Temporal trends in fracture rates and postdischarge outcomes among hemodialysis patients

Orthopaedic fracture site and wound healing risk among end-stage renal disease patients undergoing open reduction internal fixation: A database analysis

Introduction

The aims of this study are to 1) identify incidence rate of fracture occurrence among end-stage renal disease (ESRD) patients requiring open reduction internal fixation (ORIF) stratified by anatomic site and 2) assess the risk of perioperative wound complications among ESRD fracture patients requiring ORIF compared to non-ESRD patients.

Materials and methods

This retrospective cohort study utilized the Nationwide Inpatient Sample database, covering the period from January 2002 to December 2014, to examine patients over 18 years of age who underwent ORIF for extremity fractures in the United States. Two-sample Z-tests were employed to assess differences in patient demographics, comorbidities, and anatomical fracture sites between ESRD and non-ESRD cohorts. Additionally, multivariate logistic regression was used to examine differences in specific wound complications between these cohorts, and ANOVA tests assessed the effect of dialysis modality on wound complication risk.

Results

A total of 867,378 patients undergoing ORIF, with 7055 (0.8 %) reported ESRD. ESRD patients had a significantly higher incidence of femur fractures compared to those without ESRD (61.9 % vs. 42.1 %, p < 0.05). Furthermore, ESRD patients had a 1.55, 2.14, and 2.57 times increased odds of wound complication (p = 0.001), wound dehiscence (p = 0.003), and non-healing wound (p = 0.007) compared to patients without ESRD, respectively. No significant differences were found in the impact of dialysis modality on overall wound complication, wound dehiscence, non-healing wounds, seroma, and wound infection rates (p > 0.05 for all).

Conclusions

ESRD patients are predisposed to more frequent fractures, particularly of the femur, than those without ESRD. Furthermore, it underscores the increased incidence of perioperative wound complications, such as infections and delayed healing, in patients with ESRD undergoing ORIF.

Higher Serum Alkaline Phosphatase Is a Risk Factor of Death and Fracture: A Nationwide Cohort Study of Japanese Patients on Dialysis

Key Points

In the lower-parathyroid hormone (PTH) group, associations between serum alkaline phosphatase (ALP) and all-cause mortality were positive and linear. In the higher-PTH group, lower serum ALP tended to have higher risk than those with intermediate serum ALP. Serum ALP was independently and linearly associated with new hip fracture regardless of intact PTH level.

Background

Monitoring of serum alkaline phosphatase (ALP) is recommended in the management of CKD–mineral bone disorder because of associations with poor outcomes among patients on dialysis. However, such associations may have changed with several advances in the management of CKD–mineral bone disorder over the past decade.

Methods

Baseline data of 241,670 patients on dialysis (mean age, 69±12 years; male, 65.9%; median dialysis duration, 68 months) were extracted from a nationwide dialysis registry in Japan at the end of 2019. Outcomes, including all-cause and cardiovascular (CV) mortality and hip fracture, were evaluated using the registry at the end of 2020 and 2021. All-cause mortality was assessed using Cox regression analysis, whereas CV mortality and new hip fracture were assessed using competing-risks regression analysis. Multiple imputations for missing values were performed.

Results

Within the 2-year study period, a total of 40,449 patients (16.7%) died, including 13,562 CV deaths (5.6%). Of the 168,836 patients with no history of hip fracture at the end of 2019, 4136 (2.4%) suffered hip fracture within 2 years. Higher serum ALP was independently associated with higher all-cause and CV mortality and new hip fracture, but the association with CV mortality was marginal (hazard ratio, 1.21; 95% confidence interval [CI], 1.18 to 1.24; subhazard ratio, 1.07; 95% CI, 1.03 to 1.12 and subhazard ratio, 1.28, 95% CI, 1.19 to 1.38, respectively). There is a linear association between serum ALP and all-cause mortality among the lower parathyroid hormone (PTH) group, whereas lower serum ALP tended to have higher all-cause mortality than intermediate serum ALP among patients in the higher PTH group.

Conclusions

Higher serum ALP was independently and linearly associated with higher all-cause and CV mortality and new hip fracture in Japanese patients on dialysis. Higher serum ALP and higher intact PTH were synergistic in increasing all-cause and CV mortality but were not associated with new hip fracture.

Lower serum magnesium levels are associated with a higher risk of fractures and vascular calcifications in hemodialysis patients

Background

Magnesium (Mg) deficiency seems to be associated with altered bone metabolism and vascular calcifications (VC). This study aimed to evaluate the association between serum Mg levels and incident bone fragility fractures and VC in a cohort of prevalent hemodialysis (HD) patients.

Methods

We performed a retrospective study of 206 patients, with a mean age of 68.3 ± 13.1 years; 121 (59%) were male, and the median follow-up time was 58 months.

Results

Thirty-seven episodes of fragility fractures were identified with a median HD vintage of 42 months-an incidence rate of 29 per 1000 person-years. Patients with fractures showed lower Mg levels compared with those without fractures (P < .001) and more VC (P = .01). In a Cox regression analysis, time to fragility fracture was independently associated with serum Mg <2.2 mg/dL (P < .001), in a model adjusted to age, female gender, HD vintage, diabetes mellitus, body mass index, albumin, parathyroid hormone, active vitamin D therapy and the presence of VC. Patients with Mg serum levels <2.2 mg/dL had a 1.32-fold higher risk of fragility fractures (P < .001).

Conclusions

This study showed that the incidence of bone fragility fractures in HD patients is high and is significantly associated with lower Mg levels and with the presence of more VC.

Lower body bone fractures have high mortality rates and poor prognosis in the patients with hemodialysis

INTRODUCTION

The objective of the current study was to investigate the association between lower body bone fractures occurring during maintenance hemodialysis and prognosis.

METHODS

This study included 151 hemodialysis patients at the dialysis center of our hospital as of December 2017, and data were systematically gathered from medical records over a period of 5 years, concluding in December 2022.

RESULTS

Fourteen patients, 3.0 per 100 person-years, in 151 hemodialysis patients suffered from lower body bone fractures. The ratio of males was significantly lower, and age was significantly higher in the lower body bone fracture group than in the no lower body bone fracture group. Duration of hemodialysis prior to entry into this study was significantly shorter in the lower body bone fracture group than in the no lower body bone fracture group. Serum albumin was significantly lower and alkaline phosphatase was significantly higher in the lower body bone fracture group than in the no lower body bone fracture group. Mortality rate was significantly higher in the lower body bone fracture group (85.7%) compared to no lower body bone fracture group (28.5%) (p = 0.01). Kaplan-Meier survival curves for mortality showed that lower body bone fracture group had poor prognosis compared to no lower body bone fracture group. Multivariable-adjusted odds ratio for mortality were significantly higher for cases with lower body bone fractures.

CONCLUSION

Lower body bone fractures have high mortality rates and poor prognosis in the patients with hemodialysis.

Fibroblast growth factor 23 and its role in bone diseases

Fibroblast growth factor 23 (FGF23) has been casually linked to numerous hypophosphatemic bone diseases, however connection with bone loss or fragility fractures is still a matter of debate. The purpose of this review is to explore and summarise the known actions of FGF23 in various pathological bone conditions. Besides implication in bone mineralisation, elevated FGF23 showed a pathological effecton bone remodelling, primarily by inhibiting osteoblast function. Unlike the weak association with bone mineral density, high values of FGF23 have been connected with fragility fracture prevalence. This review shows that its effects on bone are concomitantly present on multiple levels, affecting both qualitative and quantitative part of bone strength, eventually leading to impaired bone strength and increased tendency of fractures. Recognising FGF23 as a risk factor for the development of bone diseases and correcting its levels could lead to the reduction of morbidity and mortality in specific groups of patients.

Changes in Bone Quality after Treatment with Etelcalcetide

INTRODUCTION

Secondary hyperparathyroidism is associated with osteoporosis and fractures. Etelcalcetide is an intravenous calcimimetic for the control of hyperparathyroidism in patients on hemodialysis. Effects of etelcalcetide on the skeleton are unknown.

METHODS

In a single-arm, open-label, 36-week prospective trial, we hypothesized that etelcalcetide improves bone quality and strength without damaging bone-tissue quality. Participants were 18 years or older, on hemodialysis ≥1 year, without calcimimetic exposure within 12 weeks of enrollment. We measured pretreatment and post-treatment areal bone mineral density by dual-energy X-ray absorptiometry, central skeleton trabecular microarchitecture by trabecular bone score, and peripheral skeleton volumetric bone density, geometry, microarchitecture, and estimated strength by high-resolution peripheral quantitative computed tomography. Bone-tissue quality was assessed using quadruple-label bone biopsy in a subset of patients. Paired t tests were used in our analysis.

RESULTS

Twenty-two participants were enrolled; 13 completed follow-up (mean±SD age 51±14 years, 53% male, and 15% White). Five underwent bone biopsy (mean±SD age 52±16 years and 80% female). Over 36 weeks, parathyroid hormone levels declined 67%±9% ( P < 0.001); areal bone mineral density at the spine, femoral neck, and total hip increased 3%±1%, 7%±2%, and 3%±1%, respectively ( P < 0.05); spine trabecular bone score increased 10%±2% ( P < 0.001); and radius stiffness and failure load trended to a 7%±4% ( P = 0.05) and 6%±4% increase ( P = 0.06), respectively. Bone biopsy demonstrated a decreased bone formation rate (mean difference -25±4 µ m 3 / µ m 2 per year; P < 0.01).

CONCLUSIONS

Treatment with etelcalcetide for 36 weeks was associated with improvements in central skeleton areal bone mineral density and trabecular quality and lowered bone turnover without affecting bone material properties.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

The Effect of Etelcalcetide on CKD-MBD (Parsabiv-MBD), NCT03960437.

Mortality After Hip and Spine Fractures in Patients With End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

Fractures represent a major cause of disability in the elderly, and patients with fractures exhibit a higher mortality rate than those without. Fractures are also an important health problem among patients with end-stage kidney disease (ESKD) requiring hemodialysis, peritoneal dialysis, or kidney transplantation. To the best of our knowledge, no study in the literature has yet quantitatively summarized the mortality rates, and a summary of evidence on post-hip and spine fracture mortality in patients with ESKD is lacking. The purpose of this study is to quantitatively evaluate the mortality rate, one-year mortality rate, and five-year mortality rate after hip and spine fractures in patients with ESKD receiving kidney replacement therapy. The MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and ClinicalTrials.gov databases were comprehensively searched for reports on mortality rate and time-period mortality in patients with ESKD after hip or spine fractures up to June 2022. Prospective and retrospective cohort studies, as well as case series involving four or more patients, were included. Pooled mortality rate, one-year rate, and five-year mortality rate with 95% confidence intervals (CIs) were examined using a random-effects model. The risk of bias was assessed using the Joanna Briggs Institute (JBI) Prevalence Critical Appraisal Tool. Additionally, heterogeneity between studies was evaluated. A total of 26 studies were included in this meta-analysis. The one-year and five-year mortality rates after hip and spine fractures were 215.35-774.0 per 1,000 person-year and 148-194.1 per 1,000 person-year, respectively. After hip fractures, the one-year mortality rate was 27% (95% CI: 18-38%, I2 = 98%), whereas the five-year mortality rate was 56% (95% CI: 41-71%, I2 = 99%). After spine fractures, the one-year mortality rate was 10% (95% CI: 4-17%, I2 = 70%), whereas the five-year mortality rate was 48.3%. The post-fracture mortality rate was high in patients with ESKD, particularly within one year after the occurrence of fractures. Additionally, the five-year mortality rate after hip femoral or spine fractures was high at approximately 50%.

Comprehensive Associations between Acidosis and the Skeleton in Patients with Kidney Disease

SIGNIFICANCE STATEMENT

Renal osteodystrophy (ROD) contributes substantially to morbidity in CKD, including increased fracture risk. Metabolic acidosis (MA) contributes to the development of ROD, but an up-to-date skeletal phenotype in CKD-associated acidosis has not been described. We comprehensively studied associations between acidosis and bone in patients with CKD using advanced methods to image the skeleton and analyze bone-tissue, along with biochemical testing. Cross-sectionally, acidosis was associated with higher markers of bone remodeling and female-specific impairments in cortical and trabecular bone quality. Prospectively, acidosis was associated with cortical expansion and trabecular microarchitectural deterioration. At the bone-tissue level, acidosis was associated with deficits in bone mineral content. Future work investigating acidosis correction on bone quality is warranted.

BACKGROUND

Renal osteodystrophy is a state of impaired bone quality and strength. Metabolic acidosis (MA) is associated with alterations in bone quality including remodeling, microarchitecture, and mineralization. No studies in patients with CKD have provided a comprehensive multimodal skeletal phenotype of MA. We aim to describe the structure and makeup of bone in patients with MA in the setting of CKD using biochemistry, noninvasive imaging, and histomorphometry.

METHODS

The retrospective cross-sectional analyses included 180 patients with CKD. MA was defined as bicarbonate ≤22 mEq/L. We evaluated circulating bone turnover markers and skeletal imaging with dual energy x-ray absorptiometry and high-resolution peripheral computed tomography. A subset of 54 participants had follow-up. We assessed associations between baseline and change in bicarbonate with change in bone outcomes. Histomorphometry, microCT, and quantitative backscatter electron microscopy assessed bone biopsy outcomes in 22 participants.

RESULTS

The mean age was 68±10 years, 54% of participants were male, and 55% were White. At baseline, acidotic subjects had higher markers of bone turnover, lower areal bone mineral density at the radius by dual energy x-ray absorptiometry, and lower cortical and trabecular volumetric bone mineral density and impaired trabecular microarchitecture. Over time, acidosis was associated with opposing cortical and trabecular effects: cortical expansion but trabecular deterioration. Bone-tissue analyses showed reduced tissue mineral density with increased heterogeneity of calcium distribution in acidotic participants.

CONCLUSIONS

MA is associated with multiple impairments in bone quality. Future work should examine whether correction of acidosis improves bone quality and strength in patients with CKD.

Hypocalcemia Risk of Denosumab Across the Spectrum of Kidney Disease: A Population-Based Cohort Study

Denosumab can be used in patients with chronic kidney disease (CKD) but has been linked with cases of severe hypocalcemia. The incidence of and risk factors for hypocalcemia after denosumab use are not well established. Using linked health care databases at ICES, we conducted a population-based cohort study of adults >65 years old with a new prescription for denosumab or a bisphosphonate between 2012 and 2020. We assessed incidence of hypocalcemia within 180 days of drug dispensing and stratified results by estimated glomerular filtration rate (eGFR in mL/min/1.73 m² ). We used Cox proportional hazards to assess risk factors for hypocalcemia. There were 59,151 and 56,847 new denosumab and oral bisphosphonate users, respectively. Of the denosumab users, 29% had serum calcium measured in the year before their prescription, and one-third had their serum calcium checked within 180 days after their prescription. Mild hypocalcemia (albumin corrected calcium <2.00 mmol/L) occurred in 0.6% (95% confidence interval [CI] 0.6, 0.7) of new denosumab users and severe hypocalcemia (<1.8 mmol/L) in 0.2% (95% CI 0.2, 0.3). In those with an eGFR <15 or receiving maintenance dialysis, the incidence of mild and severe hypocalcemia was 24.1% (95% CI 18.1, 30.7) and 14.9% (95% CI 10.1, 20.7), respectively. In this group, kidney function and baseline serum calcium were strong predictors of hypocalcemia. We did not have information on over-the-counter vitamin D or calcium supplementation. In new bisphosphonate users, the incidence of mild hypocalcemia was 0.3% (95% CI 0.3, 0.3) with an incidence of 4.7% (95% CI 1.5, 10.8) in those with an eGFR <15 or receiving maintenance dialysis. In this large population-based cohort, we found that the overall risk of hypocalcemia with new denosumab use was low but increased substantially in those with eGFR <15 mL/min/1.73 m² . Future studies should investigate strategies to mitigate hypocalcemia. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Magnesium and Fracture Risk in the General Population and Patients Receiving Dialysis: A Narrative Review

Purpose of Review

Magnesium is an essential mineral for bone metabolism, but little is known about how magnesium intake alters fracture risk. We conducted a narrative review to better understand how magnesium intake, through supplementation, diet, or altering the concentration of dialysate magnesium, affects mineral bone disease and the risk of fracture in individuals across the spectrum of kidney disease.

Sources of Information

Peer-reviewed clinical trials and observational studies.

Methods

We searched for relevant articles in MEDLINE and EMBASE databases. The methodologic quality of clinical trials was assessed using a modified version of the Downs and Black criteria checklist.

Key Findings

The role of magnesium intake in fracture prevention is unclear in both the general population and in patients receiving maintenance dialysis. In those with normal kidney function, 2 meta-analyses showed higher bone mineral density in those with higher dietary magnesium, whereas 1 systematic review showed no effect on fracture risk. In patients receiving maintenance hemodialysis or peritoneal dialysis, a higher concentration of dialysate magnesium is associated with a lower concentration of parathyroid hormone, but little is known about other bone-related outcomes. In 2 observational studies of patients receiving hemodialysis, a higher concentration of serum magnesium was associated with a lower risk of hip fracture.

Limitations

This narrative review included only articles written in English. Observed effects of magnesium intake in the general population may not be applicable to those with chronic kidney disease particularly in those receiving dialysis.

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.

Skeletal Outcomes in Children and Young Adults with Glomerular Disease

BACKGROUND

Children with glomerular disease have unique risk factors for compromised bone health. Studies addressing skeletal complications in this population are lacking.

METHODS

This retrospective cohort study utilized data from PEDSnet, a national network of pediatric health systems with standardized electronic health record data for more than 6.5 million patients from 2009 to 2021. Incidence rates (per 10,000 person-years) of fracture, slipped capital femoral epiphysis (SCFE), and avascular necrosis/osteonecrosis (AVN) in 4598 children and young adults with glomerular disease were compared with those among 553,624 general pediatric patients using Poisson regression analysis. The glomerular disease cohort was identified using a published computable phenotype. Inclusion criteria for the general pediatric cohort were two or more primary care visits 1 year or more apart between 1 and 21 years of age, one visit or more every 18 months if followed >3 years, and no chronic progressive conditions defined by the Pediatric Medical Complexity Algorithm. Fracture, SCFE, and AVN were identified using SNOMED-CT diagnosis codes; fracture required an associated x-ray or splinting/casting procedure within 48 hours.

RESULTS

We found a higher risk of fracture for the glomerular disease cohort compared with the general pediatric cohort in girls only (incidence rate ratio [IRR], 1.6; 95% CI, 1.3 to 1.9). Hip/femur and vertebral fracture risk were increased in the glomerular disease cohort: adjusted IRR was 2.2 (95% CI, 1.3 to 3.7) and 5 (95% CI, 3.2 to 7.6), respectively. For SCFE, the adjusted IRR was 3.4 (95% CI, 1.9 to 5.9). For AVN, the adjusted IRR was 56.2 (95% CI, 40.7 to 77.5).

CONCLUSIONS

Children and young adults with glomerular disease have significantly higher burden of skeletal complications than the general pediatric population.

Comparison of bone microstructures via high-resolution peripheral quantitative computed tomography in patients with different stages of chronic kidney disease before and after starting hemodialysis

Chronic kidney disease (CKD) negatively affects bone strength; however, the osteoporotic conditions in patients with CKD are not fully understood. Moreover, the changes in bone microstructure between pre-dialysis and dialysis are unknown. High-resolution peripheral quantitative computed tomography (HR-pQCT) reveals the three-dimensional microstructures of the bone. We aimed to evaluate bone microstructures in patients with different stages of CKD. This study included 119 healthy men and 40 men admitted to Nagasaki University Hospital for inpatient education or the initiation of hemodialysis. The distal radius and tibia were scanned with HR-pQCT. Patient clinical characteristics and bone microstructures were evaluated within 3 months of initiation of hemodialysis (in patients with CKD stage 5 D), patients with CKD stage 4-5, and healthy volunteers. Cortical bone parameters were lower in the CKD group than in healthy controls. Tibial cortical and trabecular bone parameters (cortical thickness, cortical area, trabecular volumetric bone mineral density, trabecular-bone volume fraction, and trabecular thickness) differed between patients with CKD stage 5 D and those with CKD stage 4-5 (p < 0.01). These differences were also observed between patients with CKD stage 5 and those with CKD stage 5 D (p < 0.017), but not between patients with CKD stage 4 and those with CKD stage 5, suggesting that the bone microstructure rapidly changed at the start of hemodialysis. Patients with CKD stage 5 D exhibited tibial microstructural impairment compared with those with CKD stage 4-5. HR-pQCT is useful for elucidation of the pathology of bone microstructures in patients with renal failure.

The impact of chronic kidney disease and dialysis therapy on outcomes of elderly patients with hip fractures: A systematic review and meta-analysis

BACKGROUND AND AIMS

Hip fractures are a commonly occurring comorbidity in patients with chronic kidney disease. To evaluate the comparative rates of post-operative complications, revision surgery, and mortality after hip fracture surgery in chronic kidney disease patients undergoing hemodialysis.

METHODS

A systematic search of the academic literature was performed according to the PRISMA guidelines across five databases: Web of Science, EMBASE, CENTRAL, Scopus, and MEDLINE. A random-effect meta-analysis was conducted to evaluate the overall comparative risks of post-operative complications in chronic kidney disease patients.

RESULTS

Out of 993 studies, 11 eligible studies were included in the review, with a total of 72618 chronic kidney disease patients (mean age: 75.3  ±  3.0 years), and 50566 healthy controls (75.3  ±  2.6 years). Meta-analysis revealed a higher risk of post-operative complications (Odd's ratio: 1.76), revision surgeries (1.69), and mortality-related outcomes (2.47) after hip fracture surgery in chronic kidney disease patients undergoing hemodialysis as compared to chronic kidney disease patients not undergoing hemodialysis.

CONCLUSION

We report higher risks of post-operative complications, revision surgery, and mortality in chronic kidney disease patients undergoing hemodialysis as compared to chronic kidney disease patients not undergoing hemodialysis.

Kidney Transplantation, Immunosuppression and the Risk of Fracture: Clinical and Economic Implications

Rationale & Objective

Disorders of bone and mineral metabolism frequently develop with advanced kidney disease, may be exacerbated by immunosuppression after kidney transplantation, and increase the risk of fractures.

Study Design

Retrospective database study.

Setting & Participants

Kidney-only transplant recipients aged ≥18 years from 2005 to 2016 in the United States captured in US Renal Data System records, which integrate Organ Procurement and Transplantation Network/United Network for Organ Sharing records with Medicare billing claims.

Exposures

Various immunosuppression regimens in the first 3 months after kidney transplantation.

Outcomes

The development of fractures, as ascertained using diagnostic codes on Medicare billing claims.

Analytical Approach

We used multivariable Cox regression with inverse propensity weighting to compare the incidence of fractures >3 months-to-3 years after kidney transplantation associated with various immunosuppression regimens compared to a reference regimen of antithymocyte globulin (TMG) or alemtuzumab (ALEM) with tacrolimus + mycophenolic acid + prednisone using inverse probability treatment weighting.

Results

Overall, fractures were identified in 7.5% of kidney transplant recipients (women, 8.8%; men, 6.7%; age < 55 years, 5.9%; age ≥ 55 years, 9.3%). In time-varying regression, experiencing a fracture was associated with a substantially increased risk of subsequent death within 3 months (adjusted hazard ratio [aHR], 3.06; 95% confidence interval [CI], 2.45-3.81). Fractures were also associated with increased Medicare spending (first year: $5,122; second year: $10,890; third year: $11,083; [P < 0.001]). Induction with TMG or ALEM and the avoidance or early withdrawal of steroids significantly reduced the risk of fractures in younger (aHR, 0.63; 95% CI, 0.54-0.73) and older (aHR, 0.83; 95% CI, 0.74-0.94) patients. The avoidance or early withdrawal of steroids with any induction was associated with a reduced risk of fractures in women.

Limitations

This was a retrospective study which lacked data on immunosuppression levels.

Conclusions

Fractures after kidney transplantation are associated with significantly increased mortality risk and costs. The early avoidance or early withdrawal of steroids after induction with TMG or ALEM reduces the risk of fractures after kidney transplantation and should be considered for patients at high-risk of this complication, including older adults and women.

Prevalence and predictors of asymptomatic vertebral fracture in patients with end-stage renal disease

Objective

This study aimed to investigate the prevalence and predictors of asymptomatic vertebral fracture in patients with end-stage renal disease undergoing hemodialysis.

Methods

This cross-sectional study included 80 patients with end-stage renal disease undergoing hemodialysis. Medical history, Fracture Risk Assessment Tool and anteroposterior and lateral radiographs of the thoracolumbar and lumbosacral spine were obtained. Vertebral fractures were identified using the Genant semiquantitative assessment.

Results

Radiography demonstrated asymptomatic vertebral fracture in 22 patients (27.5%). FRAX® results for major osteoporotic fracture (area under the curve, 0.64) and hip fracture (area under the curve, 0.62) were able to discriminate patients with prevalent asymptomatic vertebral fracture. A multivariate analysis demonstrated that a 1-year average corrected calcium (odds ratio, 0.38), steroid use (odds ratio, 8.99), and a serum albumin concentration <25 g/dL (odds ratio, 28.82) significantly predicted prevalent asymptomatic vertebral fracture (clinical model; area under the curve, 0.82). Combining the 1-year average corrected calcium and serum albumin concentration <25 g/dL with FRAX® results for major osteoporotic fracture (area under the curve, 0.78) and FRAX® results for hip (area under the curve, 0.75) produced a significantly greater area under the curve value to predict fracture when compared with FRAX® result for major osteoporotic fracture and FRAX® result for hip (P = 0.022).

Conclusion

Asymptomatic vertebral fracture is prevalent. FRAX® results for major osteoporotic fracture and hip provided lower ability in predicting asymptomatic vertebral facture when compared to the clinical model. Combining a 1-year average corrected calcium and serum albumin concentration <25 g/dL with FRAX® result for major osteoporotic fracture or hip improved the model's performance and provided comparable area under the curve to the clinical model.

Effects of osteoporosis medications on bone fracture in patients with chronic kidney disease

PURPOSE OF THE STUDY

The risk of bone fracture is high in patients with chronic kidney disease (CKD), and aggressive treatment to reduce fragility fracture risk is the major strategy. However, the outcomes of osteoporosis medications in patients with CKD remain unclear.

STUDY DESIGN

Patients with stage 3-5 CKD during 2011-2019 were enrolled. Patients were divided into two groups based on receiving osteoporosis medications (bisphosphonates, raloxifene, teriparatide or denosumab) or not. Two groups were matched at a 1:1 ratio by using propensity scores. The outcomes of interest were bone fractures, cardiovascular (CV) events and all-cause mortality. Cox proportional hazard regression models were applied to identify the risk factors. Additional stratified analyses by cumulative dose, treatment length and menopause condition were performed.

RESULTS AND CONCLUSIONS

67 650 patients were included. After propensity score matching, 1654 patients were included in the study and control group, respectively. The mean age was 70.2±12.4 years, and 32.0% of patients were men. After a mean follow-up of 3.9 years, the incidence rates of bone fracture, CV events and all-cause mortality were 2.0, 1.7 and 6.5 per 1000 person-months, respectively. Multivariate analysis results showed that osteoporosis medications reduced the risk of CV events (HR, 0.35; 95% CI, 0.18 to 0.71; p=0.004), but did not alleviate the risks of bone fracture (HR, 1.48; 95% CI, 0.73 to 2.98; p=0.28) and all-cause mortality (HR, 0.93; 95% CI, 0.67 to 1.28; p=0.65). Stratified analysis showed that bisphosphonates users have most benefits in the reduction of CV events (HR, 0.26; 95% CI, 0.11 to 0.64; p=0.003). In conclusion, osteoporosis medications did not reduce the risk of bone fractures, or mortality, but improved CV outcomes in patients with CKD.

Oral Calcitriol Use, Vertebral Fractures, and Vitamin K in Hemodialysis Patients: A Cross-Sectional Study

Fractures and vascular calcifications (VCs) are common in patients with chronic kidney disease (CKD). They are related to abnormalities in vitamin D metabolism, calcium, phosphorus, parathyroid hormone, and fibroblast growth factor 23 (FGF23)/Klotho that occur with CKD. Impaired vitamin D metabolism and abnormal levels of calcium, phosphate, parathyroid hormone (PTH), and FGF23/Klotho drive bone and vascular changes in CKD. It is unclear if oral calcitriol safely mitigates fracture risk without increasing the burden of calcifications. Therefore, we investigated whether treatment with calcitriol affected the prevalence of fractures and VC progression in hemodialysis (HD) patients. This report is a secondary analysis of the Vitamin K Italian (VIKI) study, a cross-sectional study involving 387 HD patients. We assessed vitamin 25(OH)D, alkaline phosphatase, PTH, calcium, phosphate, osteocalcin or bone Gla protein, matrix Gla protein, and vitamin K levels. Vertebral fractures (VFs) and VCs were determined by spine radiograph. A reduction of >20% of vertebral body height was considered a VF. VCs were quantified by the length of calcific lesions along the arteries. The patients treated with oral calcitriol were 177 of 387 patients (45.7%). The prevalence of VF was lower in patients receiving oral calcitriol than in those untreated (48.6% versus 61.0%, p = 0.015), whereas the presence of aortic and iliac calcifications was similar (aortic: 81.9% versus 79.5%, respectively, p = 0.552; iliac: 52.0% and 59.5%, respectively, p = 0.167). In multivariable logistic regression analysis, oral calcitriol was associated with a 40.2% reduced odds of fracture (OR 0.598; 95% confidence interval [CI], 0.363-0.985; p = 0.043). In conclusion, we found a significant association between oral calcitriol and lower VF in HD patients without an increase in the burden of VC. Further prospective and interventional studies are needed to confirm these findings. © 2021 American Society for Bone and Mineral Research (ASBMR).

Smoking and risk of fractures requiring hospitalization in hemodialysis patients: a nationwide cohort study in Japan

BACKGROUND

Smoking is a well-established lifestyle risk factor for fractures in the general population, but evidence specific to hemodialysis populations is lacking. This nationwide cohort study used data from the Japanese Society for Dialysis Therapy Renal Data Registry to examine the association between smoking status and fractures.

METHODS

A total of 154,077 patients (64.2% men; mean age, 68 years) aged ≥20 years undergoing maintenance hemodialysis thrice a week at the end of 2016 were followed for 1 year. Among these, 19,004 (12.3%) patients were current smokers. Standardized incidence rate ratios of hospitalization due to any fracture were calculated and analyzed by multivariable logistic regression analysis, controlling for potential confounders. Propensity score matching and subgroup analyses were also performed as sensitivity analyses.

RESULTS

During the 1-year follow-up period, 3,337 fractures requiring hospitalization (1,201 hip, 479 vertebral, and 1,657 other fractures) occurred in 3,291 patients. The age- and sex-standardized incidence ratio for current smokers was 1.24 (95% confidence interval, 1.12-1.39) relative to non-smokers. Standardized incidence ratios were similar after stratification by age group and sex. Multivariable logistic regression analysis revealed a 1.25-fold higher risk of any fracture requiring hospitalization (95% confidence interval, 1.10-1.42) in current smokers relative to non-smokers in a fully adjusted model. Propensity score matching showed similar results (odds ratio, 1.25; 95% confidence interval, 1.05-1.48). Subgroup analyses for baseline covariates revealed no significant interactions.

CONCLUSIONS

Smoking is a significant risk factor for any fracture requiring hospitalization in hemodialysis patients.

The Role of DMP1 in CKD-MBD

PURPOSE OF REVIEW

Chronic kidney disease-mineral and bone disorder (CKD-MBD) has become a global health crisis with very limited therapeutic options. Dentin matrix protein 1 (DMP1) is a matrix extracellular protein secreted by osteocytes that has generated recent interest for its possible involvement in CKD-MBD pathogenesis. This is a review of DMP1 established regulation and function, and early studies implicating DMP1 in CKD-MBD.

RECENT FINDINGS

Patients and mice with CKD show perturbations of DMP1 expression in bone, associated with impaired osteocyte maturation, mineralization, and increased fibroblast growth factor 23 (FGF23) production. In humans with CKD, low circulating DMP1 levels are independently associated with increased cardiovascular events. We recently showed that DMP1 supplementation lowers circulating FGF23 levels and improves bone mineralization and cardiac outcomes in mice with CKD. Mortality rates are extremely high among patients with CKD and have only marginally improved over decades. Bone disease and FGF23 excess contribute to mortality in CKD by increasing the risk of bone fractures and cardiovascular disease, respectively. Previous studies focused on DMP1 loss-of-function mutations have established its role in the regulation of FGF23 and bone mineralization. Recent studies show that DMP1 supplementation may fill a crucial therapeutic gap by improving bone and cardiac health in CKD.

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.

Incidence of fractures in middle-aged individuals with early chronic kidney disease: a population-based analysis of CARTaGENE

BACKGROUND

Previous studies evaluating fractures in chronic kidney disease (CKD) have mostly focused on hip or major fractures in aged populations with moderate to advanced CKD. We aimed at evaluating the association between early CKD and fracture incidence at all sites across age and sex in middle-aged individuals.

METHODS

We analyzed CARTaGENE, a prospective population-based survey of 40- to 69-year-old individuals from Quebec (Canada). Estimated glomerular filtration rate (eGFR) at baseline was evaluated categorically or continuously using restricted cubic splines. Fractures at any site (except toes, hand and craniofacial) for up to 7 years of follow-up were identified through administrative databases using a validated algorithm. Adjusted Cox models were used to evaluate the association of CKD with fracture. Interaction terms for age and sex were also added.

RESULTS

A total of 19 391 individuals (756 CKD Stage 3; 9114 Stage 2; 9521 non-CKD) were included and 829 fractures occurred during a median follow-up of 70 months. Compared with the median eGFR of 90 mL/min/1.73 m2, eGFRs of ≤60 mL/min/1.73 m2 were associated with increased fracture incidence in unadjusted and adjusted models [adjusted hazard ratio (HR) = 1.25 (95% confidence interval 1.05-1.49) for 60 mL/min/1.73 m2; 1.65 (1.14-2.37) for 45 mL/min/1.73 m2]. The eGFR was linearly associated with fracture incidence <75 mL/min/1.73 m2 [HR = 1.18 (1.04-1.34) per 10 mL/min/1.73 m2 decrease] but not above [HR = 0.98 (0.91-1.06) per 10 mL/min/1.73 m2 decrease). The effect of decreased eGFR on fracture incidence was more pronounced in younger individuals [HR = 2.45 (1.28-4.67) at 45 years; 1.11 (0.73-1.67) at 65 years] and in men.

CONCLUSIONS

Even early CKD increases fracture incidence, especially in younger individuals and in men.

Zolpidem Versus Trazodone Initiation and the Risk of Fall-Related Fractures among Individuals Receiving Maintenance Hemodialysis

BACKGROUND AND OBJECTIVES

Zolpidem, a nonbenzodiazepine hypnotic, and trazodone, a sedating antidepressant, are the most common medications used to treat insomnia in the United States. Both drugs have side effect profiles (e.g., drowsiness, dizziness, and cognitive and motor impairment) that can heighten the risk of falls and fractures. Despite widespread zolpidem and trazodone use, little is known about the comparative safety of these medications in patients receiving hemodialysis, a vulnerable population with an exceedingly high fracture rate.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using data from the United States Renal Data System registry (2013-2016), we conducted a retrospective cohort study to investigate the association between the initiation of zolpidem versus trazodone therapy and the 30-day risk of hospitalized fall-related fractures among Medicare-enrolled patients receiving maintenance hemodialysis. We used an active comparator new-user design and estimated 30-day inverse probability of treatment-weighted hazard ratios and risk differences. We treated death as a competing event.

RESULTS

A total of 31,055 patients were included: 18,941 zolpidem initiators (61%) and 12,114 trazodone initiators (39%). During the 30-day follow-up period, 101 fall-related fractures occurred. Zolpidem versus trazodone initiation was associated with a higher risk of hospitalized fall-related fracture (weighted hazard ratio, 1.71; 95% confidence interval, 1.11 to 2.63; weighted risk difference, 0.17%; 95% confidence interval, 0.07% to 0.29%). This association was more pronounced among individuals prescribed higher zolpidem doses (hazard ratio, 1.85; 95% confidence interval, 1.10 to 3.01; and risk difference, 0.20%; 95% confidence interval, 0.04% to 0.38% for higher-dose zolpidem versus trazodone; and hazard ratio, 1.60; 95% confidence interval, 1.01 to 2.55 and risk difference, 0.14%; 95% confidence interval, 0.03% to 0.27% for lower-dose zolpidem versus trazodone). Sensitivity analyses using longer follow-up durations yielded similar results.

CONCLUSIONS

Among individuals receiving maintenance hemodialysis, zolpidem initiators had a higher risk of hospitalized fall-related fracture compared with trazodone initiators.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_12_18_CJN10070620_final.mp3.

Fractures after kidney transplantation: Incidence, predictors, and association with mortality

BACKGROUND

Major fractures (MF) are associated with increased mortality in the general population and represent an even higher risk in patients with chronic kidney disease. We investigated incidence, predictors and clinical outcomes associated with first MF (MF_first) following kidney transplantation (KT).

METHODS

We used the Swedish National Renal Registry of 3992 first KT recipients (2005-2016) (median age 53 years, 65% men) and identified all MF_first in hip, spine, humerus and forearm following KT. We estimated incidence rates and predictors of MF_first using flexible parametric hazard models and Fine-Gray analysis accounting for competing risk of death, and risk of all-cause mortality following MF_first using Cox proportional hazards models with fracture as time-varying exposure.

RESULTS

During median follow-up of 4.8 years (IQR 2.2-7.9 years), there were 279 fractures of which 139 were forearm fractures. The crude incidence rate of MF_first (n = 279) was 13.5/1000 patient-years and that of hip fractures (n = 69) 3.4/1000 patient-years. The multivariate-adjusted fracture incidence rates were highest during the first 6 months following KT, and 86% higher in women than in men. High age, female sex, previous history of MF, diabetes nephropathy, pretransplant dialysis therapy and acute rejection were associated with increased risk for MF_first, whereas pre-emptive KT was associated with lower risk of MF_first. Spline curves showed markedly higher impact of higher age on risk of MF_first in women than in men. MF_first (n = 279) independently predicted increased all-cause mortality risk (hazard ratio, HR, 1.78(95%CI 1.35-2.36)). Among MF_first, with humerus fracture as reference, hip fracture (HR, 4.68(95%CI 1.56-14.06)) and spine fracture (HR, 4.02(95%CI 1.19-13.54)), but not forearm fracture (HR, 1.17 (95%CI 0.38-3.53)), were associated with increased all-cause mortality risk.

CONCLUSIONS

The initial 6 months following kidney transplantation is a high-risk period for MF. Among MF, hip fracture and spine fracture associate with substantially increased all-cause mortality risk.

Fractures and their sequelae in non-dialysis-dependent chronic kidney disease: the Stockholm CREAtinine Measurement project

Introduction

People undergoing maintenance dialysis are at high risk for fractures, but less is known about fracture incidence and associated outcomes in earlier stages of chronic kidney disease (CKD).

Methods

We conducted an observational analysis from the Stockholm Creatinine Measurement project, a Swedish health care utilization cohort during 2006–11. We identified all adults with confirmed CKD Stages 3–5 and no documented history of fractures and extracted information on comorbid history, ongoing medication, cardiovascular events and death. We studied incidence rates of fractures (overall and by location), with the estimated glomerular filtration rate (eGFR) as time-dependent exposure. We then studied hazard ratios [HRs and 95% confidence intervals (CIs)] for the events of death and major adverse cardiac events (MACE) using Cox regression with fracture as time-varying exposure.

Results

We identified 68 764 individuals with confirmed CKD (mean age 79 years, 56% women). During a median follow-up of 2.7 years, 9219 fractures occurred, of which 3105 were hip fractures. A more severe CKD stage was associated with a higher risk of fractures, particularly hip fractures: compared with CKD Stage 3a, the adjusted HR was 1.10 (95% CI 1.02–1.19), 1.32 (1.17–1.49) and 2.47 (1.94–3.15) for CKD Stage 3b, 4 and 5, respectively. Spline curves suggested a linear association with fracture risk with an eGFR <30 mL/min/1.73 m². Compared with non-fracture periods, incident fracture was associated with a 4-fold increased mortality within 90 days [HR 4.21 (95% CI 3.95–4.49)]. The risk remained elevated beyond 90 days [HR 1.47 (95% CI 1.40–1.54)] and was stronger after hip fractures. Post-fracture MACE risk was also highest in the first 90 days [HR 4.02 (95% CI 3.73–4.33)], particularly after hip fractures, and persisted beyond 90 days [HR 1.20 (95% CI 1.10–1.30)].

Conclusion

Our findings highlight the commonness of fractures and the increased risk for subsequent adverse outcomes in CKD patients. These results may inform clinical decisions regarding post-fracture clinical surveillance and fracture prevention strategies.

Radiographic absorptiometry: a step in solving the CKD fracture puzzle

Patients on dialysis are highly prone to fracture, and radiographic absorptiometry can be used to measure their bone mineral density and assess fracture risk. However, to determine its place in management, radiographic absorptiometry should be compared with dual-energy X-ray absorptiometry, and with fracture risk assessment tools such as FRAX, tests of muscle strength, biomarkers, and newer dual-energy X-ray absorptiometry techniques. The convenience, accessibility, and cost of radiographic absorptiometry may contribute to its utility in a number of clinical settings.

Long-term excess mortality after hip fracture in hemodialysis patients: a nationwide cohort study in Japan

INTRODUCTION

Fracture dialysis patients have a higher risk of 1-year mortality compared with non-fracture dialysis patients. However, it is unclear whether excess mortality persists for more than a year.

MATERIALS AND METHODS

We conducted a nationwide cohort study in 162,360 hemodialysis patients in Japan. Study outcomes were 5-year all-cause mortality and cause-specific mortality. Cox proportional hazards regression was used to examine the association between hip fracture and mortality in two cohorts: the full cohort, which included potential confounders as covariates in multivariable-adjusted regression models, and the propensity score-matched cohort.

RESULTS

Crude mortality rates for fracture patients were double those of non-fracture patients and persisted during the 5-year period. The association between hip fracture and mortality was significant even after adjusting for premorbid conditions (hazard ratio (HR) 1.22, 95% confidence interval (CI) 1.13-1.32). Similar findings were observed in the propensity score-matched cohort of 2410 patients (HR 1.20, 95% CI 1.05-1.36). While cause-specific mortality rates for all categories, with the exception of sudden deaths, were higher for fracture patients relative to non-fracture patients in the full unmatched cohort, only the mortality rate for heart disease was significantly higher for fracture patients relative to non-fracture patients in the propensity score-matched cohort.

CONCLUSION

Excess mortality persisted for many years after hip fracture in hemodialysis patients, and was still present after adjusting for several premorbid conditions and propensity score matching.

Hip hemiarthroplasty for femoral neck fractures in end-stage renal disease patients on dialysis compared to patients with late-stage chronic kidney disease

INTRODUCTION

Hip fractures in patients with end-stage renal disease (ESRD) are associated with frequent complications and poorer outcomes. Patients on chronic dialysis are at additional risk of dialysis-related complications such as myocardial infarction and early osteolysis. We analysed the complications and implant survivorship of hemiarthroplasty in patients with femoral neck fractures with late-stage chronic kidney disease with and without pre-existing dialysis.

METHODS

We conducted a retrospective case-control study of 28 patients with ESRD and 31 patients with chronic kidney disease (CKD) Stages 3-5, who had a total of 62 fractures treated with hemiarthroplasty between 2005 and 2015. The mean age of the patients was 68.33 (50.21-86.45) years. The mean follow-up time of the group was 39 months. Patient demographics, complications, outcomes and follow-up radiographs were analysed for differences.

RESULTS

Patient in both groups had statistically similar demographics and comorbidity scores except for a higher incidence of hyperparathyroidism in ESRD patients on chronic dialysis (nine patients vs. zero patients; p = 0.001). These patients were more likely to develop cardiopulmonary complications in the perioperative period (odds ratio [OR] 5.04; p = 0.04) and implant loosening on radiographic analysis (OR 8.75; p = 0.02). The incidence of loosening was higher in patients with hyperparathyroidism (OR 9.80; p = 0.002). Cemented techniques, however, did not appear to be significantly associated with intraoperative fractures or loosening.

CONCLUSION

Patients with ESRD on chronic dialysis were more likely to develop cardiopulmonary complications and implant loosening after hemiarthroplasty for femoral neck fractures. Hyperparathyroidism should be optimised, as it may prevent loosening. Our study did not show any difference in complications or outcomes for cemented fixation.

Transcriptomics: a Solution for Renal Osteodystrophy?

PURPOSE OF REVIEW

The molecular mechanisms of the bone disease associated with chronic kidney disease (CKD), called renal osteodystrophy (ROD), are poorly understood. New transcriptomics technologies may provide clinically relevant insights into the pathogenesis of ROD. This review summarizes current progress and limitations in the study and treatment of ROD, and in transcriptomics analyses of skeletal tissues.

RECENT FINDINGS

ROD is characterized by poor bone quality and strength leading to increased risk of fracture. Recent studies indicate permanent alterations in bone cell populations during ROD. Single-cell transcriptomics analyses, successful at identifying specialized cell subpopulations in bone, have not yet been performed in ROD. ROD is a widespread poorly understood bone disease with limited treatment options. Transcriptomics analyses of bone are needed to identify the bone cell subtypes and their role in the pathogenesis of ROD, and to develop adequate diagnosis and treatment strategies.

Simultaneous bilateral femoral neck fractures in a dialysis-dependent patient: case report and literature review

BACKGROUND

Simultaneous bilateral femoral neck fractures are extremely rare without obvious injury. Herein, we report the case of a patient on dialysis presenting with bilateral femoral neck fractures, which is a condition with high complication and mortality rates according to a review of the pertinent literature.

CASE PRESENTATION

We report the case a 47-year-old female with a history of 8 years of haemodialysis due to polycystic kidney disease who presented with bilateral hip pain during walking. The clinical history and results of physical and radiographic examinations of this patient are shown. Single-stage bilateral hemiarthroplasty was performed after a multidisciplinary team consultation. Three days after the operation, she could ambulate with a walker. The woman gradually regained her previous ability to walk over 6 months after surgery.

CONCLUSIONS

A multidisciplinary team consultation for perioperative management is necessary and effective in patients on dialysis. Early diagnosis with prompt surgical treatment could lead to favourable recovery.

Bone fragility in patients with chronic kidney disease

Mineral and bone diseases (MBD) are predominant in patients with chronic kidney disease (CKD) and lead to several bone manifestations, from pain to skeletal fractures. Cumulative traditional clinical risk factors, such as age and gender, in addition to those related to CKD, enhance the risk of comorbidity and mortality related to fractures. Despite great advances in understanding MBD in CKD, clinical and biological targets are lacking, which leads to under-management of fractures. Optimal PTH control results in a net improvement in defining the levels of bone remodeling. In addition, circulating biomarkers such as bone-specific alkaline phosphatase and cross-linked collagen type I peptide will also provide additional information about remodeling rate, bone mineralization and the evaluation of fracture risk. Imaging techniques identify patients at risk by measurement of bone mineral density by DEXA or by high peripheral QCT, which allow the discrimination of trabecular and cortical bone. Here, we have reviewed the literature related to epidemiology and the pathophysiological role of mineral and biochemical factors involved in CKD-MBD with a special focus on fracture risk. We also provide an algorithm that could be used for the management of bone diseases and to guide treatment decisions. Finally, the combined expertise of clinicians from various disciplines is crucial for the best prevention of fractures.

Impact of Weekly Teriparatide on the Bone and Mineral Metabolism in Hemodialysis Patients With Relatively Low Serum Parathyroid Hormone: A Pilot Study

Adynamic bone disease in HD patients is characterized by skeletal resistance to parathyroid hormone (PTH) or suppression of PTH release, leading to a downregulated bone turnover and bone fracture. Hence, we examined the efficacy of weekly teriparatide for HD patients with low PTH indicating adynamic bone disease without a history of parathyroidectomy. Fifteen HD patients with low PTH were recruited in this prospective observational study. Of them, 10 received teriparatide for 12 months and five nontreated patients were enrolled as control. Primary outcomes were defined as the changes in bone mineral density and bone turnover markers. Bone mineral density at the lumbar spine increased by 3.7% and 2.5% at 6 and 12 months, respectively, and bone formation markers increased, while bone resorption markers did not change in the teriparatide group. At 12 months after teriparatide administration, endogenous PTH was secreted followed by the recovery of low bone turnover. 40% of patients in the teriparatide group dropped out due to adverse events and the most common adverse event was transient hypotension. This study suggests that weekly teriparatide for HD patients with low PTH in the absence of parathyroidectomy accelerates bone formation and bone turnover, leading to increased trabecular bone mass and secretion of endogenous PTH.

The prevalence and incidence of vertebral fractures in end-stage renal disease and the role of parathyroid hormone

The risk of vertebral fracture is unclear in end-stage renal disease. We report a high vertebral fracture prevalence and incidence in transplantation-eligible patients on dialysis, suggesting that these patients may benefit from radiographic screening for vertebral fractures. Parathyroid hormone had a U-shaped association with vertebral fracture risk.

INTRODUCTION

Vertebral fractures are often overlooked, but even undiagnosed vertebral fractures negatively impact physical functioning, quality of life, and mortality. The risk of vertebral fractures in end-stage renal disease (ESRD) patients is unclear, and parathyroid hormone (PTH) might play a role in the development of vertebral fractures. We therefore determined vertebral fracture prevalence and incidence in ESRD patients and assessed associations of vertebral trabecular bone mineral density (BMD) and PTH with vertebral fracture.

METHODS

In 146 transplantation-eligible patients on dialysis, we determined vertebral fractures on lateral chest radiographs, which image the thoracic and upper lumbar spine. We determined incident vertebral fractures in 70 patients with follow-up radiographs (23 received a kidney transplant) after median 1.8 years. Vertebral trabecular BMD was measured with computed tomography, and PTH measured with 2-site immunoassays, categorized in tertiles with the middle tertile as reference. We used Poisson regression to assess associations of vertebral trabecular BMD and PTH with vertebral fracture.

RESULTS

Mean age of the study population was 52 ± 13 years, and 98 (67%) were male. Median dialysis duration was 26 (IQR 13-55) months. Vertebral fractures were present in 50/146 patients (34%) and incident vertebral fractures occurred in 20/70 patients (29%). Vertebral trabecular BMD was not associated with vertebral fracture prevalence (relative risk 0.97, 95% CI 0.89 to 1.04). For the lowest PTH tertile (< 11 pmol/L), the relative risk of vertebral fracture was greater although not significant (2.28, 95% CI 0.97 to 5.97) and was significantly greater for the highest PTH tertile (≥ 30 pmol/L; 2.82, 95% CI 1.22 to 7.27) after adjustment for potential confounders.

CONCLUSIONS

The prevalence and incidence of vertebral fractures is high even in relatively young and healthy ESRD patients. Vertebral trabecular BMD is not associated with vertebral fracture, and the association of PTH with vertebral fracture risk appears U-shaped. Nevertheless, our study did not measure vertebral BMD using DXA and assessed vertebral fractures using lateral chest radiographs and not spine radiographs.

Bone fracture risk factors in prevalent hemodialysis patients

Bone fractures are an important cause of morbidity and mortality in hemodialysis (HD) patients. The aim of this study was to quantify the incidence of fractures in a cohort of prevalent HD patients and evaluate its relationship with possible risk factors. We performed a retrospective analysis of 341 patients, since they started HD (median of 51 months). Demographic, clinical, and biochemical parameters as well as vascular calcifications (VC) were evaluated. Fifty-seven episodes of fracture were identified with a median HD vintage of 47 months (incidence rate of 31 per 1000 person-years). Age (p < 0.001), female gender (p < 0.001), lower albumin (p = 0.02), and higher VC score (p < 0.001) were independently associated with increased risk of fracture, while active vitamin D therapy (p = 0.03) was associated with decreased risk. A significantly higher risk of incident fracture was also associated with higher values of bone-specific alkaline phosphatase (bALP) (p = 0.01) and intact parathyroid hormone (iPTH) levels either < 300 pg/mL (p = 0.02) or > 800 pg/mL (p < 0.001) compared with 300-800 pg/mL. In conclusion, bone fracture incidence in HD patients is high and its risk increases with age, female gender, lower serum albumin, and with the presence of more VC. Prevalent HD patients with low or high iPTH levels or increased bALP also had a higher fracture risk. Therapy with active vitamin D seems to have a protective role. Assessment of fracture risk and management in dialysis patients at greatest risk requires further study.

Use of proton pump inhibitors is associated with an increase in adverse cardiovascular events in patients with hemodialysis: Insight from the kids registry

BACKGROUND

Proton pump inhibitors (PPIs) are known to increase the risk of mortality and cardiovascular events in the general population. However, in patients with maintenance hemodialysis, PPI effects are under investigated.

METHODS

We analyzed the risk of PPIs for cardiovascular events using the Kagoshima Dialysis (KIDS) registry, a prospective, multicenter, observational study in patients with maintenance hemodialysis in Japan.

RESULTS

In all, 531 patients were enrolled from June 2015 to December 2018. One-year follow-up data were available for 376 patients (Use of PPIs at baseline (PPI group): 217 patients and without PPIs (No PPI group): 159 patients). The incidence of a composite outcome (all-cause mortality, non-fatal myocardial infarction, or non-fatal stroke) was higher in patients in the PPI group than the No PPI group (15.2% vs. 4.4%; hazard ratio (HR): 3.65, 95% confidence interval (CI): 1.61-8.23, P = 0.002). In the multivariate analysis, even after adjustment for covariates, the use of PPIs was an independent risk factor for a composite outcome (HR: 2.38, 95% CI: 1.02-5.54, P = 0.045). We performed propensity score matching analysis as a sensitivity analysis, showing a consistent result. The incidence of bleeding showed no difference between the two groups (15.7% vs. 11.3%; HR: 1.46, 95% CI: 0.83-2.59, P = 0.19).

CONCLUSIONS

These results indicate that the use of PPIs in patients with maintenance hemodialysis might increase mortality and cardiovascular events without decreasing the risk of bleeding. Therefore, it should always be analyzed if a patient truly needs PPIs.

Bone Health in Glomerular Kidney Disease

PURPOSE OF REVIEW

To summarize the literature regarding alterations in bone health in patients with glomerular kidney disease and highlight areas in need of additional investigation.

RECENT FINDINGS

There is mounting evidence that children and adults with glomerular conditions, with or without compromised kidney function, comprise a distinct subgroup of patients with unique risk factors for altered bone health. Patients with glomerular kidney disease are exposed to both disease-related and treatment-related factors that affect bone structure and function. In addition to chronic kidney disease-related risk factors for impaired bone health, high rates of exposure to osteotoxic medications, varying degrees of systemic inflammation, and altered vitamin D metabolism may contribute to compromised bone health in individuals with glomerular disease. Further study is needed to better understand these risk factors and the complex interaction between the immune system and bone cells in glomerular disease.

Hospitalized fracture rates amongst patients with chronic kidney disease in Australia using data linkage

BACKGROUND

Renal osteodystrophy leading to fractures in chronic kidney disease (CKD) is associated with significant hospitalization, morbidity, mortality and health care costs. There is a paucity of data on fractures in the CKD population in Australia.

AIM

To describe the trends and impact of hospitalized fractures in an Australian population of non-dialysis CKD patients.

METHODS

Retrospective observational data derived using data linkage. Fracture rates, trends in hospital admissions, comorbidity burden and mortality were analysed in a non-dialysis CKD population between 2000 and 2010 in the Australian state of New South Wales. Hospitalized patients with CKD and fractures were compared with CKD patients without fracture.

RESULTS

A total of 149 839 hospitalized patients with CKD were included, of whom 9898 (6.6%) experienced one or more fractures. Patients with fracture were older, more likely to be female with a higher comorbidity burden than those without. Hospital admissions involving fracture were longer than non-fracture admissions (14.3 vs 5.9 days, P < .0001) and patients were less likely to be discharged home (28.3% vs 80.9%, P < .0001). The 12-month mortality rate was high at 41%.

CONCLUSION

Australian non-dialysis CKD patients with hospitalized fractures were older, had a greater burden of disease, and have similar rates of fracture and associated mortality compared to international CKD cohorts. Implications of fracture requiring hospitalization are considerable, with longer admissions, greater healthcare costs, lower likelihood of discharge home and significant mortality. As fracture prevention in the CKD population evolves, treatment algorithms should account for those at greatest risk.

Anticoagulants and Osteoporosis

Anticoagulant agents are widely used in the treatment of thromboembolic events and in stroke prevention. Data about their effects on bone tissue are in some cases limited or inconsistent (oral anti-vitamin K agents), and in others are sufficiently strong (heparins) to suggest caution in their use in subjects at risk of osteoporosis. This review analyses the effects of this group of drugs on bone metabolism, on bone mineral density, and on fragility fractures. A literature search strategy was developed by an experienced team of specialists by consulting the MEDLINE platform, including published papers and reviews updated to March 2019. Literature supports a detrimental effect of heparin on bone, with an increase in fracture rate. Low molecular weight heparins (LMWHs) seem to be safer than heparin. Although anti-vitamin K agents (VKAs) have a significant impact on bone metabolism, and in particular, on osteocalcin, data on bone mineral density (BMD) and fractures are contrasting. To date, the new direct oral anticoagulants (DOACs) are found to safe for bone health.

Selective Serotonin Reuptake Inhibitor Use and Hip Fracture Risk Among Patients on Hemodialysis

RATIONALE & OBJECTIVE

Use of selective serotonin reuptake inhibitors (SSRIs) has been associated with hip fracture risk in the general population. This study examined this relationship among patients with kidney failure treated by hemodialysis, a unique high-risk subpopulation, within which the impact of SSRIs on hip fracture risk remains unexplored.

STUDY DESIGN

Case-control study.

SETTINGS & PARTICIPANTS

Eligible cases of hip fracture among maintenance hemodialysis patients between January 1, 2009, and September 30, 2015, were identified using the US Renal Data System. Each case was matched on index date with 10 eligible controls. To be eligible, study participants needed to have more than 1 year of Medicare Parts A and B coverage and more than 3 years of Part D coverage. For a separate examination of new short-term SSRI exposure, we selected cases and controls with more than 18 months of Part D coverage and no prior antidepressant use for 1 year.

EXPOSURE

During the 3-year Part D coverage period, use of SSRIs characterized as any (≥1 prescription filled), low, moderate, and high use (<20%, 20%-<80%, and≥80% of days covered by filled prescriptions, respectively).

OUTCOME

We selected cases using International Classification of Diseases, Ninth Revision codes 820.xx and 821.xx. In addition to 1 of these codes tied to a hospitalization, we required a corresponding surgical procedural code within 7 days of diagnosis.

ANALYTIC APPROACH

Conditional logistic regression to estimate unadjusted and multivariable-adjusted ORs and 95% CIs.

RESULTS

We identified 4,912 cases and 49,120 controls. SSRI use was associated with increased hip fracture risk (adjusted OR, 1.25; 95% CI, 1.17-1.35). Risk for fracture was estimated for any, low, moderate, and high SSRI use: adjusted conditional ORs were 1.25 (95% CI, 1.17-1.35), 1.20 (95% CI, 1.08-1.32), 1.31 (95% CI, 1.18-1.43), and 1.26 (95% CI, 1.12-1.41), respectively. The association between hip fracture events and SSRI use was also seen in the examination of new short-term use (adjusted OR, 1.43; 95% CI, 1.23-1.67).

LIMITATIONS

Biomarkers of mineral bone disorder were not captured and accounted for in this analysis.

CONCLUSIONS

We demonstrated an association between increased hip fracture risk and both long- and new short-term SSRI use. The stronger association with new short-term use may suggest an acute mechanism potentially related to falls.

A multi-imaging modality study of bone density, bone structure and the muscle - bone unit in end-stage renal disease

End stage renal disease (ESRD) is associated with sarcopenia and skeletal fragility. The objectives of this cross-sectional study were to (1) characterize body composition, bone mineral density (BMD) and bone structure in hemodialysis patients compared with controls, (2) assess whether DXA areal BMD (aBMD) correlates with peripheral quantitative CT (pQCT) measures of volumetric BMD (vBMD), cortical dimensions and MRI measures of trabecular microarchitecture, and (3) determine the magnitude of bone deficits in ESRD after adjustment for muscle mass. Thirty ESRD participants, ages 25 to 64 years, were compared with 403 controls for DXA and pQCT outcomes and 104 controls for MRI outcomes; results were expressed as race- and sex- specific Z-scores relative to age. DXA appendicular lean mass index (ALMI kg/m2) and total hip, femoral neck, ultradistal and 1/3rd radius aBMD were significantly lower in ESRD, vs. controls (all p < 0.01). pQCT trabecular vBMD (p < 0.01), cortical vBMD (p < 0.001) and cortical thickness (due to a greater endosteal circumference, p < 0.02) and MRI measures of trabecular number, trabecular thickness, and whole bone stiffness were lower (all p < 0.01) in ESRD, vs. controls. ALMI was positively associated with total hip, femoral neck, ultradistal radius and 1/3rd radius aBMD and with tibia cortical thickness (R = 0.46 to 0.64). Adjustment for ALMI significantly attenuated bone deficits at these sites: e.g. mean femoral neck aBMD was 0.79 SD lower in ESRD, compared with controls and this was attenuated to 0.33 with adjustment for ALMI. In multivariate models within the dialysis participants, pQCT trabecular vBMD and cortical area Z-scores were significant and independently (all p < 0.02) associated with DXA femoral neck, total hip, and ultradistal radius aBMD Z-scores. Cortical vBMD (p = 0.01) and cortical area (p < 0.001) Z-scores were significantly and independently associated with 1/3rd radius areal aBMD Z-scores (R2 = 0.62). These data demonstrate that DXA aBMD captures deficits in trabecular and cortical vBMD and cortical area. The strong associations with ALMI, as an index of skeletal muscle, highlight the importance of considering the role of sarcopenia in skeletal fragility in patients with ESRD.

Fracture risk and treatment in chronic kidney disease

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is associated with the development of mineral bone disorder (MBD), osteoporosis, and fragility fractures. The purpose of this review is to provide an update on recent findings in the diagnosis and treatment of osteoporosis in patients with CKD.

RECENT FINDINGS

Multiple observational studies have shown that bone mineral density measurement using DEXA is equally predictive in CKD stages 1-3, as in the general population. Post hoc analyses from randomized trials of bisphosphonates, SERM, RANKL inhibitors and PTH agonists all suggest equal efficacy in mild-moderate CKD. A recent systematic review also found evidence for efficacy of bisphosphonates in patients with a kidney transplant.

SUMMARY

Bone mineral density measurement using DEXA is accurate in patients with CKD stages 1-3 and should be considered to guide treatment of osteoporosis. Current treatments are unaffected by mild-to-moderate decline in kidney function, and physicians should use bisphosphonates and other osteoporosis treatments in this population, whenever indicated. Studies evaluating the optimal diagnostic and management strategy in patients with CKD stages (G4-5D) are needed.

A Systematic Review and Meta-analysis of the Association Between Vitamin K Antagonist Use and Fracture

BACKGROUND

Vitamin K antagonist (VKA) anticoagulant use is suspected to increase the risk of bone fracture through inhibition of vitamin K-dependent cofactors of bone formation, an effect not seen with non-vitamin K antagonist oral anticoagulants (NOACs). The purpose of our systematic review and meta-analysis is to investigate the association between VKA use and fracture.

METHODS

We searched PubMed, EMBASE, and Cochrane Library for studies analyzing fracture in adults using VKAs versus controls. Two authors independently reviewed articles. We assessed for risk of bias using the Newcastle-Ottawa Quality Assessment Scale and the Cochrane Risk of Bias Tool and calculated pooled effects using random effects models.

RESULTS

We included 23 articles (22 observational studies and 1 randomized controlled trial), studying 1,121,582 subjects. There was no increased odds of fracture in VKA users versus controls (pooled OR 1.01, 95% CI 0.89, 1.14) or in VKA users versus NOAC users (pooled OR 0.95, 95% CI 0.78, 1.15). Subjects using a VKA for 1 year or longer did not have increased odds of fracture (pooled OR 1.07, 95% CI 0.90, 1.27). Compared to controls, there was increased odds of fracture in women (pooled OR 1.11, 95% CI 1.02, 1.21) and older VKA users (≥ 65) (pooled OR 1.07, 95% CI 1.01, 1.14).

DISCUSSION

We found no increase in odds of fracture in VKA users versus controls or NOAC users. There was a small increase in odds of fracture among female and elderly VKA users, which may not be clinically important when accounting for other considerations in choosing an anticoagulant. Our findings suggest that, when anticoagulation is necessary, fracture risk should not be a major consideration in choice of an agent. Future studies directly comparing VKA to NOAC users and studies with longer duration of VKA use may be needed.

Fracture Risk in Dialysis and Kidney Transplanted Patients: A Systematic Review

Chronic kidney disease is associated with an increased risk of fracture and cardiovascular mortality. The risk of fracture in hemodialysis (HD), peritoneal dialysis (PD) and kidney transplant (KT) patients is higher when compared with the general population. However, there exists a knowledge gap concerning which group has the highest risk of fracture. We aimed to compare the risk of fracture in HD, PD, and KT populations. We conducted a systematic review of observational studies evaluating the risk of fracture in HD, PD, or KT patients. Eligible studies were searched using MEDLINE, Embase, Web of Science, and Cochrane Library from their inception to January 2016, and in grey literature. Incidences (cumulative and rate) of fracture were described together using the median, according to fracture sites, the data source (administrative database or cohort and clinical registry), and fracture diagnosis method. Prevalence estimates were described separately. We included 47 studies evaluating the risk of fracture in HD, PD, and KT populations. In administrative database studies, incidence of hip fracture in HD (median 11.45 per 1000 person-years [p-y]), range: 9.3 to 13.6 was higher than in KT (median 2.6 per 1000 p-y; range 1.5 to 3.8) or in PD (median 5.2 per 1000 p-y; range 4.1 to 6.3). In dialysis (HD+PD), three studies reported a higher incidence of hip fracture than in KT. Prevalent vertebral fracture (assessed by X-rays or questionnaire) reported in HD was in a similar range as that reported in KT. Incidence of overall fracture was similar in HD and KT, from administrative databases studies, but lower in HD compared with KT, from cohorts or clinical registry studies. This systematic review suggests an important difference in fracture risk between HD, PD, and KT population, which vary according to the diagnosis method for fracture identification. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

The Likelihood of Self-reporting Balance Problems in Those With Advanced Chronic Kidney Disease, Slow Gait Speed, or Low Vitamin D

OBJECTIVE

The purpose of this study was to determine the prevalence of vitamin D (25(OH)D) and balance deficits in persons with chronic kidney disease (CKD) and the likelihood of self-reporting balance and falling problems, measured gait speed in persons with kidney disease, and low levels of vitamin D and albumin.

DESIGN

Analysis of the National Health and Nutrition Examination Survey 1999-2004 data set.

SUBJECTS

The study included 8,554 subjects aged >40 years who were categorized into CKD stages based on the glomerular filtration rate (normal kidney function and stages 1 and 2 served as the control group, and stages 3 and 4/5 served as the CKD groups).

MAIN OUTCOME MEASURES

Measured 25(OH)D levels, timed 20-feet walk, Romberg standing balance task, and self-reported balance and falling issues.

RESULTS

The prevalence of balance deficits was found to be high in this CKD sample, with fail rates increasing with kidney disease severity. Similarly, when examining the relationship between CKD stage and the measurement of balance, fail rates (impaired balance) increased and gait speed decreased with kidney disease severity. In addition, the likelihood of self-reporting a balance and falling problem in the past year was higher in persons who had advanced CKD, were of older age, were of female sex, were with former or current smoking status, had lower 25(OH)D levels, and had lower albumin levels. Similarly, the likelihood of having a 20-feet walk time of more than 8 seconds was associated with those who were older, had higher body mass index, and had lower levels of 25(OH)D and albumin.

CONCLUSION

The unique finding of this study is that increased reporting of balance and falling issues (both perceived and measured) and slower gait were found in persons with increased CKD severity and lower 25(OH)D status.

Rethinking Bone Disease in Kidney Disease

Renal osteodystrophy (ROD) is the bone component of chronic kidney disease mineral and bone disorder (CKD-MBD). ROD affects bone quality and strength through the numerous hormonal and metabolic disturbances that occur in patients with kidney disease. Collectively these disorders in bone quality increase fracture risk in CKD patients compared with the general population. Fractures are a serious complication of kidney disease and are associated with higher morbidity and mortality compared with the general population. Furthermore, at a population level, fractures are at historically high levels in patients with end-stage kidney disease (ESKD), whereas in contrast the general population has experienced a steady decline in fracture incidence rates. Based on these findings, it is clear that a paradigm shift is needed in our approach to diagnosing and managing ROD. In clinical practice, our ability to diagnose ROD and initiate antifracture treatments is impeded by the lack of accurate noninvasive methods that identify ROD type. The past decade has seen advances in the noninvasive measurement of bone quality and strength that have been studied in kidney disease patients. Below we review the current literature pertaining to the epidemiology, pathology, diagnosis, and management of ROD. We aim to highlight the pressing need for a greater awareness of this condition and the need for the implementation of strategies that prevent fractures in kidney disease patients. Research is needed for more accurate noninvasive assessment of ROD type, clinical studies of existing osteoporosis therapies in patients across the spectrum of kidney disease, and the development of CKD-specific treatments. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

The trabecular bone score: Relationships with trabecular and cortical microarchitecture measured by HR-pQCT and histomorphometry in patients with chronic kidney disease

The trabecular bone score (TBS) is a novel tool using grayscale variograms of the lumbar spine bone mineral density (BMD) to assess trabecular bone microarchitecture. Studies in patients with chronic kidney disease (CKD) suggest it may be helpful in assessing fracture risk. However, TBS has not been validated as a measure of trabecular architecture against transiliac bone biopsy with histomorphometry in CKD patients. We hypothesized that TBS would reflect trabecular architecture at the iliac crest in CKD patients. We obtained tetracycline double labeled transiliac crest bone biopsy, areal BMD of the spine, total hip, femoral neck (FN) and spine TBS by dual energy X-ray absorptiometry (DXA), and cortical and trabecular volumetric density and microarchitecture by high resolution peripheral quantitative computed tomography (HR-pQCT) in CKD patients from two centers: twenty-two patients from Columbia University Medical Center, USA and thirty patients from Hospital das Clinicas - Universidade de São Paulo, Brazil. Two patients were excluded for outlier status. Univariate and multivariate relationships between TBS and measures from DXA, HR-pQCT and histomorphometry were determined. Patients were 50.2 ± 15.8 years old, 23 (46%) were men, and 33 (66%) were on dialysis. TBS was <1.31 in 21 (42%) patients and 22%, 14% and 10% had T-scores ≤ -2.5 at spine, FN and total hip respectively. In univariate regression, TBS was significantly associated with trabecular bone volume (BV/TV), trabecular width (Tb.Wi), trabecular spacing, cortical width but not with trabecular number or cortical porosity. FN Z-score and height were also associated with cancellous BV/TV and Tb.Wi, In multivariate analysis, TBS remained an independent predictor of BV/TV and Tb.Wi. There were no relationships between TBS and dynamic parameters from histomorphometry. These data suggest that TBS reflected trabecular microarchitecture and cortical width measured by bone biopsy in CKD patients. Future studies should address its utility in the identification of CKD patients who may benefit from fracture prevention strategies.

Proton Pump Inhibitors, Histamine-2 Receptor Antagonists, and Hip Fracture Risk among Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

An association between proton pump inhibitor (PPI) use and hip fracture risk has been described in the general population, where the primary causative hypothesis focuses on impaired gastrointestinal calcium absorption. The impact of acid suppressor use on hip fracture risk in a high-risk subset, patients with ESKD requiring hemodialysis, is unknown and could help further distinguish the reason for higher susceptibility among PPI users.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the US Renal Data System, we identified all hip fracture events recorded between 2009 and 2014 among patients dependent on hemodialysis. Eligible cases were matched on index date with ten controls. We identified PPI and histamine-2 receptor antagonist use from Medicare Part D claims covering 3 years before the index date and stratified according to proportion of days covered by filled prescriptions. Using logistic regression with multiple imputation for missing data, we estimated unadjusted and multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

We studied 4551 cases and 45,510 controls. Patients were older, more likely to be female and white, and had shorter dialysis vintage; fewer were obese. A larger proportion of patients had any prior PPI (70% versus 63%) or histamine-2 receptor antagonist (25% versus 23%) use. Use of PPI was associated with higher risk of hip fracture (adjusted OR, 1.19; 95% CI, 1.11 to 1.28). This association remained within subgroups of low, moderate, and high PPI use, yielding adjusted ORs of 1.16 (95% CI, 1.06 to 1.27), 1.21 (95% CI, 1.11 to 1.31), and 1.19 (95% CI, 1.08 to 1.31), respectively.

CONCLUSIONS

Among patients with ESKD on hemodialysis, PPIs and not histamine-2 receptor antagonists were associated with hip fracture events.

Management of Osteoporosis in CKD

CKD mineral and bone disease is a common complication of kidney disease, and it affects the majority of patients with moderate to severe CKD. Recently, prospective studies have shown that measurement of bone mineral density by dual energy x-ray absorptiometry predicts incident fracture, providing nephrologists the ability to risk classify patients for skeletal fragility and targeted antifracture strategies for the first time. Furthermore, an expanding body of literature and anecdotal evidence suggest that pharmacologic agents used to treat osteoporosis in the general population can be safely used in patients with CKD. This review highlights the effects of the Kidney Disease Improving Global Outcomes updates on the management of CKD-associated osteoporosis, discusses recent investigations on the effects of antiosteoporotic agents in patients with CKD, and provides an overview of novel antiosteoporosis agents and the potential challenges related to their use in CKD.