Plasma concentration of apolipoprotein B is a slightly better predictor of coronary heart disease than is non-HDL cholesterol and a much better predictor than is LDL cholesterol, reported Dr. Tobias Pischon of the Harvard School of Public Health, Boston, and his associates.
This finding is sure to add to the controversy over which lipid measurement is the best for assessing both coronary risk and treatment efficacy. According to current National Cholesterol Education Program guidelines, LDL cholesterol is recommended as the primary target for lipid-lowering therapy, HDL cholesterol is considered a secondary treatment target, and apolipoprotein B (apoB) is not considered a target at all, the investigators said.
In the first large prospective study to directly compare these three measures, apoB was the best predictor of coronary heart disease (CHD) risk (Circulation 2005;112:3375–83). The researchers used a database of more than 51,000 male health professionals who had been followed every 2 years since 1986 to identify 243 subjects who had developed CHD during a 6-year study period and 496 matched control subjects who had not developed the disease. The baseline level of apoB was the strongest predictor of CHD, with a relative risk of 2.98. The concentration of non-HDL cholesterol also was strongly predictive, with a relative risk of 2.75, and the LDL cholesterol level was predictive but less so, with a relative risk of 2.07.
“The practical application of our findings,” the investigators wrote, would be to switch from assessing LDL and non-HDL cholesterol in screening and treatment of CHD to assessing apoB instead. However, the cost of such a switch relative to the potential improvement in risk assessment “needs to be further evaluated,” they said.