Potassium and Insulin Relationship

[standout22]

Speaking in terms of relationships, I understand that insulin effects K+. I also understand that with increased insulin production or administration you can have a state of hypokalemia. I just don't understand why, on an intracellular level why and how does insulin production or administration decreased serum K+?

I appreciate any insight and help!

[Valharley]

Maybe then you can explain to me what an RBC potassium test is? And why is there such a test if there is no potassium stored there?

[shaas, ASN, RN]

Red blood cells are anucelated cells. So, the environment within a RBC would be considered 'intracellular' whereas the space inside the blood vessel sans RBCs would be considered 'extracellular.'

So, conclusively, even within the blood vessel there are two disparate compartments; IC and EC (this is what I've been taught in science courses). Not a new fact; just a well-established yet not-too-well explained fact in some NS programs, I gather. And, below is another long-been-established facts on the contents of the RBCs.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC292863/?page=1

[CuriousMe]

Valharley said:

Actually there is a lab test for intracellular Potassium called an RBC Potassium test. I found this site looking for more information about my OWN issues as I have been on 120mEq potasisum for about 2 years now and just had to raise my insulin a little and now I am feeling the old low potassium symptoms again. It starts as muscle pain and fluid retention, so common in Diabetics I have to wonder how many on insulin need potassium and do not know it. My serum K was 4.2 when I started supplementing and now it is 4.0, but symptoms relief is amazing, I was ready to go into forced retirement 2 years ago now I am good to go for another 5-7 years. I also had 15 years chronic IBS that stopped like turning off a faucet when I started supplementing 40mEq potassium. Hip pain I thought was arthritis, gone, back pain, same. Urinary leakage I thought was due to early hysterectomy, gone. The lab that did my RBC potassium testing stated they had NEVER done this test before! Please become pioneers with Diabetics in running this test.

I've managed patients in DKA in the ICU with incredibly high blood sugars...I've never seen an RBC Potassium lab. The practitioners didn't order it, and it's not part of our order set.

Is this new? Or just older and not commonly requested any more?

[motyandproudofit]

I need some help understanding the Na/K pump and the relation between hypomagnesemia and potassium levels.

The Na/K pump requires Mag to activate. If a person has a low magnesium level the K will not get to the cells but will sit in the intravasuclar space then the kidneys will excrete the excess K, correct?

If that is correct than the labs would show a normal K level right?

The person would be low on needed potassium in the cells but the labs would not show that. One would just assume the intracellular K is low due to the low mag level? or is this when a RBC potassium test would be done? Any other test to find out? Are the signs and symptoms of low intracellular potassium the same as low serum potassium?

[motyandproudofit]

Could you explain a bit more?

[psu_213, BSN, RN]

motyandproudofit said:

Could you explain a bit more?

I realize this is a really old thread, but which part of it would like explained in greater detail?

P.S. to the person who thinks it is idiotic to lower potassium with insulin...don't argue that here. Argue that with the doctors (the very highly trained and in many cases highly experienced doctors) who order insulin, sodium bicarb, and albuterol to treat a case of hyperkalemia. In the short term, those 'idiots' (said with a lot of sarcasm) will push the potassium back into the cells. In the long term, they give kayexelate and consider dialysis.

[turnforthenurse, MSN, NP]

motyandproudofit said:

I need some help understanding the Na/K pump and the relation between hypomagnesemia and potassium levels.

The Na/K pump requires Mag to activate. If a person has a low magnesium level the K will not get to the cells but will sit in the intravasuclar space then the kidneys will excrete the excess K, correct?

If that is correct than the labs would show a normal K level right?

Serum K would be low because it is being excreted. That's why if you have hypokalemia that is refractory to treatment, look at the magnesium level, too. If the mag level is low, replace that first before replacing the potassium.

psu_213 said:

P.S. to the person who thinks it is idiotic to lower potassium with insulin...don't argue that here. Argue that with the doctors (the very highly trained and in many cases highly experienced doctors) who order insulin, sodium bicarb, and albuterol to treat a case of hyperkalemia. In the short term, those 'idiots' (said with a lot of sarcasm) will push the potassium back into the cells. In the long term, they give kayexelate and consider dialysis.

Also an amp of D50 (to prevent potential hypoglycemia associated with regular insulin, which is usually always given IV and the effects are immediate) and possibly calcium gluconate to protect the heart if the serum potassium level is really high. The insulin isn't a solve-all for hyperkalemia; it will temporarily push the K into the cells but after time it will start to leak out again. That's why they are also given kayexalate.

[psu_213, BSN, RN]

turnforthenurseRN said:

Also an amp of D50 (to prevent potential hypoglycemia associated with regular insulin, which is usually always given IV and the effects are immediate) and possibly calcium gluconate to protect the heart if the serum potassium level is really high. The insulin isn't a solve-all for hyperkalemia; it will temporarily push the K into the cells but after time it will start to leak out again. That's why they are also given kayexalate.

That is true. Although some nephrologists prefer that their dialysis pts. go right to emergent dialysis from the ER. In that case, the insulin is counter productive--it 'hides' the potassium inside the cells where it cannot be removed by dialysis. Although, as you said, it will be back.

[kumar5753]

I was thinking by reading these discussions, can insulin secretion be increased by higher intake of Potassium?

I wonder, how ICF Potassium level can be checked because I think K come out of cell on cells taken out of body.

[bgxyrnf, MSN, RN]

kumar5753 said:

I was thinking by reading these discussions, can insulin secretion be increased by higher intake of Potassium?

No... potassium does not induce the pancreas to secrete insulin.

Quote

I wonder, how ICF Potassium level can be checked because I think K come out of cell on cells taken out of body.

I have no idea how it's actually done but some ideas occur to me:

Simplest might be to take a specimen... clean it up... measure ECF K level... lyse the cells... measure K in the specimen... the increase in K comes from the cells.

Could also use a microneedle to extract an ICF specimen.

Could probably tag K with radioisotopes and measure their concentration in cells.

[gert42]

Pancreas Potassium Insulin Relationship

What does insulin do to potassium and what does potassium do to insulin secretion is a concept that is frequently tested in USMLE Step 1.

Insulin causes Potassium to shift into the cells thereby decreasing the extracellular K level. That's why insulin is used in the treatment of hyperkalemia.

Level of Potassium in the serum also affects insulin secretion from the pancreas. Because the beta cells have an ATP dependent K channel which is when closed leads to retained K inside the beta cell which favors depolarization thereby enhancing Calcium mediated release of secretory granules. Therefore, in hyperkalemia more K will enter the beta cell and insulin secretion will increase and conversely in hypokalemia the K ions are more likely to leave the beta cell and so insulin secretion will decrease.

Ahmed-USMLE

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