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Determination of Kidney Function

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 4, 2017 by National Institutes of Health Clinical Center (CC)
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) ) Identifier:
First received: January 20, 2000
Last updated: April 20, 2017
Last verified: January 4, 2017

Much more about kidney disorders can be learned by determining kidney function. This research proposes to study the kidneys function by several parameters known as glomerular filtration rate (GFR), Renal Plasma Flow (RPF), and Glomerular Capillary Wall Permselectivity.

The study will select patients suffering from different types of kidney diseases. These patients will be selected based on the presence of significant amounts of protein in their urine (proteinuria).

Standard blood and urine tests are often unable to provide completely accurate information about the kidney. In order for researchers to have a more accurate idea of kidney function, they will use alternative tests. Test materials (para aminohippurate and inulin) will be injected into patients veins that provides information based on their filtration through the kidneys.

Kidney Disease
Autoimmune / Connective Tissue Diseases

Study Type: Observational
Official Title: Determination of Glomerular Filtration Rate, Effective Renal Plasma Flow and Glomerular Capillary Wall Permselectivity

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 9999999
Study Start Date: August 24, 1989
Detailed Description:

The study of various kidney disorders will be facilitated by determinations of true glomerular filtration rate and/or effective renal plasma flow employing inulin or non-radioactive iothalamate and/or para aminohippurate (PAH), respectively.

Selected patients with proteinuria will be asked to participate in studies of glomerular capillary wall permselectivity calculated from the fractional clearances of the endogenous proteins, albumin and IgG and from the fractional clearances of polydisperse neutral dextran with effective molecular radii ranging from 20-60 angstroms. To achieve this, low molecular weight dextran will be administered by slow IV injection immediately following the inulin or iothalamate and/or PAH priming doses.

Glomerular filtration rate, effective renal plasma flow and/or glomerular permselectivity can be measured simultaneously during a standard hydrated urinary clearance study. Timed urine and blood collections will be obtained, typically requiring a total of 60 to 90 minutes. The total test time, including pre-test hydration, is 4 to 5 hours.

Alternatively, glomerular filtration rate can be measured by one of two plasma clearance methods that do not require urine collections. For one method, a steady-state plasma concentration of iothalamate will be achieved in ambulatory patients by a 24-hour subcutaneous infusion of iothalamate using an insulin pump. For the second method, the decline in plasma concentration of iothalamate will be measured after an intravenous dose of iothalamate.


Ages Eligible for Study:   7 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Ability to provide informed assent to all aspects of the study after full information is provided.

An indication to measure kidney function as accurately as possible in the context of an approved clinical protocol within the intramural programs of the National Institutes of Health:

  • For minor subjects, a clinical indication will be required.
  • For adult subjects, a clinical and/or research indication will be required.


Pregnant females or nursing mothers will be excluded from all aspects of this study (at least until the infant is stable on a regimen of formula feeding).

Patients will not receive a test material if there is a history of allergy to that material.

Patients with a history of bronchial asthma or allergy to iodine-containing contrast material will not receive iothalamate.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00001978

Contact: Howard A Austin, M.D. (301) 435-5055

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike Recruiting
Bethesda, Maryland, United States, 20892
Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL)    800-411-1222 ext TTY8664111010   
Sponsors and Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: Howard A Austin, M.D. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  More Information

Additional Information:
Responsible Party: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Identifier: NCT00001978     History of Changes
Other Study ID Numbers: 890152
Study First Received: January 20, 2000
Last Updated: April 20, 2017

Keywords provided by National Institutes of Health Clinical Center (CC):
Kidney Disease
Kidney Function Tests

Additional relevant MeSH terms:
Kidney Diseases
Connective Tissue Diseases
Urologic Diseases
Urination Disorders
Urological Manifestations
Signs and Symptoms processed this record on May 25, 2017