Protein in CKD2

Hey Docs,

A fellow doc here (FM) looking for some objective advice. After a wicked encounter with rhabdo several years ago, I’m left with CKD2 (eGFR 63-65) and a creatinine that hovers around the upper limit of normal. I’m 5’11” 163lb, have been weight training for years, and I’m currently in the early stages of a muscle building phase to make up for lean tissue loss from injury and a period of underfueling.

In your opinions, should I be limiting my protein intake? My gut says to likely aim no higher than approx 1.6g/kg/day to maintain MPS without taxing the system.

Thank you for your thoughts!

Are you able to provide your demographic & lab data? Have you had a cystatin C measured?

Hi Austin,

37yo white male. No proteinuria, normal lytes. Pre-rhabdo renal function always WNL. What additional labs would you like? No cystatin C yet. I’m going to ask my doc to order one for me.

Thanks for the reply!

Andy

I would be curious to know prior baseline Cr/eGFR, current Cr/eGFR, and a cystatin C.

In the meantime, there is no compelling reason to exceed 1.6 g/kg/d in your situation anyway, so that range (say, 1.2-1.6) is likely going to be fine, particularly if you are training.

Thanks again, Austin. I just got my cystatin C back. Pretty revealing.

Cr/eGFR prior to 2019 1.06/92
Subsequent to rhabdo (presumed due to clinical presentation/urine appearance and elevated Cr), Cr/eGFR have been in the upper 1.30s/60s.
Most recent Cr/eGFR 1.4/61
Cystatin C this past week with eGFR: 0.73/120.

My interpretation of this is that some increase in muscle mass, as well as creatine use, may have confounded the creatinine and creatinine-based eGFR.

Thoughts on your end?

This result is what I expected; I agree with that conclusion.

My own labs look the same: Cr 1.3-1.4, Cystatin C 0.7.