Enzyme Linked to Coronary Heart Disease Risk
Lp-PLA2 tied to higher risk to same extent as cholesterol, holds potential as therapeutic target
FRIDAY, April 30 (HealthDay News) -- Lipoprotein-associated phospholipase A2 (Lp-PLA2), an inflammatory enzyme expressed in atherosclerotic plaques, is associated with coronary heart disease risk to about the same extent as non-high-density lipoprotein cholesterol (non-HDL-C) or systolic blood pressure, according to an analysis published in the May 1 issue of The Lancet.
Alexander Thompson, Ph.D., of the University of Cambridge in the United Kingdom, and colleagues in the Lp-PLA2 Studies Collaboration, performed a meta-analysis of 32 studies with 79,036 participants and calculated the relationship of Lp-PLA2 mass and activity to the risk of coronary heart disease, stroke, and death.
The researchers found that higher levels of Lp-PLA2 in the blood were associated with increased risk for coronary heart disease to a degree similar to that from high blood pressure or high levels of non-HDL-C. Lp-PLA2 activity and mass both were associated with risk: for coronary heart disease, the risk ratio (RR) was 1.10 for activity and 1.11 for mass; for ischemic stroke, the RR was 1.08 for activity and 1.14 for mass; and for vascular mortality, the RR was 1.16 for activity and 1.13 for mass. For nonvascular mortality, the RR was 1.10 for both activity and mass. The researchers note that randomized clinical trials of Lp-PLA2 inhibitors are needed to determine if lowering enzyme levels could reduce cardiovascular risk.
"Lp-PLA2 activity and mass each show continuous associations with risk of coronary heart disease, similar in magnitude to that with non-HDL-C or systolic blood pressure in this population. Associations of Lp-PLA2 mass and activity are not exclusive to vascular outcomes, and the vascular associations depend at least partly on lipids," the authors write.
The study was partly supported by GlaxoSmithKline; several authors disclosed financial ties to GlaxoSmithKline and other pharmaceutical companies.