Objective
To assess the frequency of obstructive sleep apnoea among women with and without hypertensive disorders of pregnancy.
Design
Cohort study.
Setting
Obstetric clinics at an academic medical ...centre.
Population
Pregnant women with hypertensive disorders (chronic hypertension, gestational hypertension, or pre‐eclampsia) and women who were normotensive.
Methods
Women completed a questionnaire about habitual snoring and underwent overnight ambulatory polysomnography.
Main outcome measures
The presence and severity of obstructive sleep apnoea.
Results
Obstructive sleep apnoea was found among 21 of 51 women with hypertensive disorders (41%), but in only three of 16 women who were normotensive (19%, chi‐square test, P = 0.005). Author correction added on 16 June 2014, after first online publication: Results mentioned in the were amended. Non‐snoring women with hypertensive disorders typically had mild obstructive sleep apnoea, but >25% of snoring women with hypertensive disorders had moderate to severe obstructive sleep apnoea. Among women with hypertensive disorders, the mean apnoea/hypopnoea index was substantially higher in snorers than in non‐snorers (19.9 ± 34.1 versus 3.4 ± 3.1, P = 0.013), and the oxyhaemoglobin saturation nadir was significantly lower (86.4 ± 6.6 versus 90.2 ± 3.5, P = 0.021). Among women with hypertensive disorders, after stratification by obesity, the pooled relative risk for obstructive sleep apnoea in snoring women with hypertension compared with non‐snoring women with hypertension was 2.0 (95% CI 1.4–2.8).
Conclusions
Pregnant women with hypertension are at high risk for unrecognised obstructive sleep apnoea. Although longitudinal and intervention studies are urgently needed, given the known relationship between obstructive sleep apnoea and hypertension in the general population, it would seem pertinent that hypertensive pregnant women who snore should be tested for obstructive sleep apnoea, a condition believed to cause or promote hypertension.
There is increasing evidence that obstructive sleep apnea (OSA) is an independent risk factor for arterial hypertension. Because there are no controlled studies showing a substantial effect of nasal ...continuous positive airway pressure (nCPAP) therapy on hypertension in OSA, the impact of treatment on cardiovascular sequelae has been questioned altogether. Therefore, we studied the effect of nCPAP on arterial hypertension in patients with OSA.
Sixty consecutive patients with moderate to severe OSA were randomly assigned to either effective or subtherapeutic nCPAP for 9 weeks on average. Nocturnal polysomnography and continuous noninvasive blood pressure recording for 19 hours was performed before and with treatment. Thirty two patients, 16 in each group, completed the study. Apneas and hypopneas were reduced by approximately 95% and 50% in the therapeutic and subtherapeutic groups, respectively. Mean arterial blood pressure decreased by 9.9+/-11.4 mm Hg with effective nCPAP treatment, whereas no relevant change occurred with subtherapeutic nCPAP (P=0.01). Mean, diastolic, and systolic blood pressures all decreased significantly by approximately 10 mm Hg, both at night and during the day.
Effective nCPAP treatment in patients with moderate to severe OSA leads to a substantial reduction in both day and night arterial blood pressure. The fact that a 50% reduction in the apnea-hypopnea index did not result in a decrease in blood pressure emphasizes the importance of highly effective treatment. The drop in mean blood pressure by 10 mm Hg would be predicted to reduce coronary heart disease event risk by 37% and stroke risk by 56%.
The purpose of this review is to provide guidelines for the use of oral appliances (OAs) for the treatment of snoring and obstructive sleep apnoea (OSA) in Australia. A review of the scientific ...literature up to June 2012 regarding the clinical use of OAs in the treatment of snoring and OSA was undertaken by a dental and medical sleep specialists team consisting of respiratory sleep physicians, an otolaryngologist, orthodontist, oral and maxillofacial surgeon and an oral medicine specialist. The recommendations are based on the most recent evidence from studies obtained from peer reviewed literature. Oral appliances can be an effective therapeutic option for the treatment of snoring and OSA across a broad range of disease severity. However, the response to therapy is variable. While a significant proportion of subjects have a near complete control of the apnoea and snoring when using an OA, a significant proportion do not respond, and others show a partial response. Measurements of baseline and treatment success should ideally be undertaken. A coordinated team approach between medical practitioner and dentist should be fostered to enhance treatment outcomes. Ongoing patient follow‐up to monitor treatment efficacy, OA comfort and side effects are cardinal to long‐term treatment success and OA compliance.
Recent studies suggest a specific association between intrauterine growth restriction that commonly occurs in preeclampsia and decreased maternal cardiac output. Sleep is associated with marked ...hypertension in preeclampsia. We therefore aimed to determine how sleep influences other hemodynamic parameters in preeclampsia, specifically to determine if sleep-induced exacerbation of hypertension was associated with reductions in cardiac output.
Randomized controlled trial of nasal continuous positive airway pressure.
King George V, Royal Prince Alfred Hospital.
Twenty-four women with severe preeclampsia and 15 control nulliparous subjects.
Full polysomnography including beat-to-beat blood-pressure recording. Stroke volume, heart rate, cardiac output, total peripheral resistance, and ejection duration were derived from the blood pressure waveform. Half of the 24 preeclamptic subjects were randomly assigned to receive treatment with nasal continuous positive airway pressure and the other half to receive no treatment.
Heart rate, stroke volume, and cardiac output were similar in controls and patients with preeclampsia during wakefulness, while total peripheral resistance was significantly elevated. Sleep induced marked decrements in heart rate, stroke volume, and cardiac output in preeclamptic subjects and resulted in further increments in total peripheral resistance. Cardiac output during sleep was correlated with fetal birth weight (r2 = 0.64, P < .001). When preeclamptic subjects were treated with continuous positive airway pressure, reductions in cardiac output were minimized, while increments in total peripheral resistance were also reduced.
These data indicate that sleep is associated with adverse hemodynamic changes in women with preeclampsia. These changes are minimized with the use of continuous positive airway pressure. Reduced cardiac output during sleep may have an adverse effect on fetal development.
Changes in sleep-disordered breathing associated with late pregnancy have not previously been systematically investigated; however, a number of case reports indicate exacerbation of obstructive sleep ...apnea in late pregnancy, often in association with maternal hypertension. We aimed to compare the severity of sleep-disordered breathing and associated maternal blood-pressure responses in late pregnancy with the nonpregnant state.
Case-controlled, longitudinal study of sleep-disordered breathing during late pregnancy and postpartum.
Ten women referred for suspected sleep-disordered breathing during the third trimester of pregnancy.
None.
Full overnight polysomnography and continuous systemic blood pressure were measured during the third trimester of pregnancy and 3 months following delivery. Parameters of sleep-disordered breathing, including apnea hypopnea index and minimum overnight arterial oxyhemoglobin saturation, were compared between antenatal and postnatal studies. An improvement in both apnea-hypopnea index and minimum arterial oxyhemoglobin saturation occurred consistently in all subjects postnatally. In non-rapid eye movement sleep, mean apnea-hypopnea index was reduced from 63 +/- 15 per hour antenatally to 18 +/- 4 per hour postnatally (P = .03), and in rapid eye movement sleep, from 64 +/- 11 per hour to 22 +/- 4 per hour (P = .002). Minimum arterial oxyhemoglobin saturation was increased from 86% +/- 2% antenatally to 91% +/- 1% postnatally (P = .01). Arterial blood-pressure responses to apnea peaked at 170 to 180 mm Hg antenatally, while they only peaked at 130 to 140 mm Hg postnatally.
This study indicates that late pregnancy may be associated with increased severity of sleep-disordered breathing and associated blood-pressure responses.
To determine the frequency and correlates of pulmonary hypertension in sleep-disordered breathing, pulmonary artery pressure, lung function and arterial blood gases were measured in 100 consecutive ...patients with obstructive sleep apnoea (OSA) (respiratory disturbance index (RDI) of > 20 episodes.h-1). Twenty six of the patients had significant chronic airflow limitation (CAL). Overall, 42% of patients had awake pulmonary artery pressure > 20 mmHg. Patients with pulmonary hypertension were older, had higher arterial carbon dioxide tension (PaCO2), lower arterial oxygen tension (PaO2) and lower forced expiratory volume in one second (FEV1) values compared with normotensive patients. Pao2, PaCO2 and FEV1 were correlated with the levels of pulmonary artery pressure (correlation coefficient (r2) 0.50, 0.46 and 0.49, respectively). These three factors combined could explain 33% of the variability in pulmonary artery pressure. Six patients had pulmonary hypertension despite a PaO2 in excess of 10.7 kPa (80 mmHg). We conclude that pulmonary hypertension is common in patients with moderate and severe sleep apnoea, especially those with coexisting chronic airflow limitation. The presence of daytime hypoxaemia is not a prerequisite in the development of pulmonary hypertension in these patients.
...because of risk factor clustering this is likely to be a substantial underestimate with the real figure probably being nearer to 30%. ...studies of patients with coronary heart disease are likely ...to include a significant minority of patients with OSA whose pathophysiology has potentially been substantially affected by concurrent OSA. While treatment of OSA eliminates recurrent episodes of hypoxaemia, reduces overall blood pressure levels and variability, may reduce insulin resistance and therefore reduce triglycerides, it has little effect on weight or fat distribution. ...the relative contributions of improvements in associated risk factors versus elimination of the haemodynamic and respiratory stresses, which occur during sleep in untreated OSA, remain to be fully elucidated.
Preeclampsia is the predominant cause of admissions to neonatal intensive care. The diurnal blood pressure pattern is flattened or reversed in preeclampsia. We hypothesized that snoring and partial ...upper airway obstruction contribute to nocturnal rises in blood pressure. We tested this hypothesis by controlling sleep- induced upper airway flow limitation and snoring with nasal positive pressure. Eleven women with preeclampsia underwent two consecutive polygraphic sleep studies with simultaneous beat-to-beat blood pressure monitoring. Average blood pressure for the night overall and in each sleep stage was calculated. Sleep architecture was similar on the two study nights. Sleep-induced partial upper airway flow limitation occurred in all patients in the initial study. Autosetting nasal continuous positive airway pressure (CPAP) applied at a mean maximal pressure of 6 +/- 1 cm H(2)O eliminated flow limitation throughout sleep on the treatment night. Blood pressure was markedly reduced on the treatment night (128 +/- 3)/(73 +/- 3) when compared with the initial nontreatment study night (146 +/- 6)/(92 +/- 4), p = (0.007)/(0.002). We conclude that partial upper airway obstruction during sleep in women with preeclampsia is associated with increments in blood pressure, which can be eliminated with the use of nasal CPAP.
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