How does hyperglycemia (diabetes) affect serum Na and K?

[tarsuc]

Pg 330 of FA 2016 says that hyperglycemia leading to osmotic diuresis can cause loss of water, Na and K.

Just wondering how osmotic diuresis leads to hyponatremia and hypokalemia ?

more volume filtered at kidneys -> -> more Na and K lost along with it? is it?

Sorry if this is dumb.

Cant hyperglycemia lead to hypernatremia as well?

found this post:

http://forums.studentdoctor.net/threads/glucose-mediated-osmotic-diuresis-does-what-to-na.808939/

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[tasar1898]

I dont remember about the hyper- stuff , but hyponatremia is due to the diluting effect of the extra glucose.. Imagine the vessels filled up with glucose that initially draws tons of free water outta the cells , and you have kinda the same amount of Na , but diluted in more intravascular volume (H2o) , so the Na concentration falls , and you get hyponatremia.. Thats why when you correct these abnormalities you gotta be careful , coz for every 100mg/dl serum Glc reduction you get an increase of Na concentration ( don't remember the exact number)

 

[Qester]

It's been a long day of studying for me so I could be completely off to lunch here but my initial idea is that having osmotic diuresis could act in a similar mechanism as Diabetes Inspidus, in that because the urine is so dilute your body doesn't attempt to reabsorb any sodium or potassium.

Or maybe not, someone who knows more can confirm

 

[AZ7]

Since Insulin sends K+ into the cells, i think in diabetes you've got excess of K outside the cells, therefore more amounts being excreted = eventual hypokalemia. Na levels seem to be explained by the two posts above.

 

[worldbeater]

Since Insulin sends K+ into the cells, i think in diabetes you've got excess of K outside the cells, therefore more amounts being excreted = eventual hypokalemia.

Yeah this is right for DKA, you have high amounts of extracellular K+ and low amounts of intracellular K+, when you correct the acidosis you will have a shift of potassium into the cells and have hypokalemia in the serum.

 

[ortnakas]

Yeah this is right for DKA, you have high amounts of extracellular K+ and low amounts of intracellular K+, when you correct the acidosis you will have a shift of potassium into the cells and have hypokalemia in the serum.

Right -- DKA involves hyperkalemia but depleted intracellular stores. Insulin causes a shift of potassium into cells, so when you give insulin for DKA you have to also give potassium (despite the hyperkalemia) due to the transcellular shift.