Dietary Oxalate and Innate Immunity in Kidney Stone Disease

The University of Alabama at Birmingham

Status: Active, not recruiting

Conditions: Kidney Stone

Treatments: Dietary Supplement: Low Oxalate Diet; Dietary Supplement: High Oxalate Diet

Study type: Interventional

Funder types: Other

Identifiers

NCT04051346

IRB-300003865

Details and patient eligibility

About

This study will test whether oxalate stimulates urinary crystals and impacts the immune system in healthy subjects using two controlled diets (low and high oxalate).

Full description

Oxalate is a small molecule found in plants and plant-derived food. It has been shown that meals containing high amounts of oxalate can increase urinary oxalate excretion, which is a risk factor for calcium oxalate kidney stones (CaOx KS). Small increases in oxalate can stimulate urinary crystals to form which can elicit an immune response. This study consists of having healthy subjects consume both low and oxalate enriched diets to evaluate the effect of oxalate on urinary crystals and immune responses. Participants will receive a low or high oxalate diet for 4 days prior to having a wash out period for 6 days. Participants will then crossover to the opposite oxalate diet for four more days.

Enrollment: 20 estimated patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy subjects (men and women) between the ages of 18 and 60 years of age
• No calcium oxalate kidney stones or other medical conditions
• Normal comprehensive metabolic panel (CMP)
• Non tobacco users
• Not pregnant
• BMI between 20-30 kg/m2
• Willing to abstain from vigorous exercise and vitamins/supplements during the study
• Willing to consume only provided diets, accurately collect 24-hour urine samples, and have blood drawn

Exclusion criteria

• Inability to sign and read the informed consent
• Any medical, psychiatric, or social conditions that would prohibit participants from abiding by the study requirements
• Physician refusal
• Pregnant women
• Active medical problems
• History of kidney stones or any medical condition that could influence absorption or excretion of oxalate
• Tobacco users
• Taking medications or dietary supplements
• BMI >30 or <20

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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20 participants in 2 patient groups

Low Oxalate Diet Followed by High Oxalate Diet

Experimental group

Description:

Subjects will consume a low oxalate diet for four days, with blood and 24-hour urine collections occurring at baseline and post diet. A ten day wash out period will follow, during which the subject will consume a self-selected diet. Subjects will then consume the high oxalate diet for the final four days, with blood and 24-hour urine collections once again occurring at baseline and post diet.

Treatment:

Dietary Supplement: High Oxalate Diet

Dietary Supplement: Low Oxalate Diet

High Oxalate Diet Followed by Low Oxalate Diet

Experimental group

Description:

Subjects will consume a high oxalate diet for four days, with blood and 24-hour urine collections occurring at baseline and post diet. A ten day wash out period will follow, during which the subject will consume a self-selected diet. Subjects will then consume the low oxalate diet for the final four days, with blood and 24-hour urine collections once again occurring at baseline and post diet.

Treatment:

Dietary Supplement: High Oxalate Diet

Dietary Supplement: Low Oxalate Diet