Finally! Our own Creatine study, Feigenbaum et al

[Mark Rippetoe]

Dietary creatine supplements raise serum creatinine mimicking acute kidney injury

[Crom]

I am a long-time creatine user, and I though that effect was already pretty well accepted.
Just because it mimics the serum creatine levels of kidney failure does not mean that anything harmful is happening. Does it ?
Or am I missing something ?

"While no long-term changes in kidney function have been associated with creatine supplementation, it is important to be aware of possible confounders when evaluating renal function in a patient supplementing with creatine."


And I thought that the performance-enhancing effects of creatine were pretty well corroborated (correct?)
I had convinced myself that it really did work for road cycle racing...but that is a one-of anecdote that wouldn't convince anyone else but me. But I am convince, because it was me.

[ithryn]

Oh nice, wow. Impressive. So my takeaway is that

1. both forms of creatine can (temporarily?) elevate the common lab marker, serum/urine creatinine*, to what would usually be considered kidney injury levels and

2. that creatine ethyl ester, disturbingly (to your wallet anyway), may break down into creatinine and be excreted without ever being used by your muscles.

A wealth of further reading in the References section there. Thanks.



* I almost feel like we should spell it creatine / creatinINe like they do with pharmaceuticals to make the difference more noticeable to the eyes.

[MattWI]

Great study. It's helpful to be armed with this when discussing creatine and the selection of monohydrate over "designer" forms.

[tfranc]

I am a long-time creatine user, and I though that effect was already pretty well accepted.
Just because it mimics the serum creatine levels of kidney failure does not mean that anything harmful is happening. Does it ?
Or am I missing something ?

"While no long-term changes in kidney function have been associated with creatine supplementation, it is important to be aware of possible confounders when evaluating renal function in a patient supplementing with creatine."


And I thought that the performance-enhancing effects of creatine were pretty well corroborated (correct?)
I had convinced myself that it really did work for road cycle racing...but that is a one-of anecdote that wouldn't convince anyone else but me. But I am convince, because it was me.

I think it's just saying that creatine users can fool emergency personnel or doctors into thinking they have a kidney injury or risk of kidney failure, because creatine monohydrate and especially ethel ester increase serum levels to points that are read as "dangerous" when assessing a patient's status, and that everyone should be aware of this.

[Tiburon]

"p<0.00"

That's impressive. And impossible.

[ithryn]

Unless this has already been answered, it's basically this: your kidney clears out creatinINe, as a waste product, all day long. If your kidneys are hosed they can't clear it as fast, so the amount in your blood starts creeping up.

Orrrrrr maybe you just took a few grams of pure creatine powder, which would get broken down to creatinINe and therefore also spike the level in your blood. But since nobody takes creatine (<3% is nobody, and even that seems large to me, I dunno), 10 times out of 10 that a doctor sees a creatinINe of 5 they know you need dialysis. 0.001 times out of 10 it's just because you're a bro ingesting creatine.

That business with the ethyl ester form just converting straight to creatinINe = mostly just a waste of money, right? And ironically, if guys are taking that to avoid "water weight", they probably are avoiding the water weight because it isn't even getting into the muscles?

[m_sporkboy]

Is this a different paper than the one Mr. Feigenbaum talked about having written on Rip's podcast some months back?

[Jordan Feigenbaum]

"p<0.00"

That's impressive. And impossible.

Heh, yea. I had edited that originally to be p<0.01, but then switched it back because I still find it funny.

Unless this has already been answered, it's basically this: your kidney clears out creatinINe, as a waste product, all day long. If your kidneys are hosed they can't clear it as fast, so the amount in your blood starts creeping up.

Pretty much.

Orrrrrr maybe you just took a few grams of pure creatine powder, which would get broken down to creatinINe and therefore also spike the level in your blood. But since nobody takes creatine (<3% is nobody, and even that seems large to me, I dunno), 10 times out of 10 that a doctor sees a creatinINe of 5 they know you need dialysis. 0.001 times out of 10 it's just because you're a bro ingesting creatine.

The pre test probability would be significantly different depending on the population. Young military folks? Much higher to catch a creatine related issue there compared to a homeless older guy.

That business with the ethyl ester form just converting straight to creatinINe = mostly just a waste of money, right? And ironically, if guys are taking that to avoid "water weight", they probably are avoiding the water weight because it isn't even getting into the muscles?

Correct.

Is this a different paper than the one Mr. Feigenbaum talked about having written on Rip's podcast some months back?

Same one.

[Meshuggah]

Nice write up.

I went through this last year. My doctor jumped the gun and said that I had kidney disease because of elevated creatinine levels.
My problem ended up being something entirely different. My mistrust for doctors is now even greater.