LIPOPROTEIN(A) IS AN INDEPENDENT RISK FACTOR FOR CARDIOVASCULAR-DISEASE IN HEMODIALYSIS-PATIENTS

Background. Although serum lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerosis in the general population and Lp(a) levels are increased in hemodialysis patients, an association of Lp(a) with the risk of clinical events attributed to atherosclerosis has not been established in the chronic hemodialysis patient population. We therefore determined the association between Lp(a) levels and the risk of clinical events of presumed atherosclerotic etiology in a prospective study of an outpatient hemodialysis population. Methods and Results. Lp(a) was measured by radioimmunoassay in a baseline cardiovascular disease risk assessment in a consecutive series of 129 hemodialysis patients. The relation between baseline Lp(a) and clinical events of presumed atherosclerotic etiology was determined during 48 months of follow-up. Hemodialysis patients had a median Lp(a) concentration that was approximately four times as high as the median Lp(a) concentration in normal controls and twice as high as the levels in controls with angiographic evidence of coronary artery disease [median Lp(a), 38.4 versus 16.9 mg/dl; p<0.001]. Baseline Lp(a) levels were no different in participants with or with no history of a previous clinical event at the time of the baseline examination. However, baseline Lp(a) concentration (p<0.001) and a history of atherosclerotic clinical events (p=0.001) were associated with clinical events during the period of follow-up. In contrast, baseline serum total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, age, gender, race, or duration of hemodialysis were unrelated to this risk in the prospective study. Stepwise multiple logistic regression analysis demonstrated that serum Lp(a) concentration (p=0.001) and the presence of a previous clinical event (p=0.004) were the only independent contributors to the risk of a clinical event during the period of follow-up. Conclusions. Lp(a) is an independent risk factor for clinical events attributed to atherosclerotic cardiovascular disease in patients receiving chronic hemodialysis treatment of end-stage renal disease.