Demystifying Routine Labs #1-3: Creatinine And EGFR (my Absurd Videos)

[mr.mag]

I thought it'd be nice to make a summary thread for each of the (simpler) blood markers to help people who are reading through their labs. But don't murder me if I only do a few, it turned out to be a lot more work than I expected.

So, for serum creatinine (the one on routine bloodwork), here's my intro:

And my followup to introduce the concepts around the eGFR number that's based on creatinine:

And the actual discussion of eGFR:


Optimal levels
As you probably can guess from the video, optimal serum levels are going to depend on the person's muscle mass, creatine intake, and other factors. But the 0.8-1.1 mg/dL "optimal level" I saw in Blood Chemistry and CBC Analysis seems like a reasonable "things are probably working well" number to me. They also mention >1.6 as being the "alarm" level.

Conventional interpretations of high levels
Combining the suggested problems from Life Extension, Quest, and LabCorp's guides: dehydration, creatine supplementation, renal disease / insufficiency with low glomerular filtration, high consumption of red meat, muscle diseases, urinary tract obstruction, reduced renal bloodflow, rhabdomyolysis.

Conventional interpretations of low levels
Combining the suggested problems from Life Extension, Quest, and LabCorp's guides: inadequate protein, decreased muscle mass, severe liver disease, small stature.

Additional conventional reading

• The AACC
• MedlinePlus
• Medscape

Peat-related influences on levels
Here's some factors that are particularly relevant to us Peat-heads:

• Thyroid function: it seems like thyroid function greatly affects creatinine levels, and generally in the direction you'd expect (more thyroid -> lower creatinine because of increased filtration rate in the kidneys). The detailed reasons look like they're underexplored and complicated.
• Light: I haven't looked into this, but I get the impression some light therapies can help the kidneys. See the "Kidney" category in Valtsu's terrifyingly huge spreadsheet for more.
• Hydration: I'd love to quantify how much people's hydration status affects creatinine. I think we have everyone from people living off milk/OJ to the Eat-for-Heat types who look suspiciously at anything that sloshes around. But I've only found a thirsty-bird study, so it's hard to tell how much this actually matters. Anyone have a better resource?
• Aspirin: I haven't looked into this in detail, but aspirin might raise levels (references for evidence in the elderly number 1 and number 2, and a vague possible mechanism). I wonder if this is one reason my levels were wonky for a while.
• Niacinamide (and phosphate management): see Haidut's thread on niacinamide for kidney health.
• Oxidative stress and inflammation: I'm out of my depth on this, but I get the impression the biggest factors in kidney function decreasing with age are oxidative stress and inflammation. Which I suppose is not surprising.

Further testing

• For people really digging deep into kidney function, it sounds like a newer test that measures "Cystatin C" might be superior at identifying kidney issues with less ambiguity, and might be especially useful when combined with creatinine. Health Tests Direct is the cheapest source I know of at $56.
• There's an easy way to resolve that ambiguity about whether creatinine levels are high because of a lot of production, or because the kidneys aren't filtering it. It's called a "creatinine clearance" test, and involves collecting your urine for comparison between the amount of creatinine in it and in the blood. The cheapest provider I've seen is RequestATest at $59 (if you choose LabCorp).
• There are urine creatinine test strips (like these), but I haven't seen any that are very sensitive.

Please let me know any feedback or suggestions, positive or negative. For all I know I've made 27 mistakes in the post/video without realizing it.

 

[mr.mag]

who can you recommend to interpret blood tests?

 

[Dan W]

who can you recommend to interpret blood tests?

There's usually good suggestions from forum members if you wanted to post a thread with your labs. On the high end, I know Chris Masterjohn does consultations, although they're pretty expensive.

 

[mr.mag]

thanks Dan
wanna look at mine and tell me what you think?

 

[Dan W]

wanna look at mine and tell me what you think?

You might be better off just posting 'em for everyone's feedback, I'm still very much in learning mode.

 

[mr.mag]

good idea
thanks

 

[Dan W]

I had a forehead-smacking moment when I realized I've been making videos in a kind of "textbook" order instead of asking people what they would find useful. So I made a quick poll if there's a blood test you'd be curious to have me cover.

So far thyroid is #1 and prolactin is #2, which surprises me.

 

[mr.mag]

testosterone FR, FREE,etc -, cholesterol, rev T3

 

[Dan W]

testosterone FR, FREE,etc -, cholesterol, rev T3

Perfect, I was actually going to work those in (like testosterone and thyroid would both have the whole "pipeline" of inputs/outputs/related-hormones). I probably should've included a cholesterol choice, but I'm thinking it's probably pretty well-covered by other people.

 

[mr.mag]

1 more time please

 

[Dan W]

1 more time please

I'm not sure what you mean, is that in regards to the poll? It might have something that prevents vote-changing, but if it does I'm not sure how to disable it.

 

[Dan W]

Here's the results of the poll if anyone was curious.

I'm brainstormin' away, and I think I've figured out a cool way to show the basics of thyroid hormone interactions.

 

[ddjd]

I thought it'd be nice to make a summary thread for each of the (simpler) blood markers to help people who are reading through their labs. But don't murder me if I only do a few, it turned out to be a lot more work than I expected.

So, for serum creatinine (the one on routine bloodwork), here's my intro:

And my followup to introduce the concepts around the eGFR number that's based on creatinine:

And the actual discussion of eGFR:


Optimal levels
As you probably can guess from the video, optimal serum levels are going to depend on the person's muscle mass, creatine intake, and other factors. But the 0.8-1.1 mg/dL "optimal level" I saw in Blood Chemistry and CBC Analysis seems like a reasonable "things are probably working well" number to me. They also mention >1.6 as being the "alarm" level.

Conventional interpretations of high levels
Combining the suggested problems from Life Extension, Quest, and LabCorp's guides: dehydration, creatine supplementation, renal disease / insufficiency with low glomerular filtration, high consumption of red meat, muscle diseases, urinary tract obstruction, reduced renal bloodflow, rhabdomyolysis.

Conventional interpretations of low levels
Combining the suggested problems from Life Extension, Quest, and LabCorp's guides: inadequate protein, decreased muscle mass, severe liver disease, small stature.

Additional conventional reading

• The AACC
• MedlinePlus
• Medscape

Peat-related influences on levels
Here's some factors that are particularly relevant to us Peat-heads:

• Thyroid function: it seems like thyroid function greatly affects creatinine levels, and generally in the direction you'd expect (more thyroid -> lower creatinine because of increased filtration rate in the kidneys). The detailed reasons look like they're underexplored and complicated.
• Light: I haven't looked into this, but I get the impression some light therapies can help the kidneys. See the "Kidney" category in Valtsu's terrifyingly huge spreadsheet for more.
• Hydration: I'd love to quantify how much people's hydration status affects creatinine. I think we have everyone from people living off milk/OJ to the Eat-for-Heat types who look suspiciously at anything that sloshes around. But I've only found a thirsty-bird study, so it's hard to tell how much this actually matters. Anyone have a better resource?
• Aspirin: I haven't looked into this in detail, but aspirin might raise levels (references for evidence in the elderly number 1 and number 2, and a vague possible mechanism). I wonder if this is one reason my levels were wonky for a while.
• Niacinamide (and phosphate management): see Haidut's thread on niacinamide for kidney health.
• Oxidative stress and inflammation: I'm out of my depth on this, but I get the impression the biggest factors in kidney function decreasing with age are oxidative stress and inflammation. Which I suppose is not surprising.

Further testing

• For people really digging deep into kidney function, it sounds like a newer test that measures "Cystatin C" might be superior at identifying kidney issues with less ambiguity, and might be especially useful when combined with creatinine. Health Tests Direct is the cheapest source I know of at $56.
• There's an easy way to resolve that ambiguity about whether creatinine levels are high because of a lot of production, or because the kidneys aren't filtering it. It's called a "creatinine clearance" test, and involves collecting your urine for comparison between the amount of creatinine in it and in the blood. The cheapest provider I've seen is RequestATest at $59 (if you choose LabCorp).
• There are urine creatinine test strips (like these), but I haven't seen any that are very sensitive.

Please let me know any feedback or suggestions, positive or negative. For all I know I've made 27 mistakes in the post/video without realizing it.

dan what do you think sent your creatinine down to 0.64...?

 

[Dan W]

dan what do you think sent your creatinine down to 0.64...?

I'm *still* trying to unravel all the mysteries of what happened at that point. That's when I first started trying Peat's ideas and had my bloodwork change dramatically in a few months. I've wondered if the creatinine might somehow have been related to my body improving in fluid handling / hydration. And maybe there was some metabolic influence on it too.