טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentYinon Dafna
SubjectThe Association between Pre-eclampsia, Endothelial
Dysfunction and Sleep Disordered Breathing
DepartmentDepartment of Medicine
Supervisor Professor Giora Pillar


Abstract

Pre-Eclamptic Toxemia (PET, Pre-eclampsia), is a pregnancy-specific disorder characterized by hypertension, proteinuria and edema. Recent evidence suggested that vascular endothelial dysfunction (ED) may play an important role in the pathogenesis of PET.

In addition, pregnancy may be associated with altered breathing during sleep. Several changes in the respiratory system occur during pregnancy, which can alter respiratory function during sleep, and increase the incidence and severity of sleep disorder breathing (SDB). These physiological changes may be particularly pronounced in women with PET.

We hypothesized that women with PET would demonstrate both SDB and ED, and that a correlation between these two would suggest a potential causative association.   Seventeen women with PET and 25 matched women with uncomplicated pregnancy have been studied.  They underwent a nocturnal ambulatory sleep study (WP100) and non-invasive evaluation of endothelial function utilizing the reactive hyperemia test (Endo_PAT 2000).  A higher ratio of post-to pre-occlusion pulse wave amplitude (endothelial function index, EFI) indicates better endothelial function.   Women with PET had significantly higher respiratory disturbance index (RDI) and lower EFI than controls (18.4±8.4 vs 8.3±1.3/h, 1.5±0.1 vs 1.8±0.1, respectively, p<0.05 for both).  Blood pressure significantly correlated with RDI (r=0.41) and with EFI (r=-0.41, p<0.05 for both).

EFI correlated with birth-weigh of the infants (r=0.37, p<0.05), and with RDI (r=-0. 19 , p<0.1).   These results suggest that both sleep disordered breathing and endothelial dysfunction are more likely to occur in women with PET than in women with uncomplicated pregnancies.  The association between SDB, ED and blood pressure may suggest that respiratory disturbances contribute to or perpetuate the functional abnormality of the blood vessels seen in women with PET.