When LDL is resolved with electrophoresis, it reveals several subfractions. These subfractions are simply different size populations of LDL particles.

Age, gender and lipid status can all affect the LDL subfractionation profile. Individuals who have less dense (so called 'buoyant') LDL have most of their LDL in subfractions 1 and 2. These results are referred to as pattern or phenotype "A" and are normal.

Those with significant amounts of subfractions 3- 7 (more dense particles) are at higher cardiovascular risk. These patients have pattern or phenotype "B". The B pattern rarely occurs as an isolated disorder. It is usually accompanied by characteristics of the metabolic syndrome: hypertriglyceridemia, reduced HDL-C , abdominal obesity, insulin resistance, etc.