Klotho Gene Polymorphism in Dialyzed Patients With Hyperphosphatemia

November 6, 2007 updated by: Assistance Publique - Hôpitaux de Paris

Study of Klotho Gene Polymorphisms in the Regulation of Serum Phosphate Levels in Hemodialysis Patients

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.

Study Overview

Status

Terminated

Conditions

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.

Study Type

Observational

Enrollment (Actual)

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Aubervilliers, France, 93300
        • Clinique de l'Orangerie - Service de Néphrologie et Dialyse

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Adult, end-stage renal disease patients treated by standard hemodialysis

Description

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)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assistance Publique - Hôpitaux de Paris

Collaborators

Institut National de la Santé Et de la Recherche Médicale, France

Investigators

  • Principal Investigator: Pablo URENA TORRES, MD, Clinique de l'Orangerie, France

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2005

Study Completion (Actual)

November 1, 2007

Study Registration Dates

First Submitted

September 12, 2005

First Submitted That Met QC Criteria

September 8, 2006

First Posted (Estimate)

September 11, 2006

Study Record Updates

Last Update Posted (Estimate)

November 8, 2007

Last Update Submitted That Met QC Criteria

November 6, 2007

Last Verified

November 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • P031010
  • CRC 03161

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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