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Klotho Gene Polymorphism in Dialyzed Patients With Hyperphosphatemia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00374712
Recruitment Status : Terminated (terminated)
First Posted : September 11, 2006
Last Update Posted : November 8, 2007
Institut National de la Santé Et de la Recherche Médicale, France
Information provided by:
Assistance Publique - Hôpitaux de Paris

Brief Summary:
Patients 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.

Condition or disease
Chronic Kidney Disease End Stage Renal Disease Hyperphosphatemia Renal Osteodystrophy

Detailed Description:
The entire coding region of the klotho gene will be sequenced looking for functional variants and polymorphisms that differentiate two groups of adult dialyzed ESRD patients, matched for age and gender, and with comparable values for dialysis dose and daily protein intake. These two groups consist of one group of 20 adult, dialyzed patients with serum phosphate levels > 2.50 mM compared to another group of 20 adult, dialyzed ESRD patients with serum phosphate levels < 1.50 mM. The results of this study will allow to determine whether there is a relationship between extreme hyperphosphatemia and klotho gene polymorphisms in dialysed ESRD patients.

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Study Type : Observational
Actual Enrollment : 40 participants
Time Perspective: Prospective
Official Title: Study of Klotho Gene Polymorphisms in the Regulation of Serum Phosphate Levels in Hemodialysis Patients
Study Start Date : January 2005
Actual Study Completion Date : November 2007

Resource links provided by the National Library of Medicine

Biospecimen Retention:   Samples With DNA

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Adult, end-stage renal disease patients treated by standard hemodialysis

Inclusion Criteria:

Group 1

  • Stable hemodialysis patients for at least 3 months
  • Phosphatemia > 2.5 mM
  • Kt/V > 1.2
  • Total weekly phosphate removal > 75 millimoles

Group 2

  • Stable hemodialysis patients for at least 3 months
  • Phosphatemia < 1.5 mM
  • Kt/V > 1.2
  • Total weekly phosphate removal > 25 millimoles

Exclusion Criteria:

  • Age > 80 years
  • Insufficient dialysis dose (Kt/V < 1.2)
  • Total weekly phosphate removal < 25 mM
  • Problems with vascular access for hemodialysis (central catheter, arteriovenous [A-V] fistula dysfunction)
  • Methods of dialysis different than the classical hemodialysis (peritoneal, hemofiltration, or hemodiafiltration with or without acetate)
  • Intolerance or allergy to ARYLANE M9 dialyzers
  • Hypocalcemia < 2.0 mmol/liter
  • Hypophosphatemia < 0.6 mmol/liter
  • Daily protein intake < 0.6 g/kg/j
  • Parathyroidectomy at least 3 months prior to the study
  • Evolutive neoplasia with or without secondary lytic bone lesions
  • Intestinal malabsorption
  • Alcoholism
  • Corticotherapy
  • Treatment by bisphosphonates, fluor or recombinant PTH
  • Malnutrition (body mass index [BMI] < 15)
  • Amputation of lower members (> 10% of total body)
  • Prolonged immobilization
  • Secondary hyperparathyroidism (PTH > 1400 pg/ml)
  • Vitamin D deficiency (25OHD3 < 10 ng/ml)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00374712

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Clinique de l'Orangerie - Service de Néphrologie et Dialyse
Aubervilliers, France, 93300
Sponsors and Collaborators
Assistance Publique - Hôpitaux de Paris
Institut National de la Santé Et de la Recherche Médicale, France
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Principal Investigator: Pablo URENA TORRES, MD Clinique de l'Orangerie, France
Publications of Results:
Layout table for additonal information Identifier: NCT00374712    
Other Study ID Numbers: P031010
CRC 03161
First Posted: September 11, 2006    Key Record Dates
Last Update Posted: November 8, 2007
Last Verified: November 2007
Keywords provided by Assistance Publique - Hôpitaux de Paris:
Additional relevant MeSH terms:
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Chronic Kidney Disease-Mineral and Bone Disorder
Kidney Diseases
Renal Insufficiency, Chronic
Kidney Failure, Chronic
Urologic Diseases
Renal Insufficiency
Phosphorus Metabolism Disorders
Metabolic Diseases
Bone Diseases, Metabolic
Bone Diseases
Musculoskeletal Diseases
Calcium Metabolism Disorders
Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders
Hyperparathyroidism, Secondary
Parathyroid Diseases
Endocrine System Diseases