1/4 "also is the LEM (Lipid Energy Model) mutually exclusive with high LDL being atherogenic?"
Yes and no.
Yes -- in that the two should be treated as separate questions. It may well be that LEM is true, yet high LDL is independently atherogenetic and vice versa.
2/4 No -- in that it was actually metabolic dynamics having an impact on lipid profiles that led me down the road we're at now.
Function vs dysfunction (or successful regulation vs unsuccessful regulation) having an upstream impact on lipid levels should be strongly considered.
3/4 But currently, it is assumed these influences are either irrelevant or the impact known -- at least to the extent that it is commonly assumed high LDL is pathogenic in every context (hence, little need to prospectively study metabolically healthy populations with high LDL)
1/ Got lots of pings on this one (including from @theproof)
But it's worth unpacking just how many variables are in play and why I obsess so much about controlling for them when the shifts are relatively small...
2/ If you're just tuning in, I've done over 50 experiments with many of them hypercontrolled (like below) where I literally eat to an exact meal plan with exact timing, have nearly identical exercise, and try to sync sleep schedule as best as possible. cholesterolcode.com/the-oxldl-repl…
3/ It's because I know there's already a lot of things that can alter lipid levels even in the very short term. Not just days, but *hours*.
Check out this prelim data where I was testing 6 times over each day. And these are the means of the last 3 days...
1/2 Example 1:
🚬 Imagine if the average person from the moment they're born were taught to be 2 pack a day smoker.
⛔️ Now imagine a fraction were born into families that were 0 pack a day smokers.
Would we expect that latter group to have greater longevity than the former?
2/2 Example 2:
Now imagine most people averaged 100 #LDL cholesterol over their lifetime.
But a fraction were born with a genetic mutation that kept their average at 20.
Would we expect that latter group to have greater longevity?
If genetically low LDL/ApoB had universally a net benefit -- this would be strong evidence that indeed this particle is pathogenic -- which is to say, disease-causing overall (not just atherogenic)
But does existing genetic data support this hypothesis? Is there clear longevity?
For those who've followed my work and know where I'm coming from, WHY would I fully expect LDL-TG (triglyceride content per LDL particle) to closely associate with atherosclerosis?
For example, I’ve known many who are into fitness (or just now getting into it) that are seeing better results on PE.
To be sure, that’s anecdotal, and it’s hard to know for sure if they were getting adequate protein in the first place…
… conversely, I’ve also seen a kind of resurgence in people discovering KetoAF after struggling with various versions of keto (high protein or not). Many have health challenges, with many of those preventing their being fitness-centric. (Thus, confounder + cofounder potentially)
2/ "My point is, there is no athero or chronic vascular inflammation without a lipid disorder."
I have a nuanced difference with Sam on this -- but the important point here is that we need to disentangle the disorder/disfunction from the athero to test..
3/ In other words, to confirm/disconfirm the contribution of LDL-P independently to atherosclerosis, we'd want to look to populations without a likely form of disorder or dysfunction (be it genetic or acquired).
Obviously, I think LMHRs provide a unique opportunity on this...