Intracellular Phosphate and Adenosine Triphosphate (ATP) Concentration Evolution by Magnetic Resonance (MR) Spectroscopy in Patients During Hemodialysis
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 11
- 试验地点
- 2
- 主要终点
- Change in phosphate intracellular concentration
研究概览
简要总结
End-stage renal disease is associated with hyperphosphatemia due to a decrease of renal phosphate excretion. This hyperphosphatemia is associated with an increase of cardiovascular risk and mortality. Thus, three therapeutic options have been developed: dietary restriction, administration of phosphate binders and phosphorus clearance by hemodialysis (HD).
During a standard HD session, around 600 to 700mg phosphate is removed from the plasma, whereas it contains only 90 mg inorganic phosphate (Pi); 85% of phosphate is stored in bones and teeth in hydroxyapatite form, 14% is stored in the intracellular space (90% organic phosphate and 10% Pi), and 1% remains in the extracellular space.
Currently, the source of Pi cleared during HD remains to be determined. Phosphorus (31P) magnetic resonance spectroscopy allows reliable, dynamic and non-invasive measurements of phosphate intracellular concentration. The investigator's team recently published data obtained in anephric pigs, suggesting that phosphate intracellular concentration increases during a HD session. In parallel, we showed that ATP intracellular concentration decreased. These results suggest that the source of Pi cleared during HD could be located inside the cell.
In this study, investigators will measure intracellular phosphate and ATP concentrations and intracellular potential of hydrogen (pH) evolution during hemodialysis in 12 patients suffering from end-stage renal disease by MR spectroscopy.
If these results were confirmed in humans, it could explain, at least in part, HD intolerance in some patients and would lead to modify therapeutic approaches of hyperphosphatemia, for example, by modifying HD sessions time.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 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
- 否
入选标准
- •Patient suffering from end-stage renal disease, treated by chronic hemodialysis since at less 6 months
- •Phosphatemia (at the start of the session) ≥ 1,5 mmol/L and ≤ 3 mmol/L
- •written consent signed
排除标准
- •Major subject protected by law
- •Prisoners or subjects who are involuntarily incarcerated
- •Denutrition (weight loss ≥ 5 kg in one months/10 kg in 6 months, Body Mass Index (BMI) ≤ 21 kg/m2, albuminemia ≤ 35 g/L)
- •Obesity (BMI ≥ 30 kg/m2)
- •Phosphatemia at the start of the dialysis < 1,5 mmol/L or > 3 mmol/L
- •Secondary hyperparathyroidism with parathormone (PTH) ≥ 1000 pg/mL
- •Adynamic osteopathy (PTH ≤ 50 pg/mL)
- •Hypoparathyroidism with a history of parathyroidectomy
- •Hemoglobin ≤ 100 g/L
- •Contraindication to heparin
- •Temporary vascular access
- •Contraindication to resonance magnetic spectroscopy (pacemaker or insulin pump, metallic valvular prosthesis, valvular prosthesis not compatible with resonance magnetic spectroscopy, dental appliance, intracerebral clip, claustrophobic subject).
- •Simultaneous participation to another research protocol
- •Patient not affiliated to a social security system
研究组 & 干预措施
Patients suffering from ESRD treated by chronic hemodialysis
Patients aged from 18 to 80 years old, suffering from ESRD, treated by chronic hemodialysis since at least 6 months and whose phosphatemia at the beginning of HD sessions ranged from 1.5 to 3 mmol/L. Phosphorus (31P) magnetic resonance spectroscopy will be performed in these patients during hemodialysis in order to measure intracellular phosphate and ATP concentrations and intracellular pH evolution during hemodialysis.
干预措施: Phosphorus (31P) magnetic resonance spectroscopy (Device)
Patients suffering from ESRD treated by chronic hemodialysis
Patients aged from 18 to 80 years old, suffering from ESRD, treated by chronic hemodialysis since at least 6 months and whose phosphatemia at the beginning of HD sessions ranged from 1.5 to 3 mmol/L. Phosphorus (31P) magnetic resonance spectroscopy will be performed in these patients during hemodialysis in order to measure intracellular phosphate and ATP concentrations and intracellular pH evolution during hemodialysis.
干预措施: Hemodialysis (Other)
结局指标
主要结局
Change in phosphate intracellular concentration
时间窗: Baseline, at start of HD, every 160 seconds during HD, at the end of HD and 30 minutes after HD
Measurement of phosphate intracellular concentration evolution during a 4 hours hemodialysis (HD) session using phosphorus magnetic resonance spectroscopy.
次要结局
- Change in ATP intracellular concentration(Baseline, at start of HD, every 160 seconds during HD, at the end of HD and 30 minutes after HD)
- Change in intracellular pH(Baseline, at start of HD, every 160 seconds during HD, at the end of HD and 30 minutes after HD)
- Change in phosphatemia(At start of HD, every 15 minutes during first hour of HD, then every hour during HD, at the end of HD and 30 minutes after HD)
- Calcium balance(At the end of a 4 hours HD session)