Interesting observation, Lance. Yeah, it seems like FH should have been excluded...
Kudos, Ski. You KNOW how happy I am with your results When you get a chance, please post all of your results & various strategies (and add them to our spreadsheet!) so that we can learn from you. Without the confounder of statins and other lipid lowering medications/supplements, my observation seems to have held true so far… That being said, we need to add a category in our spreadsheet to account for lipid lowering agents. Any volunteers?
Lipoprotein Insulin Resistance Index: A Lipoprotein Particle–Derived Measure of Insulin Resistance http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4175429/
LipoProfile-3 algorithm is the formula used to determine LPIR. It can be found on page 6 of the paper.
Conclusions: LP-IR scores had strong associations with multiple measures, HOMA-IR, and GDR, the former being more reflective of hepatic and the latter of peripheral insulin sensitivity, and may represent a simple means to identify individuals with IR.
From everything I've found, LPIR seems to matter... a lot.
Juliegee wrote:From everything I've found, LPIR seems to matter... a lot.
Heck yea it matters. Its a mathematicians attempt to quantify MetS and it works pretty well. Metabolic syndrome usually means hyperinsulinemia, hyperglycemia, hypertriglycemia, etc as well. These things definitely matter. It doesn't mean its a valid goal of therapy. Target ApoB or LDL-P as low as we can go!
If I could get LDL-P under 700 without meds I have no doubt my risks of CVD, dementia, and yes AD would be multitudes lower. I am about to do it and I hope you guys will all be my witness.
If my warm and caring demeanor isnt coming across the cold black and white text , Peace, love, Hugs.
My worst NMR with its highest LPIR score and with the insulin reading of 3 was without any meds/supplements. So if I understand it correctly, shouldnt my insulin reading have been quite elevated to justify an elevated LPIR "score"?
Ive also seen comments from diabetics that are definitely insulin resistant with scores in the single digits!
Ski wrote:My worst NMR with its highest LPIR score and with the insulin reading of 3 was without any meds/supplements. So if I understand it correctly, shouldnt my insulin reading have been quite elevated to justify an elevated LPIR "score"?
Ive also seen comments from diabetics that are definitely insulin resistant with scores in the single digits!
I am guessing this comes back to the difference between physiologic insulin resistance and metabolically deranged insulin resistance.
But from a tracking metric standpoint, it may be that because the two populations are not separable you can't really use LPIR. My guess is a body fat % would do a pretty good job of segmenting them.
So LPIR only matters if you have a relatively high body fat %.
The other thing about Attia's blog was that it tracked PEAK particle size. I didn't even know I could order such a test. Doesn't seem to be a commonly tracked metric by Dayspring, Gundry, etc, etc. Maybe they were thinking it was highly correlated to some other metric???
Thanks Lance.
I think that was my point in that I agree Insulin Resistance is VERY important, but that I wouldnt put too much emphasis on the NMR's method in determining that. Seems to be a "correlative" method that is simply not going to apply in many cases.
Hepoberman wrote:
...After you've all actually read Part VI then tell me particle size somehow matters more than particle count in assesing the optimal health program. Its just not congurent with the facts.
Has anyone actually read it? I don't need to prove whats already been proven and explained.
This table shows us that when LDL-P is NOT taken into account (i.e., “unadjusted” analysis), an increase of one standard deviation in particle size is associated with 20.9 microns of LESS atherosclerosis, what one might expect if one believes particle size matters. Bigger particles, less atherosclerosis.
However, and this is the important part, when the authors adjusted for the number of LDL particles (in yellow), the same phenomenon was not observed. Now an increase in LDL particle size by 1 standard deviation was associated with an ADDITIONAL 14.5 microns of atherosclerosis, albeit of barely any significance (p=0.05).
Let me repeat this point: Once you account for LDL-P, the relationship of atherosclerosis to particle size is abolished (and even trends towards moving in the “wrong” direction – i.e., bigger particles, more atherosclerosis).
Hep,
I see on that graph that the correlation between LDL-P and size is -0.64. That is a potentially big problem with your argument in my view. The issue of multicollinearity http://en.wikipedia.org/wiki/Multicollinearity must be considered when trying to interpret the value of an individual factor (size) when another, highly correlated factor (LDL-P) is in the regression model.
From the multicollinearity wiki page: "That is, a multiple regression model with correlated predictors can indicate how well the entire bundle of predictors predicts the outcome variable, but it may not give valid results about any individual predictor, or about which predictors are redundant with respect to others."
I think it is inappropriate to lay too strong an argument on LDL-P to the exclusion of size based on this data. Do you have other data to support your position?
Good observation, Richard. We're blessed to have your well-trained eye help us sort this out.
Lance & Ski- LP-IR (Lipoprotein Insulin Resistance Index) is simply an algorithm, not a correlation. It is NOT an actual measure of insulin sensitivity, or glucose homeostasis, but rather a prediction of impending IR based on lipid values.
Among the earliest manifestations of IR, are alterations in lipid and lipoprotein metabolism. From everything I've been able to find, it is HIGHLY predictive of emerging insulin resistance and is relevant regardless of body fat. Younger people, especially, can have zero indications of actual IR, but their lipids can reliably predict an emerging problem.
THIS matters as CAD/CVD and Alzheimer's risk also increase with age and IR is strongly correlated with both.
The way I see this is there are two different trains of thought due to different knowledge with one side trying to present their view as correct and the other trying to present their side as correct or that the data for either side is not sufficient to make a definitive answer. So one side is trying to collect data and do their own clinical trial analysis of the data to make a paper worth publishing and is trying to convince the other side to join in with any data they may have to contribute. And of course this would be our first citizen driven paper from this web site. But then again I could be wrong.
I just re-read the LPIR paper and found this potentially important nugget regarding how statin lowering agents affect an accurate LPIR:
A potential limitation of relying solely on lipoprotein information to identify IR is that results may be compromised by particular lipid-altering medications. Statins, for example, would not be expected to have profound effects on the ability of the LP-IR score to detect IR in a subject with reduced insulin sensitivity because statins have a relatively small effect on the lipoprotein parameters that are heavily weighted in the LP-IR algorithm (i.e., TGs-enriched large VLDL-P, VLDL size, and HDL size). In contrast, niacin treatment, which reduces TGs and increases large HDL-P,30 may lower the LP-IR score, giving the illusion of improved insulin sensitivity in a subject who may experience increased IR,31–33 FPG,34 and risk of progressing to T2DM on niacin therapy.35 An analysis of the effects of lipid-modifying therapy on the LP-IR score confirmed that the use of lipid-modifying drugs did not have a substantial effect on the mean LP-IR score in the MESA population. Additional studies comparing the LP-IR scores of patients before and after treatment with lipid-altering drugs are required to fully understand the changes that may impact LP-IR assay results and what that would mean to the clinical interpretation of the LP-IR score.
So even with statins, one's LPIR score may be fairly accurate. Niacin, on the other hand, apparently gives the illusion of improved IR- good to know.
When you get a chance, please post all of your results & various strategies (and add them to our spreadsheet!) so that we can learn from you. Without the confounder of statins and other lipid lowering medications/supplements, my observation seems to have held true so far… That being said, we need to add a category in our spreadsheet to account for lipid lowering agents. Any volunteers? 
