Effect of Over-the-counter Dietary Supplements on Kidney Stone Risk

Hyperoxaluria Clinical Trial

Official title:

Effect of Over-the-counter Dietary Supplements on Kidney Stone Risk

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02404701
• Other study ID #: 2015-0076
• Status: Completed
• Phase: N/A
• First received: March 26, 2015
• Last updated: October 26, 2016
• Start date: February 2015
• Est. completion date: October 2016

Study information

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

Clinical Trial Summary

The purpose of this study is to ascertain whether certain supplements promote excessive urinary oxalate excretion and increase the risk for calcium oxalate kidney stones. Supplements that enhance urinary oxalate excretion, as a result of their oxalate concentration or from some other mechanism (e.g., providing substrate for oxalate biosynthesis) will be identified by the investigators.

Description:

The investigators hypothesize that certain over-the-counter dietary supplements will increase urinary excretion of oxalate as measured in 24-h urine collections. The investigators further hypothesize that the concentration of oxalate in dietary supplements may not be associated with urinary oxalate excretion, suggesting that other nutritional components of the supplements may be exerting an influence over oxalate biosynthesis, oxalate absorption in the gastrointestinal tract, and/or renal oxalate handling. These other factors include the form of oxalate in the supplement (water- vs. non water-soluble) and the supplement's concentration of ascorbic acid.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 45
• Est. completion date: October 2016
• Est. primary completion date: October 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• At least 18 years of age, no prior personal history of kidney stones

Exclusion Criteria:

• Personal history of kidney stones (by subjects' report); known allergy to any of the dietary supplements to be used in the study (by subjects' report); short bowel; active ulcerative colitis or irritable bowel disease; Crohns or Celiac disease; renal tubular acidosis; current use of topiramate or other carbonic anhydrase inhibitor, steroids, allopurinol, thiazide diuretics, or supplemental ascorbic acid >250 mg/day.

Study Design

Allocation: Randomized, Endpoint Classification: Bio-availability Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Hyperoxaluria
• Kidney Calculi
• Nephrolithiasis

Intervention

Dietary Supplement:
• Aloe vera with cactus
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Cranberry
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Green tea extract
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Bilberry
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Cinnamon
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Milk thistle
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Turmeric
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.
• Aloe vera
Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Locations

Country	Name	City	State
United States	Department of Urology, School of Medicine & Public Health, University of Wisconsin	Madison	Wisconsin

Sponsors (1)

Lead Sponsor	Collaborator
University of Wisconsin, Madison

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Within-subject change in 24-hour urinary oxalate excretion from before and after supplementation	24-hour urine samples will be analyzed for oxalate by ion chromatography. The difference in oxalate between the baseline (non-supplement) and supplement phase will be assessed.	7 days	No