Osteoporosis in chronic kidney disease

The relationship between dietary inflammatory index and osteoporosis among chronic kidney disease population

Dietary inflammation index (DII) is an epidemiological survey tool to evaluate dietary inflammation potential. Osteoporosis, whose development is deeply affected by inflammation, may be also affected by dietary inflammatory patterns. However, the relationship between DII and osteoporosis is unclear for chronic kidney disease (CKD) population. Our study involved 526 CKD patients from the US National Health and Nutrition Examination Survey (NHANES). DII levels were stratified into four quantile groups. Multivariable regression models were used to examine the association between DII and osteoporosis. Restricted cubic splines and subgroup analysis were additionally adopted. Results showed that the overall prevalence of osteoporosis among CKD patients was 25.3%. After fully adjusted, OR (95% confidence interval) for Q4 group compared with Q3 (reference group) in total and female population were 2.09 (1.05, 4.23) and 2.80 (1.14, 7.08), respectively. Subgroup analysis indicated that these results had no interaction with age, gender, body mass index (BMI), renal function, urinary protein, calcium, phosphorus and total 25-hydroxyvitamin D. DII was negatively correlated with lumbar spine bone mineral density (BMD) in CKD population (P < 0.05). Therefore, in CKD patients, higher DII was associated with higher osteoporosis risk and lower BMD of lumber spine, especially in female. Anti-inflammatory diet patterns may be a protective intervention for some CKD-related osteoporosis.

Study on the Effect of Low Calcium Dialysate on Biochemical Profile of Adynamic Bone Disease in Patients on Maintenance Hemodialysis

In recent years, adynamic bone disease (ABD) has become a common skeletal lesion in adult patients with chronic kidney disease. We aimed to compare the effects of low calcium dialysate (LCD) and standard calcium dialysate of our facility [high calcium dialysate (HCD)] on the evolution of bone and mineral parameter related to ABD in dialysis patients. Forty patients with predialysis intact parathyroid hormone (iPTH) <100 pg/mL and/or bone-specific alkaline phosphatase (BAP) <27 U/L were included in this study and were equally distributed over LCD (1.25 mmol/L) or HCD (1.75 mmol/L) treatment. The duration of the study was 6 months. There was no significant difference in baseline characters and biochemical parameters related to chronic kidney disease-mineral and bone disorder in both the groups. The groups did not differ in the mean tCa before dialysis, but this parameter was significantly lower in the LCD group versus HCD at the end of the study. The mean serum levels of iPTH, total alkaline phosphatase, and BAP in the LCD group were increased at 3 months and at the end of the study compared with the baseline levels. The bone markers in the HCD group did not change significantly. At the end of the study, all bone parameters in the LCD group were significantly higher than in the HCD group. Development of measures indicating increased bone turnover in patients receiving 1.25 mmol/L of dialysate calcium, most likely as a result of inhibiting a positive calcium balance and allowing for long-term PTH secretion stimulation. Hence, LCD might be considered a valuable therapeutic option for ABD patients.

Challenges of Emerging Wearable Sensors for Remote Monitoring toward Telemedicine Healthcare

Digitized telemedicine tools with the Internet of Things (IoT) started advancing into our daily lives and have been incorporated with commercial wearable gadgets for noninvasive remote health monitoring. The newly established tools have been steered toward a new era of decentralized healthcare. The advancement of a telemedicine wearable monitoring system has attracted enormous interest in the multimodal big data acquisition of real-time physiological and biochemical information via noninvasive methods for any health-related industries. The expectation of telemedicine wearable creation has been focused on early diagnosis of multiple diseases and minimizing the cost of high-tech and invasive treatments. However, only limited progress has been directed toward the development of telemedicine wearable sensors. This Perspective addresses the advancement of these wearable sensors that encounter multiple challenges on the forefront and technological gaps hampering the realization of health monitoring at molecular levels related to smart materials mostly limited to single use, issues of selectivity to analytes, low sensitivity to targets, miniaturization, and lack of artificial intelligence to perform multiple tasks and secure big data transfer. Sensor stability with minimized signal drift, on-body sensor reusability, and long-term continuous health monitoring provides key analytical challenges. This Perspective also focuses on, promotes, and highlights wearable sensors with a distinct capability to interconnect with telemedicine healthcare for physical sensing and multiplex sensing at deeper levels. Moreover, it points out some critical challenges in different material aspects and promotes what it will take to advance the current state-of-art wearable sensors for telemedicine healthcare. Ultimately, this Perspective is to draw attention to some potential blind spots of wearable technology development and to inspire further development of this integrated technology in mitigating multimorbidity in aging societies through health monitoring at molecular levels to identify signs of diseases.

Bone Disease in Chronic Kidney Disease and Kidney Transplant

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

Impact of parathyroidectomy among nondiabetic hemodialysis patients with severe hyperparathyroidism

Background

Parathyroidectomy (PTX) is a treatment for hyperparathyroidism (HPT) and has uncertain risks and benefits. The aim of this study was to evaluate the effect of PTX versus nonoperative treatment among nondiabetic hemodialysis patients.

Methods

A retrospective matched cohort study was performed. Each PTX patient was matched with one patient who had severe HPT but rejected PTX. The patients were matched by sex, birth date, date of first dialysis, nondiabetic status, and left ventricular ejection fraction. The serum markers, survival, main adverse cardiovascular and cerebrovascular event (MACCE) rates, and hospitalization were compared between the PTX patients and matched non-PTX patients.

Results

There were 1143 patients at our center in the Chinese National Renal Data System (CNRDS) between 2010 and 2020. Of these, 75 PTX patients were matched with 75 non-PTX patients. Rapid decreases in the mean intact parathyroid hormone, calcium and phosphorus concentrations, and a gradual increase in hemoglobin concentration were observed in the PTX group. The mortality was 2.9 per 100 patient-years in the PTX group and 10.9 per 100 patient-years in the non-PTX group (p < 0.001). Compared with non-PTX patients, PTX patients had an adjusted HR for death of 0.236 (95% CI 0.108–0.518). The cumulative MACCE rates were 6.7 per 100 patient-years in the PTX group and 15.2 per 100 patient-years in the non-PTX group (p < 0.001). The adjusted HR of the occurrence of first MACCE for PTX patients compared with non-PTX patients was 0.524 (95% CI 0.279-0.982). The cumulative hospitalization rates were 50.3 per 100 patient-years in the PTX group and 66.5 per 100 patient-years in the matched non-PTX group (p < 0.001).

Conclusions

Compared with non-PTX patients, PTX was associated with an improvement in the biochemical measures and patient-level outcomes in nondiabetic hemodialysis patients with severe HPT.

The Effect of Hand Dominance, Age, Gender, Fracture Comminution and ASA Status on Time to Fracture Healing Following Surgical Fixation of Distal Radius Fractures

Background: There is recent renewed interest in the effect of hand dominance on distal radius fractures. Current studies focus on functional or patient-reported outcomes, with lack of studies pertaining to radiological outcomes. The primary aim of this study is to examine the effect of hand dominance on time to fracture healing following surgical fixation of distal radius fracture. We also looked at the effect of age, gender, fracture comminution and American Society of Anaesthesiologists (ASA) status on time to fracture healing.

Methods: Patients who underwent distal radius fracture fixation surgery in our department from 1 January 2015 to 31 December 2015 were included. Time to fracture healing was taken from the day of surgery to when radiographic union was present as evidence by bridging callus or osseous bone. We looked at the effect of hand dominance, age, gender, fracture comminution and ASA status on time to fracture healing.

Results: One hundred and forty-five consecutive patients (80 females and 65 males) had a mean period of 56.2 ± 41.8 days to fracture healing post-operatively. Patients with dominant hand injury had a shorter duration to fracture healing than patients with non-dominant hand injury (mean 47.3 ± 31.1 days versus 62.1 ± 46.8 days, p = 0.023). Patients ≥ 65 years and with pre-existing medical conditions (ASA Class II and above) had a longer duration to fracture healing (mean 63.7 ± 53.0 days versus 51.9 ± 33.4 days, p = 0.036 and mean 47.9 ± 30.0 days versus 62.0 ± 47.7 days, p = 0.016, respectively). In addition, patients with comminuted fractures took longer to heal than patients with non-comminuted fractures (mean 57.6 ± 33.4 days versus 48.3 ± 20.8 days, p = 0.038).

Conclusion: Time to fracture healing post distal radius fracture fixation surgery was significantly related to hand dominance, as well as age, ASA classification and fracture configuration. Dominant wrist injuries had shorter time to fracture healing.

Level of Evidence: Level IV (Therapeutic)

Renal impairment and time to fracture healing following surgical fixation of distal radius fracture

INTRODUCTION

Despite the prevalence of renal impairments, the existing literature examining fracture healing in the upper limb in patients with renal impairment is sparse. This study hence aims to investigate the effect of renal impairment on time to fracture healing after distal radius fracture fixation surgery.

MATERIALS AND METHODS

Patients above 50 years old who underwent distal radius fracture fixation via volar plating were included. Time to fracture healing was defined as duration between day of surgery and presence of radiographic union as evidence by bridging of callus or osseous bone. To assess for renal impairment, estimated glomerular filtration rate (eGFR) was calculated based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Pre-existing comorbidities were also collected and analysed.

RESULTS

Ninety-nine consecutive patients took mean 65.5 ± 8.0 days to fracture healing post-operatively. Patients with renal impairment had longer time to fracture healing than patients without (67.1 ± 50.4 days versus 50.4 ± 31.8 days, p = 0.044). Patients ≥ 65 years also had a longer duration to fracture healing compared to patients < 65 years (mean 63.7 ± 53.0 days versus 50.2 ± 27.2 days, p = 0.033). Similarly, patients with ASA Class I had a shorter mean time to fracture healing than patients with ASA Class II and above (mean 42.5 ± 22.8 days versus 62.8 ± 47.6 days, p = 0.028).

CONCLUSIONS

Time to fracture healing post-distal radius fracture fixation was significantly related to renal impairment, age and ASA classification.

Detecting respiratory chain defects in osteoblasts from osteoarthritic patients using imaging mass cytometry

Osteoporosis is a skeletal disease which is characterised by reduced bone mass and microarchitecture, with a subsequent loss of strength that predisposes to fragility and risk of fractures. The pathogenesis of falling bone mineral density, ultimately leading to a diagnosis of osteoporosis is incompletely understood but the disease is currently thought to be multifactorial. Humans are known to accumulate mitochondrial mutations and respiratory chain deficiency with age and mounting evidence suggests that this may indeed be the overarching cause intrinsic to the changing phenotype in advancing age and age-related disease. Mitochondrial mutations are detectable from the age of about 30 years onwards. Mitochondria contain their own genome which encodes 13 essential mitochondrial proteins and accumulates somatic variants at up to 10 times the rate of the nuclear genome. Once the concentration of any pathogenic mitochondrial genome variant exceeds a threshold, respiratory chain deficiency and cellular dysfunction occur. The Polg^D257A/D257A mouse model is a knock-in mutant that expresses a proof-reading-deficient version of PolgA, a nuclear encoded subunit of mtDNA polymerase. These mice are a useful model of age-related accumulation of mtDNA mutations in humans since their defective proof-reading mechanism leads to a mitochondrial DNA mutation rate 3-5 times higher than in wild-type mice. These mice showed enhanced levels of age-related osteoporosis along with respiratory chain deficiency in osteoblasts. To explore whether respiratory chain deficiency is also seen in human osteoblasts, we developed a protocol and analysis framework for imaging mass cytometry in bone tissue sections to analyse osteoblasts in situ. By comparing bone tissue sampled at one timepoint from femoral neck of 10 older healthy volunteers aged 40-85 with samples from young patients aged 1-19, we have identified complex I defect in osteoblasts from 6 out of 10 older volunteers, complex II defect in 2 out of 10 older volunteers, complex IV defect in 1 out of 10 older volunteers and complex V defect in 4 out of 10 older volunteers. These observations are consistent with findings from the Polg^D257A/D257A mouse model and suggest that respiratory chain deficiency, as a consequence of the accumulation of age-related pathogenic mitochondrial DNA mutations, may play a significant role in the pathogenesis of human age-related osteoporosis.

Bilateral Quadriceps Tendon Rupture and Femoral Neck Fracture After Generalized Tonic-Clonic Seizures: A Case Report

CASE

We report on a 19-year-old male renal transplant patient with multiple medical issues who sustained simultaneous bilateral quadriceps tendon ruptures and bilateral femoral neck fractures after 2 generalized tonic-clonic seizures. The quadriceps tendon ruptures were detected early surgically repaired; the femoral neck fractures were not detected and managed with bilateral total hip arthroplasty for almost 2 weeks.

CONCLUSION

Tonic-clonic seizures can be associated with unique and complex acute orthopaedic injuries that can be initially missed. Physicians should be cognizant of the need for a thorough medical history and physical examination to avoid orthopaedic postseizure missed diagnoses.

Real-World Diagnosis and Treatment of Diabetic Kidney Disease

INTRODUCTION

People with type 2 diabetes mellitus (T2DM) and diabetic kidney disease (DKD) have increased morbidity and mortality risk. Angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB) are recommended to slow kidney function decline in DKD. This representative, real-world data analysis of patients with T2DM was performed to detect onset of DKD and determine methods and timing of DKD diagnosis and time to initiation of ACEi/ARB therapy.

METHODS

Patients diagnosed with T2DM before January 1, 2016 who developed DKD between January 1, 2017 and June 30, 2019 were identified from a longitudinal ambulatory electronic health record (EHR) dataset (Veradigm Inc). Each record was analyzed using the CLinical INTelligence engine (CLINT™, HealthPals, Inc.) to identify delays and gaps in diagnosing DKD. DKD was diagnosed through two reduced estimated glomerular filtration rate (eGFR; < 60 mL/min/1.73 m²) measurements at least 90 days apart, a single elevated urine albumin-to-creatinine ratio (UACR; > 30 mg/g) measurement, or ICD-9/10 diagnosis codes for DKD and/or albuminuria. Time to diagnose (TTD), time to treat (TTT), and diagnosis to treatment time were assessed.

RESULTS

Of 6,499,409 patients with T2DM before January 2016, 245,978 developed DKD between January 1, 2017 and June 30, 2019. In this DKD cohort, ca. 50% were first identified through EHR diagnosis and ca. 50% by UACR or eGFR lab-based diagnosis. In patients who had UACR/eGFR assessed, more than 90% exhibited DKD-level results on the first diagnostic test. Average TTD after eGFR labs was 2 years; average TTT with ACEi/ARB was 6-9 months after DKD lab evidence. The majority of patients who developed DKD received ACEi/ARB therapy 6-7 months after diagnosis.

CONCLUSION

In a contemporary, large national cohort of patients with T2DM, progression to DKD was common but likely underrepresented. The low rate of DKD-screening labs, along with sizable delays in diagnosis of DKD and initiation of ACEi/ARB therapy, indicates that many patients who progress to DKD are not being properly treated.

Lab-on-Eyeglasses to Monitor Kidneys and Strengthen Vulnerable Populations in Pandemics: Machine Learning in Predicting Serum Creatinine Using Tear Creatinine

The serum creatinine level is commonly recognized as a measure of glomerular filtration rate (GFR) and is defined as an indicator of overall renal health. A typical procedure in determining kidney performance is venipuncture to obtain serum creatinine in the blood, which requires a skilled technician to perform on a laboratory basis and multiple clinical steps to acquire a meaningful result. Recently, wearable sensors have undergone immense development, especially for noninvasive health monitoring without a need for a blood sample. This article addresses a fiber-based sensing device selective for tear creatinine, which was fabricated using a copper-containing benzenedicarboxylate (BDC) metal-organic framework (MOF) bound with graphene oxide-Cu(II) and hybridized with Cu₂O nanoparticles (NPs). Density functional theory (DFT) was employed to study the binding energies of creatinine toward the ternary hybrid materials that irreversibly occurred at pendant copper ions attached with the BDC segments. Electrochemical impedance spectroscopy (EIS) was utilized to probe the unique charge-transfer resistances of the derived sensing materials. The single-use modified sensor achieved 95.1% selectivity efficiency toward the determination of tear creatinine contents from 1.6 to 2400 μM of 10 repeated measurements in the presence of interfering species of dopamine, urea, and uric acid. The machine learning with the supervised training estimated 83.3% algorithm accuracy to distinguish among low, moderate, and high normal serum creatinine by evaluating tear creatinine. With only one step of collecting tears, this lab-on-eyeglasses with disposable hybrid textile electrodes selective for tear creatinine may be greatly beneficial for point-of-care (POC) kidney monitoring for vulnerable populations remotely, especially during pandemics.

Pharmacological interventions versus placebo, no treatment or usual care for osteoporosis in people with chronic kidney disease stages 3-5D

BACKGROUND

Chronic kidney disease (CKD) is an independent risk factor for osteoporosis and is more prevalent among people with CKD than among people who do not have CKD. Although several drugs have been used to effectively treat osteoporosis in the general population, it is unclear whether they are also effective and safe for people with CKD, who have altered systemic mineral and bone metabolism.

OBJECTIVES

To assess the efficacy and safety of pharmacological interventions for osteoporosis in patients with CKD stages 3-5, and those undergoing dialysis (5D).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 25 January 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials comparing any anti-osteoporotic drugs with a placebo, no treatment or usual care in patients with osteoporosis and CKD stages 3 to 5D were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed their quality using the risk of bias tool, and extracted data. The main outcomes were the incidence of fracture at any sites; mean change in the bone mineral density (BMD; measured using dual-energy radiographic absorptiometry (DXA)) of the femoral neck, total hip, lumbar spine, and distal radius; death from all causes; incidence of adverse events; and quality of life (QoL). Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Seven studies involving 9164 randomised participants with osteoporosis and CKD stages 3 to 5D met the inclusion criteria; all participants were postmenopausal women. Five studies included patients with CKD stages 3-4, and two studies included patients with CKD stages 5 or 5D. Five pharmacological interventions were identified (abaloparatide, alendronate, denosumab, raloxifene, and teriparatide). All studies were judged to be at an overall high risk of bias. Among patients with CKD stages 3-4, anti-osteoporotic drugs may reduce the risk of vertebral fracture (RR 0.52, 95% CI 0.39 to 0.69; low certainty evidence). Anti-osteoporotic drugs probably makes little or no difference to the risk of clinical fracture (RR 0.91, 95% CI 0.79 to 1.05; moderate certainty evidence) and adverse events (RR 0.99, 95% CI 0.98 to 1.00; moderate certainty evidence). We were unable to incorporate studies into the meta-analyses for BMD at the femoral neck, lumbar spine and total hip as they only reported the percentage change in the BMD in the intervention group. Among patients with severe CKD stages 5 or 5D, it is uncertain whether anti-osteoporotic drug reduces the risk of clinical fracture (RR 0.33, 95% CI 0.01 to 7.87; very low certainty evidence). It is uncertain whether anti-osteoporotic drug improves the BMD at the femoral neck because the certainty of this evidence is very low (MD 0.01, 95% CI 0.00 to 0.02). Anti-osteoporotic drug may slightly improve the BMD at the lumbar spine (MD 0.03, 95% CI 0.03 to 0.04, low certainty evidence). No adverse events were reported in the included studies. It is uncertain whether anti-osteoporotic drug reduces the risk of death (RR 1.00, 95% CI 0.22 to 4.56; very low certainty evidence).

AUTHORS' CONCLUSIONS

Among patients with CKD stages 3-4, anti-osteoporotic drugs may reduce the risk of vertebral fracture in low certainty evidence. Anti-osteoporotic drugs make little or no difference to the risk of clinical fracture and adverse events in moderate certainty evidence. Among patients with CKD stages 5 and 5D, it is uncertain whether anti-osteoporotic drug reduces the risk of clinical fracture and death because the certainty of this evidence is very low. Anti-osteoporotic drug may slightly improve the BMD at the lumbar spine in low certainty evidence. It is uncertain whether anti-osteoporotic drug improves the BMD at the femoral neck because the certainty of this evidence is very low. Larger studies including men, paediatric patients or individuals with unstable CKD-mineral and bone disorder are required to assess the effect of each anti-osteoporotic drug at each stage of CKD.

The Influence of Dietary Interventions on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)

Chronic kidney disease is a health problem whose prevalence is increasing worldwide. The kidney plays an important role in the metabolism of minerals and bone health and therefore, even at the early stages of CKD, disturbances in bone metabolism are observed. In the course of CKD, various bone turnover or mineralization disturbances can develop including adynamic hyperparathyroid, mixed renal bone disease, osteomalacia. The increased risk of fragility fractures is present at any age in these patients. Nutritional treatment of patients with advanced stages of CKD is aiming at prevention or correction of signs, symptoms of renal failure, avoidance of protein-energy wasting (PEW), delaying or prevention of the occurrence of mineral/bone disturbances, and delaying the start of dialysis. The results of studies suggest that progressive protein restriction is beneficial with the progression of renal insufficiency; however, other aspects of dietary management of CKD patients, including changes in sodium, phosphorus, and energy intake, as well as the source of protein and lipids (animal or plant origin) should also be considered carefully. Energy intake must cover patients' energy requirement, in order to enable correct metabolic adaptation in the course of protein-restricted regimens and prevent negative nitrogen balance and protein-energy wasting.

Fibroblast growth factor 21 (FGF21) is a sensitive marker of osteoporosis in haemodialysis patients: a cross-sectional observational study

Introduction

Osteoporosis is one of the important bone abnormalities in chronic kidney disease-mineral and bone disorder (CKD-MBD) and still lacks a sensitive biomarker to diagnose. Fibroblast growth factor 21 (FGF21) can stimulate bone loss in patients with diabetes and increase in CKD patients. In this study, we investigated whether FGF21 could serve as a biomarker to predict osteoporosis in a haemodialysis cohort.

Methods

We recorded demographic information, biochemical data, and serum FGF21 and FGF23 levels and measured the CT attenuation values of 339 haemodialysis patients from two large medical centres. We assessed the correlation of CT attenuation values with serum FGF21 and FGF23 levels and tested whether they were independent factors for osteoporosis. ROC curves were constructed to compare the prognostic value of FGF21 and FGF23 for osteoporosis.

Results

Based on the CT attenuation value, serum FGF21 levels were higher in our osteoporosis group (median 640.86 pg/ml vs. 245.46 pg/ml, P ˂ 0.01). Meanwhile, FGF21 (r = -0.136, P < 0.05) and FGF23 (r = -0.151, P < 0.05) were both negatively associated with osteoporosis. Moreover, FGF21 (β = -0.067, P < 0.05) was an independent factor for osteoporosis. Furthermore, FGF21 combined with age yielded a marked specificity (90.5 %) and sensitivity (61.8 %) in predicting osteoporosis of haemodialysis patients with less residual renal function.

Conclusions

FGF21 has a positive relationship with the incidence of osteoporosis in patients on haemodialysis. FGF21 combined with age is a good predictive biomarker for osteoporosis in patients on haemodialysis, especially those with less residual renal function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02393-z.

Risk of failure in dual therapy versus triple therapy in naïve HIV patients: a systematic review and meta-analysis

OBJECTIVES

Several attempts have been made to test different drug-sparing strategies to reduce the drug-burden and drug-related toxicities. The objective of this meta-analysis was to evaluate the relative risk (RR) of failure of dual therapies compared to triple therapies in HIV-naïve patients.

METHODS

We searched MEDLINE, Google Scholar and the Cochrane Library. The following criteria were used: present data from original articles comparing the two treatment regimens; published from January 2007 up to January, 2020. No language or study design restriction was applied. Subjects were HIV-positive naïve patients treated with dual or triple antiretroviral therapy (ART). A systematic review and meta-analysis was performed. Treatment failure (TF) was the primary outcome evaluated; heterogeneity was assessed using the Q statistic and I².

RESULTS

Fourteen studies were included, allowing a meta-analysis on 5205 patients. The meta-analysis performed on studies that presented data at 48 weeks showed that the RR of TF (RR > 1 favouring triple therapy) in 10 studies was 1.20 (95% confidence interval (CI): 0.91-1.59, I²: 49.2%); the RR of virological failure (VF) in eight studies was 1.54 (95% CI: 0.84-2.86, I²: 54%); the RR of adverse drug reaction leading to discontinuation of the regimen at 48 weeks in eight studies was 0.76 (95% CI: 0.43-1.33, I²: 17.7%). In patients with less than 200 CD4+, the RR of TF in two studies without maraviroc was 2.09 (95% CI: 1.05-4.17, I²: 0.0%). Regarding the studies at 96 weeks there was no difference except in rate of development of resistance, RR 1.94 (95% CI: 1.06-3.53, I²: 6.2%).

CONCLUSION

Dual therapies are as effective as those with three drugs, showing no difference according to the different dual therapies, except in patients with less than 200 CD4; however, they are associated with a higher selection of resistance-associated mutations at 96 weeks of therapy.

Canagliflozin for the Treatment of Diabetic Kidney Disease and Implications for Clinical Practice: A Narrative Review

Type 2 diabetes mellitus (T2DM) affects millions of people worldwide, elevating their risk of developing a range of complications, including chronic kidney disease (CKD). People with T2DM and CKD (i.e., diabetic kidney disease, DKD) have an increased risk of progressing to end-stage kidney disease (ESKD), experiencing cardiovascular complications, and premature death. Despite this, DKD is primarily addressed through management of risk factors, and there are few pharmaceutical treatments capable of reversing or delaying disease progression. Canagliflozin is a sodium glucose co-transporter 2 inhibitor that was initially developed as a blood glucose-lowering agent for people with T2DM. Evidence from clinical trials of canagliflozin in people with T2DM, as well as evidence from cardiovascular outcomes trials in people with T2DM and high cardiovascular risk, provided preliminary evidence suggesting that it may also have beneficial renal effects. The Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial was a dedicated renal outcomes trial of canagliflozin that assessed its renal effects in people with DKD. Overall, the CREDENCE trial demonstrated that canagliflozin improves renal outcomes and slows early disease progression in people with DKD. These data supported the approval of canagliflozin for the treatment DKD, the first new treatment in almost 20 years; therefore, it is important for clinicians to understand how to implement this treatment in their clinical practice.

Pharmacological interventions for osteoporosis in people with chronic kidney disease stages 3‐5D

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

This review aims to assess the effects of pharmacological interventions for osteoporosis in patients with CKD stages 3‐5D.

Cardiovascular and Cerebrovascular Events After Parathyroidectomy in Patients on Renal Replacement Therapy

BACKGROUND

A majority of patients with end-stage renal disease suffer from secondary hyperparathyroidism, which is associated with osteoporosis and cardiovascular disease. Parathyroidectomy (PTX) is often necessary despite medical treatment. However, the effect of PTX on cardio- and cerebrovascular events (CVE) remains unclear. Data on the effect of PTX from population-based studies are scarce. Some studies have shown decreased incidence of CVE after PTX. The aim of this study was to evaluate the effect of PTX on risk of CVE in patients on renal replacement therapy.

METHODS

We performed a nested case-control study within the Swedish Renal Registry (SRR) by matching PTX patients on dialysis or with functioning renal allograft with up to five non-PTX controls for age, sex and underlying renal disease. To calculate time to CVE, i.e., myocardial infarct, stroke and transient ischemic attack, control patients were assigned the calendar date (d) of the PTX of the case patient. Crude and adjusted proportional hazards regressions with random effect (frailty) were used to calculate hazard ratios for CVE.

RESULTS

The study cohort included 20,056 patients in the SRR between 1991 and 2009. Among these, 579 patients had undergone PTX, 423 during dialysis and 156 during time with functioning renal allograft. These patients were matched with 1234 dialysis and 736 transplanted non-PTX patients. The adjusted hazard ratio (HR) with 95% confidence interval (CI) of CVE after PTX was 1.24 (1.03-1.49) for dialysis patients compared with non-PTX patients. Corresponding results for patients with renal allograft at d were HR (95% CI) 0.53 (0.34-0.84).

CONCLUSIONS

PTX patients on dialysis at d had a higher risk of CVE than patients without PTX. Patients with renal allograft at d on the other had a lower risk after PTX than patients without PTX.

Serum sclerostin levels are positively related to bone mineral density in peritoneal dialysis patients: a cross-sectional study

Background

Sclerostin, an antagonist of the Wingless-type mouse mammary tumor virus integration site (Wnt) pathway that regulates bone metabolism, is a potential contributor of chronic kidney disease (CKD)–mineral and bone disorder (MBD), which has various forms of presentation, from osteoporosis to vascular calcification. The positive association of sclerostin with bone mineral density (BMD) has been demonstrated in CKD and hemodialysis (HD) patients but not in peritoneal dialysis (PD) patients. This study assessed the association between sclerostin and BMD in PD patients.

Methods

Eighty-nine PD patients were enrolled; their sera were collected for measurement of sclerostin and other CKD–MBD-related markers. BMD was also assessed simultaneously. We examined the relationship between sclerostin and each parameter through Spearman correlation analysis and by comparing group data between patients with above- and below-median sclerostin levels. Univariate and multiple logistic regression models were employed to define the most predictive of sclerostin levels in the above-median category.

Results

Bivariate analysis revealed that sclerostin was correlated with spine BMD (r = 0.271, P = 0.011), spine BMD T-score (r = 0.274, P = 0.010), spine BMD Z-score (r = 0.237, P = 0.027), and intact parathyroid hormone (PTH; r = − 0.357, P < 0.001) after adjustments for age and sex. High BMD, old age, male sex, increased weight and height, diabetes, and high osteocalcin and uric acid levels were observed in patients with high serum sclerostin levels and an inverse relation was noticed between PTH and sclerostin. Univariate logistic regression analysis demonstrated that BMD is positively correlated with above-median sclerostin levels (odds ratio [OR] = 65.61, P = 0.002); the correlation was retained even after multivariate adjustment (OR = 121.5, P = 0.007).

Conclusions

For the first time, this study demonstrated a positive association between serum sclerostin levels and BMD in the PD population.

Kidney Stones and Risk of Osteoporotic Fracture in Chronic Kidney Disease

Osteoporotic fracture associated with calcium dysregulation is more common in patients with kidney stones. However, little is known about the association of kidney stones and bone health status in patients with chronic kidney disease (CKD). This retrospective medical record-based study included 2282 patients with stable stage 3–4 CKD between 2007 and 2017. Of these, 113 patients were diagnosed with kidney stones. Propensity score matching for 226 patients with and without kidney stones showed that osteoporotic fracture occurred more often in patients with kidney stones (33, 29.2%) than in patients without kidney stones (16, 14.2%), resulting in rates of 5.56 and 2.63/100 patient-years, respectively (p < 0.01). In particular, Cox proportional hazard analysis revealed that kidney stones were significantly associated with osteoporotic fracture, even after adjusting for age, sex, body mass index, kidney stones, estimated glomerular filtration rate, excessive alcohol consumption, current smoking, and steroid use in patients with CKD stage 3–4 (hazard ratio, 2.32, 95% CI 1.24–4.34, p = 0.01). This study showed that the presence of kidney stones was a significant predictor for osteoporotic fracture in patients with CKD, suggesting that it should be considered as a clinical risk factor for osteoporotic fracture in them.

Systemic Activation of Activin A Signaling Causes Chronic Kidney Disease-Mineral Bone Disorder

The high cardiovascular mortality associated with chronic kidney disease (CKD) is caused in part by the CKD-mineral bone disorder (CKD-MBD) syndrome. The CKD-MBD consists of skeletal, vascular and cardiac pathology caused by metabolic derangements produced by kidney disease. The prevalence of osteopenia/osteoporosis resulting from the skeletal component of the CKD-MBD, renal osteodystrophy (ROD), in patients with CKD exceeds that of the general population and is a major public health concern. That CKD is associated with compromised bone health is widely accepted, yet the mechanisms underlying impaired bone metabolism in CKD are not fully understood. Therefore, clarification of the molecular mechanisms by which CKD produces ROD is of crucial significance. We have shown that activin A, a member of the transforming growth factor (TGF)-β super family, is an important positive regulator of receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis with Smad-mediated signaling being crucial for inducing osteoclast development and function. Recently, we have demonstrated systemic activation of activin receptors and activin A levels in CKD mouse models, such as diabetic CKD and Alport (AL) syndrome. In these CKD mouse models, bone remodeling caused by increased osteoclast numbers and activated osteoclastic bone resorption was observed and treatment with an activin receptor ligand trap repaired CKD-induced-osteoclastic bone resorption and stimulated individual osteoblastic bone formation, irrespective of parathyroid hormone (PTH) elevation. These findings have opened a new field for exploring mechanisms of activin A-enhanced osteoclast formation and function in CKD. Activin A appears to be a strong candidate for CKD-induced high-turnover ROD. Therefore, the treatment with the decoy receptor for activin A might be a good candidate for treatment for CKD-induced osteopenia or osteoporosis, indicating that the new findings from in these studies will lead to the identification of novel therapeutic targets for CKD-related and osteopenia and osteoporosis in general. In this review, we describe the impact of CKD-induced Smad signaling in osteoclasts, osteoblasts and vascular cells in CKD.

Where are we with injectables against HIV infection and what are the remaining challenges?

INTRODUCTION

Drug adherence has been a recurring issue in the field of HIV treatment, and low treatment adherence is typically associated with emergence of drug resistance, treatment failure and increased risks of transmission. Injectable antiretroviral drugs offer a unique opportunity to counter this issue for the treatment of HIV-positive individuals. In addition, injectables offer a remarkable opportunity to reduce new HIV infections, if applied in the context of both treatment-as-prevention and pre-exposure prophylaxis. Areas covered: Researchers and drug companies are developing long-acting agents that possess long biological half-life and excellent pharmacokinetic profiles that can be administered intramuscularly, intravenously, or subcutaneously. These long-acting injectables are categorized as drugs that target different steps of HIV replication cycle or monoclonal antibodies that target HIV entry. Expert commentary: Injectables against HIV have the potential to revolutionize the fight against HIV by facilitating both treatment and prevention in a wide variety of clinical settings. Several challenges remain including the identification of potent two-drug combinations of drugs that can be formulated as injectables, and thorough drug-drug interaction studies with a broad variety of medications. Finally we believe that the healthcare benefits of injectables will require regulatory changes to allow self-injection before they reach their full potential.

Declining Rates of Hip Fracture in End-Stage Renal Disease: Analysis From the 2003-2011 Nationwide Inpatient Sample

The incidence of hip fracture in patients with end-stage renal disease (ESRD) is considerably higher than that in the general age- and sex-matched population. Although medical therapy for chronic kidney disease mineral bone disorder (CKD-MBD) has changed considerably over the last decade, rates of hip fracture in the entire ESRD population have not been well-characterized. Herein, we evaluated temporal trends in rates of hip fracture, in-hospital mortality, and costs of associated hospital stay in ESRD. We identified hospitalizations for hip fracture from 2003 to 2011 using the Nationwide Inpatient Sample, a representative national database inclusive of all ages and payers. We incorporated data from the United States Renal Data System and the US Census to calculate population-specific rates. Between 2003 and 2011, we identified 47,510 hip fractures in the ESRD population. The overall rate of hip fracture was 10.04/1000 person-years. The rate was 3.73/1000 person-years in patients aged less than 65 years, and 20.97/1000 person-years in patients aged 65 or older. Age- and sex-standardized rates decreased by 12.6% from 2003 (10.23/1000 person-years; 95% confidence interval [CI], 7.99/1000 to 12.47/1000) to 2011 (8.94/1000 person-years; 95% CI, 7.12/1000 to 10.75/1000). Hip fracture rates over time were virtually identical in patients aged less than 65 years; however, rates decreased by 15.3% among patients aged 65 years or older; rates declined more rapidly in older women compared with older men (p for interaction = 0.047). In-hospital mortality rate after hip fracture operation declined by 26.7% from 2003 (8.6%; 95% CI, 6.8 to 10.4) to 2011 (6.3%; 95% CI, 4.9 to 7.7). In ESRD, age- and sex-standardized hip fracture rates and associated in-hospital mortality have declined substantially over the last decade. © 2017 American Society for Bone and Mineral Research.

Osteoporosis in Frail Patients: A Consensus Paper of the Belgian Bone Club

In this consensus paper, the Belgian Bone Club aims to provide a state of the art on the epidemiology, diagnosis, and management of osteoporosis in frail individuals, including patients with anorexia nervosa, patients on dialysis, cancer patients, persons with sarcopenia, and the oldest old. All these conditions may indeed induce bone loss that is superimposed on physiological bone loss and often remains under-recognized and under-treated. This is of particular concern because of the major burden of osteoporotic fractures in terms of morbidity, mortality, and economic cost. Therefore, there is an urgent need to appreciate bone loss associated with these conditions, as this may improve diagnosis and management of bone loss and fracture risk in clinical practice.

The chronic kidney disease - Mineral bone disorder (CKD-MBD): Advances in pathophysiology

The causes of excess cardiovascular mortality associated with chronic kidney disease (CKD) have been attributed in part to the CKD-mineral bone disorder syndrome (CKD-MBD), wherein, novel cardiovascular risk factors have been identified. New advances in the causes of the CKD-MBD are discussed in this review. They demonstrate that repair and disease processes in the kidneys release factors to the circulation that cause the systemic complications of CKD. The discovery of WNT inhibitors, especially Dickkopf 1 (Dkk1), produced during renal repair as participating in the pathogenesis of the vascular and skeletal components of the CKD-MBD implied that additional pathogenic factors are critical. This lead to the discovery that activin A is a second renal repair factor circulating in increased levels during CKD. Activin A derives from peritubular myofibroblasts of diseased kidneys, wherein it stimulates fibrosis, and decreases tubular klotho expression. Activin A binds to the type 2 activin A receptor, ActRIIA, which is variably affected by CKD in the vasculature. In diabetic/atherosclerotic aortas, specifically in vascular smooth muscle cells (VSMC), ActRIIA signaling is inhibited and contributes to CKD induced VSMC dedifferentiation, osteogenic transition and neointimal atherosclerotic calcification. In nondiabetic/nonatherosclerotic aortas, CKD increases VSMC ActRIIA signaling, and vascular fibroblast signaling causing the latter to undergo osteogenic transition and stimulate vascular calcification. In both vascular situations, a ligand trap for ActRIIA prevented vascular calcification. In the skeleton, activin A is responsible for CKD stimulation of osteoclastogenesis and bone remodeling increasing bone turnover. These studies demonstrate that circulating renal repair and injury factors are causal of the CKD-MBD and CKD associated cardiovascular disease.

The Results of Proximal Femoral Nail for Intertrochanteric Fracture in Hemodialysis Patient

Purpose

Hip fractures in hemodialysis patients are accompanied by high rates of complications and morbidities. Previous studies have mainly reported on nonunion and avascular necrosis of femoral neck fractures in this patient group. In this study the complication and clinical results of hemodialysis patients with intertrochanteric fractures treated with proximal femoral intramedullary nailing have been investigated through comparison with patients with normal kidney function.

Materials and Methods

Forty-seven patients were included; the hemodialysis group (n=17) and the control group with normal kidney function (n=30). The medical history and clinical findings including preoperative and postoperative blood examinations, radiological examinations and ambulatory status (measured using the Koval score). The rate of complications and morbidities were also investigated and compared.

Results

Preoperative hemoglobin/hematocrit was lower but a significant increase in partial thromboplastin time was observed in the hemodialysis group. The amount of bleeding/transfusions were higher and operative time was longer in the hemodialysis group. Upon radiologic examination, there was no significant difference in rate of unstable fracture and nonunion between the two groups. However the postoperative Koval score was significantly worse and the odds ratio of inability to walk after surgery was 13.5 times higher in the hemodialysis group.

Conclusion

There was no significant difference in radiological results, but the risk of inability to walk after surgery was 13.5 times higher in the hemodialysis group. Hemodialysis patients have more morbidities and are hemodynamically unstable therefore require special attention. Accurate reduction and firm fixation is required and attentive postoperative rehabilitation is needed.

The Use of Parenteral Nutrition in a Severely Malnourished Hemodialysis Patient With Hypercalcemia

There is a high prevalence of protein-energy malnutrition (PEM) in chronic dialysis patients. Causes of PEM include the catabolic effects of hemodialysis treatments, acidemia associated with end-stage renal disease, common comorbid conditions, and uremia-induced anorexia. Morbidity and mortality increase with PEM. Before considering parenteral nutrition (PN) as a nutrition intervention in a maintenance dialysis patient, all other efforts to promote optimal nutrition need to be exhausted. The first step is careful evaluation of protein-energy status, followed by intensive nutrition counseling. If necessary, this is followed by oral nutrition supplementation, appetite stimulation, enteral tube feedings, and finally PN. Short-term parenteral nutrition (PN) became a crucial component of the management of a 38-year-old hemodialysis (HD) patient who endured serious complications after kidney transplant rejection. A profound and prolonged malnourished state followed her treatment for necrotizing pancreatitis. She had developed persistent hypercalcemia believed secondary to tertiary hyperparathyroidism (HPT) and immobilization. Later, she developed hungry bone syndrome (HBS) after parathyroidectomy (PTX). She also developed refeeding syndrome after initiation of PN. The patient's persistent, poorly understood hypercalcemia did not resolve even after PTX and removal of all other sources of vitamin D and calcium from her feedings, medications, and dialysis bath. The close communication of the inpatient and outpatient dialysis multidisciplinary teams became a key component to the successful outcome in this complex patient.

Association of bone mineral density with biochemical markers of bone turnover in hemodialysis children

Introduction: Although some descriptive and cross-sectional studies have been reported about bone mass in chronic kidney disease (CKD) children, only a few studies investigated markers of bone turnover and the bone mass measurements.

Objectives: The aim of this study was to evaluate the association between bone mineral density (BMD) and biochemical markers of bone turnover in hemodialysis (HD) children.

Patients and Methods: The children who had received dialysis for at least the preceding 6‐month were included. BMD was measured for total body, the lumbar spine and the femoral neck and the blood samples were tested to assess biochemical bone turnover markers.

Results: The study group was comprised of 27 patients with CKD, 9 males (33%) and 18 females (67%) with the mean±SD age of the subjects 14.9±4.5 years. Positive significant correlations of parathyroid hormone (PTH) with total body bone densitometry Z-score, lumbar spine and femoral neck Z-score(r=0.43, P=0.06; r=0.41, P=0.08 and r=0.45, P=0.05, respectively) was noted. In addition, positive significant correlations calcium and total body, lumbar spine and femoral neck Z-score (r=0.52, P=0.02; r=0.28, P=0.23 and r=0.36, P=0.12, respectively) was seen. Interestingly, a positive significant correlation between alkaline phosphatase (ALP) and lumbar spine Z-score was found (r=0.46, P=0.04), while the correlation of this parameter with total body and femoral neck Z-score was not significant (P>0.05).

Conclusion: In our study, majority of patients with CKD had low level of BMD. In addition, lower levels of calcium (Ca), phosphorus (P), PTH and 25 (OH) vitamins D in patients with abnormal BMD Z-scores were detected.

Hip Fracture in Patients With Non-Dialysis-Requiring Chronic Kidney Disease

Patients with end-stage renal disease (ESRD) are at a high risk for hip fracture. Little is known about the risk for, and consequences of, hip fracture among patients with non-dialysis-requiring chronic kidney disease (CKD). We examined the incidence of hip fracture, in-hospital mortality, length of stay, and costs among patients with ESRD, non-dialysis-requiring CKD, and normal or near normal kidney function. Using the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, a nationally representative database, we identified hospitalizations for hip fracture in 2010. We incorporated data from the United States Renal Data System (USRDS) and the US census to calculate population-specific rates. Age-standardized incidence of hip fracture was highest among patients with ESRD (3.89/1000 person-years), followed by non-dialysis-requiring CKD (1.81/1000 persons) and patients with normal or near normal kidney function (1.18/1000 persons). In-hospital mo rtality (odds ratio [OR] = 1.69, 95% confidence interval [CI] 1.46 to 1.96), lengths of stay (median [10th, 90th percentiles] 5 [3 to 11] versus 5 [3 to 10] days) and costs (median $14,807 versus $13,314) were significantly higher in patients with non-dialysis-requiring CKD relative to patients with normal or near normal kidney function. In summary, non-dialysis-requiring CKD is associated with higher age-standardized rates of hip fracture and post-hip fracture mortality and higher resource utilization. © 2016 American Society for Bone and Mineral Research.

Can lumbar spine bone mineral density predict readmission in denosumab-treated patients with chronic kidney disease?

This study investigated whether bone mineral density (BMD) affects readmission risk in patients with chronic kidney diseases (CKD) who received denosumab therapy. The study design was a retrospective case review of patients with CKD. Baseline age, sex, and body mass index were recorded for all patients included in the study. All comorbidities were recorded. All subjects underwent dual energy X-ray absorptiometry assay of the lumbar spine and right hip for BMD. The primary outcome was readmission. Predictive variables were categorized and compared between readmitted and non-readmitted patients. Logistic regression was used for multivariable analysis. A total of 121 patients with CKD who received denosumab therapy were enrolled. Of these, 29 were readmitted within 2 years, and 92 had no readmission. The lumbar BMD differed between the readmission (−2.94±0.68) and non-readmission (−2.09±1.48) groups. The readmission group had a lower T score than the non-readmission group. When adjusted for potential confounding factors, a decreased lumbar BMD had a higher readmission risk. When the cut-off points determined by receiver operating characteristic curve analysis were applied, the most precise point was set at a T score of −3. Osteoporosis in patients with CKD is associated with a high risk of readmission; the best predictor after denosumab therapy was the lumbar spine T score. A lower T score (especially if <−3) was associated with a higher probability of fracture readmission. It is essential to optimize primary and secondary prevention in these patients to improve their quality of life.

The Kidney-Vascular-Bone Axis in the Chronic Kidney Disease-Mineral Bone Disorder

The last 25 years have been characterized by dramatic improvements in short-term patient and allograft survival after kidney transplantation. Long-term patient and allograft survival remains limited by cardiovascular disease and chronic allograft injury, among other factors. Cardiovascular disease remains a significant contributor to mortality in native chronic kidney disease as well as cardiovascular mortality in chronic kidney disease more than doubles that of the general population. The chronic kidney disease (CKD)-mineral bone disorder (MBD) is a syndrome recently coined to embody the biochemical, skeletal, and cardiovascular pathophysiology that results from disrupting the complex systems biology between the kidney, skeleton, and cardiovascular system in native and transplant kidney disease. The CKD-MBD is a unique kidney disease-specific syndrome containing novel cardiovascular risk factors, with an impact reaching far beyond traditional notions of renal osteodystrophy and hyperparathyroidism. This overview reviews current knowledge of the pathophysiology of the CKD-MBD, including emerging concepts surrounding the importance of circulating pathogenic factors released from the injured kidney that directly cause cardiovascular disease in native and transplant chronic kidney disease, with potential application to mechanisms of chronic allograft injury and vasculopathy.

Bone Density Is Directly Associated With Glomerular Filtration and Metabolic Acidosis but Do Not Predict Fragility Fractures in Men With Moderate Chronic Kidney Disease

Hyperparathyroidism, vitamin D deficiency, increased fibroblast growth factor-23 (FGF-23), and metabolic acidosis promote bone fragility in chronic kidney disease (CKD). Although useful in predicting fracture risk in the general population, the role of dual-energy X-ray absorptiometry (DXA) in CKD remains uncertain. This cross-sectional study included 51 men aged 50-75 yr with moderate CKD. The stage 4 CKD patients had higher levels of parathyroid hormone (p<0.001), FGF-23 (p=0.029), and lowest 25-hydroxyvitamin D (p=0.016), bicarbonate (p<0.001), total femur (p=0.003), and femoral neck (p=0.011) T-scores compared with stage 3 CKD patients. Total femur and femoral neck T-scores were directly correlated with serum bicarbonate (p=0.003, r=0.447 and p=0.005, r=0.427, respectively) and estimated glomerular filtration rate (p=0.024, r=0.325 and p=0.003, r=0.313, respectively) but were not significantly associated with parathyroid hormone, 25-hydroxyvitamin D, or FGF-23. Only 3.9% of the participants had osteoporosis on DXA scan, whereas 31.4% reported a low-impact fracture. Our data point to a pivotal role of metabolic acidosis for bone impairment and to the inadequacy of DXA to evaluate bone fragility in CKD patients.

Dual Therapy Treatment Strategies for the Management of Patients Infected with HIV: A Systematic Review of Current Evidence in ARV-Naive or ARV-Experienced, Virologically Suppressed Patients

OBJECTIVE

We reviewed the current literature regarding antiretroviral (ARV)-sparing therapy strategies to determine whether these novel regimens can be considered appropriate alternatives to standard regimens for the initial treatment of ARV-naive patients or as switch therapy for those patients with virologically suppressed HIV infection.

METHODS

A search for studies related to HIV dual therapy published from January 2000 through April 2014 was performed using Biosis, Derwent Drug File, Embase, International Pharmaceutical Abstracts, Medline, Pascal, SciSearch, and TOXNET databases; seven major trial registries, and the abstracts of major conferences. Using predetermined criteria for inclusion, an expert review committee critically reviewed and qualitatively evaluated all identified trials for efficacy and safety results and potential limitations.

RESULTS

Sixteen studies of dual therapy regimens were critiqued for the ARV-naive population. Studies of a protease inhibitor/ritonavir in combination with the integrase inhibitor raltegravir or the nucleoside reverse transcriptase inhibitor lamivudine provided the most definitive evidence supporting a role for dual therapy. In particular, lopinavir/ritonavir or darunavir/ritonavir combined with raltegravir and lopinavir/ritonavir combined with lamivudine demonstrated noninferiority to standard of care triple therapy after 48 weeks of treatment. Thirteen trials were critiqued in ARV-experienced, virologically suppressed patients. The virologic efficacy outcomes were mixed. Although overall data regarding toxicity are limited, when compared with standard triple therapy, certain dual therapy regimens may offer advantages in renal function, bone mineral density, and limb fat changes; however, some dual combinations may elevate lipid or bilirubin levels.

CONCLUSIONS

The potential benefits of dual therapy regimens include reduced toxicity, improved tolerability and adherence, and reduced cost. Although the data reviewed here provide valuable insights into the effectiveness and tolerability of dual therapy regimens, it remains unclear whether these potential benefits can be maintained long-term. Appropriately powered studies with longer follow-up periods are needed to more definitively assess potential toxicity reduction advantages with dual therapy.

Inflammation and the bone-vascular axis in end-stage renal disease

Bone loss and vascular calcification coincide in patients with end-stage renal disease, similar as to what is observed in the general population. In the present bone biopsy study, we provide further evidence that (micro-)inflammation may represent a common soil for both diseases.

INTRODUCTION

Vascular calcification is a common complication of end-stage renal disease (ESRD) and is predictive of subsequent cardiovascular disease and mortality. Mounting evidence linking bone disorders with vascular calcification has contributed to the development of the concept of the bone-vascular axis. Inflammation is involved in the pathogenesis of both disorders. The aim of the present study was to evaluate the relationship between aortic calcification, inflammation, and bone histomorphometry in patients with ESRD.

METHODS

Parameters of inflammation and mineral metabolism were assessed in 81 ESRD patients (55 ± 13 year, 68 % male) referred for renal transplantation. Static bone histomorphometry parameters were determined on transiliac bone biopsies performed during the transplant procedure. Aortic calcification was quantified on lateral lumbar X-rays using the Kauppila method.

RESULTS

Aortic calcification, low bone turnover, and low bone area were observed in 53, 37, and 21 % of patients respectively. Inflammatory markers were found to be independently associated with aortic calcification (hsIL-6) and low bone area (TNF-α). Low bone area associated with aortic calcification, independent of age, diabetes, and inflammation.

CONCLUSIONS

Low bone area and inflammation associates with aortic calcification, independent of each other and traditional risk factors. Our data emphasize the role of (micro-)inflammation in the bone-vascular axis in CKD.

The effect of parathyroidectomy on patient survival in secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism is a common condition in patients with end-stage renal disease and is associated with osteoporosis and cardiovascular disease. Despite improved medical treatment, parathyroidectomy (PTX) is still necessary for many patients on renal replacement therapy. The aim of this study was to evaluate the effect of PTX on patient survival.

METHODS

A nested index-referent study was performed within the Swedish Renal Registry (SRR). Patients on maintenance dialysis and transplantation at the time of PTX were analysed separately. The PTX patients in each of these strata were matched for age, sex and underlying renal diseases with up to five referent patients who had not undergone PTX. To calculate survival time and hazard ratios, indexes and referents were assigned the calendar date (d) of the PTX of the index patient. The risk of death after PTX was calculated using crude and adjusted Cox proportional hazards regressions.

RESULTS

There were 20 056 patients in the SRR between 1991 and 2009. Of these, 579 (423 on dialysis and 156 with a renal transplant at d) incident patients with PTX were matched with 1234/892 non-PTX patients. The adjusted relative risk of death was a hazard ratio (HR) of 0.80 [95% confidence interval (CI) 0.65-0.99] for dialysis patients at d who had undergone PTX compared with matched patients who had not. Corresponding results for the patients with a renal allograft at d were an HR of 1.10 (95% CI 0.71-1.70).

CONCLUSIONS

PTX was associated with improved survival in patients on maintenance dialysis but not in patients with renal allograft.

Pathophysiology of the chronic kidney disease-mineral bone disorder

PURPOSE OF REVIEW

The causes of excess cardiovascular mortality associated with chronic kidney disease (CKD) have been attributed in part to the CKD-mineral bone disorder syndrome (CKD-MBD), wherein, novel cardiovascular risk factors have been identified. The causes of the CKD-MBD are not well known and they will be discussed in this review

RECENT FINDINGS

The discovery of WNT (portmanteau of wingless and int) inhibitors, especially Dickkopf 1, produced during renal repair and participating in the pathogenesis of the vascular and skeletal components of the CKD-MBD implied that additional pathogenic factors are critical, leading to the finding that activin A is a second renal repair factor circulating in increased levels during CKD. Activin A derives from peritubular myofibroblasts of diseased kidneys, where it stimulates fibrosis, and decreases tubular klotho expression. The type 2 activin A receptor, ActRIIA, is decreased by CKD in atherosclerotic aortas, specifically in vascular smooth muscle cells (VSMC). Inhibition of activin signaling by a ligand trap inhibited CKD induced VSMC dedifferentiation, osteogenic transition and atherosclerotic calcification. Inhibition of activin signaling in the kidney decreased renal fibrosis and proteinuria.

SUMMARY

These studies demonstrate that circulating renal repair factors are causal for the CKD-MBD and CKD associated cardiovascular disease, and identify ActRIIA signaling as a therapeutic target in CKD that links progression of renal disease and vascular disease.

Increased risk of cardiovascular events in end-stage renal disease patients with osteoporosis: a nationwide population-based cohort study

SUMMARY

We investigated the cardiovascular disease risk and mortality in end-stage renal disease (ESRD) patients. A total of 12,535 patients with ESRD undergoing incident dialysis were enrolled, 4,153 (33.13 %) of whom had osteoporosis. The osteoporosis group was associated with a significantly higher risk of coronary artery disease, congestive heart failure, stroke, and mortality.

INTRODUCTION

In this study, we aimed to investigate the risk of cardiovascular disease and mortality in a sample of end-stage renal disease patients with osteoporosis.

METHODS

We conducted this retrospective cohort study of incident dialysis patients with and without osteoporosis to evaluate the risk of overall mortality and cardiovascular complications including stroke, coronary heart disease, and congestive heart failure between the two groups. A total of 12,535 patients with ESRD undergoing incident dialysis were enrolled, 4,153 (33.13 %) of whom had osteoporosis, from the National Health Insurance Research Database of Taiwan for the years 1998 through 2011. The osteoporosis group had more comorbidities than the group without osteoporosis including hypertension, hyperlipidemia, mental disorders, and hepatitis C infection.

RESULTS

After adjusting for age, gender, and related comorbidities, the osteoporosis group was associated with a significantly higher risk of coronary artery disease (hazard ratio (HR)=1.32, 95 % confidence interval (CI)=1.20-1.45) which was significant in both genders (women, HR=1.35, 95% CI=1.20-1.50; men HR=1.27, 95% CI=1.06-1.52) and all age groups (≤49 years HR=1.41, 95% CI=1.16-1.70; >49 years HR=1.30, 95% CI=1.16-1.45). Similar results were observed for the outcomes of congestive heart failure, stroke, and mortality.

CONCLUSIONS

The results showed that osteoporosis was significantly associated with the subsequent risk of cardiovascular events in patients with ESRD. When encountering patients with ESRD and osteoporosis, physicians should be alert to the subsequent cardiovascular risk in incident dialysis patients to prevent the subsequent occurrence of these adverse events.

Osteoporosis after renal transplantation

Bone loss and fracture are serious sequelae of kidney transplantation, associated with morbidity, mortality and high economic costs. The pathogenesis of post-transplantation bone loss is multifactorial and complex. Pre-existing bone mineral disease is responsible for a significant part, but it is aggravated by risk factors emerging after renal transplantation with immunosuppressive agents being one of the key contributors. The decrease in bone mass is particularly prominent during the first 6-12 months after transplantation, continuing at a lower rate thereafter. Bone mineral density measurements do not predict bone histology and bone biopsy findings reveal heterogeneous lesions, which vary according to time after transplantation. Currently, vitamin D and bisphosphonates are the most extensively tested therapeutic agents against this accelerated bone loss in renal transplant recipients. Both of these agents have proven effective, but there is no evidence that they decrease fracture risk. More studies are needed to examine the complex pathophysiologic mechanisms implicated in this population, as well as the effects of different therapeutic interventions on bone disorders after kidney transplantation.

Safety of drugs used in the treatment of osteoporosis

A number of drug classes are licensed for the treatment of osteoporosis including bisphosphonates, recombinant human parathyroid hormone (PTH), strontium, hormone replacement therapy (HRT), selective oestrogen receptor modulators (SERMS) and denosumab. This review discusses the safety of osteoporosis treatments and their efficacies. Recent concerns about the safety of calcium and high-dose vitamin D are discussed. Bisphosphonates have substantial postmarketing experience and a clearer picture of safety issues is emerging. Along with the well recognized effects on the gastrointestinal tract and kidney function, recently described adverse effects such as osteonecrosis of the jaw, oesophageal cancer, atrial fibrillation, subtrochanteric femur fractures and ocular complications of bisphosphonate therapy are discussed. Therapy with PTH is limited to two years' duration because of the development of osteogenic sarcomas in animal studies, which appeared related to dose, duration and timing of therapy. Strontium should be used with caution in patients with renal impairment and its use has been associated with venous thromboembolism. The role of HRT and SERMs in the treatment of postmenopausal osteoporosis is restricted as a result of an increased risk of stroke, venous thromboembolism and breast cancer. Postmarketing experience with denusomab is limited but a number of potential safety concerns including osteonecrosis of the jaw are emerging. All of these drugs have been proven to reduce fractures. The decision to use a drug to reduce fracture risk should be based on risk-benefit analysis of the drug and its suitability for individual patients.

Osteoporosis management in patient with renal function impairment

Aging is associated with decreases in bone quality and in glomerular filtration. Consequently, osteoporosis and chronic kidney disease (CKD) are common comorbid conditions in the elderly, and often coexist. Biochemical abnormalities in the homeostasis of calcium and phosphorus begin early in CKD, leading to an increase in fracture risk and cardiovascular complications since early stages of the disease. The ability of DXA (dual energy X-ray absorptiometry) to diagnose osteoporosis and to predict fractures in this population remains unclear. The management of the disease is also controversial: calcium and vitamin D, although recommended, must be prescribed with caution, considering vascular calcification risk and the development of adynamic bone disease. Furthermore, safety and effectiveness of osteoporosis drugs are not established in patients with CKD. Thus, risks and benefits of antiosteoporosis treatment must be considered individually.