12-month Study of AMG 073 in Renal Osteodystrophy
Renal Osteodystrophy4 doses of AMG 073 or placebo over 52 weeks after a 30-day screening period. Throughout the study, labs will be drawn to measure analytes such as iPTH and corrected calcium. In addition, a bone biopsy will be performed at screening and at the end of study.
Cholecalciferol Versus Doxercalciferol in the Treatment of Secondary Hyperparathyroidism in Chronic...
Renal OsteodystrophyThe majority of patients with moderate to severe chronic kidney disease (CKD) (stages 3 and 4) develop secondary hyperparathyroidism (2°HPT), but the optimal therapy to control hyperparathyroidism in this group is unknown. The National Kidney Foundation presented guidelines in 2003 recommending vitamin D supplementation for vitamin D insufficient patients and active vitamin D therapy in patients with sufficient levels. These guidelines are based on opinion since there are no significant trials to determine if vitamin D supplementation is effective in this population. The active vitamin D metabolites doxercalciferol, paricalcitol, and calcitriol have been shown to effectively suppress parathyroid hormone (PTH), but have not been compared with vitamin D supplementation with a calciferol (ergocalciferol or cholecalciferol). Beyond hyperparathyroidism, small studies suggest vitamin D replacement in vitamin D insufficient non-CKD subjects result in improved pain, feeling of well being, blood pressure and strength. In this proposed study we wish to directly compare the effectiveness of cholecalciferol versus doxercalciferol in suppressing elevated PTH levels in subjects with CKD not on dialysis who have vitamin D insufficiency in a three month study. Secondary endpoints will be change in blood pressure.
Calcium Balance Studies in Children With CKD and on Dialysis
Chronic Kidney Disease Mineral and Bone DisorderThis is a novel, non-invasive method of assessing Ca balance by natural Ca isotope fractionation.
Renal Osteodystrophy: An Individual Management Approach
Kidney FailureChronicRenal osteodystrophy (ROD) represents the bone histologic abnormalities resulting from loss of renal function. It starts early during the loss of kidney function and is seen in virtually all chronic end stage kidney disease patients on dialysis (CKD-5D). A major component of ROD is bone loss leading to chronic kidney disease (CKD) associated osteoporosis. Debilitating hip fractures occur in patients with CKD at a rate 4.4 times higher than in the general population, with associated high costs, morbidity and an annual mortality of 64%. CKD osteoporosis is distinctly different from post-menopausal osteoporosis. Presently, no uniformly accepted CKD osteoporosis treatment protocol exists because of challenges related to racially specific bone turnover states. Therefore, most physicians are reluctant to treat this disorder despite the profound impact on health and quality of life, and its association with vascular calcifications. These vascular calcifications confer an increased risk for cardiovascular events which are the major cause of the over 20% annual mortality rate in CKD-5D patients. The goal of the proposed controlled randomized study is to test the concept that CKD osteoporosis can be successfully treated when treatment is individualized by patients' turnover status. The study will demonstrate that reversal of bone loss can be achieved by increasing bone formation in low turnover patients, and by reducing bone resorption in normal or high turnover patients. A second aim of this study is to provide new information whether these treatments will also retard progression of vascular calcifications. Blood tests measuring FGF23, indicators of Wnt pathway activity, bone resorption and formation will be followed to understand potential mechanisms and to evaluate their usefulness for prediction of changes in bone mass and vascular calcifications. CKD-5D patients with established osteoporosis will be enrolled into one of two treatment arms based on bone turnover status. Each arm will be adaptively randomized by race, age and gender into treatment or control groups. In the low turnover arm, teriparatide combined with cinacalcet will be given, and in the normal or high turnover arm, alendronate will be administered. Bone mineral density will be measured at baseline and after one year of treatment by quantitative computed tomography. Calcifications of the coronaries, aorta and heart valves will also be measured at the same times by multi-detector computed tomography. If this proof-of-concept study is successful, it will offer a heretofore unavailable treatment for osteoporosis in CKD-5D patients thus changing the prevailing clinical practice paradigm. This will provide immediate benefit to CKD patients by reducing fracture risk, bone pain, and cardiovascular risk, while greatly improving their quality of life. These improvements will also convey major socioeconomic benefits by decreasing the high associated treatment costs. The proposed study is highly relevant to the National Institute of Diabetes and Digestive and Kidney Diseases' mission of disseminating science-based information to improve the health and quality of life for patients with endocrine, metabolic and kidney diseases.
Osteopenia and Renal Osteodystrophy: Evaluation and Management
OsteopeniaRenal OsteodystrophyThe purpose of this study is to demonstrate whether pamidronate will preserve or increase bone mass in patients with adynamic bone disease, caused by low bone turnover.
Klotho Gene Polymorphism in Dialyzed Patients With Hyperphosphatemia
Chronic Kidney DiseaseEnd Stage Renal Disease2 morePatients with chronic kidney disease (CKD) and those with end-stage renal disease (ESRD) undergoing renal replacement therapies show elevated serum phosphate levels which predispose them to cardiovascular calcifications and high risks of death from cardiovascular diseases. However, in certain patients hyperphosphatemia is not related to dialysis insufficiency, excessive daily dietary phosphorus intake or high serum parathyroid hormone (PTH) levels, suggesting that other mechanisms could be involved. Transgenic mice lacking the klotho gene showed a phenotype which resembles that of dialyzed ESRD patients, in the sense that they have hyperphosphatemia, vascular calcifications, and a short lifespan. This study will analyze whether functional polymorphisms or variants in the human klotho gene are associated with hyperphosphatemia in these patients.
Vitamin D3 Substitution in Vitamin D Deficient Kidney Transplant Recipients
Kidney TransplantationVitamin D Deficiency1 moreThe purpose of the study is to evaluate the effects of Cholecalciferol (Vitamin D3) substitution on the posttransplant outcome (glomerular filtration rate as well as serum creatinine levels, number of acute rejection episodes, number of infections and C-reactive protein levels within the first year after transplantation) in vitamin D deficient kidney transplant recipients.
Pathogenesis of Compromised Bone Quality and Mechanics in Chronic Kidney Disease
Chronic Kidney DiseaseEnd Stage Kidney Disease3 moreKidney disease patients have a variety of bone disorders that result in bone loss and fractures. The mechanisms of these bone disorders are not clear but may be related to abnormal modification of a bone protein known as collagen. Therefore, the investigators are conducting this research study to identify underlying mechanisms that are responsible for the disruption of bone collagen and determining whether the abnormal bone collagen impairs bone strength. The investigators intend to identify these mechanisms through studying relationships between kidney disease and bone strength via bone imaging, bone biopsy and non-invasive measures from blood and skin.
SOP's for CKD-MBD-Biomarkers
Chronic Kidney DiseasesCKD-MBD (Chronic Kidney Disease - Mineral and Bone Disorder) is an extensive disease and includes dysfunction of the mineral metabolism, the bone metabolism and cardiovascular diseases in the context of renal insufficiency. Clinical pictures of peripheral artery occlusive disease (PAOD), Coronary artery disease (CAD) and arterial hypertension favours among other main risk factors (smoking, obesity, etc.) additional cardiovascular complications. For this reason it makes sense to monitor these patients regularly. For this purpose the determination of different biomarkers would be appropriate for control of the course of disease. During various studies the biomarkers FGF23, s-klotho, sclerostin, DKK1, BMP2, YKL-40 und MGP were established as indicators for the disease activity, as diagnostic criteria for the existence of CKD-MBD or as risk markers for the incidence of adverse events (incl. death) within the scope of CKD-MBD. For the clinical routine care application of these parameters standard operating procedures (SOP) are missing for the determination method relating to optimal pre-analytic and analytic procedures. These analyses are necessary to ensure the reproducibility of study results and to transfer these parameters in the clinical daily routine for risk stratification.
The Longitudinal PTH-Study
CKD-MBD - Chronic Kidney Disease Mineral and Bone DisorderSecondary Hyperparathyroidism1 moreThe main study aim is to quantify the agreement between the analytical results provided by two third generation and two second generation Parathyroid hormone (PTH) assays. The primary comparison will be performed between the second-generation PTH assay"Intact PTH assay" from Siemens Healthcare Diagnostics Inc. and the third-generation PTH assay "biointact (1-84)" from Roche Diagnostics in terms of a Bland-Altman analysis. Several studies have evaluated the correlation between various PTH assays at a single time-point, but no previous study has tested the hypothesis that longitudinal changes in PTH levels, which are important for making treatment decisions, can be monitored by several PTH assays alike. To this aim, the key secondary objective is to analyze the longitudinal variance in PTH over the course of 1 year, using each of two assays of the second and third generations, respectively. Other secondary objectives include determining changes in serum phosphate, serum calcium, fibroblast growth factor 23 (FGF23), with respect to treatment decisions. For clinical applicability of the results to be obtained here, an important goal of the present study will be not to influence treatment decisions, which will remain independent of the study investigators, at the full responsibility of the hemodialysis physicians. At every quarterly blood draw over the course of one year, the investigators will freeze the serum from 100 patients, and at the end of 4 quarters the investigators will analyze PTH-levels using the following assays: Intact Parathyroid Hormone (Advia Centaur, Siemens Healthcare), PTH-Intact (Cobas, Roche), PTH (1-84) - The agreement between the PTH assays will be analyzed at baseline, as well as at the subsequent quarterly evaluation time-points by Bland-Altman analysis and complemented by Passing-Bablok regression. The longitudinal changes in PTH will be displayed graphically and analyzed by estimating the within-patient variance across time, the between patient variance at each time-point as well as effects on the mean log-PTH level due to course of disease and therapeutic interventions from a linear mixed model.