Mechanisms of Diabetic Kidney Disease in American Indians

This study is enrolling participants by invitation only.
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: June 12, 2013
Last updated: March 4, 2015
Last verified: December 2014


- An ongoing study is looking at American Indians who have kidney problems caused by type 2 diabetes. Kidney disease due to type 2 diabetes is a major problem in American Indians. We previously found that early treatment of kidney disease with losartan was probably beneficial for reducing progression of the disease. Researchers now want to see if these benefits continue to be seen several years after the end of the treatment study.


- To study long-term benefit of losartan treatment for diabetic kidney disease in American Indians with type 2 diabetes.


- Participants in the American Indian diabetic kidney disease study (OH95-DK-N037).


  • Participants will have a physical exam and medical history before starting the study. Blood and urine samples will be collected.
  • Participants will have a set of tests as part of this study. Those who have severe kidney problems, such as kidney failure, will only have a basic kidney exam with scans. The remaining participants will have a full urine collection and analysis. They will also provide a kidney biopsy.
  • Treatment will not be provided as part of this study.

Nervous System
Diabetic Kidney Disease
Diabetes Mellitus, Type 2

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Determinants of Diabetic Nephropathy in American Indians

Resource links provided by NLM:

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

Primary Outcome Measures:
  • End-Stage Renal Disease [ Time Frame: On-going ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Diabetic Neuropathy [ Time Frame: On-going ] [ Designated as safety issue: No ]
  • Diabetic Retinopathy [ Time Frame: On-going ] [ Designated as safety issue: No ]

Estimated Enrollment: 200
Study Start Date: May 2013
Estimated Study Completion Date: January 2035
Estimated Primary Completion Date: December 2022 (Final data collection date for primary outcome measure)
Detailed Description:

The purpose of this protocol is to examine the long-term impact of treatment with the angiotensin receptor blocker losartan on progression of diabetic kidney disease in American Indians with type 2 diabetes. All participants were enrolled previously in a 6-year randomized clinical trial under Protocol OH95-DK-N037. Once randomized treatment was completed, the subjects continued to be followed under that protocol with annual renal clearance studies. Of the 170 participants originally enrolled in the trial, about 110 remain and they are eligible to enroll in this observational study. The present protocol replaces the clinical trial protocol and expands the scope of observational studies to be conducted in these well-characterized patients.

Participants will continue to undergo annual renal clearance studies to measure glomerular filtration rate and renal plasma flow, unless they have developed kidney failure. At the initial visit, we will also conduct tests of the peripheral and autonomic nervous system to determine the frequency and severity of diabetic neuropathy in this cohort and identify linkages between diabetic kidney disease and diabetic neuropathy. We will also perform a kidney biopsy at the initial visit to examine the extent of structural changes that have occurred since the last kidney biopsy done at the end of the clinical trial. Tissue from this biopsy will also be used for further gene expression and epigenetic studies. Data from these studies will be used to guide the search for candidate biomarkers for diabetic end-organ damage in serum and urine and to identify mechanisms of diabetic kidney disease that may be amenable to new treatment strategies.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

To be eligible for participation in the study, subjects must meet the following criteria:

  • Previous enrollment in protocol OH95-DK-N037.
  • Willingness, after receiving a thorough explanation of the study, to participate.


Subjects will be excluded for the following reasons:

  • Clinically significant disorders of the liver [cirrhosis, portal hypertension, hepatitis, increased bilirubin (greater than or equal to 1.5 mg/dl), decreased serum albumin (< 3.5 gm/l)], cardiovascular disease (angina pectoris, history of myocardial infarction, left ventricular ejection fraction < 40%, congestive heart failure of New York Heart Association Class I to IV), cerebrovascular disease, peripheral vascular disease, pulmonary diseases (asthma and restrictive or obstructive lung disease requiring therapy), renal-urinary disorders (calculi, urinary tract obstruction, glomerulonephritis, chronic infection), gastrointestinal disorders (nausea, vomiting, diarrhea or anorexia sufficient to cause weight loss or wasting), or hematocrit levels less than or equal to 30 percent in women or less than or equal to 35 percent in men.
  • Renovascular or malignant hypertension; uncontrolled hypertension (systolic blood pressure greater than or equal to 160 or diastolic greater than or equal to 95 mm Hg) despite treatment with three antihypertensive drugs; or hypertension that is being treated with antihypertensive medicines and the primary care physician or the patient refuses to adopt the blood pressure treatment regimen outlined in the study protocol.
  • Hematuria of unknown etiology. Prior to entry into the study, any subject with hematuria should be evaluated, the etiology established and documented, and treatment rendered as appropriate.
  • Chronic debilitating disorders with or without treatment (e.g., systemic lupus erythematosus (SLE), cancer, amyloidosis, and chronic infection) that would interfere with the assessment of kidney function or that might reduce the chances of survival for a sufficient length of time to evaluate the efficacy of treatment.
  • Currently receiving a drug regimen that includes: steroids, immunosuppressants, or investigational new drugs.
  • Pregnancy. Women of childbearing potential must have a negative pregnancy test prior to entry and prior to each renal clearance study.
  • Hypersensitivity to iodine.
  • Bleeding disorders, since kidney biopsies could not be performed safely in these individuals.
  • Massive obesity with body mass index greater than or equal to 45 kg/m(2). Kidney biopsies are more difficult and present greater hazards to persons with massive obesity.
  • Conditions likely to interfere with informed consent or compliance with the protocol.
  Contacts and Locations
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Please refer to this study by its identifier: NCT01878045

United States, Arizona
NIDDK, Phoenix
Phoenix, Arizona, United States, 85014
Sponsors and Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: Robert G Nelson, M.D. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  More Information

Responsible Party: National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) ) Identifier: NCT01878045     History of Changes
Other Study ID Numbers: 999913151, 13-DK-N151
Study First Received: June 12, 2013
Last Updated: March 4, 2015
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
American Indians
Diabetic Nephropathy
Kidney Biopsy
Type 2 Diabetes Mellitus

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Diabetic Nephropathies
Kidney Diseases
Diabetes Complications
Endocrine System Diseases
Glucose Metabolism Disorders
Metabolic Diseases
Urologic Diseases processed this record on October 02, 2015