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Imagine that there was a drug that reduced your renal function by 25% in two weeks.[1] People will see in this what they want to see. This is why case reports

Imagine that there was a drug that reduced your renal function by 25% in two weeks.[1] People will see in this what they want to see. This is why case reports are evidence of the lowest grade. This is more a curio than it is evidence, and there is nothing wrong with writing a blog post about a curio. 1 = I think the creatinine bump is quite likely due to stochastic fluctuation, but if for discussion's sake we attribute all positive changes to Soylent, we should do the same for the negative ones.

vidarh 13y ago
As my doctor pointed out to me when I warned her to expect significantly elevated creatinine because of my protein supplementation: Raised creatinine in itself is not a "negative". Substantially raised creatinine may be a symptom of reduced renal function, but it is also a symptom of any number of other things - such as, indeed, increased protein intake. It could be just fluctuating in his case, or it could very well be, given his past diet (how could he survive on that), that he was finally getting decent amounts of protein.
- carbocation 13y ago
  I think you might be thinking of BUN. For creatinine, there is peer-reviewed data demonstrating that in people without renal disease, increasing the protein in your diet tends to improve your eGFR, not decrease it (which is what happened here). So for him, it either fluctuated or was a marker of true kidney disease, but in any case this is not just a marker of adequate protein intake.
  - vidarh 13y ago
    Neither. I'm talking of creatinine levels in the blood, and my doctor was also very clear on that, and that it wasn't normally a concern at the levels she would expect to see from protein supplementation, but if it was too high, she'd need to establish filtration rate to rule out renal problems. Also, while you may very well be right that GFR would improve, the little bits of reading I've had time to do indicates that unless they did eGFR by measuring his urine over 24 hours, then they likely estimated it from his creatinine levels, and so anything increasing creatinine levels would presumably cause the eGFR value to drop whether or not the increased creatinine levels are due to renal function or anything else.
    - carbocation 13y ago
      The definition of eGFR is generally done from a random serum measurement (if you measure it in the classical but rarely done fashion, then you don't have to call it an estimate). Also, creatinine is measured in serum to estimate gfr. Urine creatinine is more used as part of a test to look for nephrotic syndrome. Creatinine is produced constantly, filtered and not resorbed, without active secretion, which is why it is an excellent proxy for glomerular filtration rate.

vidarh 13y ago

As my doctor pointed out to me when I warned her to expect significantly elevated creatinine because of my protein supplementation: Raised creatinine in itself is not a "negative". Substantially raised creatinine may be a symptom of reduced renal function, but it is also a symptom of any number of other things - such as, indeed, increased protein intake. It could be just fluctuating in his case, or it could very well be, given his past diet (how could he survive on that), that he was finally getting decent amounts of protein.

carbocation 13y ago
I think you might be thinking of BUN. For creatinine, there is peer-reviewed data demonstrating that in people without renal disease, increasing the protein in your diet tends to improve your eGFR, not decrease it (which is what happened here). So for him, it either fluctuated or was a marker of true kidney disease, but in any case this is not just a marker of adequate protein intake.
- vidarh 13y ago
  Neither. I'm talking of creatinine levels in the blood, and my doctor was also very clear on that, and that it wasn't normally a concern at the levels she would expect to see from protein supplementation, but if it was too high, she'd need to establish filtration rate to rule out renal problems. Also, while you may very well be right that GFR would improve, the little bits of reading I've had time to do indicates that unless they did eGFR by measuring his urine over 24 hours, then they likely estimated it from his creatinine levels, and so anything increasing creatinine levels would presumably cause the eGFR value to drop whether or not the increased creatinine levels are due to renal function or anything else.
  - carbocation 13y ago
    The definition of eGFR is generally done from a random serum measurement (if you measure it in the classical but rarely done fashion, then you don't have to call it an estimate). Also, creatinine is measured in serum to estimate gfr. Urine creatinine is more used as part of a test to look for nephrotic syndrome. Creatinine is produced constantly, filtered and not resorbed, without active secretion, which is why it is an excellent proxy for glomerular filtration rate.