Rhubarb and Angiotensin Converting Enzyme Inhibitor
Condition: Diabetic Kidney Disease
MeSH terms: Kidney Diseases; Diabetic Nephropathies
Intervention: rhubarb extract; placebo
Intervention description: titrate rhubarb extract titrated up to 6grams daily by mouth; placebo titrated up to 6 pills daily as patient tolerates
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 8.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: diabetic kidney disease; albuminuria

Summary:

      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.
    

Eligibility criteria:

        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.