INCREASED PLASMA-CONCENTRATIONS OF LIPOPROTEIN(A) FOR EVERY PHENOTYPEOF APOLIPOPROTEIN(A) IN PATIENTS WITH CHRONIC-RENAL-FAILURE TREATED BY HEMODIALYSIS

Background and Aims: Uremic patients on hemodialysis show high levels of lipoprotein(a) [Lp(a)]. Whereas in Japanese and Spanish hemodialysi s patients high Lp(a) levels have been found for every apo(a) phenotyp e, in Austrian hemodialysis patients two studies showed an apo(a) phen otype-associated elevation of Lp(a) concentration In this investigatio n we studied the influence of apo(a) genetic polymorphism on Lp(a) con centrations in a large group of Italian patients with chronic renal fa ilure on hemodialysis. Methods and Results: Lp(a) levels were about th ree times higher in patients (n=138) than in controls (n=148): 27.7 mg /dl (2.5-131) vs 10.0 mg/dl (0-64.5); p<0.001. In hemodialysis patient s Lp(a) plasma concentrations were increased for every apo(a) isoform. The Lp(a) elevation was present in both patients with apo(a) isoforms of high Molecular Weight (MW) and those with apo(a) isoforms of low M W. In addition, the linear interpolation curve, which correlates each apo(a) isoform MW with the corresponding median of Lp(a) levels, in pa tients is shifted toward higher Lp(a) values compared with that of the controls. Conclusions: Our results indicate that in Italian patients on hemodialysis the elevation of Lp(a) involves every apo(a) phenotype . This finding suggests that the cardiovascular risk related to Lp(a) concentration might be increased in all hemodialysis patients. Moreove r, we found that Lp(a) levels were not related to hemodialysis duratio n. Therefore, the unselective increase in Lp(a) might be the consequen ce of chronic renal failure. In conclusion although apo(a) phenotypes influence Lp(a) concentration, increased Lp(a) levels in hemodialysis are related in part to other non-generic factors, such as chronic rena l failure. (C) 1996, Medikal Press