I stumbled upon this paper because I'm experiencing a severe crash and had some private blood work done. As usual (and frustratingly) all seemed normal except Copeptin (2,36) and serum osmolality (330). High osmolality suggests dehydration but than Copeptin should be way higher as a compensation mechanism. ChatGTP claims this is highly suggestive (95-100% specificity and sensitivity) of central diabetes inspidus. A friend endocrinologist agreed but had some reservations about the accuracy of the tests as the blood was send by mail.
I'm now getting a retest including urine osmolality and then probably a copeptin stimulation test at the hospital.
After a 20 year struggle I hope to have finally found the silver bullet.!It does make sense. As long as I remember I've been drinking 5-10 liter water per day, it all started with orthostatic symptoms, never had the myalgia aspect always pee in 0,5-1l increments and since this crash I've been experiencing extremely dry skin and a huge increase in orthostatic symptoms.
These researchers might be on to something, at least in a subset of patients!
