Clinical trial NCT04333745: Influence of Obesity on Oxalate Metabolism and Handling in Calcium Oxalate Stone Formers
Official title: Influence of Obesity on Oxalate Metabolism and Handling in Calcium Oxalate Stone Formers
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Kidney Stone
Keywords: oxalate
kidney stone
Lead sponsor: University of Alabama at Birmingham
Sponsor class: OTHER
First posted: 2020-04-03
Enrollment: 22
Sex: ALL
Minimum age (years): 19
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: The primary goals of this study are to determine the contribution of dietary oxalate absorption, renal oxalate handling, and endogenous oxalate synthesis to urinary oxalate excretion in normal Body Mass Index (BMI) and obese calcium oxalate kidney stone formers.


Eligibility criteria: Inclusion Criteria:

* Normal Body Mass Index (≥ 18.5 to \< 25); Obese Body Mass Index (≥ 30 to ≤ 45)
* Able to provide informed consent
* Willingness to consume controlled diet
* Composition of most recent stone \> 50% calcium oxalate, no uric acid component
* First time or recurrent calcium oxalate stone former
* 24-hour urine collections with creatinine values within 20% of appropriate ratio of creatinine (mg)/body weight (kg) for gender, and with creatinine values that are consistent between collections (within 20% of each other)
* Willingness to stop supplements \[vitamins, Ca (citrate or carbonate) and other minerals, herbal supplements, nutritional aids, probiotics\] for 14 days before start and during study
* Willingness to not undertake vigorous exercise during the controlled dietary study
* Normal fasting blood Comprehensive Metabolic Panel
* Hemoglobin A1c \< 6.5%
* No food allergies or intolerance to any of the food in study menus
* Permitted/willing to discontinue medications for kidney stone prevention, including thiazides, allopurinol, and febuxostat and citrate preparations, for 14 days before start and during the studies. They will be instructed to restart these medications at the conclusion of the study

Exclusion Criteria:

* Diabetes
* Abnormal fasting comprehensive metabolic panel (CMP)
* Hemoglobin A1c (HbA1c) result ≥ 6.5%
* Gout
* Estimated Glomerular Filtration Rate (eGFR) \<60 ml/min/1.73m\^2
* Primary hyperoxaluria
* Cystic fibrosis
* Cystinuria
* Uric acid stone former
* Utilization of immunosuppressive medication
* Nephrotic syndrome
* Enteric hyperoxaluria
* Gastrointestinal disorder that could impact oxalate transport
* Sarcoidosis
* Uncontrolled hypertension
* Renal tubular acidosis
* Primary hyperparathyroidism
* Liver disease
* Neurogenic bladder
* Urinary diversion
* Chronic diarrhea
* Bariatric surgery
* Active malignancy or treatment for malignancy within 12 months prior to screening
* Pregnancy
* Breast feeding/nursing
* Females of child bearing age who are not able to use an effective method of birth control during the study
* Mental/medical condition that is likely to impede successful study completion
* Illness including flu / common cold / fever 14 days before study and during study
* Diarrhea or other abnormal gastrointestinal event (e.g. abnormal bowel movements) 14 days before study or during study
* Antibiotic use within last 6 months (based on recommendations of the NIH Human Microbiome Project, Protocol A)
* Inability or unwillingness to undergo MRI

Primary outcomes:
measure: Urinary Oxalate Excretion
timeFrame: Baseline through Day 5
Secondary outcomes:
Other outcomes:
Locations:
city: Birmingham
country: United States
facility: University of Alabama at Birmingham
state: Alabama
city: Dallas
country: United States
facility: University of Texas Southwestern Medical Center
state: Texas
Study officials:
affiliation: University of Alabama at Birmingham
name: Dean Assimos, MD
role: PRINCIPAL_INVESTIGATOR
References: