Both low molecular weight apo(a) size and high lipoprotein(a) levels predict atherosclerotic cardiovascular disease risk in dialysis patients.
Led by J. Craig Longenecker of Johns Hopkins University, Baltimore, the researchers studied 833 patients starting dialysis at 81 U.S. clinics.
During follow-up ( average 27.4 months ), 297 patients suffered atherosclerotic cardiovascular events.
In statistical analyses accounting for other factors, patients with high levels of lipoprotein(a) had a 38 percent increase in the risk of cardiovascular events.
The risk was even more strongly affected by a specific subset of lipoprotein(a) particles: very small, low molecular weight forms of a particle called apolipoprotein(a), apo(a).
For patients in the smallest category of apo(a) size, the cardiovascular event rate was increased by 58 percent.
Further analyses found that apo(a) size was a more important risk factor than lipoprotein(a) level.
The cardiovascular event rate was highes ( a 73 percent elevation ) for patients who had both high lipoprotein(a) levels and small apo(a) size.
These relationships were unaffected by factors such as patient age, race, or sex or the presence of diabetes.
The new study is the first to show an independent effect of high lipoprotein(a) levels, and especially small apo(a) size, on the risk of atherosclerotic cardiovascular events in dialysis patients.
Source: Journal of the American Society of Nephrology, 2005