Please note I don’t condone what they are preaching just hope this better explains why, as so many have wondered.
Estimated GFR: time for a critical appraisalEsteban Porrini et al.
Nat Rev Nephrol. 2019 Mar.
Show details Abstract PubMed PMID Full text linksCiteErratum inAuthor
Correction: Estimated GFR: time for a critical appraisal.Porrini E, et al. Nat Rev Nephrol. 2019.PMID: 3056396
Abstract
Since 1957, over 70 equations based on creatinine and/or cystatin C levels have been developed to estimate glomerular filtration rate (GFR). However, whether these equations accurately reflect renal function is debated. In this Perspectives article, we discuss >70 studies that compared estimated GFR (eGFR) with measured GFR (mGFR), involving ~40,000 renal transplant recipients and patients with chronic kidney disease (CKD), type 2 diabetes mellitus or polycystic kidney disease. Their results show that eGFR often differed from mGFR by ±30% or more, that eGFR values incorrectly staged CKD in 30-60% of patients, and that eGFR and mGFR gave different rates of GFR decline. Errors were unpredictable, and comparable for equations based on creatinine and/or cystatin C. We argue, therefore, that the persistence of these errors (despite intensive research) suggests that the problem lies with using creatinine and/or cystatin C as markers of renal function, rather than with the mathematical methods used for GFR estimation.
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Blackknight1989
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I agree with both opinions I just wanted to point out that the actual number really is only an estimate to start and track decline or improvement. As we all know since CKD affects multiple systems and the actual lab reading can and does move up and down every time it’s tested. I had no intention of disparaging the numbers that track our disease progress decided by folks much smarter and more knowledgeable than I!
I found this fascinating. I wish doctors would look at this. they have to gage function on something. And it is indicative of decline at least.
I was just at my Nephs this week. She was pushing again to get my fistula in. I was as adamant as I could be with her by saying when and only when I start to feel a real change in my normal will I head off to that route. She said, "well it takes up to six months to get a fistula in and healed". I get it, but I am nowhere near the point where my physical abilities have changed. MY renal numbers have been pretty much the same now going on 5 years. When she looked at my lab numbers, I made her look at ALL my numbers, including my lipid panel. She started to laugh and said, Geeze, other than the CKD indicators, you're the healthiest person I know.
Informative report. eGFR is based on a number of variables - such as sex and age - and predicts your possible outcome against others with similar variables. In our experience, it mattered in the earlier stages of CKD; but other renal data such as creatinine, BUN, and other factors became of intense interest as the kidneys started to shut down in earnest. I compare it to someone with a cardiac situation. Predictions and estimations don't matter much anymore once a heart attack is underway. Same thing happens when kidneys decide they have had enough.
I would never stress enough eGfr is only a red flag that somenthing could be wrong. Renal function is always a result of syntoms and entire panel of kidney values.
I completely agree with the others take on further explaining eGFR. I could give a rats behind what specifically eGFR is or measured other than knowing the proper application to our CKD. My intention behind the OP was to maybe help explain to the new folks what eGFR meant and how by changing lifestyle factors for the better and raising eGFR for not in any way correlate to “curing” CKD as we have seen express mutiple times recently in the forum. As most who posted here know education and realistic expectations of what the different stages of CKD being, the fact that there are so many co-conditions and that this is a life altering disease (if you want to avoid dialysis and transplant) require more of a self-commitment to health than changing to Lee Hulls diet and $400 a month supplements that are just ammo-acid based probiotics and 6 weeks later self reporting raising eGFR from 40 to 78 and then considering yourself “cured.” The basis for this simplistic thinking is I am sure complicated but is centered around a one lab result eGFR significant increase. That is only setting yourself up for failure if you truly have CKD. I suspect in some cases it’s just AKI ot kidney inflammation due to an outside toxin misdiagnosed. But, whatever the case I believe it is important to know what eGFR actually measures and how it is intended to be used properly to ensure you get the best treatment of your specific disease.
This paragraph is taken from an article published by the NIH (National Institute of health). The article went into detail about how difficult it is to get the direct GFR reading or as you call it mGFR. You will see a line in this paragraph that says eGFR is most accurate once the GFR is less than 60. I think you're making this more complicated than it needs to be and you're only confusing people with a bunch of detailed reports. Nephrologists use creatinine as the measurement for kidney function and GFR is calculated from that. Period. One thing that's not talked about much is the urine test. You can tell a lot from that also. The amount of blood an protein are measured as well as the amount of creatinine. The amount of creatinine in the urine is usually the inverse of what is seen in the blood and that also helps determine how well the kidneys are filtering.
"In summary, a major challenge in preventing kidney disease relates to the early identification of high risk patients. Assessment of GFR is essential to accurately diagnose kidney disease. GFR is difficult and impractical to measure directly with current methodologies, and estimates of GFR by serum creatinine and/or cystatin C are most accurate once GFR is <60ml/min/1.73m2, a point at which half of renal function is already lost. Accurate measurement of GFR is also important to stratify renal injuries, monitor nephrotoxicity and guide medication dosing."
no sir what I want others to stop doing is obsessing over a number that by itself means nothing. That study I posted is from PubMed. NIDDK.gov and all other sites that explain eGFR talk about how inaccurate it is, shouldn’t be taken as an individual but a series of numbers used to track ongoing kidney damage. The study you quote I posted in another separate topic. Too many hang on eGFR as the true guide to My CKD is “cured” just look at the list of topics on the front page…3/4 topics about how I raised eGFR from 11 to 84 I no longer have CKD (you never had CKD if you can do that). Then look at the other topics that are 3/4 as well that say “help I’m eating all the right stuff why didn’t my eGFR improve?” If you took that lab reading every 15 minutes for an 8 hour day every reading would be different from the other.
From the NIDDK.gov:
Estimating equations reflect the best estimate for the population in which they were developed. However, there can be significant imprecision when using the equation when assessing an individual. The conventional measure of precision has been the P30, which describes the percent of GFR estimates that are within 30% of the measured GFR. Measures of P30 using the same equations vary in different studies depending on the age, muscle mass, and amount of kidney disease prevalent in different population groups that have been investigated.
Therefore, folks need to know the intent eGFR is used for. It is essential to diagnose and estimate initial damage. Then it is used as a long term trend to keep the number relatively the same means NO ADDITIONAL kidney damage. It is NOT a way to determine if your great Lee Hull diet “cured” your condition that 80/90% of us cannot have that sort of result. It crushes people and causes way more anxiety especially in newly diagnosed than just the life changing diagnosis. Finally, I’m not complicating it eGFR and the intended use is already complicated all on it’s on.
Does that make sense? If more knew maybe there would be less of the information that really devastates many of the newly diagnosed that truly have CKD not just a toxin affecting kidney performance that is removed before reaching the tipping point of true nephron damage that is unrecoverable. Plus that Hull stuff is super expensive and completely unnecessary. You can buy his amino-acid probiotics for about $20 as opposed to $500. I have helped newly diagnosed both CKD and AKI for 20 years. I have seen friends follow the snake oil and end up actually destroying their remaining function leading to dialysis/transplant and in a couple of cases death. If you really get into the NKF KIDGO practice guidelines (the guidelines released by a joint effort between ASN, NKF, NIH and Renal Dietitian society, FDA and others, as the standards for all physicians to use when treating CKD patients) for nutrition available on the NKF site all the studies they use (about 400) to back up their recommendations they still say over and over this phrase, “it is unclear whether or not there is a benefit for patients, especially stage 3 and 4 so more study is needed.” Their findings for the effect of diet at the 3/5/10/15 year mark showed no benefit in changing diet. Why? Because a VLPD is very hard to stay true to and is abandoned by most patients who start it after about 6/10 months. It is just really important to me that we get the facts absolutely correct as can be done in this life altering and potentially life changing disease that has NO CURE! If we don’t it will cause those who read that misinformation to not have the best shot to control their own disease. If we just let the “hey y’all great news I changed my diet and cured my stage 5 CKD, go unchecked the 8/10 folks who don’t see those results suffer tremendously for we know a mental health issue can be just as detrimental as a physical health affliction to an underlying chronic illness. It is my passion so my apologies if I sounded like a jerk or “know it all.” As that was NOT my intention. I just want the truths or as close to truths as we can have with this disease as there are very few definitives with it. Thanks!
I don’t understand why you think it’s so important to keep posting all these long winded studies that the average every day Nephrologist probably hasn’t even read. I’ve been seeing my Nephrologist every 3 months for the past 5 years and he uses creatinine as his main gauge along with urinalysis. He is very well known, has many patients, and uses his privileges at the 4th ranked hospital in the state of Florida. That’s good enough for me. No I don’t think you’re acting like a know it all but if I went to a doctor that started hitting me with all the information you’re posting, I would go elsewhere to get a simple straight answer. When I contracted my autoimmune disease in 2017, I too did a lot of research and reading to learn as much as I could about all my conditions and symptoms so I don’t knock you for that. It’s important to be your own advocate when it comes to health.
I agree with your assessment completely but most don’t do what you have done. I post what I post for exactly the reasons I outlined. I spent 30 years helping folks in my own business. I miss that feeling of being an aid to others and hope to help just one person overcome the anxiety associated with our disease. I know it sounds corny but there it is. I didn’t know it was bothersome to some so I’ll refrain from similar post in the future. It was never my intent to end up sideways with you sir. My apologies for any offense caused and my best to you!
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