Diabetic Nephropathy, Oxidative Stress, Proteinuria
Conditions
Keywords
silymarin, glutathione, diabetic nephropathies, oxidative stress, N-acetylcysteine, protein tholation
Brief summary
The study is done to find out whether the combined use of the nutritional supplements N-acetylcysteine and Siliphos (milk thistle extract) corrects the shedding of urine protein and oxidative damage (damage to cells and organs often compared to fast aging) in patients with Type 2 Diabetes Mellitus (T2DM) and diabetic kidney disease.
Detailed description
Oxidative stress and glutathione (GSH) imbalance are major contributors to the pathogenesis of diabetic nephropathy. Current options for the treatment of oxidative stress in diabetic nephropathy are limited and only partially effective, thus interest in the development of new strategies is high. The study intends to test the hypothesis that combined oral supplementation of the antioxidants N-acetylcysteine (NAC) and milk thistle flavonolignan silibin (as silibin-phosphatidylcholine) will reduce proteinuria and urinary and systemic manifestations of oxidative stress and inflammation, which are characteristically observed in patients with T2DM and related nephropathy. The investigators expect these effects to be achieved with minimal or no side effects, and with good patient tolerance. The trial is designed as a two-center, double-blind, placebo-controlled, randomized, modified-factorial dose-ranging design, five-arm pilot study in patients with Type 2 diabetes mellitus and advanced diabetic nephropathy with proteinuria. Intervention consists of three-month oral administration of NAC, silibin, and/or respective placebos for three months. Subjects are randomized to the following five intervention arms: (A) placebo; (B) NAC; (C) silibin; (D) NAC + silibin; and (E) NAC + double-dose silibin. The primary outcome measure is urinary excretion of albumin, a marker of glomerular injury. Secondary outcome measures are alpha-1 microglobulin, a marker of tubular injury, and urinary excretion of inflammatory cytokines and C-C chemokines, i.e. markers of renal inflammation. In addition, peripheral blood monocytes from the same patients are analyzed for GSH content and activity of GSH metabolizing enzymes. All outcome measures are monitored in relation to both treatment allocation and prevalent blood and urine levels of the active treatment. Safety and tolerability of this combination treatment are monitored throughout the trial.
Interventions
DRUGN-acetylcysteine placebo and silibin placebo
Dietary Supplement: N-acetylcysteine placebo excipient and silibin placebo orally twice daily for three months
DRUGN-acetylcysteine active and silibin placebo
Dietary Supplement: N-acetylcysteine 600 mg orally twice daily and silibin placebo orally twice a day for three months
DRUGN-acetylcysteine placebo and silibin active
Dietary Supplement: silibin 480 mg orally twice daily and N-acetylcysteine placebo orally twice a day for three months
DRUGN-acetylcysteine active and silibin active
Dietary Supplement: N-acetylcysteine 600 mg orally twice daily and silibin 480 mg orally twice daily for three months
DRUGN-acetylcysteine active + high-dose silibin active
Dietary Supplement: N-acetylcysteine 600 mg orally twice daily and silibin 960 mg orally twice daily for three months
Sponsors
National Center for Complementary and Integrative Health (NCCIH)
VA Office of Research and Development
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 76 Years
Healthy volunteers
No
Inclusion criteria
* Males or females age 18-76 years old * Type 2 diabetes mellitus * Diabetic nephropathy, as defined by: * estimated GFR between 60 and 15 ml/min * presence of proteinuria * Current medical treatment with low dose aspirin * Treatment of hypertension with (but not limited to): * one diuretic * one beta-blocker * and one medication from the classes Angiotensin Receptor Blockers (ARBs) or Angiotensin Converting Enzyme inhibitors (ACE-I) * Treatment of hyperglycemia with (but not limited to) glipizide and the medication class insulin * Treatment of hypercholesterolemia with (but not limited to) one medication from the class statins
Exclusion criteria
* Type 1 diabetes mellitus * Glycosylated hemoglobin (HbA1C) \> 10% * \>20% variation in estimated GFR, during last 6 months * Systolic Blood Pressure \>170 mmHg or Diastolic Blood Pressure \>100 mmHg on medications * Other secondary forms of hypertension (endocrine, renovascular) * History of intolerance to: * Both ACE-I and ARBs * The investigational supplements * Iodinated radiologic contrast material * Known non diabetic renal disease * or history of solid organ transplantation * Hepatitis virus or Human Immunodeficiency virus infections * Use of one of the following medications within 2 months prior to enrollment in the study: * Metformin * Thiazolidinediones (pioglitazone or rosiglitazone) * Phenytoin * Warfarin * Prescription-grade vitamin E, vitamin C, systemic steroids, and/or non-steroidal anti-inflammatory agents * Over-the-counter vitamin E, vitamin C, and/or non-steroidal anti-inflammatory agents * Over-the-counter antioxidants supplements including: * Lipoic acid * Coenzyme Q10 * N-acetyl-cysteine (NAC) * Glutathione (GSH) * Chromium * Fish-oil extracts (omega-3 fatty acids) * Soy extracts (isoflavones) * Milk thistle extract (silymarin) * Green-tea preparations * Pomegranate extracts * Grape extracts * Prickly pear extract * Active coronary artery disease or cerebral vascular disease within 3 months prior to signing the informed consent * Hepatic dysfunction as defined by abnormal total bilirubin or liver enzymes (ALT, AST) \>2 times upper limit of normal range * Active malignancy * History of drug or alcohol dependency * Psychiatric or neurological condition, preventing aware consent to the study and/or adherence to the study protocol * Unwillingness to practice birth control throughout the study * Participation to another clinical study within 1 month prior to signing the informed consent form * Planned move to outside the study area, surgery or radiographic studies utilizing iodine-based contrast material within the next one year
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Urinary Albumin Excretion | Baseline and 3 months | Urine albumin to creatinine ratio was assessed at the end of run in period and after 3 months administration of study intervention. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Hemoglobin-A1c | Baseline and 3 months | Hemoglobin A1C was assessed at the end of the run in period and after 3 months of administration of study interventions. Here is delta HgA1C is reported between the two periods |
| Urinary Alpha-1 Microglobulin, Inflammatory Cytokines and C-C Chemokines | Baseline and 3 months | Urinary alpha-1 microglobulin, inflammatory cytokines and C-C chemokines were never measured and analyzed. |
Countries
United States
Participant flow
Recruitment details
213 subjects met the inclusion criteria on screening from 2 clinic locations: VA and University Hospital Renal clinics.Many had exclusion criteria and few refused to participate. 108 subjects finally enrolled in the study.
Pre-assignment details
During Run-in phase before randomization to the experimental arms, 4 subjects were excluded due to hospitalization for various reasons and 26 were excluded due to issues with transportation or sickness in the family or themselves.
Participants by arm
| Arm | Count |
|---|---|
| NAC Placebo and Silibin Placebo N-acetylcysteine placebo + silibin placebo Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months Other Name: NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
N-acetylcysteine placebo + silibin placebo: Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months | 16 |
| NAC Active and Silibin Placebo N-acetylcysteine active + silibin placebo Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
N-acetylcysteine active + silibin placebo: Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months | 13 |
| NAC Placebo and Silibin Active N-acetylcysteine placebo + silibin active Dietary Supplement: silibin 480 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months Other Name: NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
N-acetylcysteine placebo + silibin active: Dietary Supplement: silibin 480 mg orally twice daily for three months
* (Other Name) Silibin-phosphatidylcholine placebo, Siliphos placebo
* (Other Name) NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months | 17 |
| NAC Active and Silibin Active N-acetylcysteine active + silibin active Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: silibin 480 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
N-acetylcysteine active + silibin active: Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months
* (Other Name): NAC Dietary Supplement: silibin 480 mg orally twice daily for three months Silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months
* (Other Name): Silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months | 16 |
| NAC Active and High-dose Silibin Active N-acetylcysteine active + high-dose silibin active Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: high-dose silibin 960 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos
N-acetylcysteine active + high-dose silibin active: Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months | 16 |
| Total | 78 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 |
|---|---|---|---|---|---|---|
| Overall Study | Withdrawal by Subject | 0 | 1 | 1 | 0 | 2 |
Baseline characteristics
| Characteristic | NAC Placebo and Silibin Placebo | NAC Active and Silibin Placebo | NAC Placebo and Silibin Active | NAC Active and Silibin Active | NAC Active and High-dose Silibin Active | Total |
|---|---|---|---|---|---|---|
| Age, Customized Age | 65.3 years STANDARD_DEVIATION 5.74 | 64 years STANDARD_DEVIATION 6.4 | 61.9 years STANDARD_DEVIATION 8.39 | 64.81 years STANDARD_DEVIATION 8.113 | 59.56 years STANDARD_DEVIATION 7.78 | 63.09 years STANDARD_DEVIATION 7.5 |
| BMI | 30.21 kg/M^2 STANDARD_DEVIATION 9.28 | 39.9 kg/M^2 STANDARD_DEVIATION 9.17 | 35.86 kg/M^2 STANDARD_DEVIATION 8.63 | 35.65 kg/M^2 STANDARD_DEVIATION 5.16 | 35.72 kg/M^2 STANDARD_DEVIATION 7.5 | 35.31 kg/M^2 STANDARD_DEVIATION 7.67 |
| Diastolic BP | 70.44 mmHg STANDARD_DEVIATION 15.83 | 62.71 mmHg STANDARD_DEVIATION 12.63 | 77.47 mmHg STANDARD_DEVIATION 9.53 | 70.88 mmHg STANDARD_DEVIATION 8.37 | 74.25 mmHg STANDARD_DEVIATION 9.61 | 71.93 mmHg STANDARD_DEVIATION 12.08 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 1 Participants | 1 Participants | 1 Participants | 1 Participants | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) White | 15 Participants | 12 Participants | 15 Participants | 14 Participants | 15 Participants | 71 Participants |
| Sex: Female, Male Female | 1 Participants | 2 Participants | 0 Participants | 2 Participants | 2 Participants | 7 Participants |
| Sex: Female, Male Male | 15 Participants | 11 Participants | 17 Participants | 14 Participants | 14 Participants | 71 Participants |
| Systolic BP | 138.5 mmHg STANDARD_DEVIATION 21.76 | 125.54 mmHg STANDARD_DEVIATION 22.77 | 147.41 mmHg STANDARD_DEVIATION 16.8 | 137.13 mmHg STANDARD_DEVIATION 17.1 | 142.8 mmHg STANDARD_DEVIATION 12 | 139.15 mmHg STANDARD_DEVIATION 19.02 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk |
|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 12 | 0 / 16 | 0 / 16 | 0 / 14 |
| other Total, other adverse events | 7 / 16 | 7 / 12 | 6 / 16 | 8 / 16 | 9 / 14 |
| serious Total, serious adverse events | 1 / 16 | 1 / 12 | 1 / 16 | 1 / 16 | 1 / 14 |
Outcome results
Primary
Change From Baseline in Urinary Albumin Excretion
Urine albumin to creatinine ratio was assessed at the end of run in period and after 3 months administration of study intervention.
Time frame: Baseline and 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NAC Placebo + Silibin Placebo | Change From Baseline in Urinary Albumin Excretion | 50.5 mg/g | Standard Deviation 291.2 |
| NAC Active + Silibin Placebo | Change From Baseline in Urinary Albumin Excretion | -28.13 mg/g | Standard Deviation 578.32 |
| NAC Placebo + Silibin Active | Change From Baseline in Urinary Albumin Excretion | -4.5 mg/g | Standard Deviation 541 |
| NAC Active + Silibin Active | Change From Baseline in Urinary Albumin Excretion | 96.6 mg/g | Standard Deviation 422.4 |
| NAC Active + High-dose Silibin Active | Change From Baseline in Urinary Albumin Excretion | 353.71 mg/g | Standard Deviation 732.67 |
Secondary
Change From Baseline in Hemoglobin-A1c
Hemoglobin A1C was assessed at the end of the run in period and after 3 months of administration of study interventions. Here is delta HgA1C is reported between the two periods
Time frame: Baseline and 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NAC Placebo + Silibin Placebo | Change From Baseline in Hemoglobin-A1c | 0.35 percentage | Standard Deviation 0.58 |
| NAC Active + Silibin Placebo | Change From Baseline in Hemoglobin-A1c | -0.18 percentage | Standard Deviation 0.68 |
| NAC Placebo + Silibin Active | Change From Baseline in Hemoglobin-A1c | 0.72 percentage | Standard Deviation 2.91 |
| NAC Active + Silibin Active | Change From Baseline in Hemoglobin-A1c | 0.4 percentage | Standard Deviation 2.19 |
| NAC Active + High-dose Silibin Active | Change From Baseline in Hemoglobin-A1c | 0.2 percentage | Standard Deviation 1.14 |
Secondary
Urinary Alpha-1 Microglobulin, Inflammatory Cytokines and C-C Chemokines
Urinary alpha-1 microglobulin, inflammatory cytokines and C-C chemokines were never measured and analyzed.
Time frame: Baseline and 3 months
Population: The secondary outcome measures: Urinary alpha-1 microglobulin, inflammatory cytokines and C-C chemokines could not be measured due to lack of research personnel support and change in the PI who didn't have sufficient expertise to assess these measures.