Vitamin D and Coronary Calcification Study
Summary
Patients with chronic kidney disease (CKD) have a higher mortality rate than the general population, with cardiovascular disease (CVD) accounting for approximately 50% of deaths. Vascular calcification is a common finding in patients with CKD. Furthermore, patients with CKD develop secondary hyperparathyroidism, partly because of a decrease of calcitriol synthesis on the kidney. Treatment of secondary hyperparathyroidism includes use of activated vitamin D including calcitriol and paricalcitol. Recent evidence in dialysis patients suggest an improved survival in patients using paricalcitol compared to calcitriol.
Studies in uremic rats suggests that there are differential effects of calcitriol and paricalcitol in expression of markers of soft-tissue calcification independent of calcium-phosphorus product. Calcitriol increased calcification of vascular smooth muscle cells cultured in calcification media. There was also significant increase in pulse pressure in animals treated with calcitriol.
The investigators hypothesize that these different forms of vitamin D may have differential effects in vascular calcification progression in CKD patients.
Study Design
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention
Conditions
Chronic Kidney Disease
Intervention
Calcitriol (Rocaltrol®), Paricalcitol
Location
Hospital of the University of Pennsylvania
Philadelphia
Pennsylvania
United States
19107
Status
Recruiting
Source
University of Pennsylvania
Results (where available)
Links
- Source: http://clinicaltrials.gov/show/NCT00752102
- Information obtained from ClinicalTrials.gov on July 15, 2010
Medical and Biotech [MESH] Definitions
Renal Insufficiency, Chronic
Conditions in which the KIDNEYS perform below the normal level for more than three months. Chronic kidney insufficiency is classified by five stages according to the decline in GLOMERULAR FILTRATION RATE and the degree of kidney damage (as measured by the level of PROTEINURIA). The most severe form is the end-stage renal disease (CHRONIC KIDNEY FAILURE). (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002)
Kidney Failure, Chronic
The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.
Receptors, Calcitriol
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.
Calcitriol
The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.
Hydronephrosis
Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.
Clinical Trials
Secondary Hyperparathyroidism (SHPT) occurs in many patients with kidney disease and leads to bone disease. Active forms of vitamin D, calcitriol and paricalcitol, treat SHPT, but may have...
The purpose of this study is to determine whether oral paricalcitol is safer and more efficacious compared to oral calcitriol in the treatment of hyperparathyroidism in chronic kidney dise...
Paricalcitol Injection Phase II Trial
The PK and tolerability of paricalcitol after repeated intravenous administration for 2 weeks (total 6 doses at every HD session) are studied in subjects with 2°HPT who are receiving HD 3...
The Effect of Paricalcitol on Creatinine Filtration, Secretion and Glomerular Filtration Rate
The purpose of this study is to study the effects of Paricalcitol (Zemplar) on kidney functioning. The investigators hypothesize that the increase in serum creatinine observed in recent p...
The study is about possible protective effects of paricalcitol (Zemplar) upon inflammation, blood pressure and kidney function. Kidney Inflammation occurs when white blood cells become abn...
PubMed Articles
Safety and tolerability of paricalcitol in patients with chronic kidney disease.
Introduction: Secondary hyperparathyroidism (SHPT) is a complication of chronic kidney disease (CKD). Beyond skeletal complications, uncontrolled SHPT is associated with cardiovascular mortality. Vita...
PURPOSE: Vitamin D receptor (VDR) activation is associated with cardiovascular benefits in chronic kidney disease patients, but whether VDR's hormone and prehormone exhibit similar effects requires mo...
Background/Aims: Kidney disease patients experience declining calcitriol levels and develop secondary hyperparathyroidism (SHPT). Animal models of uremia based on 5/6 nephrectomy (NTX) do not consiste...
Paricalcitol is more effective than calcitriol in hemodialysis patients (HD) with secondary hyperparathyroidism (SHPT), but it is not effective in some of them. We have investigated the relationship b...
Vitamin d and vascular calcification in chronic kidney disease.
Vascular calcification is common in patients with chronic kidney disease (CKD) and contributes to the increased rate of cardiovascular morbidity and mortality. The mechanisms regulating vascular calci...
