Confused about GFR

[itzmich]

I received my test results with a drop in GFR. My question is if all my panel results are in the normal range why does that GFR number go down.

Newest results GFR 38 creatine/bun 1.3/25

Last month GFR 41. creatine/bun 1.3/31

BUN was elevated yet my GFR was lower

Trying to understand what these numbers mean and how my diet effects them.

[Mgt8]

Hi

The egfr figure is worked out from other readings including creatinine. The 'e' is for estimated and it does fluctuate.

[RickHow]

It is confusing. The egfr is really a very simple calculation. It takes your age, sex, race and creatinine level and produces a result. Since your creatinine level was the same in both tests, the end result should be the same. Not 38 one time, and 41 the next. Plus what further confuses me is when I compare it to mine. I am male, white, 68 with creatinine level of 1.7. I get the result of 40 egfr. Your creatinine level is much better than mine so that should yield you a better egfr. to me something is not correct. Go to the website

kidney.org/professionals/kd.... There you will find a calculator that is very easy to use. And it will produce your egfr level. All that said. A change of 2 or 3 points is possible simply based upon if you were not hydrated properly one day, or other factors. But to have the same Creatinine level both times should not produce different answers. I just had a similar experience. I had a test 4 months ago. I just last week had another. Same creatinine level both times, same doctors office (lab) both times got different results, two points apart. I showed it to the doctor. He called me back the next day. The lab made a mistake on the most recent test. Human error. They entered the wrong value on the report.

[itzmich in reply to RickHow]

Thx Rick......I'll check it out.

[itzmich in reply to itzmich]

Rick....its asking for my serum cystatin C.....I don't see that on my blood panel. Any ideas?

[Zazzel]

I've had the opposite thing happen where I had the same GFR, but my creatine was off by a point. I believe like Rick said, an elevated BUN can indicate a bit of dehydration. My GFR bounces around all the time. In the last 2 years it has gone up and down within a 10 point range and certainly within 3-4 points up and down every three months or so. The key is if you start seeing it dropping on each time. If it drops again on your next reading, I would visit your Nephrologist. In the meantime, make sure to keep your salt intake low, watch your protein intake and drink an adequate amount of water. You should discuss your diet with a renal dietitian if you can find one in your area. A lot of times they won't assign you one until your numbers are lower. You can check with Davita.com and sign up for their free class in your area. They can often guide you to a local dietitian.

The amount of protein you need is based on your weight and your stage of kidney disease. You said your panel was in normal range. I'm not sure if that included your phosphorus and potassium numbers. You may need to limit your intake of those foods as well depending on your numbers.

Here is an article discussing protein intake, but again, please discuss with your doctor. nephron.org/nephsites/adp/p...

[itzmich]

Thx.....have an an appt with my dietitian next week. Good to hear about the fluctuations. Limiting protein, phosphorous and potassium in normal range. Limiting salt. Water a half gallon a day.