Apolipoprotein measurements: is more widespread use clinically indicated?

Apolipoprotein (apo) B may be a more sensitive measure of atherogenicity than low-density lipoprotein cholesterol (LDL-C) and a better index for assessing cardiovascular risk. The refined risk assessment provided by apo B may be important in patients at high cardiometabolic risk such as those with diabetes mellitus or metabolic syndrome, as these conditions are often associated with normal LDL-C values but increased numbers of small, dense low-density lipoprotein (LDL) particles (indicating increased levels of apo B). Although apo B is not currently a treatment target in the United States cholesterol-lowering guidelines, a consensus conference endorsed by the American Diabetes Association and the American College of Cardiology recently recommended that apo B be added as a therapeutic target in patients at high cardiometabolic risk and in patients with clinical cardiovascular disease or diabetes. Suggested target goals are < 90 for high risk and < 80 mg/dL for highest risk patients. Current clinical data indicate that intensive statin therapy can lower apo B to meet this aggressive goal. While the proatherogenic/antiatherogenic ratio of apo B/apo A-I is a better risk discriminator than the single proatherogenic measurement (apo B), clinical trial data are lacking regarding the impact of increasing apo A-I and high-density lipoprotein on outcomes.