784: Prolactin derived vasoinhibins are associated with endothelial dysfunction in mid-gestation

Prolactin derived vasoinhibins are anti-angiogenic protein fragments implicated in the endothelial dysfunction of preeclampsia. They have been shown to inhibit endothelial cell proliferation, disrupt endothelial cell structure, and induce apoptosis. We hypothesized that prolactin derived vasoinhibins would be associated with worsening endothelial function testing in mid-gestation. Women with a singleton gestation between 16-23 weeks were recruited without exclusion of preexisting medical conditions. Prolactin derived vasoinhibin expression was determined via immunoprecipitation and Western blot. Endothelial function testing was performed using non-invasive digital peripheral arterial tonometry and reported as a reactive hyperemia index (RHI). A greater RHI is associated with healthier endothelial function. Statistical analysis included t-test and correlation coefficients. Sixty subjects were recruited, and 59 completed endothelial function testing at an average of 19.9 ± 1.5 weeks gestation. The mean age was 22.4 ± 3.6 years and average body mass index (BMI) was 27.9 ± 7.1 kg/m2. Increasing expression of prolactin derived vasoinhibins correlated with worsening RHI (rho= -0.27, p=0.04). See Figure 1. We demonstrate an association between prolactin derived vasoinhibins and abnormal endothelial function testing in mid-gestation. This represents a feasible pathophysiologic link between the presence of prolactin derived vasoinhibins and the endothelial changes of preeclampsia that warrants further investigation.