Abnormal low creatinine level

[liamo37]

My partner had a health check up a few weeks ago. She didn't notice until the morning of the check up that she had to provide a urine sample, she had already been to the toilet that morning so she drank over a half a litre that morning and provided a sample while she was in the surgery.

She received her results back and her creatinine levels are 0.8 mmol/l, the message with the result (correctly?) suggested that a large fluid intake might be responsible and the sample was not the preferred early morning sample.

She has received a message today that she needs to repeat the urine sample as the low levels indicate kidney disease.

I was wondering would the large intake of fluid and the lack of early morning sample be responsible for the abnormal low levels?

Thanks

[Bassetmommer NKF Ambassador]

Yes, you can dilute the sample too much. First morning urine samples should be just that. No fluids before.

[Porter20 in reply to Bassetmommer]

I have never heard do not drink prior to a urine sample and thought 0.8 was normal.

[Bassetmommer NKF Ambassador in reply to Porter20]

It depends on what the doctor says. When I had to do urine collection, the first urine meant just that. Get up and go. They want to see what builds up from the night before. Diluting it with drinking something will change the results. If it is not a first urine, then drinking water won't matter. When I do labs, I always make sure I am hydrated, but not diluted.

[Hidden in reply to Porter20]

Yeah, I thought the whole post was somewhat confusing. There should not be any concern over a low creatinine level and in fact that's what you want. Personally, I generally pee anywhere from 2-5 times during the night so a first urine for me probably wouldn't be but a couple hours worth of catch anyway. I usually make my lab time for my Neph somewhere in the early afternoon. I'm generally well hydrated. Even then, there is a bit of protein and thankfully, no blood. I believe the first morning pee after a long night would actually give false results and wouldn't be a true indication of how well your kidneys are filtering. Just my opinion and my Neph has not said anything about my timing for labs.

[Chris2023]

Yeah, you can over hydrate. There is no need to drink so much to provide a sample. They really only need a very tiny amount of urine as they just dip paper and put it through a machine. Tell them just to give what they got next time.

[Darlenia in reply to Chris2023]

Yes, "overdrinking" water can skew lab results - creatinine, sodium, and others. kidney.org/blog/ask-doctor/....

[bestmom247]

Yes!!!!