RETRACTED: Kidney Function and Rate of Bone Loss at the Hip and Spine: The Canadian Multicentre Osteoporosis Study

Osteoporosis management in patients with chronic kidney disease (ERCOS Study): A challenge in nephrological care

Fracture risk assessment in patients with chronic kidney disease (CKD) has been included in the CKD-MBD ("Chronic Kidney Disease-Mineral and Bone Disorders") complex in international and national nephrology guidelines, suggesting for the first time the assessment of bone mineral density (BMD) if the results can influence therapeutic decision-making. However, there is very little information on actual clinical practice in this population. The main objective of the ERCOS (ERC-Osteoporosis) study is to describe the profile of patients with CKD G3-5D with osteoporosis (OP) and/or fragility fractures treated in specialized nephrology, rheumatology and internal medicine clinics in Spain. Fifteen centers participated and 162 patients (mostly women [71.2%] postmenopausal [98.3%]) with a median age of 77 years were included. Mean estimated glomerular filtration rate (eGFR) was 36 mL/min/1.73 m2 and 38% of the included patients were on dialysis. We highlight the high frequency of prevalent fragility fractures [37.7%), mainly vertebral (52.5%) and hip (24.6%)], the disproportionate history of patients with glomerular disease compared to purely nephrological series (corticosteroids) and undertreatment for fracture prevention, especially in nephrology consultations. This study is an immediate call to action with the dissemination of the new, more proactive, clinical guidelines, and underlines the need to standardize a coordinated and multidisciplinary care/therapeutic approach to these patients in an efficient way to avoid current discrepancies and therapeutic nihilism.

Efficacy and safety of medications for osteoporosis in kidney transplant recipients or patients with chronic kidney disease: A meta-analysis

This study conducted a meta-analysis to analyze the efficacy and safety of osteoporosis medications in kidney transplant recipients and patients with chronic kidney disease (CKD). PubMed, Embase, the Cochrane Central Register of Controlled Trials were searched from the date of their inception through October 21, 2022. We performed a meta-analysis of the efficacy and safety of osteoporosis medications in adult patients with stage 3-5 CKD or kidney transplant recipients enrolled in randomized clinical trials (RCTs). We calculated the standard mean deviations with 95% confidence intervals (CI) for bone mineral density (BMD) and T scores after 6 and 12 months treatment, pooled odds ratio and 95% CI for fracture risk, and summarized adverse events. The inclusion criteria were met by 27 studies. Out of this, 19 studies were included for the meta-analysis. In stage 3-4 CKD patients, alendronate increased lumbar spine BMD. In patients at stage 5 CKD and undergoing hemodialysis, alendronate and raloxifene increased lumbar spine BMD. After 6 months, the BMD of kidney transplant recipients was seen to be significantly increased; however, there was no difference after 12 months, and the risk of fracture did not reduce. Thus, there is no evidence that these medications reduce the risk of fracture, and their effect on BMD and fracture remains unproven. These medications may increase the incidence of adverse events and their safety needs to be further evaluated. Therefore, we cannot draw a definitive conclusion about the efficacy and safety of osteoporosis medications in the above group of patients.

Association of age-related declined renal function and osteoporosis based on trabecular bone score in Bushehr Elderly Health (BEH) program

PURPOSE

Osteoporosis is a systemic disease characterized by decreased bone strength and an increased risk of fracture in old age. Age and pathologic renal failure are independent risk factors for osteoporosis. However, it is not determined whether age-related decreased renal function, in the context of senescence, can be considered as an independent risk factor for osteoporosis. Therefore, this study was conducted to evaluate the effect of senescence-induced renal failure on bone quality and trabecular bone score.

METHODS

This study used a cross-sectional design and was carried out based on data collected during the Bushehr Elderly Health (BEH) program, Phase II. A total of 2,125 elderly participants aged over 60 years old entered the study after meeting the inclusion criteria and providing informed consent. They underwent examinations for weight, height, abdominal and hip circumference, as well as blood pressure measurement. All participants also underwent DXA to assess bone mass density (BMD). Trabecular bone score (TBS) was calculated using the DXA apparatus software output. Univariate and adjusted multivariate linear regression analyses were used to evaluate the associations.

RESULTS

In the univariate linear regression analysis, there was a direct correlation between age-related renal failure and TBS (β = 0.038, p < 0.0001), neck of femur BMD (β = 0.047, p < 0.0001), and lumbar BMD (β = 0.055, p < 0.0001). However, after adjusting for BMI, age, sex, smoking, and physical activity, no significant association was observed for these variables.

CONCLUSION

It is hypothesized that age-related renal failure cannot be considered as an independent risk factor for osteoporosis in elderly individuals aged over 60 years old.

Bisphosphonates to reduce bone fractures in stage 3B+ chronic kidney disease: a propensity score-matched cohort study

BACKGROUND

Bisphosphonates are contraindicated in patients with stage 4+ chronic kidney disease. However, they are widely used to prevent fragility fractures in stage 3 chronic kidney disease, despite a lack of good-quality data on their effects.

OBJECTIVES

The aims of each work package were as follows. Work package 1: to study the relationship between bisphosphonate use and chronic kidney disease progression. Work package 2: to study the association between using bisphosphonates and fracture risk. Work package 3: to determine the risks of hypocalcaemia, hypophosphataemia, acute kidney injury and upper gastrointestinal events associated with using bisphosphonates. Work package 4: to investigate the association between using bisphosphonates and changes in bone mineral density over time.

DESIGN

This was a new-user cohort study design with propensity score matching.

SETTING AND DATA SOURCES

Data were obtained from UK NHS primary care (Clinical Practice Research Datalink GOLD database) and linked hospital inpatient records (Hospital Episode Statistics) for work packages 1-3 and from the Danish Odense University Hospital Databases for work package 4.

PARTICIPANTS

Patients registered in the data sources who had at least one measurement of estimated glomerular filtration rate of < 45 ml/minute/1.73 m2 were eligible. A second estimated glomerular filtration rate value of < 45 ml/minute/1.73 m2 within 1 year after the first was requested for work packages 1 and 3. Patients with no Hospital Episode Statistics linkage were excluded from work packages 1-3. Patients with < 1 year of run-in data before index estimated glomerular filtration rate and previous users of anti-osteoporosis medications were excluded from work packages 1-4.

INTERVENTIONS/EXPOSURE

Bisphosphonate use, identified from primary care prescriptions (for work packages 1-3) or pharmacy dispensations (for work package 4), was the main exposure.

MAIN OUTCOME MEASURES

Work package 1: chronic kidney disease progression, defined as stage worsening or starting renal replacement. Work package 2: hip fracture. Work package 3: acute kidney injury, hypocalcaemia and hypophosphataemia identified from Hospital Episode Statistics, and gastrointestinal events identified from Clinical Practice Research Datalink or Hospital Episode Statistics. Work package 4: annualised femoral neck bone mineral density percentage change.

RESULTS

Bisphosphonate use was associated with an excess risk of chronic kidney disease progression (subdistribution hazard ratio 1.12, 95% confidence interval 1.02 to 1.24) in work package 1, but did not increase the probability of other safety outcomes in work package 3. The results from work package 2 suggested that bisphosphonate use increased fracture risk (hazard ratio 1.25, 95% confidence interval 1.13 to 1.39) for hip fractures, but sensitivity analyses suggested that this was related to unresolved confounding. Conversely, work package 4 suggested that bisphosphonates improved bone mineral density, with an average 2.65% (95% confidence interval 1.32% to 3.99%) greater gain in femoral neck bone mineral density per year in bisphosphonate users than in matched non-users.

LIMITATIONS

Confounding by indication was a concern for the clinical effectiveness (i.e. work package 2) data. Bias analyses suggested that these findings were due to inappropriate adjustment for pre-treatment risk. work packages 3 and 4 were based on small numbers of events and participants, respectively.

CONCLUSIONS

Bisphosphonates were associated with a 12% excess risk of chronic kidney disease progression in participants with stage 3B+ chronic kidney disease. No other safety concerns were identified. Bisphosphonate therapy increased bone mineral density, but the research team failed to demonstrate antifracture effectiveness.

FUTURE WORK

Randomised controlled trial data are needed to demonstrate antifracture efficacy in patients with stage 3B+ chronic kidney disease. More safety analyses are needed to characterise the renal toxicity of bisphosphonates in stage 3A chronic kidney disease, possibly using observational data.

STUDY REGISTRATION

This study is registered as EUPAS10029.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 17. See the NIHR Journals Library website for further project information. The project was also supported by the National Institute for Health Research Biomedical Research Centre, Oxford.

Hypocalcemia and bone mineral changes in hemodialysis patients with low bone mass treated with denosumab: a 2-year observational study

BACKGROUND

Increases in bone mineral density (BMD) following a single dose of denosumab and increased incidence of denosumab-associated acute hypocalcemia (DAAH) have been reported in chronic kidney disease (CKD) patients. Little is known about clinical risk factors related to DAAH and the long-term effect of denosumab on BMD in hemodialysis patients.

METHODS

An observational non-controlled study involving 47 hemodialysis patients was conducted to determine the independent risk factors related to percent changes in serum Ca levels associated with denosumab using multivariate regression analysis. Optimal predictive markers for DAAH were explored by receiver operating characteristic (ROC) analysis. Percent changes of BMD at the lumbar spine (LS) and femoral neck (FN) over 24 months were investigated.

RESULTS

The incidence of DAAH (serum corrected Ca (cCa) ≤ 8 mg/dL) following denosumab was 25.5%. Multivariate regression analysis showed baseline bone alkaline phosphatase (BAP) was independently related to percent changes in cCa levels (β = -0.407, P = 0.008). Tartrate-resistant acid phosphatase (TRACP-5b) was found to be the most accurate marker to predict DAAH with AUC of 0.750 (95% CI; 0.546-0.954, P = 0.02) and the optimal cut-off level was 670 mU/mL with sensitivity; 0.727 and specificity; 0.733. BMD significantly increased by 5.9 ± 1.7% (P = 0.01) at LS and 4.2 ± 1.5% (P = 0.04) at FN at 24 months.

CONCLUSION

In hemodialysis patients, high bone turnover was an independent risk factor for the Ca declines induced by denosumab. Denosumab significantly increased BMD at LS and FN over 24 months.

Correlation of Fgf23 and Balp with Bone Mineral Density in Hemodialysis Patients

Background

Chronic kidney disease (CKD) is associated with numerous complications such as bone mineral disorder. The aim of our study was to analyze the correlation of bone turnover markers with Bone Mineral Density (BMD) measurements in Tunisian end stage renal diseases (ESRD) patients.

Methods

This study included 100 ESRD Tunisian patients. Their estimated glomerular filtration rate (eGFR) was < 15 mL × min^-1 × (1.73 m²)^-1, which requires hemodialysis. Bone-specific alkaline phosphatase (BALP) serum concentration was determined with a chemiluminescence immunoassay. Fibroblast Growth Factor 23 (FGF23) serum was assessed by Enzyme-Linked Immunosorbent Assay method. The serum levels of 25-Hydroxyvitamin D (25(OH)D), intact parathyroid hormone (iPTH) and Beta cross-laps (CTX) was measured by Electrochemiluminescence Technology. DEXA (dual-energy x-ray absorptiometry) technique was used to evaluate BMD.

Results

We observed a statistically significant negative correlation between BALP levels and total body BMD (r = -0.268; P = 0.015) particularly in femoral neck (FN) (r = -0.219; P = 0.037). BALP concentrations were negatively associated with total BMD especially in FN for patients with BMI < 30, FGF23 concentrations were also negatively correlated with BMD in lumbar spine site (LS) (r = -0.209; P = 0.046). For osteopenic patients we found an inverse correlation between 25(OH)D concentrations and BMD in LS position (r = -0.336; P = 0.038). In men group, we have also found a negative correlation between iPTH and total BMD (r = -0.326; P = 0.015). However we found a positive correlation between calcium expression and BMD in LS site (r = 0.270; P = 0.031).

Conclusions

FGF23 and BALP can predict bone loss in ESRD through their strong correlation with BMD in LS and FN sites respectively.

Albuminuria and low bone mineral density in paediatric patients with type 1 diabetes

AIM

To evaluate glycaemic control and its influence on albuminuria and bone mineral density (BMD) in children and adolescents with type 1 diabetes (T1D).

METHODS

We collectively assessed 84 T1D children/adolescents (T1D group), aged between 6 and 17 years, and then divided them into two groups according to their glycaemic profile (T1D with good glycaemic control (T1DG group) and T1D with poor glycaemic control (T1DP group)). Serum glucose, glycated haemoglobin, serum urea, serum creatinine, urinary albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate and BMD levels were assessed.

RESULTS

Of the patients studied, 77% presented with poor glycaemic control. Patients with T1DP showed an increased ACR (P < 0.001) and a low BMD (P = 0.025) when compared to the T1DG group. In addition, five patients in the T1DP group presented with concomitant albuminuria and a low BMD for their chronological age. Significant negative correlations were identified between the ACR and glycated haemoglobin (r = 0.655, P < 0.001), BMD and glycated haemoglobin (r = -0.262, P = 0.047) and BMD and the ACR (r = -0.631, P = <0.001). In linear regression analysis, the ACR showed a negative effect on BMD (P = 0.044) in the T1D patient group.

CONCLUSION

Poor glycaemic control was correlated with albuminuria, suggestive of a negative effect on bone tissue, leading to a low BMD in children and adolescents with T1D.

Osteoporosis, bone mineral density and CKD-MBD complex (I): Diagnostic considerations

Osteoporosis (OP) and chronic kidney disease (CKD) independently influence bone and cardiovascular health. A considerable number of patients with CKD, especially those with stages 3a to 5D, have a significantly reduced bone mineral density leading to a high risk of fracture and a significant increase in associated morbidity and mortality. Independently of classic OP related to age and/or gender, the mechanical properties of bone are also affected by inherent risk factors for CKD ("uraemic OP"). In the first part of this review, we will analyse the general concepts regarding bone mineral density, OP and fractures, which have been largely undervalued until now by nephrologists due to the lack of evidence and diagnostic difficulties in the context of CKD. It has now been proven that a reduced bone mineral density is highly predictive of fracture risk in CKD patients, although it does not allow a distinction to be made between the causes which generate it (hyperparathyroidism, adynamic bone disease and/or senile osteoporosis, etc.). Therefore, in the second part, we will analyse the therapeutic indications in different CKD stages. In any case, the individual assessment of factors which represent a higher or lower risk of fracture, the quantification of this risk (i.e. using tools such as FRAX^®) and the potential indications for densitometry in patients with CKD could represent an important first step pending new clinical guidelines based on randomised studies which do not exclude CKD patients, all the while avoiding therapeutic nihilism in an area of growing importance.

Combination Therapy of Denosumab and Calcitriol for a Renal Transplant Recipient with Severe Bone Loss due to Therapy-Resistant Hyperparathyroidism

Denosumab (DMAb), a complete human type monoclonal antibody directed against the receptor activator of nuclear factor-κB ligand, has gained attention as a novel treatment for osteoporosis. However, its efficacy in patients with chronic kidney disease (CKD) remains unclear. We describe a 64-year-old man with severe bone loss and persistent secondary hyperparathyroidism (SHPT) after renal transplantation, whose condition failed to respond to conventional pharmacologic or surgical interventions. He underwent parathyroidectomy with left forearm autograft of crushed tiny parathyroid gland (PTG) particles. However, the autografted PTGs became swollen and caused persistent SHPT in spite of two additional parathyroidectomies of the left forearm. A single subcutaneous administration of DMAb induced hypocalcemia, which was corrected by calcium supplementation and high-dose calcitriol. Eventually, combination therapy with DMAb and calcitriol led to a decline in the patient's elevated serum parathyroid hormone levels, normalization of laboratory markers of bone metabolism, and improvement in bone mineral density in a short period of time. To the best of our knowledge, this is the first case report of severe bone loss with persistent SHPT in a renal transplant recipient effectively treated with the combination therapy of DMAb and vitamin D (VD). Although DMAb itself exerts no direct effects on PTGs, the DMAb treatment improved the patient's bone loss. In addition, administration of DMAb allowed for high-dose VD therapy which ultimately controlled SHPT and prevented DMAb-induced hypocalcemia. Therefore, this combination therapy might be a reasonable therapeutic strategy to reverse severe bone loss due to therapy-resistant SHPT in patients with CKD.

Association of Increased Urinary Albumin With Risk of Incident Clinical Fracture and Rate of Hip Bone Loss: the Osteoporotic Fractures in Men Study

Prior studies suggest that increased urine albumin is associated with a heightened fracture risk in women, but results in men are unclear. We used data from Osteoporotic Fractures in Men (MrOS), a prospective cohort study of community-dwelling men aged ≥65 years, to evaluate the association of increased urine albumin with subsequent fractures and annualized rate of hip bone loss. We calculated albumin/creatinine ratio (ACR) from urine collected at the 2003-2005 visit. Subsequent clinical fractures were ascertained from triannual questionnaires and centrally adjudicated by review of radiographic reports. Total hip BMD was measured by DXA at the 2003-2005 visit and again an average of 3.5 years later. We estimated risk of incident clinical fracture using Cox proportional hazards models, and annualized BMD change using ANCOVA. Of 2982 men with calculable ACR, 9.4% had ACR ≥30 mg/g (albuminuria) and 1.0% had ACR ≥300 mg/g (macroalbuminuria). During a mean of 8.7 years of follow-up, 20.0% of men had an incident clinical fracture. In multivariate-adjusted models, neither higher ACR quintile (p for trend 0.75) nor albuminuria (HR versus no albuminuria, 0.89; 95% CI, 0.65 to 1.20) was associated with increased risk of incident clinical fracture. Increased urine albumin had a borderline significant, multivariate-adjusted, positive association with rate of total hip bone loss when modeled in ACR quintiles (p = 0.06), but not when modeled as albuminuria versus no albuminuria. Macroalbuminuria was associated with a higher rate of annualized hip bone loss compared to no albuminuria (-1.8% more annualized loss than in men with ACR <30 mg/g; p < 0.001), but the limited prevalence of macroalbuminuria precluded reliable estimates of its fracture associations. In these community-dwelling older men, we found no association between urine albumin levels and risk of incident clinical fracture, but found a borderline significant, positive association with rate of hip bone loss. © 2016 American Society for Bone and Mineral Research.

Evaluation of fracture risk in chronic kidney disease

Chronic kidney disease (CKD) is associated with mineral and bone disorders (MBD) that are now considered as a syndrome. Bone fragility and a four to tenfold increased rate of skeletal fractures are often reported in CKD patients. The evaluation of the risk of these fractures in CKD patients should explore the same risk factors identified for the general population including low body weight, menopause, personal and familial history of osteoporosis, chronic inflammatory diseases, and corticosteroid therapy. The aim of this article is to provide a critical review of the tools used for the evaluation of bone loss and the risk of fracture in CKD patients, ranging from the measurement of bone mineral density (BMD), fracture risk assessment (Frax™), quantitative computed tomography (QCT), high-resolution peripheral quantitative computed tomography (HRpQTC), to circulating biomarkers of bone metabolism including vitamin D, parathyroid hormone (PTH), bone-specific alkaline phosphatase, osteocalcin, and some collagen type 1-related molecules indicators of bone remodeling.

A novel quantitative approach to the measurement of abdominal aortic calcification as applied to the Canadian Multicenter Osteoporosis Study (CaMOS)

BACKGROUND AND AIMS

Lateral spine radiographs provide an inexpensive resource for characterizing abdominal aortic calcification (AAC). A widely accepted measurement of AAC is the semi-quantitative technique generated by the Framingham Heart Study (F-AAC-24). We sought to develop an analytical method to quantify ACC (Q_AAC) on lateral spine radiographs and compare the finding to conventional subjective measurements.

METHODS

Severity of AAC was quantified by measuring pixel intensities in the user-defined region of the aorta with internal standardization to the vertebral endplates and background calibration to the density of the vertebral body. The association between bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA) and AAC measured by Q_AAC, F-AAC-24 and a modified Framingham score (F-AAC-12) was determined in 110 participants of the Canadian Multicenter Osteoporosis Study (CaMOS).

RESULTS

The inter-observer reliability for the Q_AAC was slightly higher than with the visual and semi-quantitative Framingham method and the pseudo-colored images illustrate the potential to meaningfully resolve severity of calcification. There was a significant negative association between Q_AAC and BMD measures of the hip and spine. This association remained significant after adjustment for age, sex, estimated glomerular filtration rate, phosphate and hypertension. Significant predictors of F-ACC-12 and 24 included age and hypertension.

CONCLUSIONS

The Q_AAC is a reproducible approach to measuring AAC. Whether it is capable of monitoring subtle calcific changes over time requires further study. This technique could be applied to large studies that seek to determine the impact of interventions that modify bone density as a treatment for vascular calcification and cardiovascular disease in the general population.

Changing bone patterns with progression of chronic kidney disease

It is commonly held that osteitis fibrosa and mixed uremic osteodystrophy are the predominant forms of renal osteodystrophy in patients with chronic kidney disease. Osteitis fibrosa is a high-turnover bone disease resulting mainly from secondary hyperparathyroidism, and mixed uremic osteodystrophy is in addition characterized by a mineralization defect most often attributed to vitamin D deficiency. However, there is ancient and more recent evidence that in early chronic kidney disease stages adynamic bone disease characterized by low bone turnover occurs first, at least in a significant proportion of patients. This could be due to the initial predominance of bone turnover-inhibitory conditions such as resistance to the action of parathyroid hormone (PTH), reduced calcitriol levels, sex hormone deficiency, diabetes, and, last but not least, uremic toxins leading to repression of osteocyte Wnt/β-catenin signaling and increased expression of Wnt antagonists such as sclerostin, Dickkopf-1, and sFRP4. The development of high-turnover bone disease would occur only later on, when serum PTH levels are able to overcome peripheral PTH resistance and the other inhibitory factors of bone formation. Whether FGF23 and Klotho play a direct role in the transition from low- to high-turnover bone disease or participate only indirectly via regulating PTH secretion remains to be seen.

Low bone mineral density in patients with type 1 diabetes: association with reduced expression of IGF1, IGF1R and TGF B 1 in peripheral blood mononuclear cells

BACKGROUND

The negative effects of type 1 diabetes (T1D) on growth factors of bone metabolism lead to a reduction in bone mineral density. This study aimed to evaluate the association between bone mineral density and insulin-like growth factor 1 (IGF1), insulin-like growth factor 1 receptor (IGF1R) and transforming growth factor beta 1 (TGFB1) expressions in children and adolescents with T1D. Moreover, the influences of age at diagnosis, time since diagnosis, glycaemic control and albuminuria on bone mineral density were investigated.

METHODS

Eighty-six T1D children/adolescents (T1D group) and ninety normoglycaemic controls (normoglycaemic group) were included. T1D patients were analysed as a whole and also in subsets of patients with good glycaemic control (glycated hemoglobin concentration ≤7.5%) and with poor glycaemic control (glycated hemoglobin concentration >7.5%). Bone mineral density was assessed by dual energy x-ray absorptiometry. Glycaemic control, renal function and bone markers were also assessed. IGF1, IGF1R and TGFB1 expressions were determined in peripheral blood mononuclear cells by real-time polymerase chain reaction.

RESULTS

Patients with T1D showed low bone mineral density and poor glycaemic control. Serum total calcium and urinary albumin-to-creatinine ratio were higher in patients with poor glycaemic control compared to those with good glycemic control (p = 0.003 and p = 0.035, respectively). There was a reduction of IGF1, IGF1R and TGFB1 expressions in the T1D patients and in the subset with poor glycaemic control compared to normoglycaemic controls (p < 0.05).

CONCLUSIONS

The decreased IGF1, IGF1R and TGFB1 expressions in the T1D patients, who presented with T1D at an early age, had been diagnosed with T1D for a longer time, had poor glycaemic control and albuminuria may contribute to low bone mineral density. Copyright © 2016 John Wiley & Sons, Ltd.

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.

Bone mineral density is associated with left ventricular diastolic function in men with type 2 diabetes

AIMS

Type 2 diabetes (T2DM) is associated with chronic heart failure and cardiomyopathy. Furthermore, low bone mineral density (BMD) predicts incident heart failure. Abnormal diastolic function reflects early changes in cardiac function and plays a key role in the development of heart failure. The purpose of this study was to investigate the association between BMD with left ventricular (LV) diastolic function in men with T2DM.

METHODS

In all, 344 men with T2DM and 331 age-matched control subjects were enrolled. BMD measurements were performed. LV diastolic function and structure were assessed by echocardiographic evaluation.

RESULTS

BMD was lower in men with T2DM than in controls. There were significant differences in the level of parameters reflecting cardiac structure and LV diastolic function between two groups. Moreover, LV diastolic function and structure parameters also showed significant differences as BMD reduced in T2DM group. BMD at femoral neck was correlated with LV diastolic function parameters in T2DM after adjusting for confounding factors. Multivariable logistic analysis revealed that osteopenia and osteoporosis were associated with diastolic dysfunction compared to the control in men with T2DM. However, no association between BMD and LV diastolic function was found in subjects without T2DM.

CONCLUSION

Osteoporosis may be an independent factor for LV diastolic dysfunction in men with T2DM. Our data suggested that early detection of abnormal BMD should warrant for early search of undetected LV diastolic dysfunction in diabetic men.

Renal Function and Bone Loss in a Cohort of Afro-Caribbean Men

Poor renal function is associated with increased rates of bone loss and osteoporotic fractures in Caucasian men. The importance of kidney function for skeletal health in African ancestry men, who are a population segment with a high prevalence of chronic kidney disease as well as high peak bone mass, is not well known. We examined the relationship between estimated glomerular filtration rate (eGFR) and rates of bone loss in a large population cohort of otherwise healthy Afro-Caribbean men aged 40 years and older. Dual X-ray absorptiometry of the proximal femur and quantitative computed tomography of the proximal radius and tibia were obtained approximately 6 years apart. We calculated eGFR from serum creatinine that was measured in fasting samples in 1451 men. Impaired kidney function (IKF, eGFR<60 ml/min/1.7 m(2)) was observed in 8.6% of the cohort. The relationship between IKF and baseline BMD and annualized rate of change in BMD was analyzed controlling for potentially important confounders. IKF was not associated with baseline BMD. In contrast, men with IKF experienced a rate of decline in areal BMD at the total hip, femoral neck and trochanter and cortical volumetric BMD compared to those with normal kidney function (p<0.05 for all). Impaired kidney function was not associated with changes in trabecular volumetric BMD. In conclusion, poorer kidney function is associated with accelerated bone loss among otherwise healthy Afro-Caribbean men even after controlling for age and other important medical and lifestyle related variables.

Bone health in type 1 diabetes: focus on evaluation and treatment in clinical practice

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune disease with chronic hyperglycemic state, which incidence has been globally rising during the past decades. Besides the well-known diabetic complications such as retinopathy, nephropathy and neuropathy, T1D is characterized also by poor bone health. The reduced bone mineralization, quality and strength lead to vertebral and hip fractures as the most important clinical manifestations. Suppressed bone turnover is the main characteristic of T1D-associated bone disorder.

RESULTS

This is thought to be due to hyperglycemia, hypoinsulinemia, autoimmune inflammation, low levels of insulin-like growth factor-1 and vitamin D. Young age of T1D manifestation, chronic poor glycemic control, high daily insulin dose, low body mass index, reduced renal function and the presence of diabetic complications are clinical factors useful for identifying T1D patients at risk of reduced bone mineral density. Although the clinical risk factors for fracture risk are still unknown, chronic poor glycemic control and the presence of diabetic complications might raise the suspicion of elevated fracture risk in T1D. In the presence of the above-mentioned risk factors, the assessment of bone mineral density by dual-energy X-ray absorptiometry and the search of asymptomatic vertebral fracture by vertebral fracture assessment or lateral X-ray radiography of thorax-lumbar spine should be recommended.

CONCLUSION

There is no consensus about the treatment of diabetic bone disorder. However, the improvement of glycemic control has been suggested to have a beneficial effect on bone in T1D. Recently, several experiments showed promising results on using anabolic pharmacological agents in diabetic rodents with bone disorder. Therefore, randomized clinical trials are needed to test the possible use of the bone anabolic therapies in humans with T1D.

How to predict and treat increased fracture risk in chronic kidney disease

Men and women with chronic kidney disease (CKD) are at an increased risk of fracture, and this risk increases as kidney function deteriorates. Fractures are associated with morbidity, mortality and economic costs. Despite this, there is a paucity of data regarding how to evaluate risk for fractures in CKD and how to treat high-risk patients. Evidence suggests that bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is associated with fractures and can also predict future fractures in predialysis (stages 1-3) patients with CKD. In the absence of considerable abnormalities in markers of mineral metabolism, treatment with antiresorptive agents in men and women with early CKD at high fracture risk may be appropriate. Of note, recent data suggest that low BMD as measured by DXA can also predict fractures in patients with more advanced CKD (stages 4, 5 and 5D). However, treatment in patients with advanced CKD requires bone biopsy, the gold standard to assess bone turnover, prior to treatment. Further research, focusing on noninvasive methods to assess fracture risk and bone turnover, together with randomized controlled trials of treatments to reduce fractures in patients at all stages of CKD, is required.

Increased hip fracture and mortality in chronic kidney disease individuals: the importance of competing risks

BACKGROUND

Many studies have shown a correlation between chronic kidney disease (CKD) and fracture. However, increased mortality in CKD patients is a competing risk scenario not accounted for in previous studies. Our aim was to investigate the true impact of CKD on hip fracture after accounting for a competing risk with death.

METHODS

We conducted a population-based cohort study to determine the impact of CKD on hip fractures in individuals aged ≥50years old registered in the SIDIAP(Q) database (representative of 1.9 million people in Catalonia, Spain). Cox regression was used to estimate hazard ratio (HR) for death and hip fracture according to CKD status. A competing risk (Fine and Gray) model was fitted to estimate sub-HR for hip fracture in CKD or CKD-free patients accounting for differential mortality.

RESULTS

A total of 873,073 (32,934 (3.8%) CKD) patients were observed for 3 years. During follow-up, 4,823 (14.6%) CKD and 36,328 (4.3%) CKD-free participants died (HR, 1.83 [95% CI, 1.78-1.89]), whilst 522 (1.59%) and 6,292 (0.75%) sustained hip fractures, respectively. Adjusted Cox models showed a significantly increased risk of hip fractures for the CKD group (HR, 1.16 [1.06-1.27]), but this association was attenuated in competing risk models accounting for mortality (SHR, 1.14 [1.03-1.27]).

CONCLUSIONS

Both death and hip fracture rates are increased (by 83% and 16%, respectively) in CKD patients. However, the association between CKD and hip fractures is attenuated when an excess of mortality is taken into account. A competing risk with death must be considered in future analyses of association between CKD and any health outcomes.

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.

Bone Health in Type 1 Diabetes: Where We Are Now and How We Should Proceed

Type 1 diabetes (T1D) is autoimmune disease with chronic hyperglycaemic state. Besides diabetic retinopathy, nephropathy, and neuropathy, T1D is characterized by poor bone health. The reduced bone mineralization and quality/strength, due to hyperglycemia, hypoinsulinemia, autoimmune inflammation, low levels of insulin growth factor-1 (IGF-1), and vitamin D, lead to vertebral/hip fractures. Young age of T1D manifestation, chronic poor glycemic control, high daily insulin dose, low BMI, reduced renal function, and the presence of complications can be helpful in identifying T1D patients at risk of reduced bone mineral density. Although risk factors for fracture risk are still unknown, chronic poor glycemic control and presence of diabetic complications might raise the suspicion of elevated fracture risk in T1D. In the presence of the risk factors, the assessment of bone mineral density by dual-energy X-ray absorptiometry and the search of asymptomatic vertebral fracture by lateral X-ray radiography of thorax-lumbar spine should be recommended. The improvement of glycemic control may have a beneficial effect on bone in T1D. Several experiments showed promising results on using anabolic pharmacological agents (recombinant IGF-1 and parathyroid hormone) in diabetic rodents with bone disorder. Randomized clinical trials are needed in order to test the possible use of bone anabolic therapies in humans with T1D.

Response of Bone Resorption Markers to Aristolochia longa Intake by Algerian Breast Cancer Postmenopausal Women

Aristolochia longa is widely used in traditional medicine in Algeria to treat breast cancer. The aim of the present study was to investigate the response of bone resorption markers to A. longa intake by Algerian breast cancer postmenopausal women. According to the A. longa intake, breast cancer patients were grouped into A. longa group (Al) (n = 54) and non-A. longa group (non-Al) (n = 24). 32 women constituted the control group. Bone resorption markers (from urine) pyridinoline (PYD) and deoxypyridinoline (DPD) were determined by HPLC. Serum and urinary creatinine, uric acid, and urea were measured. 1 g of A. longa intake resulted in significant rise of renal serum markers and a pronounced increase of bone resorption markers. The intake of A. longa roots is detrimental for kidney function and resulted in high bone resorption, maybe due to the reduction in renal function caused by the aristolochic acids contained in the roots.

Fragility fractures and osteoporosis in CKD: pathophysiology and diagnostic methods

Both chronic kidney disease (CKD) and osteoporosis are major public health problems associated with an aging population. Osteoporosis is characterized by reduced bone mineral density, while CKD results in qualitative changes in bone structure; both conditions increase the predisposition to fragility fractures. There is a significant coprevalence of osteoporotic fractures and CKD, particularly in the elderly population. Not only is the risk of fracture higher in the CKD population, but clinical outcomes are significantly worse, with substantial health care costs. Management of osteoporosis in the CKD population is particularly complex given the impact of renal osteodystrophy on bone quality and the limited safety and hard outcome data for current therapy in patients with severe CKD or on dialysis therapy. In this review, we discuss the pathophysiology of osteoporosis, the impact of CKD on bone strength, and the role of novel imaging techniques and biomarkers in predicting underlying renal osteodystrophy on bone histomorphometry in the context of CKD.

A review of denosumab for the treatment of osteoporosis

Osteoporosis is an age-related systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility. Bone remodeling involves two types of cells: osteoblasts and osteoclasts. Receptor activator of nuclear factor-κB ligand (RANKL) is a key regulator of the formation and function of bone-resorbing osteoclasts, and its cell surface receptor, receptor activator of nuclear factor-κB (RANK), is expressed by both osteoclast precursors and mature osteoclasts. Denosumab is a fully human monoclonal anti-RANKL antibody that inhibits the binding of RANKL to RANK, thereby decreasing osteoclastogenesis and bone-resorbing activity of mature osteoclasts. Although there are many medications available for the treatment of osteoporosis, inhibition of RANKL by denosumab has been shown to significantly affect bone metabolism. Denosumab appears to be a promising, highly effective, and safe parenteral therapy with good adherence for osteoporosis. Moreover, denosumab may be cost-effective therapy compared with existing alternatives. Therefore, in this review, we focus on studies of denosumab and the risks and benefits identified for this type of treatment for osteoporosis.

Evaluation of biochemical markers and bone mineral density in patients with chronic kidney disease stage 5D at the start of hemodialysis treatment

BACKGROUND

Patients with chronic kidney disease (CKD) have significant disorders of bone and mineral metabolism. In addition, they can also develop other bone disorders including osteoporosis. This study evaluated the bone mineral density (BMD) of patients at the start of hemodialysis treatment as well as the relationship between BMD and possible risk factors or biochemical markers.

METHODS

The study was performed in 82 patients (28 females, 54 males). BMD was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and the proximal femur.

RESULTS

We found a high prevalence of 25-hydroxyvitamin D deficiency (96%; mean levels 30.0 ± 17.7 nmol/L) and a reduction of BMD in comparison with gender- and age-matched normal population values at the total hip (Z-score = -0.31 ± 1.11) and the femoral neck (Z-score = -0.48 ± 1.16), but not at the lumbar spine (Z-score = 0.68 ± 1.81). The prevalence of T-scores ≤ -2.5 SD in the group of patients over 50 years was 52.0% in females and 33.3% in males. BMD positively correlated: with male gender and calcium levels at all measured sites, with age at the lumbar spine and with weight or BMI at the proximal femur.

CONCLUSION

CKD patients at the start of hemodialysis treatment had a high prevalence of low T-score values, corresponding to values for osteoporosis in the general population. BMD at the proximal femur was below the expected average for age and gender, but at the lumbar spine, BMD in hemodialysis patients was above average in persons without known CKD.

Rapid cortical bone loss in patients with chronic kidney disease

Chronic kidney disease (CKD) patients may have high rates of bone loss and fractures, but microarchitectural and biochemical mechanisms of bone loss in CKD patients have not been fully described. In this longitudinal study of 53 patients with CKD Stages 2 to 5D, we used dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT), and biochemical markers of bone metabolism to elucidate effects of CKD on the skeleton. Median follow-up was 1.5 years (range 0.9 to 4.3 years); bone changes were annualized and compared with baseline. By DXA, there were significant declines in areal bone mineral density (BMD) of the total hip and ultradistal radius: -1.3% (95% confidence interval [CI] -2.1 to -0.6) and -2.4% (95% CI -4.0 to -0.9), respectively. By HRpQCT at the distal radius, there were significant declines in cortical area, density, and thickness and increases in porosity: -2.9% (95% CI -3.7 to -2.2), -1.3% (95% CI -1.6 to -0.6), -2.8% (95% CI -3.6 to -1.9), and +4.2% (95% CI 2.0 to 6.4), respectively. Radius trabecular area increased significantly: +0.4% (95% CI 0.2 to 0.6), without significant changes in trabecular density or microarchitecture. Elevated time-averaged levels of parathyroid hormone (PTH) and bone turnover markers predicted cortical deterioration. Higher levels of serum 25-hydroxyvitamin D predicted decreases in trabecular network heterogeneity. These data suggest that significant cortical loss occurs with CKD, which is mediated by hyperparathyroidism and elevated turnover. Future investigations are required to determine whether these cortical losses can be attenuated by treatments that reduce PTH levels and remodeling rates.

Predictors of the rate of BMD loss in older men: findings from the CHAMP study

Though bone loss tends to accelerate with age there are modifiable factors that may influence the rate of bone loss even in very old men.

INTRODUCTION

The aim of this 2-year longitudinal study was to examine potential predictors of change in total hip bone mineral density (BMD) in older men.

METHODS

The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia. For this study, 1,122 men aged 70-97 years had baseline and follow-up measures of total hip BMD measured with dual X-ray absorptiometry. Data about mobility, muscle strength, balance, medication use, cognition, medical history and lifestyle factors were collected using questionnaires and clinical assessments. Serum 25-hydroxyvitamin D [25(OH)D] was also measured. Multivariate linear regression models were used to assess relationships between baseline predictors and change in BMD.

RESULTS

Over a mean of 2.2 years, there was a mean annualised loss of total hip BMD of 0.006 g/cm(2)/year (0.6 %) and hip BMC of 0.14 g/year (0.3 %). Annual BMD loss accelerated with increasing age, from 0.4 % in men aged between 70 and 75 years, to 1.2 % in men aged 85+ years. In multivariate regression models, predictors of faster BMD loss were anti-androgen, thiazolidinedione and loop-diuretic medications, kidney disease, poor dynamic balance, larger hip bone area, older age and lower serum 25(OH)D. Factors associated with attenuated bone loss were walking for exercise and use of beta-blocker medications. Change in BMD was not associated with baseline BMD, smoking, alcohol consumption, BMI, frailty, or osteoarthritis.

CONCLUSION

There was considerable variation in the rate of hip bone loss in older men. Walking, better balance and beta blockers may attenuate the acceleration of BMD loss that occurs with age.

Relationship between bone mineral density and moderate to severe chronic kidney disease among general population in Korea

Recent studies in Western countries have reported a significant association between glomerular filtration rate (GFR) and bone mineral density (BMD) in the absence of dialysis among the general population. However, there have been few studies regarding renal function and BMD among Korean or Asian subjects with moderate to severe (stage 3 or 4) chronic kidney disease (MS-CKD). The aim of the present study was to investigate the association between MS-CKD and BMD in the general Korean population. BMD, serum creatinine and other measures were obtained from 3,190 subjects (1,428 males and 1,762 females; the fourth Korean National Health and Nutrition Examination Survey). GFR was estimated using the Cockcroft-Gault formula, with adjustment for body surface area. After adjustment for all variables, multiple regression analysis showed that BMD in the femur neck, total femur and lumbar spine were positively associated with eGFR in both males and females. Additional analysis showed that MS-CKD was also significantly associated with osteoporosis in both males and females (odds ratio [OR] 2.20, 95% confidence interval [CI] 1.15-4.20 in males; and OR 1.96, 95% CI 1.33-2.88 in females). Individuals with MS-CKD may be at higher risk of osteoporosis even among Asians.

Bone and kidney disease: diagnostic and therapeutic implications

Fractures are common in patients with chronic kidney disease (CKD), but the diagnosis and treatment of bone disease in CKD are difficult due to the multiple etiologies of bone disease in these patients. Noninvasive imaging, including bone mineral density by dual energy x-ray absorptiometry, can be useful in diagnosing osteoporosis in predialysis CKD; however, consensus on the diagnosis of osteoporosis among those with advanced CKD-particularly stage 5 CKD patients on dialysis-is lacking. Treatments approved for osteoporosis in postmenopausal women may be used in patients with stage 1 to 3 CKD. Furthermore, post-hoc analyses show efficacy and safety of oral bisphosphonates, raloxifene, and denosumab in stage 4 CKD for short-term treatment. However, treatment decisions are more difficult in stage 5 CKD. Bone biopsy may be required, and most treatments, if used, would be off label. Overall, the diagnosis and treatment of bone disease in patients with CKD require further research.

A single-dose study of denosumab in patients with various degrees of renal impairment

This 16-week study evaluated pharmacokinetics and pharmacodynamics of denosumab in 55 subjects with renal function ranging from normal to dialysis-dependent kidney failure. Participants received a single 60-mg subcutaneous dose of denosumab. Kidney function groups were based on calculations using the Cockcroft-Gault equation and U.S. Food and Drug Administration (FDA) guidance in place when the study was designed. Renal function did not have a significant effect on denosumab pharmacokinetics or pharmacodynamics. These findings suggest denosumab dose adjustment based on glomerular filtration rate is not required. Rapid decreases in serum C-telopeptide in all groups were sustained throughout the study. The most common adverse events were hypocalcemia (15%), pain in extremity (15%), and nausea (11%). Most adverse events were mild to moderate in severity. Calcium and vitamin D supplementation was not initially required by the study protocol, but was added during the trial. No subject who received adequate calcium and vitamin D supplementation became hypocalcemic. Seven subjects had nadir serum calcium concentrations between 7.5 and <8.0 mg/dL (1.9 and <2.0 mmol/L), and 5 subjects (4 with advanced renal disease) had nadir serum calcium <7.5 mg/dL (<1.9 mmol/L). Two subjects (1 symptomatic, 1 asymptomatic) were hospitalized for intravenous calcium gluconate treatment. At the recommended dose, denosumab is a useful therapeutic option for patients with impaired renal function. Supplementation of calcium and vitamin D is strongly recommended when patients initiate denosumab therapy, particularly in patients with reduced renal function.

Association of intact parathyroid hormone levels with subsequent hip BMD loss: the Osteoporotic Fractures in Men (MrOS) Study

INTRODUCTION

There is little information on the association between intact PTH (iPTH) and longitudinal changes in bone mineral density (BMD) in older men. This association was evaluated in relation to conditions related to higher iPTH [e.g. decreased renal function, low serum 25-hydroxyvitamin D (25[OH]D)].

METHODS

Eligible men were part of a random sample of 1593 community-dwelling individuals aged 65 yr or older participating in the Osteoporotic Fractures in Men study with baseline iPTH data. Of these, 1227 had at least two BMD measurements at the total hip and femoral neck over a mean follow-up of 4.5 yr. Annualized BMD change across iPTH quartiles was estimated using mixed-effects regression models, adjusting for age, serum calcium, serum 25(OH)D, estimated glomerular filtration rate, and other factors. Splines were used to identify more optimal iPTH thresholds associated with less BMD loss.

RESULTS

Among the cohort of 1138 eligible men, men in the highest quartile of iPTH (≥38 pg/ml) lost 0.46% per year at the total hip compared with men in the lowest iPTH quartile who lost 0.22% per year (P = 0.0004). Results were similar at the femoral neck. The association between iPTH and BMD loss was not modified by baseline estimated glomerular filtration rate or 25(OH)D status. Spline results suggested that iPTH levels below 30 pg/ml were more physiologically optimal than higher iPTH values in reducing BMD loss, although an exact threshold for optimal iPTH was not identified.

CONCLUSION

Older men with higher iPTH levels had approximately a 2-fold greater rate of BMD loss compared with men with lower iPTH levels, irrespective of estimated glomerular filtration rate and 25(OH)D.

Fracture risk assessment in patients with chronic kidney disease

Fractures are common in patients with chronic kidney disease (CKD) and associated with substantially high morbidity and mortality. Bone mass measurements are commonly used to assess fracture risk in the general population, but the utility of these measurements in patients with CKD, and specifically among those on hemodialysis, is unclear. This review will outline the epidemiology and etiology of fractures in patients with CKD with a particular emphasis on men and women on hemodialysis. As well, we will summarize the published data, which describes the association between risk factors for fracture (including bone mass measurements, biochemical markers of mineral metabolism, and muscle strength) and fractures in patients with CKD. Patients with CKD suffer from fractures due to impairments in bone quantity, bone quality, and abnormalities of neuromuscular function. There is a paucity of evidence on the associations between bone quality, bone turnover markers, neuromuscular function, and fractures in patients with CKD. Furthermore, the complex etiology of fractures combined with the technical limitations of bone mineral density testing, both by dual energy X-ray absorptiometry (DXA) and by peripheral quantitative tomography (pQCT), limits the clinical utility of bone mass measurements for fracture prediction in CKD; this is particularly true among patients with stages 4 and 5 CKD. Further prospective studies to identify noninvasive measures of bone strength that can be used for fracture risk assessment are needed.

Post hoc analysis of a single IV infusion of zoledronic acid versus daily oral risedronate on lumbar spine bone mineral density in different subgroups with glucocorticoid-induced osteoporosis

This study summarizes the treatment effect of zoledronic acid infusion on lumbar spine bone mineral density in different subgroups with glucocorticoid-induced osteoporosis. Zoledronic acid is significantly more effective than risedronate in increasing lumbar spine (LS) bone mineral density (BMD) in both prevention and treatment of glucocorticoid-induced osteoporosis. Introduction In patients on glucocorticoids, a single zoledronic acid infusion significantly increased BMD versus daily oral risedronate. We assessed treatment effect on LS BMD in different patient subgroups at month 12 that contributed to the risk of osteoporosis in addition to glucocorticoids. Methods Patients randomized to a single IV infusion of zoledronic acid 5 mg or risedronate (5 mg/day) and stratified based on glucocorticoids duration [treatment (>3 months) and prevention (≤ 3 months) subpopulations]were subgrouped by age; gender; menopausal status in women; dose and duration of prednisone during the trial; and baseline serum 25-OH vitamin D, LS BMD T-score, creatinine clearance, and concomitant medication use. Results At month 12, zoledronic acid significantly increased LS BMD versus risedronate in patients ≤ 74 years (P<0.05) in the treatment and 65-74 years (P = 0.0008) in the prevention subpopulation. At month 12, zoledronic acid significantly increased LS BMD versus risedronate in both subpopulations irrespective of gender (all P<0.05), cumulative prednisone dose (all P<0.01), and postmenopausal status (all P<0.05). In premenopausal women, in both subpopulations, zoledronic acid significantly increased total hip BMD (all P<0.05) versus risedronate at month 12 but not LS BMD. Osteoporotic patients in the prevention (P=0.0189) and osteopenic patients in the treatment subpopulation (P=0.0305) showed significant LS BMD increases with zoledronic acid versus risedronate at month 12. Conclusions This post hoc analysis suggests that zoledronic acid is significantly more effective than risedronate in increasing LS BMD in prevention and treatment of glucocorticoid-induced osteoporosis across a wide range of patients.

Low bone mineral density and its predictors in type 1 diabetic patients evaluated by the classic statistics and artificial neural network analysis

OBJECTIVE

To investigate factors associated with bone mineral density (BMD) in type 1 diabetes by classic statistic and artificial neural networks.

RESEARCH DESIGN AND METHODS

A total of 175 eugonadal type 1 diabetic patients (age 32.8 ± 8.4 years) and 151 age- and BMI-matched control subjects (age 32.6 ± 4.5 years) were studied. In all subjects, BMI and BMD (as Z score) at the lumbar spine (LS-BMD) and femur (F-BMD) were measured. Daily insulin dose (DID), age at diagnosis, presence of complications, creatinine clearance (ClCr), and HbA(1c) were determined.

RESULTS

LS- and F-BMD levels were lower in patients (-0.11 ± 1.2 and -0.32 ± 1.4, respectively) than in control subjects (0.59 ± 1, P < 0.0001, and 0.63 ± 1, P < 0.0001, respectively). LS-BMD was independently associated with BMI and DID, whereas F-BMD was associated with BMI and ClCr. The cutoffs for predicting low BMD were as follows: BMI <23.5 kg/m(2), DID >0.67 units/kg, and ClCr <88.8 mL/min. The presence of all of these risk factors had a positive predictive value, and their absence had a negative predictive value for low BMD of 62.9 and 84.2%, respectively. Data were also analyzed using the TWIST system in combination with supervised artificial neural networks and a semantic connectivity map. The TWIST system selected 11 and 12 variables for F-BMD and LS-BMD prediction, which discriminated between high and low BMD with 67 and 66% accuracy, respectively. The connectivity map showed that low BMD at both sites was indirectly connected with HbA(1c) through chronic diabetes complications.

CONCLUSIONS

In type 1 diabetes, low BMD is associated with low BMI and low ClCr and high DID. Chronic complications negatively influence BMD.

Bone mass measurements in men and women with chronic kidney disease

PURPOSE OF REVIEW

Fractures are common in patients with chronic kidney disease (CKD) and are associated with substantial morbidity and mortality. Bone mass measurements are commonly used to assess fracture risk in the general population, but the utility of these measurements in patients with CKD is unclear.

RECENT FINDINGS

This review will outline the epidemiology and etiology of fractures in patients with CKD. Also, we will summarize the published data that describe the association between bone mass measurements and fracture in patients with CKD.

SUMMARY

Patients with CKD suffer from fractures due to impairments in bone quantity, bone quality, and abnormalities of neuromuscular function. The complex etiology of fractures combined with the technical limitations of bone mineral density testing, both by dual energy X-ray absorptiometry and by peripheral quantitative computed tomography, limits the clinical utility of bone mass measurements for fracture prediction in CKD; this is particularly true among patients with stages 4 and 5 CKD. As such, clinicians should not routinely order bone mineral density testing in patients with CKD. Further research, to determine whether bone mineral density together with other noninvasive measures to assess bone strength can predict fracture, is needed.