Comparison of DASH With Oxalate Restricted Diet on Urine in Recurrent Stone Formers With Hyperoxaluria

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Nazanin Noori, Shaheed Beheshti Medical University
ClinicalTrials.gov Identifier:
NCT01650935
First received: July 24, 2012
Last updated: April 15, 2013
Last verified: April 2013
  Purpose

Oxalate restricted diet is routinely prescribed in clinical practice of nephrolithiasis patients with hyperoxaluria. The effect of dietary oxalate on urinary oxalate is however controversial. Some studies do not implicate dietary oxalate as a major risk factor for nephrolithiasis. The Dietary Approaches to Stop Hypertension (DASH) diet, which is high in fruits and vegetables, moderate in low-fat dairy products, and low in animal protein represents a novel potential means of kidney stone prevention. The effect of a DASH-style diet on relative urinary supersaturations is however uncertain. Higher consumption of fruits and vegetables may increase urinary oxalate but also increases urinary citrate, an important inhibitor of calcium saturation.All the above data lead us to hypothesize that a DASH diet other than an oxalate restricted diet, which is routinely administered in clinical practice, might be beneficial in lowering urinary relative supersaturations of calcium oxalate in recurrent stone formers with hyperoxaluria.

Recurrent stone formers with hyperoxaluria (urine oxalate>32.8) are allocated into 2 groups. The first group is prescribed an oxalate restricted diet. The second group are asked to follow a calorie-controlled DASH diet plan while drink water in the same amounts. 24-h urine is collected 2 times before study visits at baseline, 1 time on week 6 and 2 times at the end of the study.


Condition Intervention
Nephrolithiasis
Behavioral: diet

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Study of the Effects of DASH Style Diet and Oxalate Restricted Diet on Urinary Supersaturation Which is a Major Predisposing Factor for Nephrolithiasis

Resource links provided by NLM:


Further study details as provided by Shahid Beheshti Medical University:

Primary Outcome Measures:
  • urinary oxalate [ Time Frame: 2 months ] [ Designated as safety issue: No ]
    24-h urine including urine oxalate is collected 2 times before study visits at baseline, and 2 times at the end of the study which is 2 months.


Secondary Outcome Measures:
  • urinary calcium oxalate supersaturation [ Time Frame: 2 months ] [ Designated as safety issue: No ]
    Urinary supersaturation is calculated before study visits at baseline, and at the end of the study which is 2 months.


Enrollment: 48
Study Start Date: September 2012
Study Completion Date: April 2013
Primary Completion Date: February 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Oxalate restricted
After a run-in period of 3 weeks patients are allocated into 2 groups. The Oxalate restricted group is prescribed an oxalate restricted diet. They are instructed to avoid oxalate-rich foods such as spinach, rhubarb, beets, chocolate, cereals, nuts, tea, wheat bran, and strawberries and to drink water in amounts of roughly 2 L during cold weather and 3 L during warm/hot weather.
Behavioral: diet
When the first set of urine samples confirmed hyperoxaluria (urine oxalate>32.8), the patients will enter the study. After a run-in period of 3 weeks patients are allocated into 2 groups that I already explained in the arms section.The patients are visited in the beginning, after 6 weeks and at the end of the study
Active Comparator: DASH diet
The second group is asked to follow a calorie-controlled DASH diet plan. DASH is an eating pattern recommended by the 2005 Department of Health and Human Services Dietary Guidelines for Americans as a model of healthy eating for the majority of individuals in the population. This group eats a diet which includes higher fruit, vegetables, and low-fat dairy products and lower in saturated fat, total fat, and cholesterol, containing more whole grains and fewer refined grains, sweets, and red meat.
Behavioral: diet
When the first set of urine samples confirmed hyperoxaluria (urine oxalate>32.8), the patients will enter the study. After a run-in period of 3 weeks patients are allocated into 2 groups that I already explained in the arms section.The patients are visited in the beginning, after 6 weeks and at the end of the study

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  Eligibility

Ages Eligible for Study:   18 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • A history of at least one time kidney stone
  • more than 18 years old
  • stones at least 50% calcium oxalate
  • normal renal function, -sterile urine samples, -
  • normal blood pressure

Exclusion Criteria:

  • primary hyperoxaluria (urine oxalate>100 mg/24h)
  • diabetes mellitus
  • hepatic, thyroid, parathyroid, CKD or immunologic disease
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01650935

Locations
Iran, Islamic Republic of
Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences
Tehran, Iran, Islamic Republic of, 1666677951
Labbafinejad Hospital
Tehran, Iran, Islamic Republic of, 5122
Sponsors and Collaborators
Shahid Beheshti Medical University
Investigators
Principal Investigator: Nazanin Noori, MD, PhD urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences
  More Information

No publications provided by Shahid Beheshti Medical University

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Nazanin Noori, MD, PhD, Shaheed Beheshti Medical University
ClinicalTrials.gov Identifier: NCT01650935     History of Changes
Other Study ID Numbers: 114
Study First Received: July 24, 2012
Last Updated: April 15, 2013
Health Authority: Iran: Ethics Committee

Keywords provided by Shahid Beheshti Medical University:
Nephrolithiasis
Recurrent stone former
DASH
Urine oxalate
Urine calcium oxalate supersaturation

Additional relevant MeSH terms:
Nephrolithiasis
Kidney Diseases
Urologic Diseases
Urolithiasis

ClinicalTrials.gov processed this record on July 24, 2014