Diabetes Insipidus

[anita]

Does anyone here have this?

I was just diagnosed on Monday.  Now the process is to determine which type of Diabetes Insipidus (DI) I have.  There is Central DI where the pituitary gland doesn't produce the hormone ADH, which concentrates urine.  The pituitary can be damaged from a tumor, or inflammation from Sjogren's (lymphocytic hypophysitis).  The other type is nephrogenic DI where the kidneys are damaged from Sjogren's (interstitial nephritis) and can't respond to the ADH.

Not being able to concentrate urine causes electrolyte imbalances and excessive loss of fluids.  It all depends on the cause as for treatment.  It's not a common condition, but yet another one that Sjogren's can play a role in.

[Linda196]

Many years ago following a surgical procedure, I was tested for DI (thought to have been brought about by cerebral edema during anaesthetic) but further testing lead to SIADH (syndrome of innappropriate anti-diuretic hormone).

This episode predated Sjogren's by a very long time, but I do remember my endocrinologist saying he was concerned about DI because of my history, which at that time included Hashi's, Sarcoidosis, myositis, polyarthritis and deQuervain's tenosynovitis - all Autoimmunes.

[anita]

Thanks Linda for your reply.  May I ask what 'further testing' you had that indicated SIADH?  I have never heard of SIADH.  What is the difference between DI & SIADH?

My water deprivation test was clearly positive, but my symptoms are not constant...they come in waves (every couple days now), which is confusing the doctors.  They believe my severe autonomic dysfunction is compounding the DI.

[Linda196]

The "further testing" involved some complicated calculations based on serum levels of Sodium, plasma volume, osmolality and osmolarity of blood and urine, and several other factors that my endo fully understood and I had no ideas about! One thing I do remember was an increased ADH (antidiuretic hormone) and the fact that vasopressin had no effect.

Apparently ADH can be produced outside the hypothalmus, called ectopic production, and Sarcoidosis can be one of the causes.

I didn't require any drug treatment, only fluid restriction for a couple of years, and the condition resolved. I do still have to have sodium levels monitored, and it they start to drop, the osmolarity/osmolality will have to be checked again.

I think the biggest difference between DI and SIADH is the fact that the hypothalmus still produces hormone, and the kidney will still respond to it, its just a matter of regulating the production.

[anita]

Thanks for the info.

They told me that increased ADH levels and when vasopressin has no effect is can be (but not always) consistent with the nephrogenic DI...because the pituitary/hypothalmus keeps putting out ADH, but the kidneys aren't responding/using it, so the level increases in the blood.  And vasopressinis know to have no effect in nephrogenic DI.

I don't know what my last ADH level was, but plan to ask.  I will also inquire about this SIADH.

Did your symptoms come in waves (particularly the frequent urination) or was it persistent all the time until diagnosed?

Thanks again.