Another EGFR Formula "flaw"

[RickHow]

My doctors all (5 different specialties) tell me to monitor my Creatinine and not my egfr as the egfr formula is not a great reflections of actual kidney function (it does not consider other medical conditions, other medications, one or two kidneys, labels people as having CKD while their Creatinine levels are still well within normal range, etc.). Well I experienced another one.

It is a given as we age our kidney function declines in all individuals. Just like the rest of the body. Well my Creatinine levels (I'm tested every 3 weeks due to also having cancer) have settled in for a few months at 1.7. This is good for my age (71, 2 months away from 72). And also that I only have one kidney. At the lab where I am tested this produces an egfr of 43 (they use the latest formula which has been adjusted to not produce differences based upon if you are African American or not).

My last test I was again 1.7 Creatinine, but they said my egfr was 42. No significant change but a change none the less and why would this be if all factors (age, creatinine, etc.) are the same. Well after investigation it was found that since I am just 2 months from a birthday they used my age as being one year older. So the result is 42. Now think about this a moment. Another crazy anomaly with EGFR formula. One would think that since kidney decline is expected as we age, yet my Creatinine (filtering capacity) remained constant that my result would be perhaps even better, or at least the same, and not reporting me as worse. I aged a year,my creatinine remained constant (all good news) but I'm worse????? (42 not 43 egfr).

No wonder my doctors all yell ignore the egfr stuff and pay attention to your Creatinine.

[Bassetmommer]

Hi Rickhow, Agreed that the measurement if flawed. I had the birthday drop on me too and it put me to the next stage... I just think of the numbers as a gauge and not as fact. If they go up.... yippee, down, not so good. My last lab results showed a remarkable improvement in my creatinine but my GFR only reflected a slight increase.

[Marvin8]

For your age and having a single kidney, my gut tells me you're probably doing considerably better than you think you are. If you had two kidneys, I would only recommend the combination formula of creatinine and cystatin-c. This is purported to be 99% as accurate as a true inulin clearance test, the gold standard for measuring true GFR.

[RickHow in reply to Marvin8]

Hi. Oh I am not complaining about where my kidney "numbers" are at for my age and one kidney. And as silly as it may sound I don't even care what my numbers are as I have stage 4 cancer and that is going to take me long before I would reach any critical stage of kidney problems. I just get irritated when I see so many posts of people who are told, based upon the current formula for calculating egfr, that they have stage 1, 2 or even 3, instilling in them total worry, concern, fear of death, etc., when so many of them have NO abnormal kidney decline. As you say there are so many better ways to determine and report kidney "condition" than a formula which over simplifies and just takes your age, creatinine level, sex and applies that "one size fits all" formula and tells people they have CKD. All at the same time they take other tests which produce results saying "your Creatinine level is in the normal range", "your efgr is above 60 but in the normal range", but then say "you have stage 2 CKD".

[Bassetmommer in reply to RickHow]

Just saw the nephrologist this week and we talked about the new GFR calculation that the medical center is finally going to. I think my GFR will go up 4 points with it. She also is for the first time going to check my Cystatin level. Took them long enough to catch up to the newest info.

[Marvin8 in reply to RickHow]

" I just get irritated when I see so many posts of people who are told, based upon the current formula for calculating egfr, that they have stage 1, 2 or even 3, instilling in them total worry, concern, fear of death, etc., when so many of them have NO abnormal kidney decline. "

Rick, you have no idea what a HUGE issue this is among the nephrology community. There are a significant number of nephs who are up in arms about the diagnoses of ckd for the precise reasons you mention above. I read an interesting article in the New York Times a couple of years ago from a nephrologist venting his anger over all of this and came away from it nearly as angry as he was. As for your cancer, all I can do is send forth my prayers, positive vibes, and good luck wishes.

[WYOAnne]

People ask me all the time what my GFR is now that I have had a transplant. I have no idea! The GFR calculation is relatively a new measurement. When I was in kidney failure 1991-1999 they only checked your creatinine. There was no GFR till much later. My nephrologist does not believe in looking at the GFR but rather the values of all of my renal labs. So, 21+ years post transplant my labs only tell me that my GFR is > 60, but my creatinine is 0.9!

[RickHow in reply to WYOAnne]

It does seem more and more doctors are just not paying that much attention to egfr and getting back to the way you were treated (measuring Creatinine).

[Darlenia in reply to RickHow]

You're absolutely right - my hubby's nephrologists only pay attention to creatinine. I noticed this when he went into ESRD and all the specialists were constantly watching his creatinine levels as they worsened. It was exclusively that data and his blood pressure numbers that determined dialysis was in the cards. Then, my hubby recently received a transplant and again, it's all about the creatinine. It's constantly monitored and and it's even graphed - beautifully graphed, actually, as a swooping line chart. All heads swivel around to stare at outcomes on the computer screen. GFR is never brought up. I think it's more or less used with those doctors interested only in a rudimentary report. In my personal opinion, GFR has wrongly labeled a lot of people and has a lot of room for improvement

[RickHow in reply to Darlenia]

I couldn't agree wit you more about everything you wrote. Oh it is so great your husband got a transplant. The waiting list is so huge and thousands never get one. It's great he did.

[Darlenia in reply to RickHow]

Thank you, RickHow. Hubby was 71 when he received the kidney. Much is happening for those of us who are getting along in years. I fervently pray you, too, will be find positive treatments coming your way. We need you to be here for a very long time! Your perspective, advice, and support is invaluable.

[RickHow in reply to Darlenia]

Thanks for your kind words. I liked how you phrased it as "those of us who are getting along in years". Better than "we are getting old", lol. I really don't feel old, but sometimes when I'm say at a doctors office or something and they say my age (71 very close to 72) it kind of shocks me. Who me?? All my life when I heard people say the time passes quickly I gave it no mind. Now that is has, I guess they were right. :).