Mechanism of development of pre-eclampsia linking breathing disorders to endothelial dysfunction

Abstract

s u m m a r yHigh blood pressure is an important component of pre-eclampsia. The underlying mechanism of development of hypertension in pre-eclampsia is complicated and still remains obscure. Several theories have been advanced including endothelial dysfunction, uteroplacental insufficiency leading to generalized vasoconstriction, increased cardiac output, and sympathetic hyperactivity. Increased blood flow and pressure are thought to lead to capillary dilatation, which damages end-organ sites, leading to hypertension, proteinuria and edema. Additional theories have been put forward based on epidemiological research, implicating immunological and genetic factors. None of these theories have been substantiated. Based on a review of literature this paper postulates that the initiating event for the development of preeclampsia is intermittent hypoxia associated with irregular breathing during sleep, hypoapnea, apnea, inadequate respiratory excursions during the waking hours and inadequate cardiopulmonary synchronization (abnormal sympatho-vagal balance).Ó 2009 Elsevier Ltd. All rights reserved. BackgroundDespite being one of leading causes of maternal death and a major contributor of maternal and perinatal morbidity, the mechanism responsible for the pathogenesis of pre-eclampsia remains unclear [1,2]. Evidence shows that inadequate oxygenation from various causes leads to the initiation of an abnormal autonomic response. Several studies show a strong association between obstructive sleep apnea (OSA) and hypertension in the non-pregnant state [3,4]. Few studies in pregnancy corroborate this finding [5,6]. Nocturnal hypertension is observed significantly more in patients who have pre-eclampsia than those with gestational hypertension or chronic hypertension [5]. Also in OSA there is relative increase of the sympathetic activity associated with vasospasm, endothelial dysfunction, and increased angiotensin II levels, findings that are also implicated in the pathogenesis of pre-eclampsia [7,8].Incidence of snoring, hypoapnea and sleep apnea in the nonpregnant state, pregnancy and pre-eclampsiaThe incidence of snoring, hypoapnea, and sleep apnea is 9% in non-pregnant females and 14% in pregnant women [9][10][11]. By the third trimester, 24% of women were reported to have a snoring problem (symptom of sleep apnea). Habitual snorers had a higher frequency of pregnancy-induced hypertension (14%) compared to 6% of non-habitual snorers. The intrauterine growth retardation incidence was 7% in habitual snorers compared to 2.6% in nonsnorers [10]. In this study it was noted that all subjects who habitually snored and developed pre-eclampsia started to snore before hypertension or proteinuria was present. Abnormalities of breathing such as inspiratory flow limitation are observed more frequently in patients with pre-eclampsia (31 ± 8%) as compared to normal pregnant women (15.5 ± 2.3%), and non-pregnant females (<5%) [9]. The autonomic imbalance associated with this abnormal breathing was found to be associated with high systoli...

The Relationship Between Sleep Disorders During Pregnancy and

“…OSA with reduction of leptin level can lead to disorder in blood sugar control. All mentioned factors are related to gestational diabetes, preeclampsia and finally, termination of pregnancy (17,(23)(24)(25)(26).…”

Czy istnieje związek między nadciśnieniem indukowanym ciążą a obturacyjnym bezdechem sennym? Opis przypadku

“…Szacuje się, że około 24% ciężarnych w III trymestrze ciąży cierpi na związane ze snem zaburzenia oddychania, a odsetek ten znacznie wzrasta w grupie kobiet ze stanem przedrzucawkowym oraz w ciążach powikłanych wewnątrzmacicz-nym ograniczeniem wzrastania płodu (IUGR, intra-uterine growth retardation) [4][5][6][7][8]. Bezdech senny u ciężarnych pozostaje najczęściej nierozpoznanym problemem, o ile nie zaobserwuje go ktoś z otoczenia.…”

“…Wyniki badań epidemiologicznych wykazały związek między istnieniem matczynych zaburzeń oddychania podczas snu a nadciśnieniem indukowanym ciążą. Wielu badaczy uznało, że epizody zwyżek ciśnienia podczas snu są swoiście związane z zaburzeniami w obrębie górnych dróg oddechowych w ciąży powikłanej nadciśnieniem tętniczym [8,14,15].…”

Augmentation of Mind-body Therapy and Role of Deep Slow Breathing

“…Decrease in incidence of pre-eclampsia and improvement of hypertension has been indicated with relaxation exercises and deep slow breathing (Jerath et al, 2009). A line of evidence supporting this theory is the decrease in the incidence of pre-eclampsia following the restoration of normal breathing.…”