Low urine creatinine levels

[Ruffmatt1982]

I am currently working with the Mayo clinic in MN to see if I am an eligible candidate to be a liver donor for my uncle and had an issue come up today.  I am 34 year old male and feel like I am in good health but my blood creatinine levels have been slightly elevated (1.5) for 7or 8 years but I have always assumed it was due to my consistent weight training routine along with a high protein diet plus an on and off use of creatine monohydrate.  My blood levels have been consistently around 1.5 and not changing so I have never really thought it was a concern but now that I am being evaluated as a liver donor they are concerned and have looked into the issue farther.  I was given a 24 hour urine test to monitor my creatinine levels in my urine and believe I may have accidentally gave them an inaccurate result because I drank to much water during the 24 hour test.  I drank approximately 1.5 gallons of water along with soda and coffee for a total of around 2 gallons of liquid in 24 hours.  I actually pee d so much that I filled the 1 gallon collection container within probably the first 10 hours.  So when I woke up to go at night I just pee'd in the toilet.  Then in the morning I had to collect more urine in plastic water bottles and then dump out some of the gallon collection tank and then dump in my morning urine samples.  Fast forward 3 weeks now my coordinator called me and said I am not an eligible candidate because my urine creatinine levels are low at 77 and was told at my age they should be around 110.  Does anyone think that my large amount of water intake and the fact that all of my urine was not collected has caused the test to be diluted and not accurate?  I called the Mayo clinic the morning of my test and explained to a nurse that I drank a lot of water and I was not able to collect all of my urine and asked if I should start over and she said just dump out some of the collection and mix in what I had collected that morning but it seems as though my samples are diluted.  I am going to get another 24 sample from my local clinic and have my numbers re checked because my instincts tell me the first test was not accurate.  I was just wondering if anyone else has had a similar situation or knows if to much water can provided in accurate test results on urine creatinine levels?

[elephant]

Dear Ruffmatt,

My blood creatinine is now usually about 1.1 - 1.2, and I also attribute it to my workouts.  Interestingly, when I was hospitalized last year with colitis, my creatinine was measured at .9.  I'd had a huge amount of IV fluid, steroids, and no workouts.  It went right back up afterwards, so I think it dropped due to the extra fluids.

When I donated, I had a nuclear test for clearance.  I got an injection of a nuclear tracer and then had blood draws at timed intervals.  I think this is supposed to be more accurate than the 24 hour urine collection.  Maybe you could ask for this kind of test?

Love, elephant

[sherri]

As a transplant coordinator for stem cell transplant, I am constantly amazed at how many of my patients do not follow the instructions for collecting a 24 hour urine even after I explain and give written instructions. A 24 hour urine is collected by flushing the first urine of the morning and collecting all the urine you produce for the next 24 hours. It is not a target goal, not too little not too much etc. It is the amount of urine that you produce over a 24 hour period. I do always stress that patients should follow what they normally do, be well hydrated. You also need to have a blood test drawn with the urine collection so don't just drop off the urine and leave. The lab can't calculate the creatinine clearance if they do not have your correct height and weight and a CMP or BMP with the sample. So I would suggest you redo the test properly (get two containers if you need). If that one comes up abnormal then you can move on to additional testing for your kidney function.

Good luck with the testing. This will be a good time for you to review your health and see if your kidney function is within normal limits.

sherri

[Fr Pat]

Yes, repeat the test. Eat and drink your normal amount, because they want to see what your "normal" is. Collect the urine EXACTLY the way they instruct you.
    Fr. Pat