BackgroundFlow-mediated dilation (FMD) measures vascular endothelial function by evaluating the vasodilatory response of blood vessels to increased blood flow. Nevertheless, the association between FMD and stroke incidence in a general population remains unclear. This study investigated the association between vascular endothelial function and stroke incidence in the general Japanese population. MethodsBased on cohort data from the Tohoku Medical Megabank Community-based Cohort Study, participants aged ≥18 years were recruited from Iwate Prefecture, with the final sample comprising 2952 subjects. ResultsThe FMD level was 0.5%–27.1%, with a median of 5.0% (interquartile, 4.2%–11.3%). The mean follow-up period was 5.5 ± 1.8 years (range, 0.6–6.9 years). After dividing the participants into two subgroups according to the median FMD value, a multivariate Cox regression analysis adjusting for gender, age, smoking, alcohol consumption, systolic blood pressure, low-density lipoprotein cholesterol, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin T and hemoglobin A1c revealed that a lower FMD value was strongly associated with incidences of total stroke (hazard ratio[HR] = 2.13, 95% confidence interval[CI] = 1.48–3.07, p < 0.001), ischemic stroke (HR = 3.33, 95%CI = 2.00–5.52, p < 0.001), nonlacunar stroke (HR = 2.77, 95%CI = 1.49–5.16, p = 0.001), and lacunar stroke (HR = 5.12, 95%CI = 1.74–16.05, p = 0.003). ConclusionsThis study showed that a low FMD value might reflect vascular endothelial dysfunction and then was associated with ischemic stroke incidence in the general Japanese population, suggesting that FMD can be used as a tool to identify future stroke risk.