The effect of high altitude on endothelial and vascular dysfunction markers in preeclamptic patients

Placental hypoxia, a major component of the pathophysiology of preeclampsia, is associated with various maternal vascular and endothelial dysfunctions. The higher incidence of preeclampsia at high altitude remains incompletely explained. The aim of the present study was to investigate the effect of high altitude on some endothelial and vascular dysfunction markers in normal and preeclamptic pregnancies. Eighty pregnant women (Paras 2-4) were enrolled in this study, which included four groups (each n = 20): normal pregnancies at low altitude (NL), normal pregnancies at high altitude (NH), preeclamptic pregnancies at low altitude (PL), and preeclamptic pregnancies at high altitude (PH). In normal pregnancies at high altitude serum ET-1, plasma TXA2, and serum TNF-α levels increased significantly with a significant reduction in plasma PGI2 (66.81 ± 7.36, 122.86 ± 13.37, 102.23 ± 13.31, 191.57 ± 19.68, respectively) compared with the NL group (48.92 ± 4.58, 89.03 ± 10.67, 69.86 ± 7.97, 238.01 ± 24.55, respectively). In preeclampsia at low altitude serum ET-1, plasma TXA2, and serum TNF-α levels increased significantly with a significant reduction in plasma PGI2 (88.39 ± 9.54, 162.73 ± 15.92, 142.39 ± 15.37, 149.155 ± 15.66, respectively) compared with both NL and NH groups. High altitude significantly augmented these changes in preeclamptic patients (117.75 ± 12.96, 211.01 ± 22.69, 196.86 ± 17.64, 111.92 ± 10.74) compared with PL, NH and NL groups. In conclusion hypoxia at high altitude aggravated the disturbances in the levels of ET-1, TXA2, PGI2 and TNF-α associated with preeclampsia. This may contribute to the higher risk of preeclampsia at high altitude.