Obesity
Conditions
Keywords
oxalate, obesity, kidney stones
Brief summary
The goal of this study is to determine if obesity is associated with increased endogenous oxalate synthesis as assessed by urinary oxalate excretion, which is a known risk factor for calcium oxalate kidney stones. The study will recruit adult participants without history of kidney stones. Participants will * Ingest fixed diets containing low amounts of oxalate for 4 days * Collect 24-hr urine samples during the fixed diet
Detailed description
In this study the investigators propose to measure the excretion of urinary oxalate on a fixed diet with controlled amounts of oxalate, in individuals of varying body sizes without history of kidney stones. The 24-hr urinary oxalate excretion on such a low-oxalate normal calcium fixed diet is determined to be an appropriate surrogate for endogenous oxalate synthesis. Screening phase. The study will enroll 60 individuals without history of kidney stones (30 males/30 females) at the University of Alabama at Birmingham (UAB). Screening will include blood complete metabolic profile, 24-hr urine specimens collected at home on self-selected diets and anthropometric measurements. Dietary phase Participants will ingest a low-oxalate (\<60 mg/day), normal calcium (1000 mg/day) fixed diet for 4 consecutive days, collect three 24-hr urines after 1 day of dietary equilibration and have a fasted blood draw on day 5.
Interventions
DIETARY_SUPPLEMENTNormal Individuals
Controlled Dietary phase: Low oxalate fixed diet 4 days of fixed normal calorie diet with low oxalate (\< 60 mg/day), normal calcium (800-1200 mg/day)
Sponsors
University of Alabama at Birmingham
National Institutes of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
19 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
Age 19-70 yrs Body Mass Index \> 18.5 kg/m2 Normal fasting serum electrolytes on comprehensive metabolic profile Willing to ingest fixed diets
Exclusion criteria
Chronic Kidney Disease, estimated glomerular filtration rate \< 60 ml/mn/1.73m2 Primary hyperoxaluria Liver, endocrine or renal diseases or any other condition that may influence the absorption, transport or urinary excretion of ions, which will compromise the interpretation of results, including: Cystic fibrosis, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion Pregnancy or breast-feeding Incompatible dietary requirements with the study, food allergies or intolerance to any of the foods in study menus Active malignancy or treatment for malignancy within 12 months prior to screening Utilization of immunosuppressive medication Uncontrolled Hypertension or diabetes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Urinary Oxalate Excretion | 3 days on the fixed diet | Mean Urinary oxalate excretion from three 24 hour urine collections on the fixed diet (mg/day) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Urinary Glycolate Excretion | 3 days on fixed diet | mean of three 24-hr urinary glycolate collected on the fixed diet (mg/day) |
| Urinary Creatinine Excretion | 3 days on the fixed diet | mean of there 24hr urinary creatinine excretion on the fixed diet ( g/day) |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORKyle D Wood, MD
University of Alabama at Birmingham
Participant flow
Recruitment details
total study enrollment
Participants by arm
| Arm | Count |
|---|---|
| Normal Individuals Normal individuals: no prior history of kidney stones
Normal Individuals: Controlled Dietary phase: Low oxalate fixed diet
4 days of fixed eucaloric diet with low oxalate (\< 60 mg/day), normal calcium (800-1200 mg/day) | 58 |
| Total | 58 |
Baseline characteristics
| Characteristic | Normal Individuals |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 58 Participants |
| Age, Continuous | 38 years STANDARD_DEVIATION 13 |
| Body Mass Index | 29 kg/m2 STANDARD_DEVIATION 7 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 5 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 52 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 28 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 29 Participants |
| Region of Enrollment United States | 58 Participants |
| Sex: Female, Male Female | 35 Participants |
| Sex: Female, Male Male | 23 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 58 |
| other Total, other adverse events | 0 / 58 |
| serious Total, serious adverse events | 0 / 58 |
Outcome results
Primary
Urinary Oxalate Excretion
Mean Urinary oxalate excretion from three 24 hour urine collections on the fixed diet (mg/day)
Time frame: 3 days on the fixed diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Normal Individuals | Urinary Oxalate Excretion | 24 mg/day | Standard Deviation 10 |
Secondary
Urinary Creatinine Excretion
mean of there 24hr urinary creatinine excretion on the fixed diet ( g/day)
Time frame: 3 days on the fixed diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Normal Individuals | Urinary Creatinine Excretion | 1.47 g/day | Standard Error 0.58 |
Secondary
Urinary Glycolate Excretion
mean of three 24-hr urinary glycolate collected on the fixed diet (mg/day)
Time frame: 3 days on fixed diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Normal Individuals | Urinary Glycolate Excretion | 32 mg/day | Standard Deviation 14 |