Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a serine lipase that enhances the instability of the atherosclerotic plaques. While in the general and cardiac population Lp-PLA2 is recognized as an important determinant of cardiovascular (CV) accidents, no data are available for the renal population. The aim of this study was to evaluate the relationship between Lp-PLA2 and acute CV events in hemodialyzed patients.
Methods: We enrolled 102 dialyzed patients, 63% male, age 71 years (59-78), 35% with diabetes, 54% hypertension, 40% coronary artery disease and 31% peripheral vascular disease. They were investigated for Lp-PLA2 (cut-off < 194 nmol/min/ml), lipoprotein profile and the occurrence of acute CV events and death in the subsequent 3 years of follow-up.
Results: The median (interquartile ranges) levels of Lp-PLA2, total-, HDL-, LDL-cholesterol and ApoB/ApoA lipoprotein ratio were 184.5 (156.5-214.5) nmol/min/ml, 158 (127-191) mg/dl, 41 (33-51) mg/dl, 79 (63-102) mg/dl and 0.72 (0.58-0.89), respectively. In 42% of patients, Lp-PLA2 was > 194 nmol/min/ml and total- and LDL-cholesterol were higher, as well as CV morbidity and mortality. During follow-up, 51% of patients developed at least one CV event; the median survival time was 36 months, with a total and CV mortality of 42 and 29%, respectively. At multivariate Cox regression, Lp-PLA2 > 194 nmol/min/ml (HR = 2.98, p = 0.005), age (HR = 1.03, p = 0.029), diabetes (HR = 2.86, p = 0.002) and hypertension (HR = 2.93, p = 0.002) were independently associated with time to CV events.
Conclusions: Lp-PLA2 activity is elevated among dialyzed patients and is an independent risk factor for acute CV events in a mean follow-up of 3 years.
Keywords: Atherosclerosis; Cardiovascular disease; Hemodialysis; Lipoprotein-associated phospholipase A2; Mortality.