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Rhubarb and Angiotensin Converting Enzyme Inhibitor (RACE II)

This study has been terminated.
(unable to meet recruitment goal)
National Institutes of Health (NIH)
Information provided by:
Wake Forest School of Medicine Identifier:
First received: May 2, 2008
Last updated: August 18, 2011
Last verified: May 2009
Rhubarb extract is a chinese herbal preparation that is used in china and other asian countries to treat constipation and chronic kidney disease. Use of angiotensin converting enzyme inhibitors (ACEI) in diabetic kidney disease has been shown to be beneficial in slowing progression. The purpose of this study is to determine the combined effect of rhubarb plus enalapril (an ACEI)in slowing the rate of decline of CKD in people with kidney disease from diabetes.

Condition Intervention
Diabetic Kidney Disease
Dietary Supplement: rhubarb extract
Dietary Supplement: placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Rhubarb and Angiotensin Converting Enzyme Inhibitor

Resource links provided by NLM:

Further study details as provided by Wake Forest School of Medicine:

Primary Outcome Measures:
  • albuminuria [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • rate of decline of GFR [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Enrollment: 8
Study Start Date: January 2008
Study Completion Date: May 2009
Primary Completion Date: May 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: rhubarb extract
will receive rhubarb extract
Dietary Supplement: rhubarb extract
titrate rhubarb extract titrated up to 6grams daily by mouth
Placebo Comparator: placebo
receive placebo
Dietary Supplement: placebo
placebo titrated up to 6 pills daily as patient tolerates

Detailed Description:

Use of angiotensin converting enzyme inhibitors (ACEI) in diabetic nephropathy has been shown to be beneficial in slowing progression of disease. This would include use of ACEI, aggressive blood pressure and blood sugar control as well as other possible interventions. Experimental studies in chronic kidney disease (CKD) patients in China has suggested that rhubarb extract when used alone is equivalent to the protection afforded by ACEI. Furthermore when used in combination with ACEI, the renoprotective effect of rhubarb appears to be additive.

Rhubarb extract is a chinese herbal preparation that is used extensively in china and other asian countries to treat constipation and CKD. Its mechanism of action in preventing progression of CKD is uncertain but perhaps related to TGF beta and TNF alpha inhibition.

The specific aim is to determine the combined effect of rhubarb plus enalapril slowing the rate of decline of CKD (using Iothalamate GFRs) in patients in diabetes. A secondary aim would be to measure serum TGF beta concentrations over time and see if any observed decrease in the rate of decline of CKD is related to changes in TGF beta levels.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Male or female patients >18 years
  2. Patients with diabetic nephropathy (history of type 1 or type 2 diabetes for > 7 years, no other cause for proteinuria listed in their medical chart). This is the definition used in most peer-reviewed trials44,45 of diabetic nephropathy. We do recognize that their proteinuria could be due to some other concomitant kidney disease but the only way to confirm that is to do a kidney biopsy which is not clinically justified.
  3. Proteinuria ≥ 0.5 g/day
  4. Ability to sign consent form

Exclusion Criteria:

  1. Pre study GFR (see section 10.7) < 20 ml/min
  2. Renal disease of etiologies other than diabetes
  3. Uncontrolled hypertension (Systolic BP >180 mmHg and Diastolic BP >110mm Hg)
  4. Patients with history of kidney stones in past 10 years
  5. Patients with active chronic liver disease (Liver enzymes ALT, AST >2.5 times normal)
  6. Patients with primary small bowel disease with malabsorption, blind loop syndrome, or jejunoileal bypass surgery (may cause unabsorbed fatty acids to combine with calcium which in turn causes too much absorption of oxalate)
  7. Patients with current alcohol, illicit drug use or any other condition (eg. Psychiatry disorder) that in the opinion of the investigator may interfere with the patient's ability to comply with the study
  8. Pregnant women or women of child bearing potential who are unwilling to use an adequate form of contraceptive during the course of the study (ACEI may be fetotoxic)
  9. Patients with significant unstable cardiovascular disease (NYHA class III and IV)
  10. Patients with active malignancy
  11. Uncontrolled infections.
  12. Patients with a known sensitivity to the study medications (including enalapril)
  13. Patients on angiotensin II receptor blockers (ARBs)
  14. Microscopic or macroscopic hematuria (to rule out kidney disease other than diabetic nephropathy)
  15. Patients on any herbal supplements unwilling to discontinue them
  16. Severe malnutrition (serum albumin <2.6mg/dL)
  17. Hyperkalemia at baseline, defined as serum potassium ≥ 5.5 mg/dL
  18. Iodine allergy.
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Please refer to this study by its identifier: NCT00672451

United States, North Carolina
Wake Forest University Heath Sciences
Winston Salem, North Carolina, United States, 27157
Sponsors and Collaborators
Wake Forest University
National Institutes of Health (NIH)
Principal Investigator: John Burkart, MD Wake Forest School of Medicine
  More Information

Responsible Party: John Burkart, Professor of Medicine, Wake Forest University Health Sciences Identifier: NCT00672451     History of Changes
Other Study ID Numbers: 1R21AT002367-01A2  00000616-  Institutional IRB number 
Study First Received: May 2, 2008
Last Updated: August 18, 2011
Health Authority: United States: Institutional Review Board

Keywords provided by Wake Forest School of Medicine:
diabetic kidney disease

Additional relevant MeSH terms:
Kidney Diseases
Diabetic Nephropathies
Urologic Diseases
Diabetes Complications
Diabetes Mellitus
Endocrine System Diseases
Angiotensin-Converting Enzyme Inhibitors
Enzyme Inhibitors
Protease Inhibitors
Molecular Mechanisms of Pharmacological Action processed this record on December 02, 2016