Vitamin K to Attenuate Coronary Artery Calcification in Hemodialysis Patients
End-stage Kidney DiseaseThe purpose of this study is to see if vitamin K supplementation three times per week reduces the progression of coronary artery calcification over 12 months in dialysis patients compared to placebo.
Natural History Study of ENPP1 Deficiency and and the Early-onset Form of ABCC6 Deficiency
Ectonucleotide Pyrophosphatase/phosphodiesterase1 DeficiencyATP-Binding Cassette Subfamily C Member 6 Deficiency2 moreThe purpose of this prospective study is to characterize the natural history of ENPP1 Deficiency (including Generalized Arterial Calcification of Infancy Type 1 [GACI] and Autosomal Recessive Hypophosphatemic Rickets Type 2 [ARHR2]) and the early-onset form of ABCC6 Deficiency (Generalized Arterial Calcification of Infancy Type 2 [GACI-2]) longitudinally.
What's Happen Under the Calcification Process in Pseudoxanthoma Elasticum
Pseudoxanthoma ElasticumThe investigators hypothesize is that in PXE patients, low grade chronic inflammation could preceed the molecular and the clinical calcification process.
THE OMEGA-SPM-DOSE and OMEGA-SPM-PAD: Specialized Pro-Resolving Mediators in Patients With Peripheral...
Peripheral Arterial DiseaseClaudication6 moreThe purpose of this study is to understand the effects of fish oil supplement (containing parts of omega-3 fatty acids) on inflammation. The investigators are aiming to identify which dose of the fish oil supplement is the most effective. The name of the fish oil supplement is "SPM Emulsion."
Vitamin K2 Supplementation to Activate Matrix Gla Protein (MGP) as Endogenous Inhibitor of Vascular...
CKD 5DHemodialysisVascular calcification (VC) is a predictor of cardiovascular morbidity and mortality. Hemodialysis (HD) patients suffer from severe vascular calcifications. Matrix Gla protein (MGP) is a central calcification inhibitor of the arterial wall and its activity depends on vitamin K-dependent γ-glutamate carboxylation. Noncarboxylated MGP, formed as a result of vitamin K deficiency, is associated with cardiovascular disease. Recent studies pointed towards poor vitamin K status in HD patients. We therefore aim to investigate whether daily vitamin K2 (MK-7) supplementation improves the bioactivity of vitamin K-dependent proteins in HD patients as assessed by circulating dephospho-noncarboxylated MGP (dp-ucMGP), noncarboxylated osteocalcin (ucOC) and noncarboxylated prothrombin (ucFII; PIVKA-II).
The Effect of Sodium Bicarbonate (Nephrotrans®) on Calcification Propensity of Serum in Kidney Transplant...
Kidney Transplant; ComplicationsThis is a single-center, prospective, open-label, randomized, cross-over study.
Vitamin D and Carboxy PTH Fragments in Coronary Calcification
Coronary CalcificationEndstage Renal Disease1 moreArterial calcification within the coronaries and other vessels is greatly accelerated among patients with chronic or end-stage kidney disease. The mechanisms leading to increased calcification are unknown, but include hyperphosphatemia, hyperparathyroidism and altered vitamin D metabolism. Moreover, recent data demonstrates that circulating carboxy fragments of PTH (7-84) are physiologic antagonists of intact PTH (1-84) and may directly contribute to vascular calcification. Current PTH assays no not distinguish between intact and carboxy PTH fragments leading to an overestimation of intact PTH levels. Because second generation PTH assays detect both 1-84 and 7-84 PTH fragments, the use of vitamin D analogues to treat secondary hyperparathyroidism could lead to excessive suppression of 1-84 and a preponderance of carboxy PTH fragments. Moreover, increased administration of vitamin D analogues amy contribute to vascular calcifications. To investigate these questions, we plan to investigate the effect of managing new ESRD patients using conventional and third generation PTH assays on vitamin D administration and the development of coronary calcification. Hypothesis #1: Clinical management of secondary hyperparathyroidism in new hemodialysis patients using the Scantibodies 1-84/7-84 PTH ratio for one year will reduce the amount of Vitamin D administration resulting in reduced coronary calcification compared to patients in which PTH management is accomplished by conventional, second generation PTH assay.
How Bone is Made in Children Receiving Dialysis
Bone Mineralization DefectThe study outlined is designed to measure and to determine whether the combined use of vitamin D2 (ergocalciferoI) and 1-alpha-hydroxyvitamin D2 (doxercalciferol)) or doxercalciferol alone will correct the mineralization defect in pediatric patients with established secondary hyperparathyroidism (2°HPT) undergoing regular peritoneal dialysis. Serum phosphorus levels will be controlled with a calcium¬-free-metal free phosphate binder; (obtained at baseline and after 8 months of treatment) sevelamer. Indices of bone mineralization obtained at baseline and after 8 months of treatment will be measured by quantitative histomorphometry in iliac crest bone biopsies after double tetracycline labeling. Immunohistochemistry will be done in specimens of bone biopsies from iliac crest to examine the expression for selected markers of bone turnover and mineralization such as FGF-23, DMP1, MEPE and OPG. Serum PTH levels will be measured with the 1st and 2nd generation immunometric assay (PTH-IMAs) and fibroblast growth factor-23 (FGF-23) will be determined by one assay with specific detection antibodies that are against epitopes within the C-terminus of FGF-23 and another assay that uses antibodies against epitopes within the N- and C-terminal portions of the molecule respectively. The value of non-invasive assessment of bone mass by quantitative computed tomography (QCT) and its relationship with vascular disease determined by ultrasound (US) of intimal carotid thickness (CIMT) will be correlated with bone histomorphometry and the different biochemical determinations.
Oral Alfacalcidol and Coronary Artery Calcification in Predialysis Chronic Kidney Disease
Vascular CalcificationActive vitamin D at therapeutic dose may prevent vascular calcification but in supraphysiologic dose may precipitate it.
Alendronate for Vascular Calcification in Peritoneal Dialysis Patients?
Peritoneal DialysisHyperphosphatemia is frequently seen in patients with end-stage renal disease (ESRD). Hyperphosphatemia usually results in a high calcium-phosphorus product (CPP) which may subsequently lead to artery and become a risk factor of cardiovascular complications. Alendronate, due to its effect of inhibiting osteoclasts, is approved for treatment of osteoporosis. Previous reports found the use of bisphosphonates could suppress arterial calcification in hemodialysis dialysis patients. The aim of this study is to evaluate the safety and efficacy of alendronate to suppress coronary artery and aortic calcifications, as well as to improve bone density in chronic peritoneal dialysis (PD) patients. This study will include ESRD patients who had received maintenance PD for more than 3 months, have high CPP level (≧55), and have chest X-ray proven aortic calcification or coronary artery calcification. All participants are randomly allocated to either group 1 or group 2. Group 1 patients receive alendronate 70 mg once weekly in the first 16 weeks, while group 2 patients receive the same dose of drug every week in the second 16 weeks. The extent of coronary artery and aortic calcification is evaluated by using multi-detector spiral computed tomography, whereas bone mineral density is measured by dual-energy X-ray absorptiometry. Both examinations are performed at week 0, 16 and 32 for each participant. Laboratory studies and possible adverse reactions were regularly monitored. We expect that alendronate can alleviate the progression of arterial calcification or even improve it. Bone density may also be improved after treatment. Besides, we wish to find the independent factor(s) influencing the efficacy of alendronate. These results may help clinical physicians for early intervention and prevention of cardiovascular complications in ESRD patients.