Quote Originally Posted by Jordan Feigenbaum View Post
ATN typically is an ischemic (not enough blood flow) or result of a toxic insult (drugs or contrast material) causing issues with cells in particular areas of the kidney. How creatine supplementation did this seems, well, odd and I would look at this case report with skepticism without knowing more history of the patient, e.g. other toxic exposures, urinary creatinine levels, and how they arrived at "creatine induced ATN"
An 18 year old bodybuilder - I'd wonder if there were under the table diuretics being taken which hit his kidneys.

If you follow the PubMed link there's a small handful of case reports like this: young lifter ingesting creatinine gets a kidney insult, young lifter ingesting whey protein gets gallstones, etc. There's no way to tell causation from at least the abstracts of these case reports, and I'm guessing no way if you read the full study either. Who knows how high of a dose they were taking, how dehydrated they were (intentionally or unintentionally), were they doing CrossFit twice a day in the sun while taking shady fat-burner bodybuilding supplements, were they taking illegal supplements they didn't disclose to their doctors, etc. For the whey protein gallstone guy: was protein powder the bulk of their diet? What else were they eating? I imagine a protein sparing keto diet could possibly cause gallstones in a susceptible person, but the massive quantities of whey ingested would raise suspicion, rather than the fat intake. I dunno.

I ran across a lit review in those links that related there's no decent evidence base for supposing creatine is harmful, but also pointed out: "Nevertheless, idiosyncratic effects may occur when large amounts of an exogenous substance containing an amino group are consumed, with the consequent increased load on the liver and kidneys." That's pretty much how I feel about it. If there isn't already a decent evidence that there's harm, then a moderate amount is obviously fine, while a large amount is possibly, maybe, getting into "who knows what'll happen" territory.