Flt-1 And Endothelial Function Soon After Delivery: Effect Of Physical Activity

Abstract

Vascular adverse pregnancy outcomes (APOs) are characterized by elevated levels of antiangiogenic Fms-like tyrosine kinase (Flt-1), attributable to placental ischemia. Flt-1 directly impairs endothelial function during pregnancy and contributes to maternal features of APOs, but infusion of Flt-1 into non-pregnant animals did not cause endothelial dysfunction. PURPOSE: The purpose was to evaluate the relation of Flt-1 and endothelial function in women 6 months – 3 years after delivery. Given the angiogenic effects of exercise, we tested the hypothesis that Flt-1 would be lower in women who achieved adequate prenatal and current physical activity (PA). METHODS: 40 nonsmoking women free from diabetes and use of protease inhibitors (mean age: 33±1 yrs, mean BMI: 26.3±1.0 kg/m2, 58% with adequate pregnancy PA) completed a blood draw and vascular testing after an overnight fast. We used an ELISA assay to determine levels of circulating Flt-1. Reactive hyperemia (RH) was measured with venous occlusion plethysmography to quantify resistance vessel endothelial function. A validated physical activity questionnaire (Godin Leisure Time Exercise Questionnaire) was used to determine current and second trimester PA; APO history was determined using self-report. We tested for associations of RH with continuous levels Flt-1 using linear regression, adjusted for APO status. We used t-tests to evaluate differences in Flt-1 between women who did versus did not achieve adequate PA during pregnancy or at the time of vascular testing. RESULTS: There was no association of Flt-1 and peak RH; β=0.01±0.01, p=0.50. There was no difference in Flt-1 levels between women who did versus did not achieve adequate PA at the time of testing (412±17 versus 443±31 pg/ml, p=0.22) or during pregnancy (408±20 versus 430±20 pg/ml, p=0.23). CONCLUSIONS: Although related to vascular dysfunction during pregnancy, Flt-1 was not related to vascular function after delivery and did differ by current or pregnancy PA level. Flt-1 might not be useful for identifying women at risk of vascular dysfunction after pregnancy ends.