LDL-C[measured] = Lp(a)-C + LDL-C[true]

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BrianR
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LDL-C[measured] = Lp(a)-C + LDL-C[true]

Post by BrianR »

Perhaps this is well known, but I hadn't absorbed it before - that LDL-C (measured) is a function of the concentration of both Lp(a) and actual LDL. I learned this from the National Lipid Association's Clinical Feature: Lipoprotein(a) – Fast Facts and Clinical Perspectives [references].

The references cite work from Sam Tsimikas' lab (unfortunately behind a paywall). The rough formula seems to be: "true" LDL-C = measured LDL-C - ( Lp(a)-C / 3 ).

Obviously, there are implications for how low LDL-C can go with statins, and another explanation for why LDL particle counts and ApoB concentrations might be better metrics for addressing the LDL specific risk.

(Since my lab results of Lp(a) > 300, I've become very, very interested in Lp(a) )
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KatieS
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Re: LDL-C[measured] = Lp(a)-C + LDL-C[true]

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Brian, like me, you run an extremely high HDL, low TG and negative FH of CHD. Have you had a coronary calcium scan? Do others in your family run a high lp(a)? Once I read that a high HDL can interfere with the lp(a) measurement, but I can't find the reference. I don't think measuring the mass size of the lp(a) is commercially available.

For me, like my 100.5 y/o, 3/4 mother, I am on a low dose (10mg) of simvastatin to lower the LDL to 75. I'm not convinced that my lp(a) which averages 180 is not a benign variant; since at 64 my coronary calcium score was zero and not increasing minimal plaque in my carotids.
BrianR
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Re: LDL-C[measured] = Lp(a)-C + LDL-C[true]

Post by BrianR »

KatieS wrote:Brian, like me, you run an extremely high HDL, low TG and negative FH of CHD. Have you had a coronary calcium scan? Do others in your family run a high lp(a)? ...
Katie, I had a coronary calcium score some time ago (6-8 years ago), my then doctor pronounced it to be within standard range for my age. I'm not sure what the score was. AFAIK, no one in my immediate family has an Lp(a) score. I was just talking to my sister about her basic lipid panel scores (very similar to mine) and talking about Lp(a), ApoB, LDL particle etc., so maybe she'll escalate with her doctor to get better tests.

Although there is no history of Alzheimer's in my parents' families, there is definitely a history of CHD in my mother's family. In fact, she had her first stroke at 64 and several more events about a decade later. (But still mentally sharp into her early eighties.) I believe that three or four of my maternal grandmother's siblings died in their late 60s or early 70s from cardiovascular related events. My grandmother lived into her early 90s, but had a lot of medical issues, some probably unrelated to CHD. I would say that, physiologically, I probably most take after that line of the family.

I meet with my new primary care physician next week to discuss what to do about the WellnessFX detailed test results. I'm going to try not to be one of those patients who walks in demanding an internet-designed treatment plan. (Even though I do have an internet-designed treatment plan in mind.) I'm hopeful he'll be knowledgeable enough to provide a treatment and testing plan to better understand what's going on with my body and mitigate the bad stuff.

Your coronary calcium score is great, it sounds like you're doing a wonderful job maintaining that aspect of your health!
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KatieS
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Re: LDL-C[measured] = Lp(a)-C + LDL-C[true]

Post by KatieS »

Actually half of women my age are predicted to have a zero calcium score. I recommend obtaining your previous scan (unless it was zero) and consider a follow-up. Tincup has been able to halt the progression of a low number.
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