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

NCT01650935 | Completed DMC

• 1 other identifier: 114
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 2

Brief Summary

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.

Conditions

Nephrolithiasis

Keywords

Nephrolithiasis; Recurrent stone former; DASH; Urine oxalate; Urine calcium oxalate supersaturation

Outcome Measures

Primary Outcomes (1)

• urinary oxalate

  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.

  2 months

Secondary Outcomes (1)

• urinary calcium oxalate supersaturation

  2 months

Study Arms (2)

Oxalate restricted

ACTIVE COMPARATOR

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

DASH diet

ACTIVE COMPARATOR

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

Interventions

diet BEHAVIORAL

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

DASH diet; Oxalate restricted

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• primary hyperoxaluria (urine oxalate\>100 mg/24h)
• diabetes mellitus
• hepatic, thyroid, parathyroid, CKD or immunologic disease

Sponsors & Collaborators

• Shahid Beheshti University of Medical Sciences: lead

Study Sites (2)

Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences

Tehran, 1666677951, Iran

Location

Labbafinejad Hospital

Tehran, 5122, Iran

Location

Related Publications (1)

• Noori N, Honarkar E, Goldfarb DS, Kalantar-Zadeh K, Taheri M, Shakhssalim N, Parvin M, Basiri A. Urinary lithogenic risk profile in recurrent stone formers with hyperoxaluria: a randomized controlled trial comparing DASH (Dietary Approaches to Stop Hypertension)-style and low-oxalate diets. Am J Kidney Dis. 2014 Mar;63(3):456-63. doi: 10.1053/j.ajkd.2013.11.022.

  PMID: 24560157 DERIVED

MeSH Terms

Conditions

Nephrolithiasis

Interventions

Diet

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Male Urogenital Diseases

Intervention Hierarchy (Ancestors)

Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Nazanin Noori, MD, PhD

  urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD, PhD

Study Record Dates

• First Submitted: July 24, 2012
• First Posted: July 26, 2012
• Study Start: September 1, 2012
• Primary Completion: February 1, 2013
• Study Completion: April 1, 2013
• Last Updated: April 16, 2013

Record last verified: 2013-04

Locations

IR (2)