Modulation of Tissue Sodium in Hemodialysis Patients

University of Erlangen-Nürnberg Medical School

Status: Completed

Conditions: Chronic Kidney Disease Requiring Chronic Dialysis

Treatments: Procedure: Change of dialysate [Na+]

Study type: Interventional

Funder types: Other

Identifiers

NCT03525223

DNa

Details and patient eligibility

About

Salt (NaCl) intake is implicated in causing hypertension and cardiovascular disease, the commonest cause of death worldwide. The investigators recently established that Na+ is stored in tissues, bound to glycosaminoglycans (GAGs) in skin and muscle. The resulting local hypertonicity leads to immune cell-driven induction of local tissue electrolyte clearance via modulation of cutaneous lymph capillary density. To visualize these complex processes in man directly, the investigators established Na+ magnetic resonance imaging (23Na-MRI) and investigated Na+ stores in hemodialysis (HD) patients. Hemodialysis patients were sodium-"overloaded" and HD treatment lowered tissue Na+ stores in this study. The observed effects were highly variable and independent of Na+ or water removal from the body during a dialysis session. Tissue Na+ mobilization correlated with circulating vascular endothelial growth factor-C (VEGF-C). The investigators believe that excessive Na+ storage is a reversible condition and therefore susceptible for therapeutic interventions. The investigators hypothesize that lowering dialysate Na+ concentration may favorably affect accelerated tissue Na+ accumulation in hemodialysis patients. Besides, improved tissue Na+ storage, osmostress-induced as well as pro-inflammatory immune cell response should be affected by such a revised dialysis management.

Full description

To evaluate effects of moderate reduction of dialysate Na+ concentration on tissue Na+ content the investigators intend to recruit 40 hemodialysis patients, who will be offered a therapeutic change of their dialysate Na+ concentration. After detection of tissue Na+ content using 23Na-MRI technique, the applied dialysate [Na+] will be initially increased stepwise by 2 mmol/l per week from 138 to 142 mmol/l and maintained for a period of 5 weeks. After another 23Na-MRI measurement, dialysate [Na+] will then be lowered stepwise by 1-2 mmol/l per week to a minimum of 135 mmol/l, which will be also maintained for a period of 5 weeks followed by a final 23Na-MRI assessment.

Hypothesis: Reduction of dialysate Na+ concentration will decrease tissue sodium storage.

Additionally, the investigators will assess changes in body fluid distribution by bioimpedance spectroscopy. Furthermore, vascular compliance in response to the modulation of dialysate [Na+] and its correlation with tissue Na+ will be assessed. To investigate the immune response to tissue Na+ accumulation, the osmostress-induced as well as pro-inflammatory immune cell response of isolated monocytes will be quantified.

Enrollment: 10 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Chronic Kidney Disease Stage 5D, hemodialysis performed for at least 6 months, three times hemodialysis per week, signed informed consent

Exclusion criteria

• Pregnancy, severe heart failure (NYHA III - IV), severe liver disease (CHILD C), acute infection, pacemaker or other non-MRI suitable conditions, hyponatremia < 132 mmol/l

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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10 participants in 2 patient groups

dialysate [Na+] 138 mmol/l

Active Comparator group

Description:

Intervention: Change of dialysate [Na+] from 138 mmol/l to 142 mmol/l The dialysate [Na+] will be increased by 2 mmol/l per week and kept constant for 5 weeks (altogether 6 weeks). Before and after intervention tissue [Na+] will be determined by sodium MRI. Additionally body fluid distribution (by bioimpedance spectroscopy) and central arterial pressure wave form, pulse wave velocity as well as flow-mediated vasodilatation will be assessed.

Treatment:

Procedure: Change of dialysate [Na+]

dialysate [Na+] 142 mmol/l

Active Comparator group

Description:

Intervention: Change of dialysate [Na+] from 142 mmol/l to 135 mmol/l The dialysate [Na+] will be decreased by 2 mmol/l per week for 3 weeks and by 1mmol/l for 1 further week. Afterwards the dialysate [Na+] will be kept constant for 5 weeks (altogether 8 weeks). Before and after intervention tissue [Na+] will be determined by sodium MRI. Additionally body fluid distribution (by bioimpedance spectroscopy) and central arterial pressure wave form, pulse wave velocity as well as flow-mediated vasodilatation will be assessed.

Treatment:

Procedure: Change of dialysate [Na+]