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

Long-Term Effect of Denosumab on Bone Disease in Patients with CKD

BACKGROUND

The effect of long-term denosumab therapy and of denosumab discontinuation on the cortical bone of the hip regions in dialysis patients has not been studied.

METHODS

This retrospective study investigated the cortical and trabecular compartments and estimated strength indices of the hip region, obtained using 3D-SHAPER software, after a maximum of 5 years of denosumab therapy in 124 dialysis patients. A Wilcoxon signed-rank test was used to identify the differences in each parameter before and after denosumab initiation. Similarly, we investigated the changes in these parameters after denosumab discontinuation in 11 dialysis patients.

RESULTS

Integral and trabecular volumetric bone mineral densities (BMD) were significantly lower at the start of denosumab therapy than those in 1 year before denosumab initiation. After starting denosumab, areal BMD (median change +7.7% [interquartile range (IQR), +4.6 to +10.6]), cortical volumetric BMD (median change +3.4% [IQR, +1.0 to +4.7]), cortical surface BMD (median change +7.1% [IQR, +3.4 to +9.4]), and cortical thickness (median change +3.2% [IQR, +1.8 to +4.9]) showed a significantly higher trend for 3.5 years, which then stabilized at a higher value compared with baseline. A similar trend in the trabecular volumetric BMD (median change +9.8% [IQR, +3.8 to +15.7]) was observed over 2.5 years, with a higher value maintained thereafter. The whole area of the hip region improved after denosumab therapy. Similar trajectories were also found in the estimated strength indices. Conversely, at 1 year after denosumab discontinuation, these 3D parameters and estimated strength indices tended to largely worsen. The lateral aspect of the greater trochanter was the most pronounced location showing volumetric BMD loss.

CONCLUSIONS

The BMD of both cortical and trabecular components in the hip region was significantly higher after starting denosumab therapy. However, these measurements exhibited a trend of declining substantially after the discontinuation of denosumab.

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

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

Association between prevalence of laxative use and history of bone fractures and cardiovascular diseases in patients with chronic kidney disease: the Fukuoka Kidney disease Registry (FKR) study

BACKGROUND

Constipation is a common complication in patients with chronic kidney disease (CKD) and is involved in the pathogenesis of dysbiosis and progression of CKD. However, little is known about its association with disorders of the bone-cardiovascular axis in patients with CKD.

METHODS

We performed a cross-sectional analysis of 3878 patients with CKD using the baseline dataset of the Fukuoka Kidney disease Registry study, as a multicenter, prospective cohort study of pre-dialysis CKD patients. The main exposure of interest was constipation defined as use of at least one type of laxative. The main outcomes were the histories of bone fractures and cardiovascular diseases (CVDs) as manifestations of disorders of the bone-cardiovascular axis.

RESULTS

The prevalences of laxative use and histories of bone fractures and CVDs increased as kidney function declined. Among the 3878 patients, 532 (13.7%) patients used laxatives, 235 (6.1%) patients had prior bone fractures, and 1001 (25.8%) patients had prior CVDs. Histories of bone fractures and CVDs were significantly more prevalent among laxative users (P < 0.05). Multivariable-adjusted logistic regression analysis revealed that patients with laxatives had a significantly higher odds ratios for histories of bone fractures and CVDs than those without laxatives [adjusted odds ratios (95% confidence intervals) 1.67 (1.20-2.31) and 1.70 (1.30-2.22), respectively, P < 0.05].

CONCLUSIONS

These results suggest that constipation indicated by laxative use is associated with increased prevalences of historical bone fractures and CVDs in pre-dialysis patients with CKD.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

SIGNIFICANCE STATEMENT

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

Role of Fracture Risk Assessment Tool and Bone Turnover Markers in Predicting All-Cause and Cardiovascular Mortality in Hemodialysis Patients

Background

Fracture Risk Assessment Tool (FRAX) and bone turnover markers (BTMs) predict fractures in the general population. However, the role of FRAX and BTMs in predicting mortality remains uncertain in hemodialysis (HD) patients.

Methods

One hundred and sixty-four HD patients stratified by low or high risk of 10-year fracture probability using FRAX. High risk of fracture was defined as 10-year probability of hip fracture ≥3% or major osteoporotic fracture ≥20%. The association of high risk of fracture and BTMs with all-cause mortality and cardiovascular (CV) mortality were evaluated using multivariate-adjusted Cox regression analysis.

Results

Eighty-five (51.8%) patients were classified as high risk of fracture based on FRAX among 164 HD patients. During a mean follow-up period of 3.5 ± 1.0 years, there were 39 all-cause deaths and 23 CV deaths. In multivariate-adjusted Cox regression, high risk of fracture based on FRAX was independently associated with all-cause mortality [hazard ratio (HR): 2.493, 95% confidence interval (CI): 1.026–6.056, p = 0.044) but not with CV mortality (HR: 2.129, 95% CI: 0.677–6.700, p = 0.196). There were no associations between BTMs and mortality risk. Furthermore, lower geriatric nutritional risk index (GNRI) was significantly associated with increased CV mortality (HR: 0.888, 95% CI: 0.802–0.983, p = 0.022) after adjusting by confounding variables.

Conclusion

High risk of fracture using FRAX was an independent predictor of all-cause mortality in patients undergoing HD. FRAX, rather than BTMs, has an important role of prognostic significance in HD patients.

The Stockholm CREAtinine Measurements (SCREAM) project: Fostering improvements in chronic kidney disease care

SCREAM (Stockholm CREAtinine Measurements project) was initiated in 2010 in collaboration with the healthcare provider of Stockholm County healthcare to quantify potential medication errors, estimate the burden of chronic kidney disease (CKD) and to illustrate the value of incorporating measures of kidney function into the medical decision process. Because most patients are unaware of their CKD and diagnoses are seldom issued, SCREAM took advantage of the commonness of serum/plasma creatinine testing, which can be used to estimate the glomerular filtration rate (eGFR) and classify the stage of CKD severity. SCREAM is periodically updated, and at present contains healthcare information of all residents in Stockholm region during 2006-2019 (about 3 million people), enriched with a broad range of laboratory measurements for those in whom creatinine or albuminuria has been measured (about 1.8 million people). This health information was linked with national administrative and quality registries via the unique personal identification number of each Swedish citizen, conforming the richest characterization in Sweden of the population's journey through health and disease. This review discusses the context of its creation, strengths and weakness, key findings and plans for the future. We summarize our findings related to the burden of CKD in Sweden, its adverse health risks (such as risk of infections, cancer or dementia) and how underlying kidney function alters the risk-benefit ratio of common medications. Results have had clinical impact and demonstrate the importance of population-based research in the spectrum of clinical research to improve health.

Chronic kidney disease and risk of postoperative cardiovascular events in elderly patients receiving hip fracture surgery

INTRODUCTION

The long-term risk of cardiovascular events caused by chronic kidney disease (CKD) is well described in the general population. Less is known concerning the risk of postoperative cardiovascular events in geriatric hip fracture patients with CKD.

METHODS

This study involved patients at least 65 years of age who received surgery for acute hip fracture between January 2000 and April 2016. We identified CKD patients with a baseline diagnosis of CKD or an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² at admission. Each CKD patient was matched, for age, gender, fracture type, and year of admission, with 4 control non-CKD patients. The primary endpoint was a compositepostoperative cardiovascular events, including pulmonary embolism, angina pectoris, myocardial infarction, heart failure, arrhythmia, stroke, and death. Conditional logistic regression was used to evaluate the association between CKD and the outcome after adjusting for potential confounders including age, gender, fracture type, body mass index, preexisting comorbidities, history of cardiovascular events, and the Charlson Comorbidity Index (CCI).

RESULTS

Three hundred and seventy-five CKD patients were matched with 1,438 non-CKD patients. The mean age of the CKD patients was 81.9 ± 7.0 (mean ± SD), 69.9% were females, and 59.2% had an intertrochanteric fracture. Compared to non-CKD patients, CKD patients had a higher proportion of preexisting comorbidities, including hypertension, coronary heart disease, heart failure, and type 2 diabetes (all p < 0.05). The risk of postoperative cardiovascular events was 125.3 per 1000 persons (95%CI, 91.8-158.8) in CKD patients and 64.7 per 1000 persons (95%CI, 52.0-77.4) in non-CKD patients. A 1.96-fold risk of cardiovascular events after hip fracture surgery was found in CKD patients than those without CKD (adjusted OR, 1.96; 95%CI, 1.23-3.12).

CONCLUSION

Patients with CKD were more likely to have cardiovascular events after hip fracture surgery than those without CKD. Appropriate preoperative cardiovascular risk assessment and corresponding preventive and therapeutic measures should be given to this vulnerable population to mitigate such complications.

Hip fracture in patients with non-dialysis chronic kidney disease stage 5

Hip fracture is a significant health problem and is associated with increased mortality. Patients with chronic kidney disease (CKD) are more at risk of hip fracture than the general population, but the hip fracture risk is not evident among non-dialysis CKD stage 5 patients. This study aims to assess the risk of hip fracture in patients with non-dialysis CKD stage 5 comparing to those with CKD stages 1–4. Patients with non-dialysis CKD stage 5 and CKD stages 1–4 were retrieved from Taiwan longitudinal health insurance database 2011–2014. All patients were followed to the end of 2018 for the development of hip fractures. We analyze the risk of hip fracture of propensity score-matched patients with CKD stage 5 compared to patients with CKD stages 1–4 using stepwise Cox regression and competing risks regression. We analyzed 5649 propensity score-matched non-dialysis CKD 1–4 patients and non-dialysis CKD 5 patients between 2011 and 2014. All patients were followed to the end of 2018, 229 (4.1%) of CKD 1–4 patients in 21,899 patient-year, and 290 (5.1%) of CKD 5 patients had hip fractures in 18,137 patient-year. CKD 5 patients had a higher risk of hip fracture than patients with CKD stages 1–4. The adjusted HR was 1.53 (95% CI 1.08–1.54) in the Cox regression with adjustments for age, gender, comorbidity, and history of fracture. In the competing risks regression, the subdistribution hazard ratio was 1.29 (95% CI 1.08–1.54). Female gender, age, history of fractures, and Charlson–Deyo comorbidity index were independently associated with increased hip fracture risks. Non-dialysis CKD 5 patients had a higher risk of hip fracture than patients with CKD stages 1–4. This association is independent of patients’ age, female gender, history of fractures, and comorbidities.

Sparing effect of peritoneal dialysis vs hemodialysis on BMD changes and its impact on mortality

INTRODUCTION

Bone loss in end stage renal disease (ESRD) patients associates with fractures, vascular calcification, cardiovascular disease (CVD) and increased mortality. We investigated factors associated with changes of bone mineral density (ΔBMD) during the initial year on dialysis therapy and associations of ΔBMD with subsequent mortality in ESRD patients initiating dialysis.

MATERIALS AND METHODS

In 242 ESRD patients (median age 55 years, 61% men) starting dialysis with peritoneal dialysis (PD; n = 138) or hemodialysis (HD; n = 104), whole-body dual-energy X-ray absorptiometry (DXA), body composition, nutritional status and circulating biomarkers were assessed at baseline and 1 year after dialysis start. We used multivariate linear regression analysis to determine factors associated with ΔBMD, and fine and gray competing risk analysis to determine associations of ΔBMD with subsequent mortality risk.

RESULTS

BMD decreased significantly in HD patients (significant reductions of BMD_total and BMD_{leg, trunk, rib, pelvis and spine}) but not in PD patients. HD compared to PD therapy associated with negative changes in BMD_{total (β=- 0.15)}, BMD_{head (β=- 0.14)}, BMD_{leg (β=- 0.18)} and BMD_{trunk (β=- 0.16)}. Better preservation of BMD associated with significantly lower all-cause mortality for ΔBMD_total (sub-hazard ratio, sHR, 0.91), ΔBMD_head (sHR 0.91) and ΔBMD_leg (sHR 0.92), while only ΔBMD_head (sHR 0.92) had a beneficial effect on CVD-mortality.

CONCLUSIONS

PD had beneficial effect compared with HD on BMD changes during first year of dialysis therapy. Better preservation of BMD, especially in bone sites rich in cortical bone, associated with lower subsequent mortality. BMD in cortical bone may have stronger association with clinical outcome than BMD in trabecular bone.

Incidence of Fractures Before and After Dialysis Initiation

Fractures are common in dialysis patients, but little is known about the trajectory of incidence rates of different types of fractures before and after dialysis initiation. To address this, we investigated the incidence of major fractures before and after dialysis initiation. We performed a retrospective statistical analysis using the Swedish Renal Registry of 9041 incident dialysis patients (median age 67 years, 67% men) starting dialysis 2005 through 2015 to identify major fractures (hip, spine, humerus, and forearm) occurring during the dialysis transition period from 1 year before until 1 year after dialysis initiation. Using flexible parametric hazard models and the Fine-Gray model, we estimated adjusted fracture incidence rates and predictors of major fractures. We identified 361 cases with primary diagnosis of major fracture, of which 196 (54%) were hip fractures. The crude incidence rate of major fractures before dialysis initiation was 17 per 1000 patient-years (n = 157) and after dialysis initiation it was 24 per 1000 patient-years (n = 204). The adjusted incidence rate of major fractures began to increase 6 months before dialysis initiation, and then stabilized at a higher rate after 1 year. The adjusted incidence rate of hip fractures started to increase sharply 3 months before dialysis initiation, peaked at initiation, and declined thereafter. In contrast, the adjusted incidence rate of non-hip fractures was stable during the transition period and gradually increased over time. Higher age, female sex, and history of previous major fractures were associated with increased fracture incidence both before and after dialysis initiation. We conclude that the incidence of major fractures, especially hip fractures, start to rise 6 months before initiation of dialysis therapy, indicating that heightened surveillance with implementation of preventive measures to avoid fractures is warranted during the transition period to dialysis. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bone mineral density and mortality in end-stage renal disease patients

Osteoporosis characterized by low bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is common among end-stage renal disease (ESRD) patients and associates with high fracture incidence and high all-cause mortality. This is because chronic kidney disease-mineral bone disorders (CKD-MBDs) promote not only bone disease (osteoporosis and renal dystrophy) but also vascular calcification and cardiovascular disease. The disturbed bone metabolism in ESRD leads to 'loss of cortical bone' with increased cortical porosity and thinning of cortical bone rather than to loss of trabecular bone. Low BMD, especially at cortical-rich bone sites, is closely linked to CKD-MBD, vascular calcification and poor cardiovascular outcomes. These effects appear to be largely mediated by shared mechanistic pathways via the 'bone-vascular axis' through which impaired bone status associates with changes in the vascular wall. Thus, bone is more than just the scaffolding that holds the body together and protects organs from external forces but is-in addition to its physical supportive function-also an active endocrine organ that interacts with the vasculature by paracrine and endocrine factors through pathways including Wnt signalling, osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand system and the Galectin-3/receptor of advanced glycation end products axis. The insight that osteogenesis and vascular calcification share many similarities-and the knowledge that vascular calcification is a cell-mediated active rather than a passive mineralization process-suggest that low BMD and vascular calcification ('vascular ossification') to a large extent represent two sides of the same coin. Here, we briefly review changes of BMD in ESRD as observed using different DXA methods (central and whole-body DXA) at different bone sites for BMD measurements, and summarize recent knowledge regarding the relationships between 'low BMD' and 'fracture incidence, vascular calcification and increased mortality' in ESRD patients, as well as potential 'molecular mechanisms' underlying these associations.

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.