Effect of Viscous Fiber on Postprandial Kalemic Response in Hemodialysis Patients

NCT ID: NCT05086185

Last Updated: 2025-03-27

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 7 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2021-06-29
• Study Completion Date: 2023-10-05

Brief Summary

High blood potassium levels (hyperkalemia) is a major problem for people with kidney failure undergoing hemodialysis treatment. In order to reduce the risk of hyperkalemia, people with kidney failure are advised to limit or avoid high-potassium foods. However, high-potassium foods comprise many healthy food choices, including commonly consumed fruits and vegetables that are key sources of dietary fiber, and other important nutrients.

Risk of hyperkalemia from dietary potassium intake is most notable in the first few hours after a meal when ingested potassium enters the bloodstream. In general, dietary potassium is very well absorbed. However, dietary fiber has been shown to increase the proportion of dietary potassium that is excreted in stool. Based on these findings, it has been proposed that fiber may help to lower the risk of hyperkalemia in people with kidney disease. It remains unclear whether dietary fiber increases potassium excretion in stool by reducing the absorption of dietary potassium, or by drawing body potassium into the bowels by increasing stool bulk. The distinction may be important, as reducing potassium absorption would be expected to be of greater benefit in preventing hyperkalemia caused by eating high-potassium foods.

In this study, the investigators will assess whether a fiber supplement can reduce the effect of dietary potassium from orange juice on blood potassium levels in people with kidney disease undergoing maintenance hemodialysis treatment.

Detailed Description

The source population for this study will be adults (18-89 years old) with kidney failure undergoing thrice weekly maintenance hemodialysis (HD) treatment. Participants will include 10 patients without diabetes mellitus, and 10 patients with type 2 diabetes mellitus (T2D) that is being managed with lifestyle with or without long-acting insulin. Patients with a moderate hyperkalemia (>6.5 mEq/L) in the last 6-months, taking potassium-lowering medications, having gastrointestinal (GI) disorders that may alter potassium digestion and absorption, and low hemoglobin concentrations (<10.0 g/dL) will be excluded. In addition, participants who are deemed inappropriate for the intervention by the study Nephrologist based on cognition, prognosis or pending treatments will be excluded.

Once enrolled, participants will be asked to complete questionnaires on demographics, dietary intake, GI symptoms, and urine output. In addition, baseline data on anthropometrics, physical function, medical history and blood parameters will be obtained by physical exam and review of medical records.

Treatment measurement visits will be conducted on the same non-dialysis treatment days at the University of Nevada, Reno Clinical Research Center with participants in a fasted state. Serial blood samples will be collected before, and 60, 120 and 180 minutes after ingesting orange juice providing 0.35 mEq/kg dose of potassium alone, or with 0.15 g/kg of psyllium-based fiber. The sequence of treatments (1) orange juice or 2) orange juice + fiber) will be randomly assigned with equal allocation by T2D status. If a participant's body weight exceeds 120% of ideal body weight (IBW), then the dose of orange juice and fiber will be based on adjusted body weight.

Blood tests at times 0 and 60-minutes post-treatment will be analyzed for the basic metabolic panel plus insulin, and the 120- and 180-minutes blood samples will be analyzed for potassium concentrations. The kalemic response to study treatments will assessed based on: 1) peak change in plasma potassium concentrations, and 2) total area under the curve for plasma potassium until 180-minutes. These parameters will be compared across treatment conditions using paired t-test. If non-normally distributed, values will be log-transformed prior to analyses.

Conditions

Hyperkalemia; Chronic Kidney Disease Requiring Chronic Dialysis

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Orange Juice (control)

Orange juice providing a 0.35 mEq/kg dose of potassium

Kalemic Response to Orange Juice

Intervention Type: DIAGNOSTIC_TEST

100% pulp-free orange juice

Orange Juice plus Fiber

Same amount of orange juice as Orange Juice treatment with 0.15 g/kg of psyllium-based fiber added

Kalemic Response to Orange Juice with Fiber

Intervention Type: DIETARY_SUPPLEMENT

100% pulp-free orange juice with psyllium-based fiber added

Interventions

Kalemic Response to Orange Juice

100% pulp-free orange juice

Intervention Type: DIAGNOSTIC_TEST

Kalemic Response to Orange Juice with Fiber

100% pulp-free orange juice with psyllium-based fiber added

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• Kidney failure undergoing thrice-weekly maintenance hemodialysis
• 10 patients without diabetes mellitus, and 10 patients with type 2 diabetes mellitus (T2D) that are being managed with lifestyle and/or long-acting insulin

Exclusion Criteria

• Moderate hyperkalemia (>6.5 mEq/L) in the last 6-months.
• Potassium-lowering medications
• Gastrointestinal (GI) diseases that may alter potassium digestion and absorption.
• Low hemoglobin concentrations (<10.0 g/dL).
• Deemed to be inappropriate for the intervention by Study Nephrologist based on cognition, prognosis, or pending treatments
• Women who are pregnant or who plan to become pregnant

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 89 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

United States Department of Agriculture (USDA)

FED

Sponsor Role: collaborator

Sierra Nevada Nephrology Consultants, Inc.

UNKNOWN

Sponsor Role: collaborator

University of Nevada, Reno

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

David E St-jules, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Nevada, Reno

Locations

University of Nevada,Reno

Reno, Nevada, United States

Countries

United States

References

St-Jules DE, Goldfarb DS, Sevick MA. Nutrient Non-equivalence: Does Restricting High-Potassium Plant Foods Help to Prevent Hyperkalemia in Hemodialysis Patients? J Ren Nutr. 2016 Sep;26(5):282-7. doi: 10.1053/j.jrn.2016.02.005. Epub 2016 Mar 12.

Reference Type: BACKGROUND

PMID: 26975777 (View on PubMed)

Cummings JH, Hill MJ, Jenkins DJ, Pearson JR, Wiggins HS. Changes in fecal composition and colonic function due to cereal fiber. Am J Clin Nutr. 1976 Dec;29(12):1468-73. doi: 10.1093/ajcn/29.12.1468.

Reference Type: BACKGROUND

PMID: 998555 (View on PubMed)

Allon M, Dansby L, Shanklin N. Glucose modulation of the disposal of an acute potassium load in patients with end-stage renal disease. Am J Med. 1993 May;94(5):475-482. doi: 10.1016/0002-9343(93)90081-Y.

Reference Type: BACKGROUND

PMID: 8498392 (View on PubMed)

Other Identifiers

1596754

Identifier Type: -

Identifier Source: org_study_id