Treatment of osteoporosis in chronic kidney disease and end-stage renal disease

The structure of mineral and bone disorders in patients with сhronic kidney disease of the 5th dialysis stage, taking into account the presence or absence of a diagnosis of type 1 diabetes mellitus

BACKGROUND: In patients with end-stage CKD, receiving renal replacement therapy (RRT) with programmed hemodialysis (HD), the severity of complications is associated with metabolic disturbances: accumulation of uremic toxins, nephrogenic anemia, secondary hyperparathyroidism (SHPT), extraskeletal calcification, impaired clearance and rhythm of hormone secretion.

AIM: To evaluate the main biochemical and hormonal parameters, and manifestations of mineral bone disease (MBD) in patients receiving RRT with HD, before and after hemodialysis, taking into account the presence or absence of diabetes mellitus.

MATERIALS AND METHODS: We divided all patients receiving RRT with HD in two groups: #1 (n=24) — patients with DM, #2 (n=16) — patients without DM. All of them had their blood analyzed before and immediately after the HD. Data analysis was performed with the Statistica 13 (StatSoft, USA). A prognostically significant model was considered at p<0.05.

RESULTS: The level of iPTH, both at baseline and after HD, was lower in group #1 (p<0.001). The level of alkaline phosphatase (AP) was significantly higher in group #2 (p=0.012). In both groups before HD, a high incidence of hypocalcemia was detected (according to albumin-corrected calcium in group #1 in 58.3%, in group #2 in 43.7% of cases, p = 0.366) and hyperphosphatemia (in 66.7% and in 43 .7% of cases, respectively, p=0.151). Hypocalcemia after HD in group #1 persisted in 14%, in group #2 — in 20% of cases (p>0.05); hyperphosphatemia in group #1 was completely leveled, in group #2 it persisted in 7% of cases (p=0.417). Prior to the HD session, group #1 had significantly higher levels of RAGE, glucagon, immunoreactive insulin (IRI), cortisol, and glucose than after the HD session (p<0.05). In group #2, after HD, the levels of glucagon, IRI and cortisol significantly decreased (p<0.05), and the level of 3-nitrotyrosine (3-HT) increased significantly (p=0.026). In group #1, fibrocalcinosis of the heart valves according to ECHO and calcification of the arteries of the lower extremities according to ultrasonic doplerography were more common than in group #2 (42% vs 25%, p<0.001 and 75% vs 37.5%, p=0.018, respectively). (χ2)). Compression fractures occurred with the same frequency in both groups (60%). A decrease in bone mineral density (BMD) to the level of osteopenia was noted more often in group #1 (50% vs 18.8%), and osteoporosis was more common in group #2 (68.8% vs 33.3%) (p<0.001, χ2).

CONCLUSION: The low level of PTH in group #1 may reflect the effect of diabetes on calcium-phosphorus metabolism. Patients with DM have an increased risk of renal osteodystrophy with a low bone turnover because of a number of metabolic factors inherent in diabetes. At the same time, the dynamics of phosphorus and calcium indicators during the HD procedure were similar.

Alendronate use in older patients with reduced renal function: challenges and opportunities in clinical practice

In this retrospective cohort study, alendronate use among older osteoporosis patients (age>65 years) with reduced renal function (creatinine clearance<35ml/min) was not associated with significant deterioration in renal function from baseline nor increased incidence of osteoporotic fractures or acute kidney injury, compared with patients conservatively managed with only calcium/vitamin D supplementation.

INTRODUCTION

Oral bisphosphonates are not recommended in patients with creatinine clearance (CrCl) <35ml/min, although this is not supported by post hoc analyses of pivotal oral bisphosphonate studies. As both osteoporosis and renal insufficiency are more prevalent with advancing age, it is important to determine the safety and efficacy of oral bisphosphonates among these patients.

METHODS

Patients with CrCl <35ml/min on alendronate (group A, n=98), with CrCl <35ml/min conservatively managed (group B, n=96), and with CrCl ≥35ml/min on alendronate (group C, n=96) were followed up to 22 months. Primary outcomes were mean change in CrCl from baseline in group A compared with groups B and C, respectively. Secondary outcomes were the incidence of osteoporotic fractures and adverse events between groups.

RESULTS

There was no significant change in CrCl from baseline when comparing group A (-1.53±6.83ml/min) with group B (0.59±5.17ml/min) (p=0.075), and group A with group C (-3.71±7.54ml/min) (p=0.163). There was no significant increase in incidences of osteoporotic fractures in group A compared with group B (adjusted relative risk (aRR) 2.02, 95% confidence interval (CI) 0.64-6.37) and group A compared with group C (aRR 1.15, 95% CI 0.46-2.89). There was no significant difference in incidences of acute kidney injury (AKI) in group A compared with group B (aRR 0.48, 95% CI 0.20-1.12). Although statistically non-significant, there was an increase in AKI incidence in group A compared with group C (RR 7.84, 95% CI 0.98-62.66).

CONCLUSION

Among patients with CrCl <35ml/min, alendronate therapy was not associated with significant deterioration in renal function from baseline. Although not powered for secondary outcomes, there were no statistically significant differences in osteoporotic fracture or AKI incidence between the groups.

Serum nuclear factor IB as a novel and noninvasive indicator in the diagnosis of secondary hyperparathyroidism

BACKGROUND

Chronic renal failure (CRF) referred to chronic progressive renal parenchymal damage caused by various causes, with metabolite retention and imbalance of water, electrolyte, and acid-base balance as the main clinical manifestations. Secondary hyperparathyroidism (sHPT) was a common complication in maintenance hemodialysis patients with CRF. Nuclear factor IB (NFIB) was a newly found tumor suppressor gene in various cancers. The present study aimed to illustrate the role of NFIB in sHPT clinical diagnosis and treatment response.

METHODS

A retrospective, case-control study, including 189 patients with sHPT and 106 CRF patients without sHPT, compared with 95 controls. Serum NFIB and 1,25(OH)₂ D₃ levels were measured by RT-qPCR and ELISAs, respectively. ROC analysis was conducted to verify the diagnostic value of NFIB in sHPT. Spearman's correlation analysis was conducted to verify the association between NFIB and bone mineral density (BMD) scores. After 6 months of treatment, the variance of NFIB and 1,25(OH)₂ D₃ in different groups was recorded.

RESULTS

The expression of NFIB was significantly lower in serum samples from sHPT and non-sHPT CRF patients, compared to controls. Clinicopathological information verified sHPT was associated with NFIB, parathyroid hormone (PTH), serum calcium, serum phosphorus, time of dialysis, and serum 1,25(OH)₂ D₃ levels. Spearman's correlation analysis illustrated the positive correlation between NFIB levels and BMD scores. At receiver operator characteristic (ROC) curve analysis, the cutoff of 1.6508 for NFIB was able to identify patients with sHPT from healthy controls; meanwhile, NFIB could also discriminate sHPT among CRF patients as well (cutoff = 1.4741). Furthermore, we found that during 6 months of treatment, NFIB levels were gradually increased, while PTH and serum P levels were decreased.

CONCLUSIONS

Serum NFIB was a highly accurate tool to identify sHPT from healthy controls and CRF patients. Due to its simplicity, specificity, and sensitivity, this candidate can be proposed as a first-line examination in the diagnostic workup in sHPT.

Effects of Denosumab and Alendronate on Bone Health and Vascular Function in Hemodialysis Patients: A Randomized, Controlled Trial

Mineral and bone disorders including osteoporosis are common in dialysis patients and contribute to increased morbimortality. However, whether denosumab and alendronate are effective and safe treatments in hemodialysis patients is not known. Thus, we conducted a prospective, three-center study of 48 hemodialysis patients who were diagnosed as having osteoporosis and had not received anti-osteoporotic agents previously. Participants were randomized to either denosumab or intravenous alendronate, and all subjects received elemental calcium and calcitriol during the initial 2 weeks. The primary endpoint was the percent change in lumbar spine bone mineral density (LSBMD) at 12 months of treatment. The secondary endpoints included the following: change in BMD at other sites; change of serum bone turnover markers (BTM), coronary artery calcium score (CACS), ankle-brachial pressure index (ABI), brachial-ankle pulse wave velocity (baPWV), flow mediated dilation (FMD), and intima-media thickness at the carotid artery (CA-IMT); change from day 0 to day 14 in serum levels of Ca and P; time course of serum calcium (Ca), phosphorus (P), and intact parathyroid hormone (i-PTH); new fractures; and adverse events. Initial supplementation with elemental calcium and calcitriol markedly ameliorated the decrease of serum corrected calcium (cCa) levels induced by denosumab during the first 2 weeks, whereas serum cCa levels in the alendronate group were increased. Denosumab and alendronate markedly decreased serum levels of BTM and increased LSBMD at 12 months compared with baseline. However, no significant differences were found in the changes in LSBMD between the two groups. The serum cCa, P, and i-PTH levels in the two groups were maintained within the appropriate range. In contrast to the anti-osteoporotic effects, no significant differences after 12 months of treatment were found in the CACS, CA-IMT, ABI, baPWV, and FMD compared with pretreatment in both groups. Denosumab and alendronate treatment improved LSBMD, reduced BTM, and appeared to be safe in hemodialysis patients with osteoporosis. © 2019 American Society for Bone and Mineral Research.

PRIMARY HIP ARTHROPLASTY IN PATIENTS WITH END-STAGE OF CHRONIC KIDNEY DISEASE (LITERATURE REVIEW)

The authors present a review of current national and international literature related to the specifics of primary hip joint arthroplasty in patients with end-stage of chronic kidney disease. epidemiology aspects of such pathology are covered in detail. Screening of the patients with hip joint pathology undergoing substitute renal therapy remains a significant issue. The authors present the outcomes of use of various implant types and their fixation in primary hip joint arthroplasty such as cemented, cementless and monopolar prostheses, as well as consider features and structure of complications following primary replacements in such patients. unfortunately, the national literature lacks sufficient number of publications on the present problem. In addition, the paper presents a promising area for development of specialized care to patients on hemodialysis with hip joint pathology.

Potentially inappropriate prescribing of renally cleared drugs in elderly patients in community and aged care settings

BACKGROUND

Limited data are available on the prevalence of inappropriate prescribing of renally cleared drugs in elderly patients in Australia.

OBJECTIVES

To quantify and compare the extent of inappropriate prescribing (defined as at least one drug prescribed in an excessive dose or when contraindicated with respect to renal function) of renally cleared drugs in elderly patients across the community and aged care settings, and to determine factors associated with patients being prescribed one or more potentially inappropriate renally cleared drugs.

METHODS

This retrospective study examined de-identified Home Medicines Review (HMR) and Residential Medication Management Review (RMMR) cases pertaining to 30,898 patients aged 65 years and over. Only 25 % (n = 7625) of these patients had documented information on their renal function. Among them, 4035 patients were prescribed at least one of the 31 renally cleared drugs examined in this study. For these patients, details including demographics, medications, medical conditions and pathology test results were extracted. Creatinine clearance was estimated using the Cockcroft-Gault formula, and the prevalence of inappropriate prescribing of the 31 drugs was examined on the basis of conformity with the recommendations in the Australian Medicines Handbook. Multivariate logistic regression was performed to determine the factors associated with patients being prescribed one or more potentially inappropriate renally cleared drugs.

RESULTS

The mean (± standard deviation) ages of the HMR patients (n = 3315; 59 % female) and RMMR patients (n = 720; 68 % female) were 78.3 ± 7.2 and 86 ± 7.3 years, respectively. Over one quarter of the patients (n = 1135 out of 4035; 28.1 %) prescribed the renally cleared drugs examined in this study had evidence of inappropriate prescribing of at least one of the drugs, with respect to their renal function. The drugs/drug classes most commonly prescribed inappropriately were perindopril, fenofibrate, glibenclamide, gliptins, metformin, olmesartan, bisphosphonates and strontium. The factors independently associated with patients being prescribed one or more potentially inappropriate renally cleared drugs were advancing age [odds ratio (OR) 1.06 per year increase, 95 % confidence interval (CI) 1.05-1.07; P < 0.001], the total number of renally cleared drugs prescribed (OR 1.44 per unit increase, 95 % CI 1.29-1.61; P < 0.001), presence of diabetes (OR 1.51, 95 % CI 1.30-1.76; P < 0.001), presence of heart failure (OR 1.38, 95 % CI 1.13-1.69; P < 0.005) and living in aged care facilities (OR 1.28, 95 % CI 1.06-1.5; P < 0.05).

CONCLUSION

Inappropriate prescribing of renally cleared drugs is common in older Australians. Intervention studies to improve prescribing of renally cleared drugs in the elderly appear to be warranted.

Bisphosphonates for Osteoporosis in Patients with Renal Insufficiency: Pharmacists' Practices and Beliefs

BACKGROUND

Clinicians often face challenges in deciding how to treat osteoporosis in patients with chronic kidney disease. As background to offering guidance to health care providers, it is important to understand their practices and beliefs.

OBJECTIVES

To describe the practices and beliefs of pharmacists regarding use of bisphosphonates for patients with osteoporosis and chronic kidney disease.

METHODS

A cross-sectional survey of pharmacists working in hospitals and related health care settings was conducted. A 34-item online questionnaire was developed consisting of 4 sections: demographic characteristics, practices, beliefs, and comfort level with making decisions about osteoporosis treatment. An e-mail invitation was sent to members of the Canadian Society of Hospital Pharmacists (n = 2499) in November 2012.

RESULTS

A total of 367 pharmacists completed the survey. Most of the respondents were women (258 [70%]), had more than 10 years in practice (213 [58%]), and were providing care to 1 or more osteoporosis patients per week (212 [58%]). Over one-third (150 [41%]) stated that they would use a bisphosphonate for patients with creatinine clearance (CrCl) of 15-30 mL/min, but more than half (207 [56%]) stated that they would avoid a bisphosphonate (and recommend another medication) for patients with CrCl below 15 mL/min. Forty-eight percent (176/363) agreed that oral bisphosphonates could be used for patients with renal failure (defined as CrCl < 30 mL/min), so long as dosage adjustments are made. More than half (206/363 [57%]) believed that the adverse effects of oral bisphosphonates increase for patients with renal failure. Respondents expressed a low level of comfort in assessing and initiating osteoporosis treatment for patients with renal failure.

CONCLUSIONS

Pharmacists had varying beliefs about managing osteoporosis in patients with chronic kidney disease. This study highlights the need for practice tools and targeted education addressing the use of bisphosphonates for these patients.

Treatment of osteoporosis in renal insufficiency

Patients with osteoporosis often have chronic kidney disease (CKD). CKD is associated with bone and mineral disturbances, renal osteodystrophy, which like osteoporosis leads to a higher risk of fractures. Bisphosphonates are first-line therapy for osteoporosis; however, these are contra-indicated in patients with a GFR <30 ml/min. In this article, we have reviewed the diagnosis and treatment of osteoporosis in moderate to severe renal failure from data of clinical trials. Results have shown that osteoporosis patients and severe CKD with no signs of renal osteodystrophy, oral bisphosphonates (risedronate) seem to be a safe choice. Renal function and PTH should subsequently be monitored strictly. Denosumab, with regularly monitoring of calcium and adequate vitamin D levels or raloxifene are a possible second choice. In any case, one should be certain that there is no adynamic bone before treatment can be started. If there is any doubt, bone biopsies should be taken.

Osteoporosis update: proceedings of the 2013 Santa Fe Bone Symposium

The 2013 Santa Fe Bone Symposium included plenary sessions on new developments in the fields of osteoporosis and metabolic bone disease, oral presentations of abstracts, and faculty panel discussions of common clinical conundrums: scenarios of perplexing circumstances where treatment decisions are not clearly defined by current medical evidence and clinical practice guidelines. Controversial issues in the care of osteoporosis were reviewed and discussed by faculty and participants. This is a review of the proceedings of the Santa Fe Bone Symposium, constituting in its entirety an update of advances in the understanding of selected bone disease topics of interest and the implications for managing patients in clinical practice. Topics included the associations of diabetes and obesity with skeletal fragility, the complexities and pitfalls in assessing the benefits and potential adverse effects of nutrients for treatment of osteoporosis, uses of dual-energy X-ray absorptiometry beyond measurement of bone mineral density, challenges in the care of osteoporosis in the very elderly, new findings on the role of osteocytes in regulating bone remodeling, and current concepts on the use of bone turnover markers in managing patients with chronic kidney disease who are at high risk for fracture.

The efficacy and safety of bazedoxifene in postmenopausal women by baseline kidney function status

INTRODUCTION

Two global, double-blind, placebo- and active-controlled, phase-3 studies (2-year prevention (n = 1583) and 3-year treatment (n = 7492)) have shown that bazedoxifene (BZA) is safe and effective for prevention and treatment of postmenopausal osteoporosis.

OBJECTIVE

To evaluate the efficacy/safety of BZA according to baseline kidney function.

METHODS

Data for the BZA 20- and 40-mg and placebo groups from both studies were integrated for assessment of bone turnover markers (BTMs), bone mineral density (BMD), and fracture incidence (treatment study only). Safety was assessed using integrated data for the BZA, placebo, and raloxifene 60-mg groups from both studies. Baseline glomerular filtration rate (GFR) was estimated by the Modification of Diet in Renal Disease Study equation; among subjects with baseline GFR, renal function categories were defined by GFR (ml/min per 1.73 m(2)): normal (GFR ≥ 90; n = 1982), mild impairment (60 ≤ GFR < 90; n = 6032), or moderate/severe impairment (GFR < 60; n = 723).

RESULTS

Demographics were similar across treatment groups and within GFR subgroups. Across GFR subgroups, BZA 20 and 40 mg reduced BTM levels and improved lumbar spine and total hip BMD versus placebo. At month 24, there were significant treatment-by-GFR (p = 0.003) and treatment-by-serum creatinine (p = 0.034) interactions for the increase in lumbar spine BMD versus placebo. Fracture incidence was lower with BZA than placebo across all GFR categories, with no treatment-by-GFR interaction. There were no significant differences among treatment groups in incidences of overall, serious, or renal-related adverse events across GFR subgroups.

CONCLUSIONS

Mild to moderate kidney impairment did not affect the efficacy and safety of BZA in postmenopausal women.

Bisphosphonates in the treatment of osteoporosis

Bisphosphonates are widely used in the treatment of osteoporosis to reduce fracture risk. Because of their long retention time in bone and uncommon side effects, questions have been raised about the optimal duration of therapy. Potential side effects appear to be rare and may not be causally related. Although there is no strong science to guide "drug holidays," there appears to be some lingering antifracture benefit when treatment is stopped, so some time off treatment should be offered to most patients on long-term bisphosphonate therapy. For most patients with osteoporosis, the benefits of treatment outweigh the risks.

Effects of oral bisphosphonate therapy on serum calcium in elderly veterans with poor kidney function

BACKGROUND

Limited data exist on the use of bisphosphonates in patients with poor kidney function due to a contraindication derived from inadequate experience among patients with kidney failure, accounting for as much as 25% of nonprescribing when otherwise appropriate.

OBJECTIVES

To determine whether bisphosphonate use in patients with decreased renal function, as outlined in the package insert (estimated creatinine clearance [eCrCl] <35 mL/min), would result in higher rates of hypocalcemia, as suggested in previous studies.

METHODS

This was a retrospective cohort study of elderly veterans 65 years of age and older at the Veterans Affairs North Texas Health Care System in Dallas, Texas. We identified 3089 patients who started oral bisphosphonate therapy between August 1, 2003 and July 12, 2010. Of the 252 patients meeting the inclusion criteria, 25 and 227 patients had an eCrCl <35 mL/min and eCrCl ≥35 mL/min, respectively. Analyses of changes in serum calcium from baseline to the 1-year study end point were performed within and between each renal function group.

RESULTS

Among the veterans with an eCrCl <35 mL/min and eCrCl ≥35 mL/min, there were decreases in median serum calcium levels from baseline to study end point from 9.8 mg/dL (interquartile range [IQR], 9.4-10.2 mg/dL) to 9.3 mg/dL (IQR, 9.0-10.0 mg/dL; P = 0.028) and 9.6 mg/dL (IQR, 9.3-9.9 mg/dL) to 9.4 mg/dL (IQR, 9.1-9.8 mg/dL; P < 0.001), respectively. However, there was no difference in Δcalcium: -0.2 mg/dL (IQR, 0-0.6 mg/dL) and 0.2 mg/dL (IQR, -0.2 to 0.5 mg/dL; P = 0.547), respectively.

CONCLUSIONS

This exploratory assessment may suggest that, in elderly veterans, the initiation of oral bisphosphonate therapy contributed to a statistically significant decrease in serum calcium levels regardless of baseline renal function; however, the clinical impact of this change does not appear to be significant. Future studies should assess serum calcium in a larger population of patients to confirm the safety of oral bisphosphonates in poor kidney function.

Impact of long-term cinacalcet, ibandronate or teriparatide therapy on bone mineral density of hemodialysis patients: a pilot study

BACKGROUND

Insufficient evidenced-based information is available for the treatment of osteoporosis in hemodialysis (HD) patients.

METHODS

In 102 HD patients, bone mineral density (BMD) was measured twice 16 ± 3 months apart. In the second BMD measurement 66 of them had a femoral neck (FN) T-score <-2.5. Of these 66 patients, 38 consented to a bone biopsy. Depending on both the bone biopsy findings and parathyroid hormone levels, patients were assigned to treatment groups. Eleven patients with osteitis fibrosa and iPTH >300 pg/ml received cinacalcet, 11 with osteitis fibrosa and iPTH <300 pg/ml received ibandronate, 9 with adynamic bone disease received teriparatide, and 7 with mild abnormalities received no treatment. A third BMD measurement was done after an average treatment period of 13-16 months. We compared the annual percent change of FN and lumbar spine (LS) BMD before and during treatment.

RESULTS

FN and LS BMD decreased significantly in the cinacalcet group, with an annual change of 3.6 and 3.4% before treatment to -4.2% (p = 0.04) and -7.7% (p = 0.02) during treatment, respectively. In the teriparatide group, FN and LS BMD increased, although not significantly, with an annual change of -5.4 and -2.6% before treatment to 2.7 and 4.9% during treatment, respectively. In both the ibandronate and the no treatment groups, BMD change rate remained negative during the whole study.

CONCLUSIONS

Teriparatide administration improved BMD in HD patients with adynamic bone disease, although these results did not reach statistical significance. In HD patients with osteitis fibrosa, ibandronate did not improve BMD while cinacalcet reduced BMD.

The kidney and bisphosphonates

Bisphosphonates are eliminated from the human body by the kidney. Renal clearance is both by glomerular filtration and proximal tubular secretion. Bisphosphonates given rapidly in high doses in animal models have induced a variety of adverse renal effects, from glomerular sclerosis to acute tubular necrosis. Nevertheless in the doses that are registered for the management of postmenopausal osteoporosis (PMO), oral bisphosphonates have never been shown to adversely affect the kidney, even (in post-hoc analysis of clinical trial data) down to estimated glomerular filtration rates of 15 ml/min. In addition fracture risk reduction has also been observed in these populations with stage 4 chronic kidney disease (CKD) with age-related reductions in glomerular filtration rate (GFR). Intravenous zoledronic acid is safe when the infusion rate is no faster than 15 min though there have been short-term (days 9-11 post-infusion) increases in serum creatinine concentrations in a small sub-set of patients from the postmenopausal registration trials. For these reasons intravenous zoledronic acid should be avoided in patients with GFR levels <35 ml/min; and the patients should be well hydrated and have avoided the concomitant use of any agent that may impair renal function. Intravenous ibandronate has not to date been reported to induce acute changes in serum creatinine concentrations in the PMO clinical trial data, but the lack of head-to-head comparative data between ibandronate and zoledronic acid precludes knowing if one intravenous bisphosphonate is safer than the other. In patients with GFR levels <30-35 ml/min, the correct diagnosis of osteoporosis becomes more complex since other forms of renal bone disease, which require different management strategies than osteoporosis, need to be excluded before the assumption can be made that fractures and/or low bone mass are due to osteoporosis. In addition, in patients who may have pre-existing adynamic renal bone disease, there is a lack of evidence of any beneficial effect or harm by reducing bone turnover by any pharmacological agent, including bisphosphonates on bone strength or vascular calcification. Bisphosphonates are safe and effective for the management of osteoporosis when used in the right dose and in the right patient population for the right duration.

Post-transplantation osteoporosis

Transplantation is an established therapy for many hematologic disorders as well as for end-stage diseases of the kidney, lung, liver, heart among others. Osteoporosis and a high incidence of fragility fractures have emerged as a complication of organ transplantation. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. In addition, most patients have some form of bone disease prior to transplantation, which is usually related to adverse effects of end-stage organ failure on the skeleton. This chapter reviews the mechanisms of bone loss that occur both in the early and late post-transplant periods including the contribution of immunosuppressive agents as well as the specific features of bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient will also be addressed.

Use of oral bisphosphonates by older adults with fractures and impaired renal function

BACKGROUND

The manufacturers of oral bisphosphonates (alendronate, risedronate) recommend avoiding use of these drugs in patients with renal impairment. However, many patients who have osteoporosis or who are at risk of fracture are elderly and may have renal impairment. This situation poses a quandary for clinicians in deciding how best to manage osteoporosis in this high-risk population.

OBJECTIVE

To synthesize published evidence regarding the use and safety of oral bisphosphonates for patients with impaired renal function.

METHODS

The following databases were searched up to October 2010: PubMed, MEDLINE, Embase, the Cochrane Library, and International Pharmaceutical Abstracts. The following key words and terms were used for the searches: bisphosphonates, alendronate, risedronate, Fosamax, Actonel, "renal failure", "renal insufficiency", "chronic kidney disease", and "end-stage renal disease". The manufacturers of Fosamax and Actonel were asked to provide information about use of their products in patients with renal impairment, including unpublished pharmacokinetic studies or reports of adverse drug events.

RESULTS

The search yielded 2 post hoc analyses of safety data, 1 case-control study, 1 case series, 4 retrospective chart analyses, and 2 prospective studies. According to these publications, numerous patients with decreased renal function have received bisphosphonates and have experienced improvement in bone mineral density and/or reduction in risk of fractures, with no increase in adverse effects. Increased renal damage occurred in some individuals with underlying renal disorders, as described in case reports.

CONCLUSIONS

Although the literature is limited, there is evidence that alendronate and risedronate are well tolerated and effective when used by individuals with renal impairment. Further research is required to confirm the benefits and risks of using these medications in patients with renal impairment.

Osteoporosis update from the 2010 santa fe bone symposium

The 11th Santa Fe Bone Symposium was held in Santa Fe, NM, USA, on August 6-7, 2010. This annual event addresses clinically relevant advances in the fields of osteoporosis and metabolic bone disease. The venue includes plenary presentations by internationally recognized experts, oral presentations of abstracts, and interactive panel discussions of challenging cases and controversial issues. Attendees are active participants throughout the symposium program. Topics for the 2010 symposium included potential applications of novel technologies for the assessment of skeletal health for research and clinical practice; new and emerging treatments for osteoporosis; appropriate use of pharmacological agents to prevent osteoporosis; controversies with bisphosphonate therapy; practical applications of the World Health Organization fracture risk assessment tool (FRAX; World Health Organization Collaborating Centre for Metabolic Bone Diseases, University of Sheffield, UK); insights into the use of osteoanabolic agents to enhance fracture healing; and challenges in laboratory testing in the assessment of factors contributing to skeletal fragility. Concurrent sessions focused on critical thinking for technologists in the acquisition and analysis of data with dual-energy X-ray absorptiometry. The key messages from each presentation, including the best available medical evidence and potential current and future clinical applications, are provided here.

Risk factors leading to reduced bone mineral density in hemodialysis patients with metabolic syndrome

Although metabolic syndrome (MS) is associated with low bone mineral density (BMD) in the general population, it is unknown whether similar associations exist in patients with chronic kidney disease. We investigated risk factors that can lead to low BMD values in hemodialysis patients with MS according to the diagnostic criteria set by International Diabetes Federation (IDF) in this study. A total of 64 patients with MS undergoing hemodialysis and 60 hemodialysis patients who were matched in terms of age, gender, and hemodialysis duration without MS were enrolled in the study. BMD was measured at lumbar vertebra (LV) and femur neck (FN) by performing dual-energy X-ray absorptiometry (DEXA). LV and/or FN-BMD results revealed that, of the hemodialysis patients with MS, 45% had osteoporosis and 48% had osteopenia. On the other hand, of the hemodialysis patients without MS, 42% had osteoporosis and 52% had osteopenia. Low BMD values were observed to be correlated negatively with age, hemodialysis period, and parathormone (PTH) both in the group with MS and in the group without MS. Height, weight, BMI, calcium, phosphorus, alkaline phosphatase, heparin, and vitamin D therapy and urea reduction ratio were not established to be correlated with BMD.

Adverse effects of bisphosphonates

Use of bisphosphonates has been growing steadily in the last decade. This follows the introduction of simpler dosing regimes, the availability of lower-priced generics, and concerns about the safety of hormone-replacement therapy. Bisphosphonates have a relatively good safety record and are tolerated by the majority of patients, but serious adverse events have been recorded in some cases. Only the most common of adverse effects are robustly observable in clinical trials. In general, studies were not powered to detect effects that were lower in incidence than fractures. This review of adverse events in bisphosphonate-treated patients was based on published information from case reports, case series, claims databases, national databases, surveys, adverse event reporting databases, and single or pooled clinical trials. The most common acute adverse events with bisphosphonates for osteoporosis are gastrointestinal discomfort and acute influenza-like illness. Renal complications are very rare with oral bisphosphonates and rare with i.v. bisphosphonates when used appropriately. Based on our current knowledge, skeletal events in the form of osteonecrosis of the jaw and atypical fragility fractures are rare compared with the risk of osteoporotic fractures, at least in patients with the same risk of fractures as those in the phase III trials. It is biologically plausible that atypical fragility fractures could follow from suppression of bone remodeling, but high-quality studies proving causality are lacking. Physicians are advised to critically reassess BMD and risk profile after 3-5 years of therapy to avoid treatment in patients at low risk.

Bisphosphonates for the treatment of osteoporosis: insights for clinicians

Osteoporosis is a common skeletal disease characterized by a reduction in bone strength and increased risk of fractures. Osteoporotic fractures are associated with substantial morbidity, mortality, and high healthcare costs. Treatments for osteoporosis have been shown to increase bone strength and reduce fracture risk. The drugs most commonly used to treat osteoporosis are bisphosphonates: stable analogs of naturally occurring inorganic pyrophosphate. The bisphosphonates share a common chemical structure with side chain variations that convey differences in their pharmacological properties, such as affinity for bone mineral and inhibitory effect on osteoclastic bone resorption. The clinical profiles of bisphosphonates, such as time of onset and offset of effect, may differ according to these pharmacological properties. Bisphosphonates can be administered orally or intravenously with a wide range of doses and dosing intervals. Randomized placebo-controlled clinical trials have shown that bisphosphonates reduce fracture risk in postmenopausal women with osteoporosis and have a generally excellent safety record. Clinical challenges in using bisphosphonates to treat osteoporosis include appropriate selection of patients for initiating therapy, choosing which bisphosphonate to use, monitoring therapy to assure that medication is taken correctly and the desired effect is achieved, determining when drug discontinuation should be considered, and managing side effects, possible side effects, and fear of side effects. Strategies for treating patients with bisphosphonates should consider each of these issues.

Femoral bone mineral density reflects histologically determined cortical bone volume in hemodialysis patients

We evaluated the associations between dual energy X-ray absorptiometry (DXA) and histologically determined cancellous and cortical bone volume by controlling for vascular calcifications and demographic variables in hemodialysis (HD) patients. Femoral bone mineral density (f-BMD) was associated with cortical porosity.

INTRODUCTION

Assessment of bone mass in chronic kidney disease patients is of clinical importance because of the association between low bone volume, fractures, and vascular calcifications. DXA is used for noninvasive assessment of bone mass whereby vertebral results reflect mainly cancellous bone and femoral results reflect mainly cortical bone. Bone histology allows direct measurements of cancellous and cortical bone volume. The present study evaluates the association between DXA and histologically determined cancellous and cortical bone volumes in HD patients.

METHODS

In 38 HD patients, DXA was performed for assessment of bone mass, anterior iliac crest bone biopsies for bone volume, and multislice computed tomography for vascular calcifications.

RESULTS

While lumbar bone mineral density (l-BMD) by DXA was not associated with histologically measured cancellous bone volume, coronary Agatson score showed a borderline statistically significant association (P = 0.055). When controlled for age and dialysis duration, f-BMD by DXA was associated with cortical porosity determined by histology (P = 0.005).

CONCLUSIONS

The usefulness of l-BMD for predicting bone volume is limited most probably because of interference by soft tissue calcifications. In contrast, f-BMD shows significant association with cortical porosity.

Long-term use of bisphosphonates in osteoporosis

CONTEXT

Bisphosphonates have been widely used in the treatment of osteoporosis. Uncommon side effects have emerged in postapproval use. Because bisphosphonates accumulate in bone and are released for months or years after treatment is stopped, it is reasonable to consider the clinical question of how long to treat.

OBJECTIVE

In this personal perspective, we review the pharmacology and mechanism of action of bisphosphonates and the clinical studies that support their efficacy. We then review the literature for longer-term studies and reports of possible side effects that were not seen in clinical trials.

RESULTS

Bisphosphonates have demonstrated antifracture efficacy in randomized, placebo-controlled trials of 3 and 4 yr duration and have been widely used since the initial release of alendronate in 1995. For zoledronic acid and risedronate, an early effect (fractures reduced within 6-12 months of starting therapy) has been shown. A sustained effect for risedronate has been shown through 5 yr and suggested through 7 yr. Ten-year data with alendronate and 8 yr data with risedronate indicated good tolerability and safety; it is unlikely that longer-term studies will be done. Side effects that emerged in clinical trials include esophageal irritation with oral administration and acute phase response with iv treatment or high-dose oral therapy. Uncommon side effects that have been noted with wide clinical use include osteonecrosis of the jaw, musculoskeletal complaints, and atypical fractures. The numbers of events are small, and a clear cause-and-effect relationship between these events and bisphosphonate treatment has not been established. Because bisphosphonates accumulate in bone, they create a reservoir leading to continued release from bone for months or years after treatment is stopped. Studies with risedronate and alendronate suggest that if treatment is stopped after 3-5 yr, there is persisting antifracture efficacy, at least for 1-2 yr.

CONCLUSIONS

Bisphosphonates are popular and effective for treatment of osteoporosis. Because they accumulate in bone and provide some residual antifracture reduction when treatment is stopped, we recommend a drug holiday after 5-10 yr of bisphosphonate treatment. The duration of treatment and length of the holiday are based on fracture risk and pharmacokinetics of the bisphosphonate used. Patients at mild risk might stop treatment after 5 yr and remain off as long as bone mineral density is stable and no fractures occur. Higher risk patients should be treated for 10 yr, have a holiday of no more than a year or two, and perhaps be on a nonbisphosphonate treatment during that time.

Approach to the patient with transplantation-related bone loss

Transplantation is an established therapy for end-stage diseases of the kidney, endocrine pancreas, heart, liver, lung, intestines and for many hematological disorders. Current immunosuppressive regimens with glucocorticoids and calcineurin inhibitors produce excellent patient and graft survival rates. This has resulted in both increases in transplant numbers and an increased recognition of previously neglected long-term complications of transplantation such as fractures and osteoporosis. Both pretransplantation bone disease and immunosuppressive therapy result in rapid bone loss and increased fracture rates. Patients are particularly at risk early after transplantation. The bone health of candidates for organ transplantation should be assessed with bone densitometry of the hip and spine. Spinal x-rays should be performed to diagnose prevalent fractures. Any secondary causes of osteoporosis should be identified and treated. Vitamin D deficiency should be corrected with vitamin D doses selected to achieve a serum 25-hydroxyvitamin D concentration of at least 20 ng/ml. All patients should receive calcium. Patients with kidney failure should be evaluated and treated for chronic kidney disease-mineral and bone disorder, including renal osteodystrophy. Secondary hyperparathyroidism, in particular, should be treated. Treatment is indicated in the immediate posttransplantation period irrespective of bone mineral density because further rapid bone loss will occur in the first several months after transplantation. Long-term organ transplant recipients should also have bone mass measurement and treatment of osteoporosis. Oral and iv bisphosphonates are the most promising approach for the management of transplantation osteoporosis. Active vitamin D metabolites may have additional benefits in reducing hyperparathyroidism, particularly after kidney transplantation.

Bisphosphonates in chronic kidney disease; balancing potential benefits and adverse effects on bone and soft tissue

Cardiovascular disease is highly prevalent in chronic kidney disease (CKD) and is often associated with increased vascular stiffness and calcification. Recent studies have suggested a complex interaction between vascular calcification and abnormalities of bone and mineral metabolism, with an inverse relationship between arterial calcification and bone mineral density (BMD). Although osteoporosis is recognized and treated in CKD 1 to 3, the interpretation of BMD levels in the osteoporotic range is controversial in CKD 4, 5, and 5D when renal osteodystrophy is generally present. In addition, there is a paucity of data for patients with CKD mineral and bone disorder (MBD), because studies using bisphosphonates in postmenopausal and glucocorticoid-induced osteoporosis have generally excluded patients with significant CKD. For these patients, treatment of low BMD using standard therapies for osteoporosis is not without potential for harm due to the possibility of worsening low bone turnover, osteomalacia, mixed uraemic osteodystrophy, and of exacerbated hyperparathyroidism; and bisphosphonates should only be used selectively and with caution. Some experimental and clinical studies have also suggested that bisphosphonates may reduce progression of extra-osseous calcification and inhibit the development of atherosclerosis. The authors review the potential benefits and risks associated with bisphosphonate use for bone protection in CKD, and assess their effect on vascular calcification and atherosclerosis.

The role of bone biopsy in patients with chronic renal failure

Renal bone disease is a heterogeneous group of metabolic bone diseases that requires quantitative bone histomorphometry to make the correct differential diagnosis. Included in this group is osteoporosis. However, osteoporosis in stage 4 to 5 chronic kidney disease cannot be diagnosed on the basis of bone mineral density criteria established by the World Health Organization or the presence of fragility fractures because patients with all forms of renal bone disease can demonstrate low bone mineral density and fragility fractures. Clinical cases in patients with either low bone mineral density and/or low-trauma fractures will be used to demonstrate the value of bone biopsy and quantitative histomorphometry in making a diagnosis of the specific renal bone disease and assisting with subsequent management decisions.

Anti-resorptives in the management of osteoporosis

Bone-active agents that decrease bone turnover (the anti-resorptive agents) have been, to date, the most thoroughly studied pharmacological agents for the management of osteoporosis in a variety of populations - postmenopausal, male, and glucocorticoid-induced osteoporosis - and have received both Food and Drug Administration (FDA) and Committee for Medicinal Products for Human Use (CHMP) as well as other worldwide registrations for the management of these conditions. While the mechanisms of action of 'anti-resorptives' as a class differ, their effect on increasing bone strength and reducing the risk of fragility fractures share common pathways: an increase in bone mineral content, and a reduction in bone turnover. Within the category of anti-resorptives: estrogen, selective estrogen receptor modulators, tibolone, calcitonin, bisphosphonates and denosumab all reduce vertebral fractures risk, but differ in their ability to reduce the risk of non-vertebral fractures in randomized clinical trials. This chapter will discuss the data on these effects for each class of anti-resorptive agent.

The effect of raloxifene treatment in postmenopausal women with CKD

It is unknown whether treatment for osteoporosis with raloxifene is safe or effective in those with chronic kidney disease (CKD). With data from a multicenter, randomized, placebo-controlled trial of 7705 postmenopausal women with osteoporosis, the effect of raloxifene on rate of change of bone mineral density (BMD), incidence of fractures, and adverse events by stage of CKD was examined over 3 yr. Baseline serum creatinine values were available for 7316 women, and these values were used to assign a category of creatinine clearance (CrCl) using the Cockcroft-Gault formula (CrCl < 45, 45 to 59, and > or = 60 ml/min). BMD was measured at baseline and annually by dual x-ray absorptiometry. Within the placebo group, lower baseline CrCl was associated with a trend for higher annual losses of BMD at the femoral neck; however, within the raloxifene group, lower baseline CrCl was associated with greater increases in femoral neck BMD. This interaction between category of CrCl and treatment assignment was significant for rate of change of BMD at the hip. Irrespective of kidney function, raloxifene treatment was associated with a greater increase in spine BMD, a reduction in vertebral fractures, and no effect on nonvertebral fractures compared with placebo. Within each category of kidney function, adverse events were similar between the raloxifene and placebo groups. In conclusion, raloxifene increases BMD at both the hip and the spine and reduces the risk for vertebral fractures among individuals with CKD. The effect ofraloxifene on hip BMD is greater among those with mild to moderate CKD.

Renal safety of intravenous bisphosphonates in the treatment of osteoporosis

Oral bisphosphonates are the mainstay of treatment for osteoporosis but cannot be used in some patients due to gastrointestinal contraindications, gastrointestinal intolerance, malabsorption or the inability to comply with dosing requirements. In such patients, intravenous bisphosphonates are a useful alternative. This review summarises the renal safety issues associated with the use of intravenous bisphosphonates for osteoporosis. Intravenous bisphosphonates are generally well tolerated, which may be a reflection of their selective activity in bone and metabolic stability. Adverse effects on renal function are primarily related to infusion rate and dose. Due to lack of data, no conclusions can be made regarding bisphosphonate safety in patients with intrinsic renal disease or an estimated glomerular filtration rate of < 30 ml/min.

Osteoporosis and chronic kidney disease

Osteoporosis (OP), the most frequent bone disease affecting the general population, is associated with high fracture risk. Patients with impaired kidney function have bone and mineral disturbances leading to extraskeletal calcifications and complex changes in bone turnover that predispose them to increased fracture risk accompanied by increased morbidity and mortality. The combination of these two bone disorders seems to have an additive effect with regard to fracture risk and its outcome, so that appropriate diagnosis and treatment of this disorder should be of primary concern when approaching patients with kidney disease. Nevertheless, the clinical and laboratory diagnostic tools used to identify OP in the general population do not suit the requirement for detecting the complex bone and metabolic changes that occur with chronic kidney disease, leading to the lack of or the initiation of inappropriate therapy. This review will focus on the bone pathophysiologic processes involved in OP and renal osteodystrophy and address some of the problems associated with our current diagnostic tools and aspects of the therapeutic approaches.

Is there a role for bisphosphonates in chronic kidney disease?

Patients with stage 5 chronic kidney disease (CKD) including those on dialysis can and do develop osteoporosis. They also develop a wide range of other metabolic bone diseases that may look like osteoporosis when it is defined by either the World Health Organization bone mineral density (BMD) criteria or by the development of fragility fractures. Those dialysis patients with osteoporosis that is due to gonadal hormone deficiency such as postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, or male osteoporosis may benefit from the administration of bisphosphonates (BPs). The challenges lie in the diagnosis of osteoporosis in this population where adynamic, osteomalacic, hyperparathyroid, or aluminum bone disease are also prevalent, with concommitant low BMD and low trauma fractures, but where BPs may be contraindicated. The only secure means to diagnose osteoporosis in this patient population is by quantitative bone histomorphometry demonstrating low trabecular bone volume and disrupted microarchitecture. Once the diagnosis of osteoporosis is established, BPs should be considered for a well-defined brief period of time (e.g., 2-3 years), even though there is no evidence for a fracture reduction benefit in this population. If a BP is chosen there may be a need for dose adjustment or slower infusion rates (for the intravenous formulations), as a greater bone retention may occur for these renally cleared agents. While it is unknown what consequences could develop from increased bone retention in patients with little renal function, data are needed if more bone retention of BP might lead to a greater risk of the development of adynamic bone disease and lower bone strength. More data are needed to define the risks and benefits of BPs in patients with stage 5 CKD.

Renal Function and Periodontal Disease in Elderly Japanese

BACKGROUND

Chronic renal failure involves a slow, progressive loss of renal function over months or years. It is possible that periodontal disease and chronic kidney disease might share common risk factors. This study investigated whether a link exists between periodontal disease and chronic renal function in community-dwelling elderly subjects.

METHODS

A total of 145 study subjects, all 77 years of age, participated in this study. A periodontal examination was carried out by trained dentists. Urine was collected over 24 hours, and blood was taken on the morning of the dental exam. The volume of creatinine per 24 hours (Cre_U) and volume of urine per 24 hours were used as urinary markers of kidney function; serum creatinine levels (Cre_S) were used as a blood marker of kidney function. Creatinine clearance per 24 hours was calculated as Cre_U/Cre_S. In addition, biochemical parameters of bone turnover were measured: urinary deoxypyridinoline (U-DPD) as a bone resorption marker and serum osteocalcin (S-OC) as a bone formation marker. Multiple regression analysis was used to evaluate the relationship between the percentage of periodontal sites with > or =6-mm clinical attachment level (% > or =6-mm CAL) and renal function, as well as the relationship between % > or =6-mm CAL and bone metabolism. The % > or =6-mm CAL was used as the dependent variable. The number of remaining teeth, smoking habit, gender, use of interdental brushes or dental floss, volume of urine per 24 hours, and creatinine clearance per 24 hours were independent variables in the first test. In addition, the number of remaining teeth, smoking habits, gender, use of interdental brushes or dental floss, U-DPD, and S-OC were independent variables in the second test.

RESULTS

Multiple regression analysis showed that creatinine clearance per 24 hours and S-OC were significantly associated with % > or =6-mm CAL per person. The standardized coefficients were 0.26 (P = 0.015) and -0.27 (P = 0.006), respectively.

CONCLUSIONS

The % > or =6-mm CAL was significantly associated with renal function and bone metabolism markers. This study suggests that the increased incidence of chronic renal failure that occurs with age might increase the probability of severe periodontal disease in community-dwelling elderly subjects.