Specific elevation in plasma tissue plasminogen activator antigen concentrations in South Asians relative to...

Elevated levels of haemostatic factors including tissue plasminogen activator (t-PA) antigen are associated with coronary heart disease in Europeans but data in South Asians are sparse. We performed a cross-sectional study of 111 healthy men and women aged 40-55 years (56 European and 55 Asian) frequency matched across a wide range of body mass index (17-34 kg/m2). All subjects had detailed adiposity and metabolic measurements, and five haemostatic factors were determined. South Asians had greater insulin resistance than Europeans (fasting insulin geometric mean, 7.1 versus 4.7 microU/ml, and 2-h insulin, 37.3 versus 14.1 microU/ml, respectively). There were no significant ethnic differences in the mean concentrations of fibrinogen, factor VII, von Willebrand factor, or fibrin D-dimer (P > 0.10). However, the t-PA antigen concentration was significantly elevated in South Asians compared with Europeans (mean, 10.6 versus 8.2 ng/ml, P = 0.001). t-PA correlated positively in both ethnic groups with features of the metabolic syndrome but the ethnic difference in t-PA persisted after adjustment for adiposity, metabolic and inflammatory variables (beta = 2.0, 95% confidence interval = 0.5-3.6, P = 0.012). We therefore hypothesize that elevated t-PA antigen may be a novel mechanism contributing to increased cardiovascular risk in South Asians.