D is for Diabetes Insipidus
It’s All in My Head
I have shared a little bit about my story in the past, but here is more about my disease, diabetes insipidus (DI). DI is essentially a malfunction of the body in relationship to vasopressin. This is completely different than diabetes mellitus which has to do with blood sugar and insulin.
There are two types of diabetes insipidus, central (hypothalamic) and nephrogenic. Nephrogenic means that it has to do with the kidneys not being able to respond to the presence of vasopressin adequately. Central, or hypothalamic, means that the body does not make vasopressin in adequate quantities if at all. I have the central form, so that is what I discuss today.
The hallmark of DI is drinking a lot of water and urinating a lot. The average person should drink 2-3 liters of water per day (or 9-13 cups) according to Mayo Clinic. When I first began to realize that I had a problem, I was drinking approximately 9-10 liters of water per day. For the average person, drinking that much water could cause major electrolyte imbalances that can be fatal. For me, not drinking that much would have resulted in severe dehydration.
There are many tests that are run to diagnose and monitor diabetes insipidus, including blood tests, MRI, and response to treatment. The final diagnostic test to separate DI from psychogenic polydipsia is a water deprivation test. In this test, initial testing is performed (weight, blood sodium concentration, etc.) and then medication and water is withheld in a controlled environment (doctor’s office or hospital), urine production is measured, and the initial tests are repeated hourly (weight, blood sodium, etc.). The general rule is to wait for the patient to lose about 3% of their body weight before the test is completed. In my case, about 2.5 hours in, I became clinically dehydrated, with nausea, vomiting, and dizziness. I also lost about 5 pounds. I “passed” the test very quickly to receive the confirmation of my diagnosis and the rest of the test was canceled.
Treatment of central diabetes insipidus is through supplementation of the body with vasopressin (DDAVP). It comes in three form injectable (usually only used in hospital situations), tablets, and a nasal spray. In animals, it can be compounded or the nasal spray can be used as an eye drop.
One of the craziest situations I had was right after my diagnosis, I had a dog come in that we also determined had DI. She and I matched symptoms and treatment response. Sadly, her DI was likely caused by a brain tumor and she passed away a number of years ago. She was a great dog.
Most cases of diabetes insipidus are caused by either an infection of the CNS (brain and spinal cord), cancer (brain tumors), trauma to the brain, or brain surgery. I have not had any of these, so I have what is caused Idiopathic Central Diabetes Insipidus. Someday, we hope to find the cause, but at least I am able to live life with just a little extra water and more visits to the bathroom!
Keep hydrated my friends!