Hello, Does anyone have any knowledge or experience of eGFR over/under estimating due to under/over weight?

[Lakotamusic]

Hello all,

I do appreciate these maybe sensitive questions.

I am currently significantly underweight and struggling with symptoms. My last eGFR was 38. I have read on valid sites that if under or over weight it can over or underestimating eGFR?

Thank you 🙏🏼

K

[Bassetmommer NKF Ambassador]

Yes it can skew with the GFR. But remember it is E GFR which means estimate. There is another test called a Cystatin c test that is more accurate. For example, my GFR was 7 but my Cystatin was 11. NOt sure if this is a test they have in the UK.

testing.com/tests/cystatin-c/

[TR6872]

If you go to the National Kidney Foundation (U.S.) website, they have an eGFR calculator which offers the option of adjusting for height and weight. Just click on "Adjust for body surface area" and enter your numbers. It can make a difference - it raises my eGFR from 45 to 55. (Keep in mind that GFR is "estimated" and has a margin of error of 10% or more - so my 45 may be anywhere between 40 and 50, and the 55 may be between 50 and 60, more or less. ) You first enter your serum creatinine number (it has an option to use U.S. or U.K. measurements, which are different) and your sex and age.

kidney.org/professionals/KD...

[appledonut in reply to TR6872]

Thanks for this helpful information! Based on my Creatinine, age, height, weight it increased my eGFR from 41 to 48 = eGFR of Stage 3a instead of 3b. I found out just last year that I’ve been in stages 3a, 3b and even 4 (after I got COVID) for at least the past 14 years!!!