001; OR, 0.89; 95% CI, 0.84, 0.94; p < 0.001; OR, 0.95; 95% CI, 0.91, 0.99; p = 0.008, respectively) compared with a low level of osteoporosis risk and to those with a lower WC, HL, and DDL. In addition, higher levels of hemoglobin (Hb) (OR, 0.79; 95% CI, 0.66, 0.95; p = 0.014), hematocrit (Hct) (OR, 0.95; 95% CI, 0.92, 0.99; p = 0.041), albumin (OR, 0.91; 95% CI, 0.83, 0.99; p = 0.030), and education (OR, 0.37; 95% CI, 0.16, 0.88; p = 0.025) were associated with a lower likelihood of a high level of osteoporosis risk. In conclusion, osteoporosis risk is highly prevalent in hemodialysis patients. Improved HL, DDL, education, WC, albumin, Hb, and Hct levels should be considered in preventing hemodialysis patients from developing osteoporosis.

DXA-derived advanced hip analysis and the trabecular bone score in end-stage kidney disease secondary to type 1 diabetes

OBJECTIVE

Patients with end-stage kidney disease (ESKD) caused by type 1 diabetes mellitus (T1DM) have a heightened fracture risk. Bone mineral density (BMD) may predict fracture less accurately in ESKD than in patients with chronic kidney disease (CKD) stages 1-3b or the general population. Alternate, readily available imaging modalities are needed to improve ESKD fracture risk assessment. This study aimed to assess dual-energy X-ray absorptiometry (DXA)-derived BMD, the trabecular bone score (TBS) and advanced hip analysis parameters in patients with ESKD due to T1DM and to compare their results with those of patients with ESKD from other causes.

METHODS

We compared the DXA-derived TBS, hip cortical thickness (CT) and femoral neck (FN) buckling ratio (BR), an index of FN stability, of patients with T1DM and ESKD undergoing simultaneous pancreas kidney transplantation, patients with ESKD from other causes receiving kidney transplants and population reference ranges.

RESULTS

Of 227 patients with ESKD, 28% had T1DM and 65% were male. Compared with other ESKD patients, patients with T1DM were younger (42 ± 7.7 vs 51 ± 13.8 years), had shorter dialysis duration (24.4 ± 21 vs 42.6 ± 40 months), had higher HbA1c (7.9 ± 1.57% vs 5.4 ± 0.95%) and had lower BMI (25 ± 6 vs 27 ± 5 kg/m2). They had lower spine, hip and UD radius BMD Z-scores (all P ≤ 0.001), TBS (1.33 ± 0.12 vs 1.36 ± 0.12; P = 0.05), CT at the FN (P = 0.03), calcar (P = 0.006) and shaft (P < 0.001) and higher BR (10.1±7.1 vs 7.7±4; P = 0.006). All ESKD parameters were lower than population-based reference ranges (P < 0.001). Adjusting for age, sex, dialysis vintage and weight, prevalent vertebral fractures in patients with T1DM and ESKD were associated with higher BR (odds ratio (OR): 3.27 (95% CI: 1.19-8.92), P = 0.002) and lower FN CT (OR: 3.70 (95% CI: 1.13-12.50)).

CONCLUSION

Patients with ESKD and T1DM have reduced TBS, reduced CT and increased BR compared with other ESKD patients. Prospective study of these parameters is warranted to determine their utility in fracture risk prediction and management.

SIGNIFICANCE STATEMENT

Patients with ESKD and T1DM have an elevated fracture risk due to decreased bone strength. As an adjunct to BMD, evaluating dual-energy X-ray absorptiometry parameters that incorporate structural change may have greater value in patients with ESKD and T1DM than in the general population. In this study, patients with ESKD due to T1DM had lower BMD, lower trabecular bone scores, more severe loss of CT and higher BR than other patients with ESKD and people from the general population. Both lower CT and higher BR were associated with prevalent vertebral fractures in patients with T1DM and ESKD. Changes to these parameters should be evaluated for incident fracture prediction.

Management of osteoporosis in patients with chronic kidney disease

Patients with CKD have a 4-fivefold higher rate of fractures. The incidence of fractures increases with deterioration of kidney function. The process of skeletal changes in CKD patients is characterized by compromised bone strength because of deterioration of bone quantity and/or quality. The fractures lead to a deleterious effect on the quality of life and higher mortality in patients with CKD. The pathogenesis of bone loss and fracture is complex and multi-factorial. Renal osteodystrophy, uremic milieu, drugs, and systemic diseases that lead to renal failure all contribute to bone damage in CKD patients. There is no consensus on the optimal diagnostic method of compromised bone assessment in patients with CKD. Bone quantity and mass can be assessed by dual-energy x-ray absorptiometry (DXA) or quantitative computed tomography (QCT). Bone quality on the other side can be assessed by non-invasive methods such as trabecular bone score (TBS), high-resolution bone imaging methods, and invasive bone biopsy. Bone turnover markers can reflect bone remodeling, but some of them are retained by kidneys. Understanding the mechanism of bone loss is pivotal in preventing fracture in patients with CKD. Several non-pharmacological and therapeutic interventions have been reported to improve bone health. Controlling laboratory abnormalities of CKD-MBD is crucial. Anti-resorptive therapies are effective in improving BMD and reducing fracture risk, but there are uncertainties about safety and efficacy especially in advanced CKD patients. Accepting the prevalent of low bone turnover in patients with advanced CKD, the osteo-anabolics are possibly promising. Parathyroidectomy should be considered a last resort for intractable cases of renal hyperparathyroidism. There is a wide unacceptable gap in osteoporosis management in patients with CKD. This article is focusing on the updated management of CKD-MBD and osteoporosis in CKD patients. Chronic kidney disease deteriorates bone quality and quantity. The mechanism of bone loss mainly determines pharmacological treatment. DXA and QCT provide information about bone quantity, but assessing bone quality, by TBS, high-resolution bone imaging, invasive bone biopsy, and bone turnover markers, can guide us about the mechanism of bone loss.

Bone mass measurement by DXA should be interpreted with caution in the CKD population with vascular calcification

BACKGROUND

KDIGO guidelines suggest the use of dual-energy X-ray absorptiometry (DXA) to assess bone mineral density (BMD) in patients with CKD 3a-5D. Previous studies have demonstrated an association between trabecular bone mass loss and coronary artery calcification (CAC) progression. This study aimed to prospectively investigate the relationship between BMD changes, quantified by DXA, and CAC progression in the non-dialyzed CKD population.

METHODS

In this post hoc study, BMD by DXA was measured at the lumbar spine and total hip at baseline and 12-months. Patients were categorized according to BMD changes into 3 different groups: LOSS, UNCHANGED and GAIN. CAC quantification was obtained by multislice computed tomography at baseline and 12-months.

RESULTS

87 patients (55.6 ± 10.7 years, 62% males, 30% diabetic, eGFR = 39.2 ± 18.1 mL/min/1.73m2) were enrolled. CAC was found in 41 (47%) of the patients at baseline and CAC progression in 25 (64%) of them. Considering the lumbar spine and total hip BMD changes together, 24%, 48%, and 25% of the patients were in the LOSS, UNCHANGED and GAIN groups, respectively. Compared to the UNCHANGED or LOSS groups, the GAIN group had an increase in calcium score (p = 0.04) and a higher proportion of patients with CAC progression (p = 0.01). In the logistic regression analysis, CAC progression was 4.5 times more likely to be in the GAIN group.

CONCLUSIONS

The association between the increase in BMD values and the progression of vascular calcification was the result of two concomitant processes overlapping, leading to a misinterpretation of DXA results. Thus, the use of DXA for the evaluation of bone mass, especially at the lumbar spine, must be applied with restraint and its results very carefully interpreted in CKD patients.

Low Turnover Renal Osteodystrophy With Abnormal Bone Quality and Vascular Calcification in Patients With Mild-to-Moderate CKD

Introduction

Limited information is available on renal osteodystrophy (ROD) and vascular calcification (VC) during early chronic kidney disease (CKD). This study was designed to evaluate ROD and VC in 32 patients with CKD stages II to IV.

Methods

Patients underwent dual-energy X-ray absorptiometry (DXA) for assessment of bone mineral density (BMD) and trabecular bone score (TBS), thoracic computed tomography for VC scoring using the Agatston method, and anterior iliac crest bone biopsy for mineralized bone histology, histomorphometry, and Fourier transform infrared spectroscopy (FTIR). Classical and novel bone markers were determined in the blood.

Results

Mean estimated glomerular filtration rate (eGFR) was 44 ± 16 ml/min per 1.73 m2. Of the patients, 84% had low bone turnover. In Whites, eGFR correlated negatively with the turnover parameter activation frequency (Ac.f) (r -0.48, P = 0.019) and with parameters of bone formation. Most patients had VC (>80%) which correlated positively with levels of phosphorus, c-terminal fibroblast growth factor-23, and activin. Aortic calcifications (ACs) correlated negatively with bone formation rate (BFR) and Ac.f (rho -0.62, -0.61, P < 0.001). TBS correlated negatively with coronary calcification (rho -0.42, P = 0.019) and AC (rho -0.57, P = 0.001). These relationships remained after adjustment of age. The mineral-to-matrix ratio, an FTIR metric reflecting bone quality, was negatively related to Ac.f and positively related to AC.

Conclusion

Low bone turnover and VC are predominant in early stages of CKD. This is the first study demonstrating mineral abnormalities indicating reduced bone quality in these stages of CKD.

Lateral spine dual-energy X-ray absorptiometry and the risk of fragility fractures in long-term kidney graft recipients

BACKGROUND

Although the prevalence of osteoporosis and fractures in the first 6-12 months post-renal transplantation is high, little is known about the utility of bone mineral density (BMD) to predict fractures in long-term kidney graft recipients. Lateral spine dual-energy X-ray absorptiometry (DXA) scanning is a reliable tool for measuring glucocorticoid-induced and age-related bone loss in the elderly population. However, little is known about the utility of lateral spine DXA for patients with chronic kidney diseases. This study aimed to analyze the utility of lateral spine BMD for fragility fractures in long-term kidney graft recipients.

METHODS

A total of 357 stable kidney transplant recipients for a minimum of 1 year after kidney transplantation underwent DXA measurements at several sites, including the lateral spine between January 2017 and December 2018. We collected data on new incident fractures from the patients' medical records.

RESULTS

The median post-transplantation time at baseline DXA measurement was 12.6 years. During the median follow-up period of 3.5 years, 41 (11.4%) fractures occurred. The lateral spine BMDs were independently associated with fractures (adjusted hazard ratio 0.076; 95% confidence interval 0.012-0.42, p = 0.003). The cumulative incidence rate of fractures was significantly higher in the lower lateral spine BMD group (< 0.471 g/cm², optimal cut-off value by receiver operating characteristic curve) than in the higher lateral spine BMD group (23.4 vs. 7.4%, adjusted hazard ratio 4.92; 95% confidence interval 2.33-10.74, p < 0.001).

CONCLUSION

Lateral lumbar spine BMD can be used to predict the risk of fragility fractures in long-term kidney graft recipients.

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Association of metabolic acidosis with fractures, falls, protein-calorie malnutrition, and failure to thrive in patients with chronic kidney disease

Background

The risk of adverse geriatric outcomes such as falls and fractures is high among patients with chronic kidney disease (CKD). Metabolic acidosis is associated with protein catabolism and bone loss in experimental animal and human studies. We sought to quantify the independent association of metabolic acidosis with adverse muscle, bone, and functional outcomes in a large U.S. community-based cohort.

Methods

The Optum's de-identified Integrated Claims-Clinical dataset of US patients (2007-2017) was used to generate a cohort of patients with non-dialysis-dependent CKD who had eGFR &gt;10 to &lt;60 mL/min/1.73 m2 and 2 serum bicarbonate values 12 to &lt;22 mmol/L or 22-29 mmol/L. The primary outcomes were failure to thrive, protein-calorie malnutrition, and fall or fracture. Cox proportional hazards models were used for the primary outcomes for up to 10 years, while logistic regression models were used at 2 years.

Results

51,558 patients qualified for the study, with a median (IQR) follow-up time of 4.2 (2.5-5.8) years. Over a ≤ 10-year period, for each 1-mmol/L increase in serum bicarbonate, the hazard ratios (adjusted for age, sex, race, eGFR, serum albumin, hemoglobin, diabetes and cardiovascular comorbidities) for failure to thrive, protein-calorie malnutrition, and fall or fracture were 0.91 (95% confidence interval [CI], 0.90-0.92), 0.91 (95% CI, 0.90-0.92), and 0.95 (95% CI, 0.95-0.96), all P &lt; 0.001, respectively.

Conclusions

The presence and severity of metabolic acidosis was a significant, independent risk factor for failure to thrive, protein-calorie malnutrition, and fall or fracture in this large community cohort of patients with stage 3-5 CKD.

Discordance in Bone Mineral Density between the Lumbar Spine and Femoral Neck Is Associated with Renal Dysfunction

PURPOSE

Bone mineral density (BMD) determined by dual-energy X-ray absorptiometry is considered a gold standard for diagnosing osteoporosis. Some people show discordance in BMD values measured at the femur and that at the lumbar spine (LS). The aim of the present study was to investigate whether differences in BMD T-scores between the LS and femur neck (FN) are associated with renal dysfunction in the general population of Korea.

MATERIALS AND METHODS

We analyzed national data for 17306 adults from the Korean National Health and Nutrition Examination Survey conducted between 2008 and 2011. BMD T-score differences between LS and FN (termed BMD offset) were calculated by subtracting FN T-scores from LS T-scores. Diminished renal function was defined as estimated glomerular filtration rates (eGFR) less than 60 mL/min/1.73 m².

RESULTS

Among those aged ≥50 years, BMD offset was negatively associated with eGFR levels. Additionally, eGFR levels decreased linearly across increasing BMD offset quartiles. Men and women with an offset of >1.5 showed a 4.79-times and 2.51-times higher risk of renal dysfunction, respectively, compared to individuals with an offset of ≤0, after adjusting for age, body mass index, educational level, current smoking, and physical activity. In contrast, there was little evidence of an association between renal dysfunction and BMD offset in subjects aged <50 years.

CONCLUSION

Discordance between LS and FN BMDs was significantly associated with renal dysfunction in subjects aged ≥50 years. When assessing bone health in older chronic kidney disease patients, physicians should consider the possibility of BMD discordance between LS and FN.

Analysis of bone in adenine-induced chronic kidney disease model rats

Objectives

The purpose of this study is to investigate the stage of chronic kidney disease (CKD) in adenine-induced CKD model rats by serum analyses, and to examine bone mineral density (BMD), bone strength, and microstructure of trabecular and cortical bone in these rats.

Methods

Eight-week-old, male Wistar rats (n = 42) were divided into 2 groups: those fed a 0.75% adenine diet for 4 weeks until 12 weeks of age to generate CKD model rats (CKD group); and sham rats. The CKD and sham groups were sacrificed at 12, 16, and 20 weeks of age (n = 7 in each group and at 12, 16, and 20 weeks), and various parameters were evaluated, including body weight, renal wet weight, muscle wet weight, renal histology, biochemical tests, BMD, biomechanical testing, and micro-computed tomography (CT). The parameters were compared between the 2 groups at the various time points.

Results

In the CKD model rats, at 20 weeks of age, serum creatinine, phosphorus, and intact-PTH levels were elevated, and serum calcium levels were normal, indicating that the CKD was stage IV and associated with secondary hyperparathyroidism. Decreased BMDs of the whole body and the femur were observed as bone changes, and micro-CT analysis showed deterioration of bone microstructure of the cortical bone that resulted in decreased bone strength in the cortical and trabecular bone.

Conclusions

These CKD model rats showed stage IV CKD and appear appropriate for evaluating the effects of several treatments for CKD-related osteoporosis and mineral bone disorder.

Low bone mineral density is associated with coronary arterial calcification progression and incident cardiovascular events in patients with chronic kidney disease

BACKGROUND

Although it is well known that low bone mineral density (BMD) is associated with an increased risk of cardiovascular disease (CVD) and mortality in the general population, the prognostic role of bone mineral density (BMD) has not been established in the chronic kidney disease (CKD) population. Therefore we aimed to evaluate the association between BMD and the risk of CVD and cardiovascular mortality in patients with predialysis CKD.

METHODS

This prospective cohort study was conducted with 1957 patients with predialysis CKD Stages 1-5. BMD was measured using dual-energy X-ray absorptiometry and coronary arterial calcification (CAC) scores were evaluated using coronary computed tomography. The primary outcome was a major adverse cardiovascular event (MACE).

RESULTS

When patients were classified based on total hip BMD T-score tertiles stratified by sex, the lowest BMD tertile was significantly associated with an increased risk of MACE {hazard ratio 2.16 [95% confidence interval (CI) 1.25-3.74]; P = 0.006}. This association was also shown with BMD at the femur neck but not with BMD at lumbar spine. In the subgroup of 977 patients with follow-up CACs at their fourth year, 97 (9.9%) showed accelerated CAC progression (>50/year), and BMD was inversely associated with accelerated CAC progression even after adjusting for the baseline CAC score [odds ratio 0.75 (95% CI 0.58-0.99); P = 0.039]. In addition, baseline CAC was associated with an increased risk of MACEs after adjusting for total hip T-score.

CONCLUSIONS

Low BMD was significantly associated with CAC progression and MACEs in patients with predialysis CKD.

Diagnosis and management of osteoporosis in chronic kidney disease stages 4 to 5D: a call for a shift from nihilism to pragmatism

The European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) CKD-MBD working group, in collaboration with the Committee of Scientific Advisors of the International Osteoporosis Foundation, published a position paper for the diagnosis and management of osteoporosis in patients with CKD stages 4-5D (eGFR < 30 ml/min 1.73 m²). The present article reports and summarizes the main recommendations included in this 2021 document. The following areas are reviewed: diagnosis of osteoporosis; risk factors for fragility fractures; fracture risk assessment; intervention thresholds for pharmacological intervention; general and pharmacological management of osteoporosis; monitoring of treatment, and systems of care, all in patients with CKD stages 4-5D. Guidance is provided for clinicians caring for CKD stages 4-5D patients with osteoporosis, allowing for a pragmatic individualized diagnostic and therapeutic approach as an alternative to current variations in care and treatment nihilism.

Fibroblast Growth Factor 23 and Klotho Are Associated With Trabecular Bone Score but Not Bone Mineral Density in the Early Stages of Chronic Kidney Disease: Results of the Cross-Sectional Study

This study evaluates bone mineral density (BMD) and trabecular bone score (TBS) in relationship with new markers of chronic kidney disease (CKD), fibroblast growth factor 23 (FGF23), and klotho. The patients in this cross-sectional study were divided as follows: group A -patients in stages G1-3; group B -patients in stages G4 - 5 according to KDIGO. Plasma levels of soluble klotho and FGF23 were determined by ELISA. Bone mineral density (BMD) and trabecular bone score (TBS) were measured. 74 patients with CKD (mean age 68.8 years) were included in the study. Higher levels of FGF23 were observed in group B (N=15) compared to group A (N=59; p=0.001) were observed. FGF23 was higher in group A compared to group B. Significant difference in TBS within the first 3 stages of CKD was observed (mean TBS in G1=1.375 vs. G2=1.340 vs. G3a=1.24; p<0.05) and negative correlation of FGF23 and TBS (R=-0.33; p=0.05) and positive correlation between klotho and TBS (R=0.419; p=0.04) was observed. This study confirmed that FGF23 and klotho are associated with TBS, but TBS reflects a decrease in kidney function only in the first 3 stages of CKD. Thus, FGF23 and klotho together with TBS are promising markers of early trabecular bone impairment in CKD.

Is dual-energy absorptiometry accurate in the assessment of bone status of patients with chronic kidney disease?

Several patients with chronic kidney disease (CKD) have deteriorated bone status. Estimation of bone status using DXA has limitations especially in patients with CKD accompanying aortic calcifications. Quantitative CT and the trabecular bone score could be more accurate methods to estimate bone status for patients with CKD and vascular calcifications.

INTRODUCTION

It remains unclear whether dual-energy absorptiometry (DXA) is appropriate for the assessment of bone status in patients with chronic kidney disease (CKD), a disease that impacts bone health. The aims of this study were to compare DXA and central quantitative computed tomography (cQCT) and to evaluate bone status in patients with pre-dialysis CKD.

METHODS

This retrospective study included 363 healthy control subjects whose bone mineral density (BMD) was evaluated with DXA and 117 CKD patients whose BMD was evaluated using both cQCT and DXA. Diagnostic discordance was assessed between the lumbar spine (LS) and femur neck (FN) from DXA or between two modalities. The trabecular bone score (TBS) was extracted from DXA images. The volume of abdominal aortic calcification (AAC) was calculated using CT images from cQCT.

RESULTS

Using LS DXA T-score, osteoporosis was less common in the CKD group than in controls. Patients with normal LS BMD using DXA were reclassified into osteopenia or osteoporosis using cQCT in CKD patients. Among discordant subjects between FN and LS in DXA, a higher BMD of LS was more common in CKD patients than in controls. CKD patients had lower TBS than controls despite having the same diagnosis using DXA. AAC volume negatively correlated with BMD from cQCT and with TBS but not with BMD from DXA.

CONCLUSIONS

TBS and cQCT could accurately assess bone status in CKD patients since DXA may overestimate LS BMD, likely due to an increased AAC volume.

Diagnosis and Management of Osteoporosis in Advanced Kidney Disease: A Review

Osteoporosis and fractures are common in persons with advanced chronic kidney disease (CKD) and on maintenance dialysis. Although the diagnosis of osteoporosis in this population can be difficult, imaging, especially with dual-energy x-ray absorptiometry (DXA), is helpful in identifying persons with CKD at the highest risk of fracture. Although blood biomarkers including parathyroid hormone and bone-specific alkaline phosphatase concentrations can aid in assessing bone turnover state, bone biopsy remains the gold standard in determining bone turnover in persons with advanced kidney disease and osteoporosis. With the increasing armamentarium of osteoporosis drugs, it now may be possible to prevent many fractures in advanced CKD. Unfortunately, data on these drugs are limited in persons with advanced CKD. Clinicians, aided by advances in imaging, biomarkers, and bone biopsy can now use these novel agents to target bone turnover abnormalities such as adynamic bone disease and high bone turnover disease. This review will discuss the most recent literature surrounding the diagnosis, management, and monitoring of osteoporosis and fractures in persons with advanced CKD or on maintenance dialysis.

Impact of serum magnesium and bone mineral density on systemic fractures in chronic hemodialysis patients

Introduction

Bone mineral density (BMD) measured with dual-energy X-ray absorptiometry (DXA) can be used to predict fractures, but its clinical utility has not been fully established in chronic kidney disease (CKD) patients. Magnesium is an essential trace element. Although magnesium is associated with the risk of fractures in non-CKD populations, the relationship is unknown in CKD patients.

Methods

BMD and serum magnesium levels were measured in 358 stable outpatients undergoing maintenance hemodialysis therapy. The primary outcome was fragility fracture. Patients were divided into groups according to the median level of magnesium and the normal threshold value of lumbar spine BMD.

Results

During the median follow-up period of 36 months, 36 (10.0%) fractures occurred. The cumulative incidence rates of fractures were 17.6% and 5.2% [adjusted hazard ratio (aHR) 2.31, 95% confidence interval (CI) 1.03–5.17, P = 0.030] in the lower (<2.6 mg/dL) and higher (≥2.6 mg/dL) magnesium (Mg) groups, respectively, and 21.2% and 7.3% (aHR 2.59, 95% CI 1.09–6.16, P = 0.027) in the low- and high-BMD groups, respectively. The lower-Mg and low-BMD group had a 9.21-fold higher risk of fractures (95% CI; 2.35–47.00; P = 0.0010) than the higher-Mg and high-BMD group. Furthermore, adding both magnesium levels and lumbar spine BMD levels to the established risk factors significantly improved the prediction of fractures (C-index: 0.784 to 0.830, p = 0.041).

Discussion/Conclusions

The combination of serum magnesium and lumbar spine BMD can be used for fracture risk stratification and synergistically improves the prediction of fractures in CKD patients.

Bone densitometry versus bone histomorphometry in renal transplanted patients: a cross-sectional study

Bone loss leads to increase risk of fractures in renal transplantation. The aim of this study was to analyse the relationship between bone densitometry (DXA) findings, bone histomorphometry and bone-related molecules 1-year after renal transplantation. We performed a cross-sectional study of de novo renal transplanted patients that agreed to perform a bone biopsy and a DXA examination 1 year after transplantation. All patients underwent a laboratory evaluation, bone biopsy, DXA examination and cardiac CT 1 year after transplantation. 67 patients were included, 16 had a normal examination, and 18 patients were classified as having osteoporosis by DXA. Correlations between bone mineral density and T-scores of total femur and femoral neck were the ones that best correlated with bone volume assessed by a bone biopsy. The sensitivity of DXA for osteoporosis diagnosis was 47.0%, and the specificity was 81.2%. The positive predictive value was 50.0%, and the negative predictive value (NPV) was 80.0%. DXA parameters also correlated with klotho and sclerostin serum levels. In this population, a normal examination excluded the presence of osteoporosis, helping in identifying patients that would not benefit from therapy. Overall, densitometry in total femur and femoral neck correlated well with bone volume measured by bone biopsy.

Patients with end-stage kidney disease have markedly abnormal cortical hip parameters by dual-energy X-ray absorptiometry

BACKGROUND

Patients with end-stage kidney disease (ESKD) have higher fracture rates and post-fracture mortality than the general population, but bone mineral density by dual-energy X-ray absorptiometry (DXA) is less predictive of fracture in this patient group. Bone biopsy and high-resolution imaging indicate that cortical thickness (CT) is reduced and cortical porosity is increased in ESKD. The aim of this study was to assess cortical parameters using DXA in patients with ESKD. It was hypothesized that these parameters would show deterioration and be associated with fracture.

METHODS

Using advanced hip analysis, normal age-related ranges were determined from 752 female and 861 male femur scans and were compared with scans of 226 patients with ESKD at the time of transplantation.

RESULTS

Compared with controls, female patients had lower mean±SD CT (mms) at the femoral neck (FN) (2.59 ± 1.42 versus 5.23 ± 1.85), calcar (3.46 ± 1.07 versus 5.09 ± 1.30) and shaft (4.42 ± 1.21 versus 7.44 ± 2.07; P < 0.001 for each), and buckling ratios were higher (8.21 ± 4.6 versus 3.63 ± 1.42; P < 0.001), indicating greater FN instability. All findings were similar for men. Prevalent fracture was documented in 28.8% of patients; 12.4% vertebral only, 8.4% non-vertebral only and 8% vertebral plus non-vertebral. In adjusted models, each 1 SD reduction in FN CT and increase in the buckling ratio was associated with a respective 1.73 (1.22-2.46)- and 1.82 (1.49-2.86)-fold increase in the risk of prevalent vertebral fracture.

CONCLUSIONS

In patients with ESKD, DXA-derived cortical parameters are markedly abnormal compared with age- and sex-matched controls. These parameters should be assessed for incident fracture prediction and targeting treatment.

Effects of Myo-inositol Hexaphosphate (SNF472) on Bone Mineral Density in Patients Receiving Hemodialysis: An Analysis of the Randomized, Placebo-Controlled CaLIPSO Study

BACKGROUND AND OBJECTIVES

In the CaLIPSO study, intravenous administration of SNF472 (300 or 600 mg) during hemodialysis significantly attenuated progression of coronary artery and aortic valve calcification. SNF472 selectively inhibits formation of hydroxyapatite, the final step in cardiovascular calcification. Because bone mineral is predominantly hydroxyapatite, we assessed changes in bone mineral density in CaLIPSO.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients with coronary artery calcification at screening (Agatston score of 100-3500 U) were randomized 1:1:1 to receive placebo, 300 mg SNF472, or 600 mg SNF472 as an intravenous infusion during hemodialysis three times weekly for 52 weeks. Dual-energy x-ray absorptiometry (DXA) scans were obtained at baseline (screening) and end of treatment, and between-group changes from baseline were compared using analysis of covariance.

RESULTS

Among 274 randomized patients, 202 had evaluable DXA scans at baseline and postrandomization (the DXA-modified intention-to-treat population). Mean (95% confidence interval) changes in total-hip bone mineral density from baseline to week 52 were -1.5% (-2.7% to -0.3%), -1.5% (-2.7% to -0.4%), and -2.5% (-3.8% to -1.2%) in the placebo, 300 mg SNF472, and 600 mg SNF472 groups, respectively. Mean (95% confidence interval) changes in femoral-neck bone mineral density from baseline to week 52 were -0.3% (-1.6% to 1.0%), -1.0% (-2.3% to 0.2%), and -2.6% (-4.0% to -1.3%), respectively. Regression analyses showed no correlation between change in coronary artery calcium volume and change in bone mineral density at either location. Changes in serum alkaline phosphatase, calcium, magnesium, phosphate, and intact parathyroid hormone levels were similar across treatment groups. Clinical fracture events were reported for four of 90, three of 92, and six of 91 patients in the placebo, 300 mg SNF472, and 600 mg SNF472 groups, respectively.

CONCLUSIONS

Bone mineral density decreased modestly in all groups over 1 year. In the 600 mg SNF472 group, the reduction appeared more pronounced. Reported fractures were infrequent in all groups.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Effect of SNF472 on Progression of Cardiovascular Calcification in End-Stage-Renal-Disease (ESRD) Patients on Hemodialysis (HD), NCT02966028.

The renal patient seen by non-renal physicians: the kidney embedded in the 'milieu intérieur'

Chronic kidney disease is defined as a decrease in renal function or evidence of kidney injury for >3 months. This represents an oversimplification that may confuse physicians. Thus kidney function is equated to glomerular filtration rate, which represents one of multiple kidney functions. Some potentially more important renal functions are lost earlier, such as the production for the anti-ageing factor Klotho. Overall, these changes modify the emergent properties of the body, altering the relationships between different organs and systems, in a manner that is difficult to predict the response to interventions based on normal physiology concepts, as there is a novel steady state of interorgan relations. In this regard we now discuss the impact of CKD on heart failure; osteomuscular and joint pain and bone fragility and fractures; and osteosarcopaenia as seen by a cardiologist, a rheumatologist and a geriatrician.

The Non-invasive Diagnosis of Bone Disorders in CKD

Abnormal bone metabolism is an integral part of the chronic kidney disease-mineral bone disorder (CKD-MBD). For several reasons, the difficult bone compartment was neglected for some time, but there has been renewed interest as a result of the conception of bone as a new endocrine organ, the increasing recognition of the cross-talk between bone and vessels, and, especially, the very high risk of osteoporotic fractures (and associated mortality) demonstrated in patients with CKD. Therefore, it has been acknowledged in different guidelines that action is needed in respect of fracture risk assessment and the diagnosis and treatment of osteoporosis in the context of CKD and CKD-MBD, even beyond renal osteodystrophy. These updated guidelines clearly underline the need to improve a non-invasive approach to these bone disorders in order to guide treatment decisions aimed at not only controlling CKD-MBD but also decreasing the risk of fracture. In this report, we review the current role of the most often clinically used or promising biochemical circulating biomarkers such as parathyroid hormone, alkaline phosphatases, and other biochemical markers of bone activity as alternatives to some aspects of bone histomorphometry. We also mention the potential role of classic and new imaging techniques for CKD patients. Information on many aspects is still scarce and heterogeneous, but many of us consider that it is indeed time for action, recognizing our definitely limited ability to base certain treatment decisions only on our current non-comprehensive knowledge.

The Role of Bone Biopsy in the Management of CKD-MBD

A bone biopsy is still considered the gold standard for diagnosis of renal osteodystrophy. It allows to measure both static and dynamic parameters of bone remodeling and is the only method able to evaluate mineralization and allows analysis of both cortical and trabecular bone. Although bone volume can be measured indirectly by dual-energy X-ray absorptiometry, mineralization defects, bone metal deposits, cellular number/activity, and even turnover abnormalities are difficult to determine by techniques other than qualitative bone histomorphometry. In this review, we evaluate the role of bone biopsy in the clinical practice.

Bone Fragility Fractures in CKD Patients

Chronic kidney diseases (CKD) are associated with mineral and bone diseases (MBD), including pain, bone loss, and fractures. Bone fragility related to CKD includes the risk factors observed in osteoporosis in addition to those related to CKD, resulting in a higher risk of mortality related to fractures. Unawareness of such complications led to a poor management of fractures and a lack of preventive approaches. The current guidelines of the Kidney Disease Improving Global Outcomes (KDIGO) recommend the assessment of bone mineral density if results will impact treatment decision. In addition to bone density, circulating biomarkers of mineral, serum bone turnover markers, and imaging techniques are currently available to evaluate the fracture risk. The purpose of this review is to provide an overview of the epidemiology and pathogenesis of CKD-associated bone loss. The contribution of the current tools and other techniques in development are discussed. We here propose a current view of how to better predict bone fragility and the therapeutic options in CKD.

Longitudinal Bone Loss Occurs at the Radius in CKD

Introduction

Chronic kidney disease (CKD) exposes to an increased incidence of fragility fractures. International guidelines recommend performing bone mineral density (BMD) if the results will impact treatment decisions. It remains unknown where bone loss occurs and what would preclude the longitudinal loss in patients with CKD. Here, we aimed to investigate factors influencing BMD and to analyze the longitudinal BMD changes.

Methods

In the NephroTest cohort, we measured BMD at the femoral neck, total hip, lumbar spine, and proximal radius, together with circulating biomarkers and standardized measured glomerular filtration rate (mGFR) by ⁵¹Cr-EDTA in a subset of patients with CKD stage 1 to 5 followed during 4.3 ± 2.0 years. A linear mixed model explored the longitudinal bone loss and the relationship of associated factors with BMD changes. A total of 858 patients (mean age 58.9 ± 15.2 years) had at least 1 and 477 had at least 2 BMD measures.

Results

At baseline, cross-sectional analysis showed a significantly lower BMD at femoral neck and total hip and a significant higher serum parathyroid hormone (PTH) along with CKD stages. Baseline age, gender, tobacco, low body mass index (BMI), and high PTH levels were significantly associated with low BMD. Longitudinal analysis during the mean 4.3 years revealed a significant bone loss at the radius only. BMD changes at the femoral neck were associated with BMI, but not CKD stages or basal PTH levels.

Conclusions

CKD is associated with low BMD and high PTH in the cross-sectional analysis. Longitudinal bone loss occurred at the proximal radius after 4.3 years.

European Consensus Statement on the diagnosis and management of osteoporosis in chronic kidney disease stages G4-G5D

Controlling the excessive fracture burden in patients with chronic kidney disease (CKD) Stages G4-G5D remains an impressive challenge. The reasons are 2-fold. First, the pathophysiology of bone fragility in patients with CKD G4-G5D is complex and multifaceted, comprising a mixture of age-related (primary male/postmenopausal), drug-induced and CKD-related bone abnormalities. Second, our current armamentarium of osteoporosis medications has not been developed for, or adequately studied in patients with CKD G4-G5D, partly related to difficulties in diagnosing osteoporosis in this specific setting and fear of complications. Doubts about the optimal diagnostic and therapeutic approach fuel inertia in daily clinical practice. The scope of the present consensus paper is to review and update the assessment and diagnosis of osteoporosis in patients with CKD G4-G5D and to discuss the therapeutic interventions available and the manner in which these can be used to develop management strategies for the prevention of fragility fracture. As such, it aims to stimulate a cohesive approach to the management of osteoporosis in patients with CKD G4-G5D to replace current variations in care and treatment nihilism.

Relationships Between Level and Change in Sarcopenia and Other Body Composition Components and Adverse Health Outcomes: Findings from the Health, Aging, and Body Composition Study

We investigated how baseline values and rates of decline in components of sarcopenia and other body composition parameters relate to adverse clinical outcomes using the Health, Aging, and Body Composition Study. 2689 participants aged 70-79 years were studied. Appendicular lean mass, whole body fat mass, and total hip BMD were ascertained using DXA; muscle strength by grip dynamometry; and muscle function by gait speed. Baseline values and 2-3 year conditional changes (independent of baseline) in each characteristic were examined as predictors of mortality, hospital admission, low trauma fracture, and recurrent falls in the subsequent 10-14 years using Cox regression (generalized estimating equations used for recurrent falls) with adjustment for sex, ethnicity, age, and potential confounders. Lower levels and greater declines in all parameters (excluding hip BMD level) were associated (p < 0.05) with increased rates of mortality; fully-adjusted hazard ratios per SD lower gait speed and grip strength were 1.27 (95% CI 1.19, 1.36) and 1.14 (1.07, 1.21), respectively. Risk factors of hospital admission included lower levels and greater declines in gait speed and grip strength, and greater declines in hip BMD. Lower levels and greater declines in fat mass and hip BMD were associated with low trauma fracture. Lower gait speed, higher fat mass, and both lower levels and greater declines in grip strength were related to recurrent falls. Lower baseline levels and greater declines in musculoskeletal parameters were related to adverse outcomes. Interventions to maximize peak levels in earlier life and reduce rates of age-related decline may reduce the burden of disease in this age group.