Effects of High Dietary Fiber Supplementation in Diabetic Chronic Kidney Disease

Kidney Disease Clinical Trial

Official title:

Effects of High Dietary Fiber Supplementation on Uremic Retention Molecules and Inflammation in Diabetic Chronic Kidney Disease (CKD)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01838330
• Other study ID #: IRB_00052609
• Status: Completed
• Phase: N/A
• First received: January 30, 2013
• Last updated: August 9, 2016
• Start date: June 2012
• Est. completion date: January 2016

Study information

• Verified date: August 2016
• Source: University of Utah
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Loss of kidney function results in accumulation in the blood of molecules that are either excreted or metabolized by the kidney. Collectively, these molecules are termed Uremic Retention Molecules (URMs) or toxins. It is increasingly recognized that colonic bacterial metabolites like p-cresyl sulfate and indoxyl sulfate that are absorbed from the colon and excreted by the kidney may contribute to the pool of compounds implied in uremic toxicity. Indeed, these URMs have been linked to increased levels of inflammation markers, chronic kidney disease (CKD) progression, cardiovascular disease and overall mortality in CKD and/ or hemodialysis patients. Therefore, interventions that target the production or absorption of URMs from the gut might decrease inflammation and oxidative stress that are commonly seen in the uremic milieu. The National Health and Nutrition Examination Survey III (NHANES III) data show that high dietary fiber intake is associated with decreased serum levels of C-reactive protein (CRP) in those with and without CKD and these associations are much stronger in the CKD population. A possible explanation of this effect is that a high fiber diet in CKD patients modulates the bacterial production, intestinal absorption and finally the serum levels of URMs like p-cresyl sulfate and indoxyl sulfate, which in turn results in decrease in inflammation.

OBJECTIVES:

Hypothesis:

1. Higher serum levels of markers of inflammation such as high sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6) and tumor necrosis factor (TNF) -α seen in stage 4 CKD (estimated Glomerular Filtration Rate 15-29 ml/min/1.73 m2) compared to stage 2 CKD (estimated Glomerular Filtration Rate 60-89 ml/min/1.73 m2) is partly explained by the higher circulating levels of URMs (p-cresyl sulfate and indoxyl sulfate) in stage 4 CKD, and

2. Dietary supplementation in stage 4 CKD with 30g/d of a soluble fiber Psyllium (brand name-Metamucil TM) will decrease circulating URMs levels and thereby, decrease serum levels of inflammation markers and urinary levels of transforming growth factor (TGF)-β, a marker of kidney fibrosis.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 44
• Est. completion date: January 2016
• Est. primary completion date: January 2016
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 90 Years

Eligibility

Inclusion Criteria:

• Patients with or without diabetes and Stage 1 or 2 CKD (estimated Glomerular Filtration Rate > 60 mL/min/1.73 m2) with urine dipstick positive for protein or urinary albumin/ creatinine > 30 mg/g of creatinine; or

• Stage 3 or 4 CKD (estimated Glomerular Filtration Rate < 60 to 15 mL/min/1.73 m2).

Exclusion Criteria:

• Pregnant women

• Prisoners

• Bowel obstruction

• Enrolled in other interventional studies.

Study Design

Allocation: Non-Randomized, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Kidney Disease
• Kidney Diseases
• Renal Insufficiency, Chronic

Intervention

Dietary Supplement:
• psyllium
15 grams/day for 1 week, followed by 30 grams/day for 4 months

Locations

Country	Name	City	State
United States	University of Utah nephrology clinics, the internal medicine and endocrinology clinics	Salt Lake City	Utah

Sponsors (1)

Lead Sponsor	Collaborator
University of Utah

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	p-cresyl sulfate serum concentration	Comparison of serum p-cresyl sulfate concentration between Stage 3-4 CKD subjects (following treatment with soluble fiber psyllium) and Stage 1-2 CKD subjects (having received no study treatment)	4 months	No
Secondary	Indoxyl sulfate serum concentration	Comparison of serum indoxyl sulfate concentration between Stage 3-4 CKD subjects (following treatment with soluble fiber psyllium) and Stage 1-2 CKD subjects (having received no study treatment)	4 months	No
Secondary	Interleukin-6 (IL-6) serum concentration	Comparison of serum IL-6 concentration between Stage 3-4 CKD subjects (following treatment with soluble fiber psyllium) and Stage 1-2 CKD subjects (having received no study treatment)	4 months	No