Urea (bun) up - Creatinine down & vice versa

[kristina]

Has anyone any knowledge or experience of Creatinine rising
& the Urea (bun) lowering and vice versa?

I can’t understand why this happens.
I would have thought, bearing in mind
the kidneys are filtering both Creatinine and Urea,
that their decrease or increase in the blood
would be related, and not one going up,
the other going down and the other way around again.
Their rise or their fall is not together.

I feel that I am better in myself when the bun (Urea) is lower ,
irrespective of what has happened to the Creatinine.
Just recently I had a substantial rise in my Creatinine
& the Urea-bun-level had decreased & I felt very well at that point.
Can anyone shine a light on this matter?
Thanks from Kristina.

[galvo]

kristina, no light shining by me, unfortunately. Prior to starting dialysis some 10 weeks ago (has it really been that long?), my creatinine was 896H (recommended range 60-110) and my urea was 39.3H (2.5-7.5).

Latest bloods - crea is 647 (has got down to 598) and urea is 15.3.

So some improvement in crea and substantial improvement in urea.

I, too, am interested in the thoughts of the wise ones!

For you 'mericans, please excuse my 'foreign' readings. You may care to translate them for all our benefit.

[kristina]

Thanks for replying, galvo.
Let us hope someone can explain a little more
about the changes in levels of Creatinine and Urea,
particularly in connection with my question above.
Wish you all the best and hope
your levels improve even more so.
Thanks from Kristina.

[monrein]

BUN (blood urea nitrogen) is a value linked to what we eat, the breakdown of foods, so it can change depending on diet.  Creatinine is the breakdown of muscle tissue and cells so it is a better refection of kidney function since we can't really control it.  Creatinine can however go up or down depending on how much we exercise or how much muscle mass we have. 

This is of course an oversimplification. 

http://www.lifeoptions.org/kidneyinfo/labvalues.php

[kristina]

Thanks for the explanation, monrein.
Everything is much clearer now.
I could not understand why my BUN (Urea) is sometimes so different from my Creatinine.
Sometimes the Creatinine is a little higher and the BUN (Urea) is lower or vice versa.
I don't change my diet and my weight does not change at all.
BUT sometimes I exercise a little bit more and sometimes perhaps not enough.
I think that might be the explanation.
Thanks again, Kristina.