I actually don’t get bloodwork for myself very often (I prefer to help others with their labs), but recently I obtained a fasting Cholesterol Panel.  And sometimes getting bloodwork is a good opportunity to discuss what each of these things mean in a more personal context (along with some allusions to relevant literature).  So today we are going to use my labs to discuss LDL-C and ApoB!

So here are my recent labs (Note: I do not take any cholesterol-lowering medications):

Total Cholesterol: 160 mg/dL

Triglycerides: 68 mg/dL

HDL-C: 67.4 mg/dL

LDL-C: 79 mg/dL

VLDL-C: 14 mg/dL

Non-HDL-C: 93 mg/dL

ApoB: 65 mg/dL

You may notice the omission of Lp(a), the “Felon of the Lipid Neighborhood,” but I’ve checked this in the past and my levels are about 10 nmol/L (very low), so that’s one less thing for me to worry about.  Since Lp(a) is primarily determined by genetics, it appears I “picked the right parents” so I don’t need to ever check it again (and for those of you who know my parents, this statement is accurate for far more than just Lp(a) levels…my parents are amazing)!

Ok, so let’s unpeel this ApoB onion:

• Number of PARTICLES dictates RISK when it comes to “potentially” atherogenic lipoproteins.  It’s not just the mass of cholesterol on LDL particles that matters…it’s the NUMBER of ApoB particles (B for Bad if they end up in your artery wall) that represents the potential criminals in your Lipid Neighborhood.
  • Since there is one ApoB-100 on every VLDL, IDL, and LDL particle, the ApoB measurement is a more accurate representation of the number of potential criminals in your Lipid Neighborhood.The equation below predicts expected ApoB from an LDL-C measurement:
    • 23.77 + (0.52 x LDL-C)And in several studies, including this most recent one, excess ApoB for the given mass of LDL-C is associated with 12% increased all-cause mortality and 24% increased cardiovascular mortality…and these were people even on medication. (This illustrates two important concepts: DISCORDANCE between LDL-C and ApoB and Residual Risk).  And for people not on any medication in this study, those with the highest Excess ApoB had a 52 to 75% increased risk of having a cardiovascular event than those with concordance between ApoB and LDL-C.
    So let’s calculate my expected ApoB from my LDL-C:
    • 23.77 + (0.52 x 79) = 64.85. Pretty much identical to my measured ApoB of 65!  Huzzah! But let’s say that my ApoB was 90 even if my LDL-C was still 79…that’s a lot more dangerous Lipid Neighborhood than the current cozy one on 65^th Street!
  • There are 2 common situations in which ApoB will be discordantly high for the concurrent LDL-C:
    • Insulin resistance (there are more small particles delivering the same mass of cholesterol along with decreased clearance of remnant particles…and number of particles dictates risk).
    • Elevated Lp(a), as this is simply included with LDL-C on a basic lipid panel since it’s in the same density range as LDL…this is why you need a separate, specific test of Lp(a).

So in summary:

The updated 2026 Cholesterol Guidelines finally recognized ApoB as a superior measurement of the potential criminals in one’s Lipid Neighborhood compared to just LDL-C.  And if your ApoB is higher than we’d expect (discordant) from your LDL-C, you still might have residual risk (your Lipid Neighborhood might still be unacceptably troublesome), since number of particles dictates lipid-mediated risk.

Next time, we’ll talk about some of the other components of the Lipid Panel!  ApoBe safe out there!