Question:
I've been having problems lately with excessive thirst. (And
the related problem of frequent urination, obviously. Though
the causality might be the other way around - I just live in
this body, I don't pretend to understand it.) I don't know if
it could be a side effect of one of the medications I'm taking.
I've asked a bunch of people about this concern...the chronic
pain support group, friends, my pharmacist. *Everyone* asked
me, "Are you sure you don't have diabetes?"
Well, no, I'm not absolutely positive I don't have diabetes. My
primary care doctor had me tested for it last summer. He was
worried that I was losing so much weight. (I'm taking an anti-
seizure drug that can cause weight loss. But generally not quite
this much weight loss.) He didn't check for glucose tolerance,
or sugar in my urine. My fasting blood sugar level was fine, so
he concluded I didn't have diabetes. And the weight loss kept
happening to me. I'm not getting dangerously thin, it's just
unsettling that more than a third of my former body weight has
gone away in a little over a year. (Though the weight loss
seems to have slowed down or stopped around the time the extreme
thirst was starting. Recently.)
A few months later, he referred me to an endocrinologist, shaking
his head and muttering, "there must me *something* else going on."
The endocrinologist did another fasting blood test, and told me my
sugar level was fine and my thyroid was fine. However, she told me
that the ratio of the different kinds of cholesterol in my blood
indicated that I was at risk of developing insulin resistance in
the future. This wasn't something she could treat, but I should
exercise more, and maybe it wouldn't develop.
My primary care doctor started pushing me to try a low-carb diet,
to try to control my seizures and migraines. (Not as restrictive
as the ketogenic diet used for young children.) Neither of us
thought I had a problem with diabetes or anything related to it.
I managed to stick with it for 5 months, though it made me feel
perfectly awful - increased pain, very low energy. After I finally
got permission to go back to a normal way of eating, I find myself
still avoiding pasta and potatoes (which is probably a good change)
and thinking about food much more obsessively than I used to (which
I don't like at all.)
I'm feeling very anxious. I don't want this new symptom to be a
side effect of my new pain medication. (It took me *years* to
persuade my doctor to prescribe effective pain medication, and
I'm afraid he'll jump on any excuse to stop it.) At the same
time, I'm afraid of having to go back on that damn low-carb diet
if I turn out to have diabetes, or even if the doctor suspects
I might. I just felt *so* sick and weak all the time, eating that
way. (I know that some people feel better on that kind of diet,
rather than worse. My doctor kept trying to persuade me that I
would miraculously turn into one of those people.)
After all this background rambling, here are my questions:
1) Is the excessive thirst a symptom of diabetes itself, or is
it a symptom of uncontrolled diabetes? High or low blood sugar?
2) Does it indicate that the disease has progressed pretty far
without anyone noticing, or is it an early symptom? If I have
diabetes now, I'm wondering if it's new, or if I had it last
August and fasting blood sugar just couldn't detect it.
3) How much water is it safe to drink? I walk 2-4 miles/day
(now that I'm off the low-carb diet, and have energy), but I
don't do seriously sweaty exercise. I'd really like to drink
more than 2 gallons/day, but I read scare stories about
hyponatremia in the paper.
4. For people who have diabetes-related thirst, who control
your blood sugar with diet, how long did it take for the
thirst to go away? (Did it?) And how severely did you
restrict carbs?
Answer:
Since you have done all the correct things, like going to an endo, my
comments should just be considered musings.
It doesn't appear that you have diabetes mellitus, based on your FPG
readings. But there is another rare type of diabetes called diabetes
insipidus. This is caused by the lack of a hormone called ADH
(anti-diuretic hormone) which is secreted by the hypothalmus in the
brain. The symptoms are pretty spot on to yours.
Further, some meds can cause this problem, among them lithium and some
of the sympathiomemetics. Some are also known to cause
hypercholesterolemia. Without knowing which meds, it is hard to say more.
The good news is that there is a drug called DDAVP (desmopressin) that
can reduce the symptoms. A couple of squirts from a nasal inhaler can
reduce the excessive urination.
I would assume that your endo would have thought of insipidus, so my
musings may only serve to bore you with more than you wanted to know
about a rare form of diabetes. But, it might be worth asking her.
