Association of kidney function with incident hip fracture in older adults

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.

Real-world fracture risk, osteoporosis treatment status, and mortality of Japanese non-dialysis patients with chronic kidney disease stages G3-5

BACKGROUND

Few studies have investigated fracture risk and mortality in a Japanese chronic kidney disease (CKD) stages G3-5 population using a large-scale clinical database.

METHODS

This retrospective cohort study extracted data from 1 April 2008 to 30 April 2023. A single age-sex-matched control without CKD was matched with each non-dialysis CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m2) patient. The incidences of all and hip fractures and all-cause mortality after the index date were calculated.

RESULTS

Among 76,598 (38,299 per group) individuals matched, the incidence of all fractures did not differ between the CKD and control groups (5.7% vs 5.8%; hazard ratio [HR] 1.022 [95% confidence interval CI 0.952-1.098], P = 0.542). The CKD group had higher risk of hip fracture than the control group (incidence of hip fracture, 1.7% vs 1.3%; HR 1.415 [95% CI 1.234-1.622], P < 0.001). Multivariable regression analysis showed an increased risk for hip fracture in the CKD vs control groups, and a greater difference in this risk was observed with younger age. Osteoporosis treatment and bone mineral density (BMD) measurements were 10.0% and 5.3% in the CKD group and 4.4% and 4.4% in the control group, respectively. Mortality was also higher in the CKD group (HR 1.413 [95% CI 1.330-1.501], P < 0.001).

CONCLUSIONS

Japanese patients with CKD had higher risk of hip fracture than those without. Treatment and BMD measurement for fracture are insufficient in Japanese patients with CKD, and more adequate management of fracture risk is needed.

Construction and validation of a predictive model for the risk of prolonged preoperative waiting time in patients with intertrochanteric fractures

Background

Intertrochanteric fractures are one of the most common types of hip fractures, with delayed surgical treatment beyond 48 h associated with increased postoperative complications and mortality, especially in older adults. This study aimed to develop a predictive model for delayed preoperative waiting times in intertrochanteric fracture cases, based on previous research, to offer a valuable reference for clinical decision-making.

Methods

A retrospective analysis was conducted on 1,116 patients with intertrochanteric fractures admitted to the Affiliated Hospital of Shandong University of Traditional Chinese Medicine for internal fixation surgery from January 2017 to January 2024. Patient demographic data and clinical examination results were collected. A logistic regression model was used to construct a predictive model, which was then visualized through a nomogram. The model's performance was subsequently validated.

Results

The predictive model developed from 728 patients in the training cohort, identified key predictors, including age, sex, lower extremity deep vein thrombosis, injury location, and biochemical markers. The model demonstrated strong discriminative ability, with an area under the receiver operating characteristic curve of 0.749 (95% confidence interval: 0.621-0.801) for the training set, and 0.745 in the validation set. Calibration curves indicated that the predicted risk of surgical delay closely aligned with observed outcomes. Furthermore, decision curve analysis verified the model's clinical utility, demonstrating its effectiveness in guiding treatment decisions.

Conclusion

The nomogram model developed in this study provides a reliable tool for predicting delayed surgical intervention in patients with intertrochanteric femur fractures. It offers clinicians a valuable reference to anticipate delays in surgical treatment and aids in the formulation of more timely and appropriate treatment strategies, potentially improving patient outcomes.

Chronic Kidney Disease in Patients with Hip Fracture: Prevalence and Outcomes

Objective. Although the association between chronic kidney disease (CKD) and osteoporotic fractures is well established, data on CKD combined with hip fracture (HF) are scarce and controversial. We aimed to assess in patients with HF the prevalence of CKD, its impact on hospital mortality and length of stay (LOS) and to determine the prognostic value of CKD to predict hospital outcomes. Methods. Prospectively collected clinical data were analysed in 3623 consecutive HF patients aged ≥65 years (mean age 83.4 ± 7.50 [standard deviation] years; 74.4% females). Results. CKD among older patients with HF is highly prevalent (39.9%), has different clinical characteristics, a 2.5-fold higher mortality rate, and 40% greater risk of prolonged LOS. The strongest risk for a poor outcome was advanced age (>80 years). The risk of death substantially increases in combination with chronic disorders, especially coronary artery disease, anaemia, hyperparathyroidism, and atrial fibrillation; models based only on three variables—CKD stage, age >80, and presence of a specific chronic condition—predicted in-hospital death with good discrimination capability (AUC ≥ 0.700) and reasonable accuracy, the number needed to predict ranged between 5.7 and 14.5. Only 12% of HF patients received osteoporotic drugs prefracture. Conclusion. In HF patients with CKD, the risk of adverse outcomes largely increases in parallel with worsening kidney function and, especially, in combination with comorbidities; models based on three admission variables predict a fatal outcome. Assessment of renal function is essential to preventing osteoporotic fractures.

Risk factors for hip and vertebral fractures in chronic kidney disease: the CRIC study

Fracture risk is high in chronic kidney disease (CKD) and underlying pathophysiology and risk factors may differ from the general population. In a cohort study of 3939 participants in the chronic renal insufficiency cohort (CRIC), we used Cox regression to test associations of putative risk factors with the composite of first hip or vertebral fracture assessed using hospital discharge codes. Mean age was 58 years, 45% were female, 42% were Black, and 13% were Hispanic. There were 82 hip and 24 vertebral fractures over a mean (SD) 11.1 (4.8) years (2.4 events per 1000 person-years [95% CI: 2.0, 2.9]). Measured at baseline, diabetes, lower body mass index (BMI), steroid use, proteinuria, and elevated parathyroid hormone (PTH) were each associated with fracture risk after adjusting for covariates. Lower time-updated estimated glomerular filtration rate (eGFR) was associated with fractures (HR 1.20 per 10 mL/min/1.73m2 lower eGFR; 95% CI: 1.04, 1.38) as were lower time-updated serum calcium and bicarbonate concentrations. Among time-updated categories of kidney function, hazard ratios (95% CI) for incident fracture were 4.53 (1.77, 11.60) for kidney failure treated with dialysis and 2.48 (0.86, 7.14) for post-kidney transplantation, compared with eGFR ≥60. Proton pump inhibitor use, dietary calcium intake, measures of vitamin D status, serum phosphate, urine calcium and phosphate, and plasma fibroblast growth factor-23 were not associated with fracture risk. In conclusion, lower eGFR in CKD is associated with higher fracture risk, which was highest in kidney failure. Diabetes, lower BMI, steroid use, proteinuria, higher serum concentrations of PTH, and lower calcium and bicarbonate concentrations were associated with fractures and may be modifiable risk factors.

Peripheral Neuropathy Associated with Higher Mortality in Population with Chronic Kidney Disease: National Health and Nutrition Examination Surveys

Introduction

Peripheral neuropathy (PN), one of the commonest neurological complications of chronic kidney disease (CKD), was associated with physical limitation. Studies showed that a decrease in physical capability in patients with CKD is related with an increased risk of mortality. The objective of our research was to directly explore the relationship between PN and risk of mortality in patients with CKD.

Method

1,836 participants with CKD and 6,036 participants without CKD, which were classified by PN based on monofilament examination in National Health and Nutrition Examination Survey (NHANES), were collected from the 1999 to 2004 National Health and Nutrition Examination Surveys. Multivariable Cox proportional hazard models were conducted to assess the relationships of PN and deaths in patients with CKD and non-CKD.

Results

During 14 years of a median follow-up from 1999 to 2015 and 2004 to 2015, 1,072 (58.4%) and 1,389 (23.0%) deaths were recorded in participants with CKD and without CKD, respectively. PN was related with increased all-cause mortality even after adjusting possible confounding factors in population with CKD (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.17-1.53) and without CKD (HR 1.27, 95% CI 1.12-1.43). And the adjusted HRs (95% CI) for cardiovascular mortality of the people with CKD and without CKD who suffered from PN were 1.42 (1.07, 1.90) and 1.23 (0.91, 1.67), respectively, versus those without PN.

Conclusion

PN was related with a higher risk of all-cause and cardiovascular death in people with CKD, which clinically suggests that the adverse prognostic impact of PN in the CKD population deserves attention and is an important target for intervention.

Fracture Management in Chronic Kidney Disease: Challenges and Considerations for Orthopedic Surgeons

Orthopedic surgeons treating fractures need to consider comorbidities, including chronic kidney disease (CKD), which affects millions worldwide. CKD patients are at elevated risk of fractures due to osteoporosis, especially in advanced stages. In addition, fractures in CKD patients pose challenges due to impaired bone healing and increased post-fracture complications including surgical site infection and nonunion. In this article, we will discuss factors that must be considered when treating fractures in CKD patients. Perioperative management includes careful adjustment of hemodialysis schedules, selection of anesthetic methods, and addressing bleeding tendencies. Tourniquet usage for fractures in limbs with arteriovenous fistulae should be cautious. Pain medication should be administered carefully, with opioids like hydromorphone preferred over nonsteroidal anti-inflammatory drugs. Medical management after fractures should address underlying factors and include physical rehabilitation to reduce the risk of subsequent fractures. A comprehensive approach to fracture management in CKD patients can improve outcomes.

Multivariable machine learning models for clinical prediction of subsequent hip fractures in older people using the Chinese population database

PURPOSE

This study aimed to develop and validate clinical prediction models using machine learning (ML) algorithms for reliable prediction of subsequent hip fractures in older individuals, who had previously sustained a first hip fracture, and facilitate early prevention and diagnosis, therefore effectively managing rapidly rising healthcare costs in China.

METHODS

Data were obtained from Grade A Tertiary hospitals for older patients (age ≥ 60 years) diagnosed with hip fractures in southwest China between 1 January 2009 and 1 April 2020. The database was built by collecting clinical and administrative data from outpatients and inpatients nationwide. Data were randomly split into training (80%) and testing datasets (20%), followed by six ML-based prediction models using 19 variables for hip fracture patients within 2 years of the first fracture.

RESULTS

A total of 40,237 patients with a median age of 66.0 years, who were admitted to acute-care hospitals for hip fractures, were randomly split into a training dataset (32,189 patients) and a testing dataset (8,048 patients). Our results indicated that three of our ML-based models delivered an excellent prediction of subsequent hip fracture outcomes (the area under the receiver operating characteristics curve: 0.92 (0.91-0.92), 0.92 (0·92-0·93), 0.92 (0·92-0·93)), outperforming previous prediction models based on claims and cohort data.

CONCLUSIONS

Our prediction models identify Chinese older people at high risk of subsequent hip fractures with specific baseline clinical and demographic variables such as length of hospital stay. These models might guide future targeted preventative treatments.

The Dietary Fiber Inulin Slows Progression of Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) in a Rat Model of CKD

Chronic kidney disease (CKD)-mineral bone disorder (CKD-MBD) leads to fractures and cardiovascular disease. Observational studies suggest beneficial effects of dietary fiber on both bone and cardiovascular outcomes, but the effect of fiber on CKD-MBD is unknown. To determine the effect of fiber on CKD-MBD, we fed the Cy/+ rat with progressive CKD a casein-based diet of 0.7% phosphate with 10% inulin (fermentable fiber) or cellulose (non-fermentable fiber) from 22 weeks to either 30 or 32 weeks of age (~30% and ~15% of normal kidney function; CKD 4 and 5). We assessed CKD-MBD end points of biochemistry, bone quantity and quality, cardiovascular health, and cecal microbiota and serum gut-derived uremic toxins. Results were analyzed by two-way analysis of variance (ANOVA) to evaluate the main effects of CKD stage and inulin, and their interaction. The results showed that in CKD animals, inulin did not alter kidney function but reduced the increase from stage 4 to 5 in serum levels of phosphate and parathyroid hormone, but not fibroblast growth factor-23 (FGF23). Bone turnover and cortical bone parameters were similarly improved but mechanical properties were not altered. Inulin slowed progression of aorta and cardiac calcification, left ventricular mass index, and fibrosis. To understand the mechanism, we assessed intestinal microbiota and found changes in alpha and beta diversity and significant changes in several taxa with inulin, together with a reduction in circulating gut derived uremic toxins such as indoxyl sulfate and short-chain fatty acids. In conclusion, the addition of the fermentable fiber inulin to the diet of CKD rats led to a slowed progression of CKD-MBD without affecting kidney function, likely mediated by changes in the gut microbiota composition and lowered gut-derived uremic toxins. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

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.

Safety of Sodium-Glucose Cotransporter-2 Inhibitors in Patients with CKD and Type 2 Diabetes: Population-Based US Cohort Study

BACKGROUND

Limited information exists regarding the safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with CKD treated in routine care. We evaluated the safety of SGLT2i in patients with CKD and type 2 diabetes treated in US routine practice.

METHODS

Using claims data from Medicare and two large US commercial databases (April 2013-December 2021), we included 96,128 adults with CKD stages 3-4 and type 2 diabetes who newly filled prescriptions for SGLT2i versus glucagon-like peptide-1 receptor agonists (GLP-1RA). Safety outcomes included diabetic ketoacidosis (DKA), lower limb amputations, nonvertebral fractures, genital infections, hypovolemia, AKI, hypoglycemia, and severe urinary tract infections (UTIs). Hazard ratios (HRs) and incidence rate differences per 1000 person-years were estimated after 1:1 propensity score matching, adjusted for >120 baseline characteristics.

RESULTS

Compared with GLP-1RA, SGLT2i initiators had a higher risk of nonvertebral fractures (HR, 1.30 [95% confidence interval (CI), 1.03 to 1.65]; incidence rate difference, 2.13 [95% CI, 0.28 to 3.97]), lower limb amputations (HR, 1.65 [95% CI, 1.22 to 2.23]; incidence rate difference, 2.46 [95% CI, 1.00 to 3.92]), and genital infections (HR, 3.08 [95% CI, 2.73 to 3.48]; incidence rate difference, 41.26 [95% CI, 37.06 to 45.46]). Similar risks of DKA (HR, 1.07 [95% CI, 0.74 to 1.54]; incidence rate difference, 0.29 [95% CI, -0.89 to 1.46]), hypovolemia (HR, 0.99 [95% CI, 0.86 to 1.14]; incidence rate difference, 0.20 [95% CI, -2.85 to 3.25]), hypoglycemia (HR, 1.08 [95% CI, 0.92 to 1.26]; incidence rate difference, 1.46 [95% CI, -1.31 to 4.23]), and severe UTI (HR, 1.02 [95% CI, 0.87 to 1.19]; incidence rate difference, 0.35 [95% CI, -2.51 to 3.21]) were observed. SGLT2i had lower risk for AKI (HR, 0.93 [95% CI, 0.87 to 0.99]; incidence rate difference, -6.75 [95% CI, -13.69 to 0.20]).

CONCLUSIONS

In US patients with CKD and type 2 diabetes receiving routine care, SGLT2i use was associated with higher risks of genital infections and potentially lower limb amputations and nonvertebral fractures.

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.

The Dietary Fermentable Fiber Inulin Alters the Intestinal Microbiome and Improves Chronic Kidney Disease Mineral-Bone Disorder in a Rat Model of CKD

Background

Dietary fiber is important for a healthy diet, but intake is low in CKD patients and the impact this has on the manifestations of CKD-Mineral Bone Disorder (MBD) is unknown.

Methods

The Cy/+ rat with progressive CKD was fed a casein-based diet of 0.7% phosphate with 10% inulin (fermentable fiber) or cellulose (non-fermentable fiber) from 22 weeks to either 30 or 32 weeks of age (~30 and ~15 % of normal kidney function). We assessed CKD-MBD, cecal microbiota, and serum gut-derived uremic toxins. Two-way ANOVA was used to evaluate the effect of age and inulin diet, and their interaction.

Results

In CKD animals, dietary inulin led to changes in microbiota alpha and beta diversity at 30 and 32 weeks, with higher relative abundance of several taxa, including Bifidobacterium and Bacteroides , and lower Lactobacillus . Inulin reduced serum levels of gut-derived uremic toxins, phosphate, and parathyroid hormone, but not fibroblast growth factor-23. Dietary inulin decreased aorta and cardiac calcification and reduced left ventricular mass index and cardiac fibrosis. Bone turnover and cortical bone parameters were improved with inulin; however, bone mechanical properties were not altered.

Conclusions

The addition of the fermentable fiber inulin to the diet of CKD rats led to changes in the gut microbiota composition, lowered gut-derived uremic toxins, and improved most parameters of CKD-MBD. Future studies should assess this fiber as an additive therapy to other pharmacologic and diet interventions in CKD.

Significance Statement

Dietary fiber has well established beneficial health effects. However, the impact of fermentable dietary fiber on the intestinal microbiome and CKD-MBD is poorly understood. We used an animal model of progressive CKD and demonstrated that the addition of 10% of the fermentable fiber inulin to the diet altered the intestinal microbiota and lowered circulating gut-derived uremic toxins, phosphorus, and parathyroid hormone. These changes were associated with improved cortical bone parameters, lower vascular calcification, and reduced cardiac hypertrophy, fibrosis and calcification. Taken together, dietary fermentable fiber may be a novel additive intervention to traditional therapies of CKD-MBD.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

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.

Evaluation and Management of Primary Hyperparathyroidism: Summary Statement and Guidelines from the Fifth International Workshop

The last international guidelines on the evaluation and management of primary hyperparathyroidism (PHPT) were published in 2014. Research since that time has led to new insights into epidemiology, pathophysiology, diagnosis, measurements, genetics, outcomes, presentations, new imaging modalities, target and other organ systems, pregnancy, evaluation, and management. Advances in all these areas are demonstrated by the reference list in which the majority of listings were published after the last set of guidelines. It was thus, timely to convene an international group of over 50 experts to review these advances in our knowledge. Four Task Forces considered: 1. Epidemiology, Pathophysiology, and Genetics; 2. Classical and Nonclassical Features; 3. Surgical Aspects; and 4. Management. For Task Force 4 on the Management of PHPT, Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology addressed surgical management of asymptomatic PHPT and non-surgical medical management of PHPT. The findings of this systematic review that applied GRADE methods to randomized trials are published as part of this series. Task Force 4 also reviewed a much larger body of new knowledge from observations studies that did not specifically fit the criteria of GRADE methodology. The full reports of these 4 Task Forces immediately follow this summary statement. Distilling the essence of all deliberations of all Task Force reports and Methodological reviews, we offer, in this summary statement, evidence-based recommendations and guidelines for the evaluation and management of PHPT. Different from the conclusions of the last workshop, these deliberations have led to revisions of renal guidelines and more evidence for the other recommendations. The accompanying papers present an in-depth discussion of topics summarized in this report. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

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.

The effect of CKD on intertrochanteric fracture treated with proximal femoral nail anti-rotation: A 7-year study

Background

Intertrochanteric fracture is one of the most burdensome osteoporotic fractures in the elderly. Chronic kidney disease is associated with sarcopenia, especially in its advanced stages and, thus may impact functional status. Combining an intertrochanteric fracture with advanced CKD may diminish results after surgical fixation. This study aims to distinguish whether CKD affects the result of intertrochanteric fracture fixation in terms of mechanical and functional outcomes.

Methods

A retrospective study reviews all intertrochanteric fractures treated with PFNA fixation from 2012 to 2018. 445 patients were classified into 5 stages of CKD and divided by eGFR = 90 ml/min/1.73 m² into CKD and non-CKD group and by eGFR = 30 ml/min/1.73 m² into advanced CKD and non-advanced CKD group. The primary outcome was one year Harris Hip Score (HHS). Secondary outcomes were medical complications, surgical complications, and a 1-year mortality rate.

Results

Harris Hip Scores (HHS) were not different between non-CKD and CKD groups (eGFR <90 mL/min/1.73 m²). However, there was a difference between non-advanced CKD and advanced CKD groups (eGFR <30 mL/min/1.73 m²) (p < 0.001). Medical complications were not different, except for sepsis in CKD stage 5 compared with stage 1 (p = 0.023). Even though AO/OTA types were more severe in the advanced CKD group, surgical complications and 1-year mortality were not different.

Conclusion

Advanced stage CKD treated with PFNA fixation is associated with lower functional outcomes at one year. Sepsis is more prone to occur after surgery in CKD stage 5.

Level of evidence

Level III; Retrospective cohort study.

Effect of Structured, Moderate Exercise on Kidney Function Decline in Sedentary Older Adults: An Ancillary Analysis of the LIFE Study Randomized Clinical Trial

Importance

Observational evidence suggests that higher physical activity is associated with slower kidney function decline; however, to our knowledge, no large trial has evaluated whether activity and exercise can ameliorate kidney function decline in older adults.

Objective

To evaluate whether a moderate-intensity exercise intervention can affect the rate of estimated glomerular filtration rate per cystatin C (eGFRCysC) change in older adults.

Design, Setting, and Participants

This ancillary analysis of the Lifestyle Interventions and Independence For Elders randomized clinical trial enrolled 1199 community-dwelling, sedentary adults aged 70 to 89 years with mobility limitations and available blood specimens. The original trial was conducted across 8 academic centers in the US from February 2010 through December 2013. Data for this study were analyzed from March 29, 2021, to February 28, 2022.

Interventions

Structured, 2-year, partially supervised, moderate-intensity physical activity and exercise (strength, flexibility) intervention compared with a health education control intervention with 2-year follow-up. Physical activity was measured by step count and minutes of moderate-intensity activity using accelerometers.

Main Outcomes and Measures

The primary outcome was change in eGFRCysC. Rapid eGFRCysC decline was defined by the high tertile threshold of 6.7%/y.

Results

Among the 1199 participants in the analysis, the mean (SD) age was 78.9 (5.2) years, and 800 (66.7%) were women. At baseline, the 2 groups were well balanced by age, comorbidity, and baseline eGFRCysC. The physical activity and exercise intervention resulted in statistically significantly lower decline in eGFRCysC over 2 years compared with the health education arm (mean difference, 0.96 mL/min/1.73 m2; 95% CI, 0.02-1.91 mL/min/1.73 m2) and lower odds of rapid eGFRCysC decline (odds ratio, 0.79; 95% CI, 0.65-0.97).

Conclusions and Relevance

Results of this ancillary analysis of a randomized clinical trial showed that when compared with health education, a physical activity and exercise intervention slowed the rate of decline in eGFRCysC among community-dwelling sedentary older adults. Clinicians should consider targeted recommendation of physical activity and moderate-intensity exercise for older adults as a treatment to slow decline in eGFRCysC.

Trial Registration

ClinicalTrials.gov Identifier: NCT01072500.

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.

Association of Sodium-Glucose Cotransporter-2 Inhibitors With Fracture Risk in Older Adults With Type 2 Diabetes

IMPORTANCE

Whether sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are associated with an increased risk of fractures in older adults with type 2 diabetes (T2D) outside of clinical trials remains unknown.

OBJECTIVE

To examine the association of incident fracture among older adults with T2D with initiating an SGLT-2i compared with initiating a dipeptidyl peptidase 4 inhibitor (DPP-4i) or a glucagon-like peptide 1 receptor agonist (GLP-1RA).

DESIGN, SETTING, AND PARTICIPANTS

This is a population-based, new-user cohort study including older adults (aged ≥65 years) with T2D enrolled in Medicare fee-for-service from April 2013 to December 2017. Data analysis was performed from October 2020 to April 2021.

EXPOSURES

New users of an SGLT-2i, DPP-4i, or GLP-1RA without a previous fracture were matched in a 1:1:1 ratio using 3-way propensity score matching.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite end point of nontraumatic pelvic fracture, hip fracture requiring surgery, or humerus, radius, or ulna fracture requiring intervention within 30 days. After 3-way 1:1:1 propensity score matching, multivariable Cox proportional hazards regression models were used to generate hazard ratios (HRs) for SGLT-2i compared with DPP-4i and GLP-1RA and Kaplan-Meier curves to visualize fracture risk over time across groups.

RESULTS

Of 466 933 new initiators of study drugs, 62 454 patients were new SGLT-2i users. After 3-way matching, 45 889 (73%) new SGLT-2i users were matched to new users of DPP-4i and GLP-1RA, yielding a cohort of 137 667 patients (mean [SD] age, 72 [5] years; 64 126 men [47%]) matched 1:1:1 for analyses. There was no difference in the risk of fracture in SGLT-2i users compared with DPP-4i users (HR, 0.90; 95% CI, 0.73-1.11) or GLP-1RA users (HR, 1.00; 95% CI, 0.80-1.25). Results were consistent across categories of sex, frailty (nonfrail, prefrail, and frail), age (<75 and ≥75 years), and insulin use (baseline users and nonusers).

CONCLUSIONS AND RELEVANCE

In this nationwide Medicare cohort, initiating an SGLT-2i was not associated with an increased risk of fracture in older adults with T2D compared with initiating a DPP-4i or GLP-1RA, with consistent results across categories of frailty, age, and insulin use. These findings add to the evidence base evaluating the potential risks associated with SGLT-2i use for older adults outside of randomized clinical trials.

Chronic kidney disease patients with intertrochanteric fracture have a high mortality rate

AIMS

The prognosis of patients with chronic kidney disease (CKD) and intertrochanteric fractures is unclear. This study was aimed to analyze the mortality and complication rates among CKD patients with intertrochanteric femoral fractures and the risk factors of one-year mortality after surgery.

PATIENTS AND METHODS

This retrospective cohort study included 49 patients diagnosed with grades III, IV, or V CKD who were surgically treated for an intertrochanteric fracture between January 2011 and February 2019 at a tertiary university hospital. Preoperative parameters, including age, gender, bone mineral density, follow-up period (mean: 8.6 months range: 1~82 months), underlying disease, American Society of Anesthesiologists classification, fracture classification, and grade of CKD were identified, and complications and mortality rates after surgery were examined. The patients were divided into two groups according to whether one-year mortality after surgery had occurred or not, and a logistic regression analysis was performed to analyze the risk factors of mortality.

RESULTS

Of the 49 total patients, 16 died <1 year postoperatively. Pneumonia (n = 11) was the most common postoperative complication. Twenty-one patients died during the follow-up period. Significant differences in gender (p = 0.006) and grade of CKD (p = 0.022) distributions were found between the two groups, divided according to whether one-year mortality had occurred or not. In a univariate analysis, CKD grade and postoperative septic shock were highly associated with one-year mortality. In a multivariate analysis, septic shock, acute kidney injury, and CKD grade were identified as the risk factors of one-year mortality.

CONCLUSION

The mortality and complication rates were high among the CKD patients with intertrochanteric fractures. Grades of CKD significantly correlated with one-year mortality after surgery; therefore, they and an important factor that must be considered when developing a strategy to improve the postoperative survival rate of patients with CKD.

Estimated Glomerular Filtration Rate (eGFR) based on cystatin C was associated with increased risk of hip and proximal humerus fractures in women and decreased risk of hip fracture in men, whereas eGFR based on creatinine was not associated with fracture risk in both sexes: The Tromsø Study

PURPOSE

Patients with end-stage kidney disease have an increased fracture risk. Whether mild to moderate reductions in kidney function is associated with increased fracture risk is uncertain. Results from previous studies may be confounded by muscle mass because of the use of creatinine-based estimates of the glomerular filtration rate (eGFRcre). We tested the hypothesis that lower eGFR within the normal range of kidney function based on serum cystatin C (eGFRcys) or both cystatin C and creatinine (eGFRcrecys) predict fractures better than eGFR based on creatinine (eGFRcre).

METHODS

In the Tromsø Study 1994-95, a cohort of 3016 women and 2836 men aged 50-84 years had eGFRcre, eGFRcys and eGFRcrecys estimated using the Chronic Kidney Disease Epidemiology Collaboration equations. Hazard ratios (HRs) (95% confidence intervals) for fracture were calculated in Cox's proportional hazards models and adjusted for age, height, body mass index, bone mineral density, diastolic blood pressure, smoking, physical activity, previous fracture, diabetes and cardiovascular disease.

RESULTS

During a median of 14.6 years follow-up, 232, 135 and 394 women and 118, 35 and 65 men suffered incident hip, proximal humerus and wrist fractures. In women, lower eGFRcre did not predict fracture, but the risk for hip and proximal humerus fracture increased per standard deviation (SD) lower eGFRcys (HRs 1.36 (1.16-1.60) and 1.33 (1.08-1.63)) and per SD lower eGFRcrecys (HRs 1.25 (1.08-1.45) and 1.30 (1.07-1.57)). In men, none of the eGFR estimates were related to increased fracture risk. In contrast, eGFRcys and eGFRcrecys were inversely associated with hip fracture risk (HRs 0.85 (0.73-0.99) and 0.82 (0.68-0.98)).

CONCLUSIONS

In women, each SD lower eGFRcys and eGFRcrecys increased the risk of hip and proximal humerus fracture by 25-36%, whereas eGFRcre did not. In men, none of the estimates of eGFR were related to increased fracture risk, and each SD lower eGFRcys and eGFRcrecys decreased the risk of hip fracture by 15-18%. The findings particularly apply to a cohort of generally healthy individuals with a normal kidney function. In future studies, the association of measured GFR using the gold standard method of iohexol clearance with fractures risk should be examined for causal inference. More clinical research is needed before robust clinical inferences can be made.

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.

Mortality Risk Assessment at the Admission in Patient With Proximal Femur Fractures: Electrolytes and Renal Function

In patients over 65y.o. who were surgically treated for a hip fracture, electrolytes have not been specifically studied as predictors of mortality. The main purpose of this study was to assess whether electrolytes and chronic kidney disease (CKD) stages, evaluated at admission, could represent a pre-operative prognostic factor in this population. Moreover, the role of epidemiological and clinical parameters was analyzed with and without a surgical timing stratification. This retrospective study included 746 patients. For each patient, their age, gender, fracture classification, Hb value, comorbidities, ASA class, chronic kidney disease, creatinine levels, electrolytes and surgical timing were collected. CKD-epi, MDRD, modified MDRD and BIS1 were used to obtain eGFR and CKD stages. All parameters were analyzed individually and in relation to the different surgical timing. Descriptive statistics, Chi-square test and survivability analysis with Kaplan Meier curve were used. In patients with a hip fracture non-significant association with increased mortality was shown for the following variables: Hb value, sodium values, calcium values, CKD stages and creatinine values. Otherwise altered kalemia was associated with a statistically significant increase in mortality as well as male gender, two or more comorbid medical conditions, advanced age (>75 years), higher ASA class. Surgery performed within 72h resulted in a statistically significant reduction in mortality at 6 months and, when performed in 24h-48h, a further reduction at 4 years. Age and ASA class statistically significant increased mortality regardless the surgical timing. Male patients operated after 48h from hospitalization were associated with a statistically significant increase in mortality rate. Two or more comorbidities were related to a statistically significant increased number of deaths when patients were treated after 96h. Altered kalemia values at hospitalization are associated with a statistically significant increase in mortality in patients operated after 72h from admission.

Denosumab Safety and Efficacy Among Participants in the FREEDOM Extension Study With Mild to Moderate Chronic Kidney Disease

CONTEXT

The effects of long-term exposure to denosumab in individuals with renal insufficiency are unknown.

OBJECTIVE

This post hoc analysis evaluates the long-term safety and efficacy of denosumab in individuals with mild-to-moderate chronic kidney disease (CKD) (stages 2 and 3) using data from the pivotal phase 3, double-blind, 3-year FREEDOM (NCT00089791) and open-label, 7-year extension (NCT00523341) studies.

PARTICIPANTS AND METHODS

Women age 60 to 90 years with a bone mineral density (BMD) T-score of less than -2.5 to greater than -4.0 at the total hip or lumbar spine were randomly assigned 1:1 to receive denosumab 60 mg subcutaneously every 6 months (long-term arm) or placebo (cross-over arm) in FREEDOM; eligible participants could enroll in the extension to receive denosumab 60 mg subcutaneously every 6 months. Change in estimated glomerular filtration rate (eGFR) from study baseline and annualized rates of fracture and adverse events (AEs) were the main outcome measures.

RESULTS

Most participants (1259/1969 [64%] long-term arm; 1173/1781 [66%] crossover arm) with baseline CKD stage 2 or 3 remained within the same CKD subgroup at study completion; less than 3% progressed to CKD stage 4. Participants in all eGFR subgroups showed similar, persistent BMD gains over time and a low incidence of fractures. The percentage of participants reporting serious AEs was similar among renal subgroups (normal, CKD stage 2, CKD stage 3a, CKD stage 3b) both for the long-term (54% vs 52% vs 57% vs 58%) and crossover (43% vs 42% vs 43% vs 68%) arms, except CKD stage 3b subgroup, crossover arm.

CONCLUSION

The safety and efficacy of denosumab did not differ among participants with mild to moderate 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.

Chronic kidney disease as a risk factor for peripheral nerve impairment in older adults: A longitudinal analysis of Health, Aging and Body Composition (Health ABC) study

Introduction

Sensory and motor nerve deficits are prevalent in older adults and are associated with loss of functional independence. We hypothesize that chronic kidney disease predisposes to worsening sensorimotor nerve function over time.

Materials and methods

Participants were from the Health, Aging and Body Composition Study (N = 1121) with longitudinal data between 2000–01 (initial visit) and 2007–08 (follow-up visit). Only participants with non-impaired nerve function at the initial visit were included. The predictor was presence of CKD (estimated GFR ≤ 60 ml/min/1.73m²) from the 1999–2000 visit. Peripheral nerve function outcomes at 7-year follow-up were 1) Motor: “new” impairments in motor parameters (nerve conduction velocity NCV < 40 m/s or peroneal compound motor action potential < 1 mv) at follow-up, and 2) Sensory: “new” impairment defined as insensitivity to standard 10-g monofilament or light 1.4-g monofilament at the great toe and “worsening” as a change from light to standard touch insensitivity over time. The association between CKD and “new” or “worsening” peripheral nerve impairment was studied using logistic regression.

Results

The study population was 45.9% male, 34.3% Black and median age 75 y. CKD participants (15.6%) were older, more hypertensive, higher in BMI and had 2.37 (95% CI 1.30–4.34) fold higher adjusted odds of developing new motor nerve impairments in NCV. CKD was associated with a 2.02 (95% CI 1.01–4.03) fold higher odds of worsening monofilament insensitivity. CKD was not associated with development of new monofilament insensitivity.

Conclusions

Pre-existing CKD leads to new and worsening sensorimotor nerve impairments over a 7-year time period in community-dwelling older adults.

Executive summary of clinical practice guide on fracture risk in lifestyle diseases

Accumulating evidence has shown that patients with lifestyle diseases such as type 2 diabetes mellitus, chronic kidney disease, and chronic obstructive pulmonary disease are at increased risk of osteoporotic fracture. Fractures deteriorate quality of life, activities of daily living, and mortality as well as a lifestyle disease. Therefore, preventing fracture is an important issue for those patients. Although the mechanism of the lifestyle diseases-induced bone fragility is still unclear, not only bone mineral density (BMD) reduction but also bone quality deterioration are involved in it. Because fracture predictive ability of BMD and FRAX^® is limited, especially for patients with lifestyle diseases, the optimal management strategy should be established. Thus, when the intervention of the lifestyle diseases-induced bone fragility is initiated, the deterioration of bone quality should be taken into account. We here review the association between lifestyle diseases and fracture risk and proposed an algorism of starting anti-osteoporosis drugs for patients with lifestyle diseases.

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.

Health-Related Quality of Life, Depressive Symptoms, and Kidney Transplant Access in Advanced CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

Rationale & Objective

Among individuals with chronic kidney disease (CKD), poor self-reported health is associated with adverse outcomes including hospitalization and death. We sought to examine the association between health-related quality-of-life (HRQoL) and depressive symptoms in advanced CKD and subsequent access to the kidney transplant waiting list.

Study Design

Prospective cohort study.

Setting & Population

1,676 Chronic Renal Insufficiency Cohort (CRIC) study participants with estimated glomerular filtration rates ≤ 30 mL/min/1.73 m² at study entry or during follow-up.

Exposures

HRQoL ascertained by 5 scales of the Kidney Disease Quality of Life-36 Survey (Physical Component Summary [PCS], Mental Component Summary, Symptoms, Burdens, and Effects), with higher scores indicating better HRQoL, and depressive symptoms ascertained using the Beck Depression Inventory.

Outcomes

Time to kidney transplant wait-listing and time to pre-emptive wait-listing.

Analytic Approach

Time-to-event analysis using Cox proportional hazards regression.

Results

During a median follow-up of 5.1 years, 652 (39%) participants were wait-listed, of whom 304 were preemptively wait-listed. Adjusted for demographics, comorbid conditions, estimated glomerular filtration rate slope, and cognitive function, participants with the highest scores on the Burden and Effects scales, respectively, had lower rates of wait-listing than those with the lowest scores on the Burden (wait-listing adjusted hazard ratio [aHR], 0.70; 95% CI, 0.57-0.85; P < 0.001) and Effects scales (wait-listing aHR, 0.74; 95% CI, 0.59-0.92; P = 0.007). Participants with fewer depressive symptoms (ie, Beck Depression Inventory score < 14) had lower wait-listing rates than those with more depressive symptoms (aHR, 0.81; 95% CI, 0.66-0.99; P = 0.04). Participants with lower Burden and Effects scale scores and those with higher Symptoms and PCS scores had higher pre-emptive wait-listing rates (aHR in highest tertile of PCS relative to lowest tertile, 1.58; 95% CI, 1.12-2.23; P = 0.01).

Limitations

Unmeasured confounders.

Conclusions

Self-reported health in late-stage CKD may influence the timing of kidney transplantation.

Trabecular bone score in patients with chronic kidney disease

Patients with chronic kidney disease have high risk of osteoporotic fractures. Lower trabecular bone score (TBS) was associated with poorer kidney function and higher fracture risk when kidney function was normal. Addition of TBS to The Fracture Risk Assessment Tool with bone mineral density did not improve fracture risk prediction.

INTRODUCTION

We sought to determine whether trabecular bone score (TBS) either independently or adjusted for The Fracture Risk Assessment Tool (FRAX) could predict risk of major osteoporotic fractures (MOFs) in a large population-based sample of patients with all stages of chronic kidney disease (CKD).

METHODS

We used population-based administrative databases to identify patients above age 20 years who had dual-energy X-ray absorptiometry (DXA) scan and serum creatinine measured within 1 year, during the years 2005 to 2010. Patients were excluded if they were on dialysis or had a functioning renal transplant. We stratified patients by estimated glomerular filtration rate (eGFR). We collected femoral neck bone mineral density (BMD), lumbar spine TBS, incident major osteoporotic fractures (MOF) and hip fractures, and other clinical characteristics.

RESULTS

Among 8289 patients, there were 6224 (75.1%) with eGFR ≥ 60 mL/min/1.73 m², 1624 (19.6%) with eGFR 30-60 mL/min/1.73 m², and 441 (5.3%) with eGFR < 30 mL/min/1.73 m². There were 593 patients (7.2%) with MOFs and 163 (2.0%) with hip fractures. Lower TBS score was associated with increased risk of MOF and hip fractures across all eGFR strata in unadjusted Cox proportional hazards models but after adjusting for FRAX with BMD, lower TBS was only statistically significant for MOF prediction for eGFR ≥ 60 mL/min/1.73 m².

CONCLUSION

Lower TBS scores were associated with lower eGFR and increased fracture risk in patients with eGFR ≥ 60 mL/min/1.73 m². However, the addition of TBS to the FRAX score with BMD did not significantly improve fracture risk prediction in patients with CKD.

Risks of Hip and Nonvertebral Fractures in Patients With CKD G3a-G5D: A Systematic Review and Meta-analysis

RATIONALE & OBJECTIVE

Disordered mineral metabolism complicates chronic kidney disease (CKD), but the effect of reduced kidney function on fracture risk has not been fully established. We conducted a systematic review and meta-analysis of the risks for hip and nonvertebral fractures in people with CKD. We also investigated the effects of age, sex, and CKD stage.

STUDY DESIGN

Systematic review and meta-analysis.

STUDY POPULATION

Adults with CKD glomerular filtration rate (GFR) categories 3a-5D (G3a-G5D) compared with adults without CKD G3a-G5D.

SELECTION CRITERIA FOR STUDIES

Observational studies.

DATA EXTRACTION

Data extraction was conducted by 1 reviewer and checked by a second reviewer.

ANALYTICAL APPROACH

MEDLINE, EMBASE, and Cochrane databases were searched in March 2018 and an update was conducted in November 2019. We used random-effects models to calculate pooled risk estimates and 95% CIs.

RESULTS

17 studies met the inclusion criteria. We included 13 studies in the hip fracture systematic review and 10 studies in the meta-analysis. Studies reported data from 250,440,035 participants; 5,798,566 with CKD G3a-G5D and 363,410 with hip fractures. 4 studies were included in the nonvertebral fracture analysis, reporting data from 1,396,976 participants; 464,978 with CKD G3a-G5D and 115,284 fractures. Studies reported data from participants aged 18 to older than 90 years. We found a significant increase in fracture risk both for hip (relative risk [RR], 2.36; 95% CI, 1.64-3.39) and nonvertebral fractures (RR, 1.47; 95% CI, 1.15-1.88). For hip fractures, younger patients (<65 years) had higher relative risk (RR, 7.66; 95% CI, 2.76-21.26) than older patients (>65 years; RR, 2.11; 95% CI, 1.41-3.16). Greater GFR loss was associated with higher relative risk for fractures.

LIMITATIONS

We could not assess the effects of bone mineral density, biochemical abnormalities, renal osteodystrophy, frailty, falls, or medications on risk for fractures.

CONCLUSIONS

Risks for hip and nonvertebral fractures are increased in CKD G3a-G5D. The relative risk of hip fracture is greater in the younger than the older population and increases progressively with loss of GFR. We suggest that fracture prevention should be a consideration in CKD at any age.

Chronic Kidney Disease Increases the Risk of Hip Fracture: A Prospective Cohort Study in Korean Adults

This study was conducted to examine the association between renal function and hip fracture. We followed up 352,624 Korean adults, who participated in health examinations during 2009-2010 until 2013. Kidney function was assessed by creatinine-based estimated glomerular filtration rate (eGFR) and albuminuria using urine reagent strip results. The incidence of hip fracture was examined by hospital discharge records. Hazard ratios (HRs) for hip fracture were calculated using Cox proportional hazard models after adjusting for multiple confounders. During a mean follow-up of 4.0 years, 1177 participants suffered a hip fracture. Lower eGFR and more severe albuminuria were associated with a higher risk of hip fracture. The HRs for hip fracture were 1.89 (95% confidence interval [CI] 1.47-2.43) and 3.75 (95% CI 2.30-6.11) among participants with eGFRs of 30 to 44 and 15 to 29 mL/min/1.73m² relative to those with an eGFR ≥60 mL/min/1.73m² , respectively. The HRs were 1.30 (95% CI 1.02-1.65) for moderate albuminuria and 1.58 (95% CI 1.07-2.35) for severe albuminuria (p for trend = 0.002). Participants with albuminuria had a higher risk of hip fracture than those without albuminuria, even when they belonged to the same eGFR category (HR = 1.75 versus 3.30 for an eGFR of 30 to 44 mL/min/1.73m² ; HR = 2.72 versus 7.84 for an eGFR of 15 to 29 mL/min/1.73m² ). The effects of each 10 mL/min/1.73m² decrease in eGFR were stronger with advancing albuminuria severity (p_interaction = 0.016). In conclusion, both low eGFR and albuminuria were risk factors for incident hip fracture in Korean adults. Moreover, these factors exerted a synergistic effect on the risk of hip fracture. © 2020 American Society for Bone and Mineral Research.

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.

Glomerular filtration rate is associated with trabecular bone score in patients with type 2 diabetes mellitus

AIMS

The present study aimed to evaluate the trabecular and cortical bone components using Trabecular Bone Score (TBS) and its association with estimated-Glomerular Filtration Rate (e-GFR) in T2DM patients.

METHODS

An assessment both of bone mineral density (BMD) and vertebral bone microarchitecture was performed in all patients using TBS iNsight® software version 3.0.2.0. Furthermore, the total population was divided into two groups based on the value of the eGFR (eGFR < o > at 60 ml/min/1.73 m²).

RESULTS

TBS value was lower in patients with low e-GFR than that in patients with higher e-GFR (1.246 ± 0.125 vs 1.337 ± 0.115, respectively, p = 0.013 adjusted by gender and age) while there was no difference in total BMD value between two groups. In the multivariate model taking into account several possible confounders, such as age, gender, duration of diabetes, BMI, LDL cholesterol, serum calcium and HbA1c, the correlation between e-GFR and TBS remained significant (p: 0.046).

CONCLUSIONS

In individuals with T2DM and reduced kidney function, TBS provides information independent of BMD, age and gender. TBS may be a useful additional tool to predict fracture risk in this unique population.

Comorbid Conditions and GFR Predict Nonvertebral Fractures in Patients With Diabetes in an Ethnic-Specific Manner

CONTEXT

Diabetes mellitus (DM) is associated with an increased risk of fracture, but it is not clear which diabetes and nondiabetes risk factors may be most important.

OBJECTIVE

The aim of the study was to evaluate risk factors for incident major osteoporotic fractures (MOFs) of the hip, wrist, and humerus in African American (AA), Hispanic (HIS), and Caucasian (CA) subjects with DM.

METHODS

This was a retrospective cohort study of 18 210 subjects with DM (7298 CA, 7009 AA and 3903 HIS) at least 40 years of age, being followed at a large healthcare system in Philadelphia, Pennsylvania.

RESULTS

In a global model in CA with DM, MOF were associated with dementia (HR 4.16; 95% CI, 2.13-8.12), OSA (HR 3.35; 95% CI, 1.78-6.29), COPD (HR 2.43; 95% CI, 1.51-3.92), and diabetic neuropathy (HR 2.52; 95% CI, 1.41-4.50). In AA, MOF were associated with prior MOF (HR 13.67; 95% CI, 5.48-34.1), dementia (HR 3.10; 95% CI, 1.07-8.98), glomerular filtration rate (GFR) less than 45 (HR 2.05; 95% CI, 1.11-3.79), thiazide use (HR 0.54; 95% CI, 0.31-0.93), metformin use (HR 0.59; 95% CI, 0.36-0.97), and chronic steroid use (HR 5.03; 95% CI, 1.51-16.7). In HIS, liver disease (HR 3.06; 95% CI, 1.38-6.79) and insulin use (HR 2.93; 95% CI, 1.76-4.87) were associated with MOF.

CONCLUSION

In patients with diabetes, the risk of fracture is related to both diabetes-specific variables and comorbid conditions, but these relationships vary by race/ethnicity.

Bisphosphonate utilization across the spectrum of eGFR

Bisphosphonates are the most common treatment for osteoporosis but there are concerns regarding its use in CKD. We evaluated the frequency of BSP by eGFR categories among patients with osteoporosis from two healthcare systems. Our results show that 56% of patients were treated, with reduced odds in those with lower eGFR.

INTRODUCTION

Osteoporosis is common in patients with chronic kidney disease (CKD). Bisphosphonates (BSP) are the most common treatment but there are concerns regarding its efficacy and toxicity in CKD. We evaluated the frequency of BSP use by level of estimated glomerular filtration rate (eGFR) in patients with osteoporosis.

METHODS

We assessed BSP use in patients with incident osteoporosis from the SCREAM-Cohort, Stockholm-Sweden, and Geisinger Healthcare, PA, USA. Osteoporosis was defined as the first encountered ICD diagnosis, and BSP use was defined as the dispensation or prescription of any BSP from 6 months prior to 3 years after the diagnosis. Multinomial logistic regression was used to account for the competing risk of death.

RESULTS

A total of 15,719 women and 3011 men in SCREAM and 17,325 women and 3568 men in Geisinger with incident osteoporosis were included. Overall, 56% of individuals used BSP in both studies, with a higher proportion in women. After adjustments, the odds of BSP was lower across lower eGFR in SCREAM, ranging from 0.90 (0.81-0.99) for eGFR 75-89 mL/min/1.73m² to 0.56 (0.46-0.68) for eGFR 30-44 mL/min/1.73m² in women and from 0.72 (0.54-0.97) for eGFR of 60-74 to 0.42 (0.25-0.70) for eGFR 30-44 mL/min/1.73m² in men. In Geisinger, odds were lower for eGFR < 30 mL/min/1.73m² in both sexes and the frequency of BSP use dropped over time.

CONCLUSION

In the two healthcare systems, approximately half of the people diagnosed with osteoporosis received BSP. Practices of prescription in relation to eGFR varied, but those with lower eGFR were less likely to receive BSP.

Bazedoxifene improves renal function and increases renal phosphate excretion in patients with postmenopausal osteoporosis

INTRODUCTION

Because aging is a predictor of renal insufficiency in the general population, renal function is a concern in postmenopausal patients undergoing treatment for osteoporosis. Although high serum phosphate concentration is a predictor of renal insufficiency, the effect of selective estrogen receptor modulator (SERM) on renal function and phosphate homeostasis remains to be established.

MATERIALS AND METHODS

We administered 20 mg/day bazedoxifene to 48 postmenopausal osteoporotic women who had been taking alfacalcidol for ≥ 6 months, and assessed lumbar spine bone mineral density (LS-BMD), renal function (by calculating estimated glomerular filtration rate using serum cystatin-C levels [eGFRcys] [range 38.0-98.2 mL/min/1.73 m²]), and phosphate homeostasis.

RESULTS

LS-BMD was significantly higher 6 months after the initiation of bazedoxifene administration. eGFRcys had increased by 3 months after initiation and was stable until 12 months. Serum phosphate gradually decreased after initiation, reaching statistical significance at 6 months. The changes in serum phosphate were also significant when the maximum tubular reabsorption rate of phosphate was normalized to glomerular filtration rate (TmP/GFR), indicating that bazedoxifene treatment reduces serum phosphate by increasing the urinary excretion of phosphate. The change in eGFRcys after the initiation of bazedoxifene was significantly negatively correlated with the change in serum phosphate, suggesting that a reduction in serum phosphate improves renal function.

CONCLUSION

Bazedoxifene improves renal function, possibly by increasing renal phosphate excretion, in postmenopausal osteoporotic women without severe renal insufficiency.

Bone Mineral Density in Relation to Chronic Kidney Disease After Heart Transplantation: A Retrospective Single-center Study at Skåne University Hospital in Lund 1988-2016

Background.

Our aim was to investigate the bone mineral density (BMD) evolution and incidence of osteoporosis in relation to chronic kidney disease (CKD) up to 10 years after heart transplantation (HT).

Methods.

A retrospective analysis was performed on 159 HT patients at Skåne University Hospital in Lund 1988–2016.

Results.

The median follow-up time was 6.1 years (interquartile range = 7.5 y). HT patients with CKD stage <3 or normal kidney function before HT exhibited a greater mean BMD loss in the lumbar spine, compared to patients with CKD stage ≥3 before HT, at the first (−6.6% versus −2.5%, P = 0.029), second (−3.7% versus 2.1%, P = 0.018), and third (−2.0% versus 4.1%, P = 0.047) postoperative years, respectively. All included HT patients exhibited a BMD loss in the femoral neck at the first postoperative year (−8.8% [−10.3 to −7.3] in patients with CKD stage <3 or normal kidney function and −9.3% [−13.2 to −5.5] in patients with CKD stage ≥3 before HT), which was not fully reversed up to 10 years after HT. In adjusted models, CKD stage <3 before HT did not predict osteopenia and osteoporosis in the lumbar spine or femoral neck.

Conclusions.

CKD before HT did not predict BMD loss or osteoporosis development after HT. The study is, however, limited by a lack of data on fractures, and further studies on the relationship between CKD and postoperative bone strength are encouraged.

Association between Bone Mineral Density and Severity of Chronic Kidney Disease

OBJECTIVE

We sought to evaluate the association between femoral neck (FN) and lumbar spine (LS) bone mineral densities (BMDs) with severity of chronic kidney disease (CKD) and prevalence of osteopenia or osteoporosis (OP) among the CKD group.

METHODS

Cross-sectional data from 11050 participants aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) were analyzed. Specifically, Pearson correlation was applied to analyze the relationship between BMD and estimated glomerular filtration rate (eGFR). General linear models (GLMs) were adjusted for potential confounders and used to analyze mean BMD, based on CKD and CKD stages.

RESULTS

FN BMD was positively correlated with the eGFR in the total and male CKD, but not in the female CKD population. LS BMD was not significantly associated with eGFR. After controlling for partial correlations, FN T-score was positively correlated with the eGFR in the total at-risk population. According to FN BMD, OP prevalence was positively associated with CKD stage. However, according to LS BMD, there was no significant association between OP and CKD stage.

CONCLUSION

Our results may explain the higher prevalence of hip fracture, relative to that of the spine, among CKD patients and generate meaningful insights to guide care, prevention, and treatment regimens for CKD patients. However, the fact that this was a cross-sectional study may limit the possibility of drawing concrete conclusions. Nevertheless, these findings open up a new frontier for further studies to uncover the higher decrease of FN BMD compared to LS BMD among CKD cases.

Kidney function and its association to imminent, short- and long-term fracture risk-a longitudinal study in older women

Reduced kidney function is associated with an increased fracture risk, although the relationship between an age-related decline and fractures needs further investigation. We followed kidney function and fracture risk for 10 years. A mild-moderate decline in kidney function was associated with fracture, but not in advanced age.

INTRODUCTION

With age, kidney function declines. Though well known that chronic kidney disease is associated with increased fracture risk, the extent to which the typical age-related decline contributes is unclear. In the OPRA cohort, a longitudinal study of older non-selected women, we investigated the association between kidney function and fracture.

METHODS

Cystatin C-based kidney function estimates were available at age 75 (n = 981) and 80 (n = 685). Women were categorized by kidney function: normal (CKD stages 1 and 2), mild-moderate (3a), poor (3b-5), and imminent, short- and long-term fracture risk investigated. BMD measurements and kidney function for risk prediction were also evaluated; women were categorized by both reduced kidney function (stages 3-5) and osteoporosis status.

RESULTS

In the short term, 2-3 years, mild-moderate kidney dysfunction was associated with the highest risk increase: osteoporotic fractures (2 years HRadj 2.21, 95% CI 1.27-3.87) and also up to 5 years (between 75 and 80 years) (HRadj 1.51, 1.04-2.18). Hip fracture risk was similarly increased. This association was not observed from age 80 nor for women with poorest kidney function. Reduced kidney function was associated with higher risk even without osteoporosis (osteoporotic fracture; HRadj 1.66, 1.08-2.54); risk increased by having both osteoporosis and reduced function (HRadj 2.53, 1.52-4.23).

CONCLUSION

Older women with mild-moderate reduction of kidney function are at increased risk of fractures, but not those with the worst function. Our findings furthermore confirm the value of osteoporosis assessment and it is possible that in this age group, age-related decline of kidney function has limited contribution compared with BMD.

The association between chronic kidney disease, falls, and fractures: a systematic review and meta-analysis

Patients with chronic kidney disease (CKD) are more likely to experience falls and fractures due to renal osteodystrophy and the high prevalence of risk factors for falls. However, it is not well established how great the risk is for falls and fractures for the different stages of CKD compared to the general population. The objective of this systematic review and meta-analysis was to assess whether, and in which degree, CKD was associated with falls and fractures in adults. A systematic search in PubMed, Embase, CINAHL, and The Cochrane Library was performed on 7 September 2018. All retrospective, cross-sectional, and longitudinal studies of adults (18 years of older) that studied the association between CKD, fractures, and falls were included. Additional studies were identified by cross-referencing. A total of 39 publications were included, of which two publications assessed three types of outcome and four publications assessed two types of outcome. Ten studies focused on accidental falling; seventeen studies focused on hip, femur, and pelvis fractures; seven studies focused on vertebral fractures; and thirteen studies focused on any type of fracture without further specification. Generally, the risk of fractures increased when kidney function worsened, with the highest risks in the patients with stage 5 CKD or dialysis. This effect was most pronounced for hip fractures and any type of fractures. Furthermore, results on the association between CKD and accidental falling were contradictory. Compared to the general population, fractures are highly prevalent in patients with CKD. Besides more awareness of timely fracture risk assessment, there also should be more focus on fall prevention.

Higher albumin:creatinine ratio and lower estimated glomerular filtration rate are potential risk factors for decline of physical performance in the elderly: the Cardiovascular Health Study

INTRODUCTION

Mildly reduced renal function and elevated urine protein levels are each prospectively associated with hip fracture risk in older adults. Here we determine whether these markers are associated with reduced appendicular muscle performance.

METHODS

We prospectively examined the associations of urine albumin:creatinine ratio (ACR) and reduced estimated glomerular filtration rate (eGFR) with longitudinal changes in grip strength and gait speed >2 years in 2317 older community-dwelling men and women (median age 77 years). The median ACR was 9.8 [interquartile range (IQR) 5.40-21.50] mg/g creatinine and the median eGFR was 71.6 (IQR 59.1-83.56) mL/min/1.73 m2. Models were adjusted for demographic factors, clinical history and biochemical measures in four candidate pathways: diabetes, oxidative stress, inflammation and fibrosis.

RESULTS

In demographic- and covariate-adjusted models, a 2-fold higher baseline urine ACR was associated with longitudinal changes of -0.17 kg [95% confidence interval (CI) -0.29 to -0.06) in grip strength and -1.10 cm/s (95% CI -1.67 to -0.53) gait speed per year. Corresponding estimates for a 10 mL/min/1.73 m2 lower baseline eGFR were -0.13 kg (95% CI -0.23 to -0.04) and -0.89 cm/s (95% CI -1.37 to -0.40), respectively. The associations of a 2-fold higher baseline ACR and a 10 mL/min/1.73 m2 lower baseline eGFR using cystatin C with grip strength and gait speed were equivalent to ∼1.2-1.9 additional years of age. Adjustment for covariates in candidate pathways did not attenuate these estimates.

CONCLUSIONS

In older adults, higher ACR and lower eGFR are potential risk factors for a decline of physical performance >2 years.

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.

Denosumab Improves Glomerular Filtration Rate in Osteoporotic Patients With Normal Kidney Function by Lowering Serum Phosphorus

Higher serum phosphorus (Pi) increases the risk for chronic kidney disease (CKD). It was reported that a single administration of denosumab or zoledronate significantly suppressed serum Pi levels as well as those of bone resorption markers in serum. Also, previous evidences suggest a link between bone anti-resorptive therapy and vasoprotective/renoprotective effects through mechanisms that remain unexplored. The aim of this study is to assess the renoprotective effect of denosumab and involvement of denosumab-induced reduction in serum Pi in osteoporotic patients. Osteoporotic patients (n = 73) without overt proteinuria in dipstick test results were treated with denosumab (60 mg) every 6 months during the study period (24 months). Estimated glomerular filtration rate based on serum cystatin C (eGFRcys) was used as a filtration marker and tartrate-resistant acid phosphatase-5b (TRACP-5b) as a bone resorption marker. For analysis of non-CKD patients (n = 56), those with eGFRcys <60 mL/min/1.73 m² were excluded. A single injection of denosumab suppressed serum Pi as well as TRACP-5b during the first 6 months, whereas age-related decline in eGFRcys was significantly reversed, with an increase of 2.75 ± 1.2 mL/min/1.73 m² after 24 months noted. Multivariate analysis showed that serum Pi reduction following the initial denosumab injection was positively associated with serum TRACP-5b suppression during that same period (β = 0.241, p = 0.049). In addition, a positive association of serum Pi suppression, but not of corrected calcium or TRACP-5b, with eGFRcys increase after 24 months (β = 0.321, p = 0.014) was found after adjustments for gender, age, BMI, antihypertensive drug use, albumin, and eGFRcys. The same was observed in osteoporotic cases restricted to non-CKD patients. In conclusion, serum Pi reduction resulting from phosphorus load decrement from bone induced by denosumab is a determinant for eGFRcys increase. Early introduction of bone antiresorptive therapy can retain glomerular filtration in osteoporosis cases, including non-CKD patients. © 2019 American Society for Bone and Mineral Research.

Association of Bone Mineral Density With Fractures Across the Spectrum of Chronic Kidney Disease: The Regina CKD-MBD Study

Background:

Recent studies have demonstrated that measurement of areal bone mineral density by dual-energy x-ray absorptiometry (DXA) predicts fractures in patients with chronic kidney disease (CKD). However, whether fracture risk prediction through bone mineral density (BMD) is enhanced due to the assessment of biochemical markers of chronic kidney disease and mineral and bone disease (CKD-MBD) or clinical risk factors is not clear. We hypothesized that in a select cohort of patients managed in a CKD clinic, that combining T-Scores with biochemical markers would optimize fracture discrimination than using DXA alone.

Objective:

To examine the relationships among BMD, biochemical markers of CKD-MBD, and fracture risk across Kidney Disease Improving Global Outcomes (KDIGO) glomerular filtration rate (GFR) categories G3a to G5.

Design:

Retrospective study.

Setting:

Patients were recruited from the multidisciplinary CKD clinic, Regina General Hospital, Canada.

Patients:

A total of 374 patients who received a DXA scan upon initial referral to Regina Multidisciplinary CKD Program from January 31, 2001 to January 31, 2010, were included in this study. The patients were followed for a total of 5 years.

Methods:

We conducted a retrospective review of 374 consecutive patients who underwent DXA imaging at the point of entry into our multidisciplinary CKD program. Areal BMD, T- and Z-Scores were obtained at the lumbar spine, total hip, mean of left and right femoral neck, and the one-third radius. We collected data on demographic, cross-sectional biochemical markers of mineral metabolism and fractures (identified through self-reported questionnaires, hospital electronic medical records, and physician billing records). We were able to gather data on 8/11 variables of Fracture Risk Assessment (FRAX) tool.

Results:

In our cohort, 14.3% of GFR categories G3a and G3b, 15.7% of GFR category G4, and 19.7% of GFR category G5 experienced a clinical fracture during the study period. On multivariate analysis, each decline of 1.0 SD in total hip BMD T-Score was associated with a significant increase in the risk of fracture (OR = 1.46, 95% confidence interval [CI], 1.12-1.89). Adding CKD-MBD markers and clinical risk factors did not further contribute to the model. Low BMD was the only independent risk factor for fracture in patients with CKD.

Limitations:

Self-reporting by patients and administrative records were used to identify fractures. We did not perform spine imaging to ascertain morphometric vertebral fractures. We were unable to gather all 11 variables of FRAX score and information on ethnicity. We were unable to capture site of fracture (hips, spine, etc) from billing records. Albumin excretion rates were not collected at baseline. Treatment of the underlying bone disease with pharmacotherapeutic agents may have attenuated patients’ fracture risk and thus underestimated the association between BMD and future fracture.

Conclusions:

Our findings confirm that BMD predicts fracture. The addition of cross-sectional CKD-MBD parameters and clinical risk factors to BMD did not add to fracture prediction. Prospective studies should investigate the utility of longitudinal biochemical markers on improving fracture risk assessment.