Endogenous Oxalate Synthesis in Idiopathic Calcium Oxalate Kidney Stone Formers
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 80
- 试验地点
- 4
- 主要终点
- Estimated endogenous oxalate synthesis (oxalate mg/day)
研究概览
简要总结
The goal of this clinical trial study is to test if patients with idiopathic calcium oxalate kidney stones have an increased production of oxalate by the body, which would lead to increased urinary excretion of oxalate.
The study will recruit adult patients with a history of calcium oxalate kidney stones and healthy volunteers without kidney stones.
Participants will
ingest fixed diets containing low amounts of oxalate for 5 days ingest a soluble form of glycolate and vitamin C collect urine, blood, stool during the dietary and oral dosing portions of the study and also collect breath sample during the oral glycolate test
详细描述
In this study the investigators propose to measure the production of oxalate by the body (endogenous oxalate synthesis), after equilibration on a low oxalate diet (<60 mg oxalate/day, 600-800 mg calcium/day) and estimate the importance of vitamin C and glycolate metabolism to oxalate production in both Calcium Oxalate Kidney Stone patients and matched controls by oral dosings of those two substances.
Phase 1. Screening and low-oxalate diet 24-hr urinary excretions. Between the University of Alabama at Birmingham (UAB) and the University of Texas Southwestern Medical Center (UTSW), the study will enroll 40 subjects with idiopathic Calcium Oxalate Kidney Stone (20 Males/20 Females) and 40 non-kidney stone forming controls (20 Males/20 Females). Participants in the two groups will be matched for age (within 10 yrs) and gender. Screening will include blood complete metabolic profile and two 24-hour urine specimens collected at home on self-choice diets and anthropometric measurements.
Participants will then ingest the controlled low-oxalate (<60 mg/day) diet for 5 consecutive days and collect two 24-hour urines after 2 days of dietary equilibration.
Phase 2. Oxalate production and 13C-glycolate dosing tests. On Day 5, participants will arrive after an overnight fast in the research unit to undergo the oral 13C-glycolate dosing test. After a 1-hour baseline urine collection, they will ingest an oral load containing 0.5 mg/kg body weight of 13C-glycolate, dissolved in bottled water. For the next 7 hours, blood and urine will be collected hourly, and breath as more time points. They will remain on the fixed diet for 24 hours with a meal 7 hours post-load, and dinner at home 12 hours post-load. They will collect the remainder of their 24-hour urine at home.
Phase 3. Oxalate production and 13C-ascorbic acid dosing tests. After 1 day of equilibration on the same low-oxalate diet, participants will arrive after an overnight fast in the research unit to provid eone blood and one urine sample and then ingest an oral dose of 13C-ascorbic acid (0.75 mg/kg), return home and continue to ingest the low-oxalate diet. The next morning, participants will arrive after an overnight fast in the research unit. For the next 7 hours, blood and urine will be collected hourly. They will remain on the fixed diet for 24 hours with a meal at the end of the visit.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •age 18-80 yrs
- •Body Mass Index > 18.5 kg/m2
- •Normal fasting serum electrolytes on comprehensive metabolic profile
- •Willing to ingest fixed diets
- •Willing to stop supplements (vitamins including vitamin C, calcium (citrate or carbonate) and other minerals, herbal supplements, nutritional aids, probiotics) for 2 weeks before start and during study.
- •For stone formers: first time or recurrent Calcium Oxalate stone former. Composition of most recent stone ≥ 50% calcium oxalate if available, uric acid component <20%
排除标准
- •Chronic Kidney Disease stage 4-5
- •Primary hyperoxaluria, Enteric (secondary) hyperoxaluria
- •Liver, bowel, endocrine or renal diseases (other than idiopathic Calcium Oxalate kidney stones) 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, Celiac disease, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion, Chronic diarrhea, Bariatric surgery, Inflammatory bowel disease
- •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
- •Diabetes type 1
研究组 & 干预措施
Idiopathic Calcium Oxalate Kidney Stone Patients
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Low-oxalate diet and glycolate dosing (Dietary Supplement)
Idiopathic Calcium Oxalate Kidney Stone Patients
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Oral glycolate dosing (Dietary Supplement)
Idiopathic Calcium Oxalate Kidney Stone Patients
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Oral 13C- ascorbic acid dosing (Dietary Supplement)
Healthy non-kidney stone forming individuals
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Low-oxalate diet and glycolate dosing (Dietary Supplement)
Healthy non-kidney stone forming individuals
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Oral glycolate dosing (Dietary Supplement)
Healthy non-kidney stone forming individuals
Low oxalate fixed diets. oral glycolate and ascorbic acid administration
干预措施: Oral 13C- ascorbic acid dosing (Dietary Supplement)
结局指标
主要结局
Estimated endogenous oxalate synthesis (oxalate mg/day)
时间窗: 1 day
Basal rate of endogenous oxalate synthesis estimated by repeat fasted hourly urine collections (mg/day)
次要结局
- 24-hour urinary oxalate excretion on low oxalate diet(2 days)
- contribution of ascorbic acid breakdown to urinary oxalate excretion(2 days)
研究者
Sonia Fargue
Associate professor
University of Alabama at Birmingham