Effect of Protein Supplementation on Plasma Sodium Levels and Urinary Urea Excretion in Patients With SIAD - a Monocentric Open- Label Proof-of-concept Study -The TREASURE Study
This study aims to investigate whether a 7-day dietary high protein supplementation of 90 grams per day increases plasma sodium levels in hyponatremic patients with chronic SIAD. Enrolled patients will receive first dietary high protein supplementation for one week. After a wash-out phase of at least one week, the patients will receive oral urea for another week.
• previous documented diagnosis of chronic SIAD
• confirmed diagnosis of SIAD at screening visit defined as:
• plasma sodium concentration <135 mmol/L, measured in lithium heparin plasma
• Plasma osmolality <300 mOsm/kg
• Urine osmolality >100 mOsm/kg
• Urine sodium concentration >30mmol/l
• Clinical euvolemia, defined as an absence of signs of hypovolemia (orthostasis, tachycardia, decreased skin turgor, dry mucous membranes) or hypervolemia (edema, ascites)