The Nation's Health

Lipoprotein testing: Apoprotein B on VAP

We've just received an announcement that, if your Vertical Auto Profile lipoprotein test (Atherotech) is provided through the national Quest laboratories (a large national laboratory company), they will include an apoprotein B.

This represents an improvement over the previous "direct LDL," a measured LDL cholesterol. Recall that standard lipid panels obtained in hospitals and doctors' offices is a calculated LDL, based on the 40-some year old Friedewald calculation. In my view, the Friedewald calculated LDL is a dinosaur that is virtually useless and needs to be retired.

Direct, or measured, LDL is a slight improvement. It removes some of the inaccuracy introduced by the assumptions built into the calculated value.

Apoprotein B (also called apoprotein B100) is yet another improvement. Apo B's have been available for years, but was not provided on the VAP. The Atherotech people have done a good job of making VAP more broadly available through "drawing stations" and proponents like Life Extension. Adding an ApoB is a favorable development, since it incorporates the risk of other ApoB-containing particles, like VLDL, IDL, and Lp(a). Several studies like the Quebec Cardiovascular Study have shown that ApoB is a superior predictor of heart disease compared to calculated LDL.

I still believe that the gold standard for assessing risk from an LDL standpoint is the LDL particle number along with the other measures provided by the NMR assay (Liposcience). However, the addition of the ApoB to VAP adds greater confidence to the measures provided by this technique. Those of you who rely on the VAP assay provided by Quest for your Track Your Plaque program for control of CT heart scan scores therefore have access to this improved panel.