Fibrinogen and plasma clot properties are associated with apolipoprotein B and apolipoprotein B-containing lipoproteins in Africans

Abstract

BACKGROUND: Case-control, intervention and laboratory studies have demonstrated a link between apolipoprotein B (ApoB)-containing lipoproteins and clot structure and thrombosis. There is, however, limited evidence on a population level.

OBJECTIVES: We determined the cross-sectional relationship between lipoprotein(a) [Lp(a)], low- density lipoprotein cholesterol (LDL-C), and ApoB with fibrinogen and plasma clot properties in 1462 Black South Africans, a population with higher fibrinogen and Lp(a) levels compared with individuals of European descent.

METHODS: Data were obtained from participants in the South African arm of the Prospective Ur-ban and Rural Epidemiology study. Clot properties analyzed included lag time, slope, maximum ab- sorbance, and clot lysis time (turbidity). Lp(a) was measured in nM using particle-enhanced immuno- turbidimetry. General linear models (GLM) were used to determine the associations between ApoB and ApoB-containing lipoproteins with fibrinogen and plasma clotproperties. Stepwise regression was used to determine contributors to clot properties and Lp(a) variance.

RESULTS: GLM and regression results combined, indicated fibrinogen concentration and rate of clot formation (slope) had the strongest association with Lp(a); clot density associated positively with both Lp(a) and LDL-C; time to clot formation associated negatively with ApoB; and clot lysis time (CLT) demonstrated strong positive associations with both ApoB and LDL-C, while its association with Lp(a) was fibrinogen concentration dependent.