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Dr. David
Dr. David, Board Certified MD
Category: Medical
Satisfied Customers: 45936
Experience:  Board Certified Physician
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i had three kidney gfr test over 6 months the first came back

Customer Question

i had three kidney gfr test over 6 months the first came back at 52.9 the second at 59.5 the third at 54.9could you tell me if this is any thing to worry about i have very mild diabetes my result from that is 47 I am 56 years old and i have always had very good blood pressure my doctor say there nothing to worry about could you tell me if the gfr can alter from blood test to blood test because the middle one came back the best.
Submitted: 3 years ago.
Category: Medical
Expert:  Dr. David replied 3 years ago.

Dr. David :

This is Dr. David

Dr. David :

GFR can be calculated as an estimated GFR from your creatine level and age and sex

Dr. David :

and this can vary as your blood creatine level varies up and down.

Dr. David :

to get an accurate GFR which is not accurate, you need a 24 hour urine collection to measure your total creatine output in a 24 hour period.

Dr. David :

it doesn't sound like you had a 24 hour urine collection

Dr. David :

and that your GFR measurements were estimated GFR measurements from your blood creatine level.

Dr. David :

does this make sense?

Dr. David :

let me know if you have questions.

Dr. David :

hello?

Dr. David :

why did you rate poor service?

Customer:

could there be such a difference between the three test and how accurate is the gfr test

Dr. David :

the GFR testing you had sounds like an estimated GFR or an eGFR

Dr. David :

which is estimated from your blood creatine level and your age and sex.

Dr. David :

so when your creatine level varies which can happen from day to day

Dr. David :

when you drink more fluids and less fluids or have more muscle break down which can vary from day to day

Dr. David :

this creatine variation can cause the eGFR to vary like you have seen.

Dr. David :

what is a more accurate GFR test is from a 24 hour urine collection.

Dr. David :

this collects your urine for 24 hours in bucket

Dr. David :

and measures how much creatine comes out in the urine

Dr. David :

have you had this test before?

Dr. David :

this is the most accurate test to test for GFR function of your kidneys.

Dr. David :

hello?

Customer:

what do you mean by muscle break down

Dr. David :

muscle is made and broken down on a daily basis.

Dr. David :

the result of muscle break down is a blood protein called creatine.

Dr. David :

this protein is filtered out by the kidneys.

Dr. David :

so if your kidneys are not working properly, your creatine levels will go up.

Dr. David :

however, if you exercise or break down more muscles than usual, this will also cause your creatine level to go up.

Dr. David :

so just changing how much water you drink isn't the only thing which can affect your creatine level and your estimated GFR levels.

Dr. David :

does that make sense?

Customer:

if I I do exercise for muscle toning exercise will this help kidney function

Dr. David :

exercise is good for your whole body.

Dr. David :

but most likely will not have a big overall effect on your GFR

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