Plasma Clot Lysis Time and Its Association with Cardiovascular Risk Factors in Black Africans

Zelda De Lange,Johann C Jerling,Marlien Pieters,Annamarie Kruger,Dingeman C Rijken

doi:10.1371/journal.pone.0048881

Abstract

Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35–60 years) were cross-sectionally analysed.Increased PAI-1act, BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

Highlights

Cardiovascular disease (CVD) is a global problem and CVD risk factors and disease rates continue to rise [1]
clot lysis times (CLT) was longer in urban than in rural women, while no difference was observed for men before adjustments
This study investigated for the first time whether urbanisation with its resultant increased CVD risk is associated with hypofibrinolysis

Summary

Introduction

Cardiovascular disease (CVD) is a global problem and CVD risk factors and disease rates continue to rise [1]. Various proteins are involved in the lysis of blood clots These proteins, such as plasminogen activator inhibitor type-1 (PAI-1), tissue-type plasminogen activator (tPA) and plasminogen can be measured individually. They serve as proxy markers for fibrinolysis. One can measure the global ability of blood or plasma to lyse clots, with the use of global fibrinolytic assays. These assays give an indication of the speed with which the body can lyse clots, often reported as lysis time. In recent years a plasma fibrinolytic potential assay that mimics the physiological initiation of coagulation by tissue factor and clot breakdown by tPA from the endothelium was developed [4]

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