Clinical trial NCT02823613: The Influence of High and Low Salt on Exosomes in the Urine
Official title: The Influence of High and Low Salt on Exosomes in the Urine
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Keywords: ENaC
Exosomes
Urinary biomarker
Salt regulation
Lead sponsor: University of Southern Denmark
Sponsor class: OTHER
Collaborators: name: Danish Diabetes Academy
name: Odense University Hospital
name: Beckett Foundation
First posted: 2016-07-06
Enrollment: 10
Sex: MALE
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: The hypothesis is that changes in the epithelial sodium channel (ENaC) in the kidney is reflected in urinary exosomes and that the amount of ENaC as well as the cleavage degree is upregulated in conditions with low salt.

Detailed description: Methods:

Exosomes will be isolated from spot urine by ultracentrifugation and tested using western blotting. In-house developed antibodies against different parts of the ENaC gamma subunit as well as commercial antibodies will be used. A marker for exosomes will validate the presence of exosomes in the urine.

Power considerations:

In this cross over salt-intervention study with quantification of ENaC the investigators refer to a published study regarding the sodium-chloride co-transporter (NCC) in the kidney, were rats where given aldosterone infusion or a low salt diet. In this study n=6 was sufficient to detect a 2-3 fold change in NCC in urinary exosomes. Furthermore 5 patients with primary aldosteronism had a significant increase in NCC in urinary exosomes (N. Lubbe et al, Hypertension 2012).

On the basis of this the investigators choose to test 10 persons, but are not able to make a regular power calculation.

Eligibility criteria: Inclusion Criteria:

* Healthy men aged 20-40
* Body Mass Index (BMI, weight/height\^2) between 18 and 25.

Exclusion Criteria:

* Increased blood pressure (hypertension) or in treatment for high blood pressure
* Diabetes
* Regular medical intake
* Smoking
* Expectation of lacking cooperation or lack of understanding of the experiment
* Clinical relevant organic or systemic disease including malign disease
* Decreased kidney function

Primary outcomes:
measure: Changes in epithelial sodium channel (ENaC) appearance in urinary exosomes
timeFrame: After 5 days on high or low salt diet
Secondary outcomes:
measure: Plasma aldosterone
timeFrame: Before study start and after 5 days on high or low salt diet
measure: Renin
timeFrame: Before study start and after 5 days on high or low salt diet
Other outcomes:
Locations:
city: Odense
country: Denmark
facility: University of Southern Denmark
Study officials:
affiliation: Cardiovascular and Renal Research, Institute of Moleculare Medicine, University of Southern Denmark
name: Boye L Jensen, dr.med., phd
role: STUDY_DIRECTOR
References:
citation: Zachar RM, Skjodt K, Marcussen N, Walter S, Toft A, Nielsen MR, Jensen BL, Svenningsen P. The epithelial sodium channel gamma-subunit is processed proteolytically in human kidney. J Am Soc Nephrol. 2015 Jan;26(1):95-106. doi: 10.1681/ASN.2013111173. Epub 2014 Jul 24.
citation: van der Lubbe N, Jansen PM, Salih M, Fenton RA, van den Meiracker AH, Danser AH, Zietse R, Hoorn EJ. The phosphorylated sodium chloride cotransporter in urinary exosomes is superior to prostasin as a marker for aldosteronism. Hypertension. 2012 Sep;60(3):741-8. doi: 10.1161/HYPERTENSIONAHA.112.198135. Epub 2012 Jul 30.