RETINAL VASODILATORY RESPONSES ARE INVERSELY ASSOCIATED WITH PLASMINOGEN ACTIVATOR INHIBITOR-1: THE AFRICAN-PREDICT STUDY

AIMS Plasminogen activator inhibitor-1 (PAI-1), traditionally associated with fibrinolysis, is increasingly implicated in impaired vascular function. However, studies on its association with microvascular function are limited to the cutaneous and coronary microvascular beds in older and diseased individuals. To better understand its potential involvement in the early stages of disease development, we investigated the associations of retinal vasodilatory responses to flicker light with PAI-1 activity (PAI-1act) in young and healthy individuals. METHODS We included healthy Black and White women and men (n = 518; aged 20-30 years), and measured plasma PAI-1act and retinal vasodilatory responses to flicker light provocation. We also collected demographic and lifestyle data, measured blood pressure, anthropometry, blood lipids, inflammatory and other biomarkers. RESULTS In multivariate regression analyses, maximal retinal venular dilation associated independently and inversely with PAI-1act (Adj. R2 = 0.11; β = -0.15; p = 0.001) in the total group. In exploratory subgroup analyses, this association remained in White women (Adj. R2 = 0.07; β = -0.23; p = 0.005), and was more robust with younger age and lower blood pressure and in non-smokers, but also with greater central adiposity, higher low-density lipoprotein cholesterol and inflammation (all p < 0.05). CONCLUSIONS Our data suggest that in young individuals, PAI-1 may already be associated with subclinical microvascular dysfunction.