Effects of Continuous Positive Airway Pressure Titration on Nocturnal Blood Pressure Fluctuation in Severe Sleep Apnea Patients with Hypertension

Abstract Introduction Previous studies have shown that continuous positive airway pressure (CPAP) therapy of adults with obstructive sleep apnea (OSA) reduces circulating levels of intercellular adhesion molecule 1 (ICAM-1). ICAM-1 levels may affect daytime sleepiness and elevated blood pressure associated with OSA. Our goals were to explore associations between changes in ICAM-1 and objective and subjective measures of sleepiness, as well as 24-hour ambulatory blood pressure monitor (ABPM) parameters in adults with OSA following 4 months of CPAP treatment. Methods We identified 140 adults with newly diagnosed OSA in the Penn Icelandic Sleep Apnea (PISA) Study, with a mean (±SD) body mass index (BMI) of 31.5±4.2 kg/m2 and apnea-hypopnea index (AHI) of 36.8±15.3 events/hour; 83.3% were males. Plasma ICAM-1 levels, 24-hour ABPM, Epworth Sleepiness Scale (ESS), and Psychomotor Vigilance Task (PVT) measures were obtained at baseline and after 4 months of CPAP treatment. Associations between changes in natural log ICAM-1 and both sleepiness and 24-hour mean arterial blood pressure (MAP) were assessed using multivariate regression models, controlling for a priori baseline covariates of age, sex, BMI, race, site, smoking status, physical activity, use of anti-hypertensive medications, AHI and hours/night of CPAP usage. Results Overall, there was no significant change in ICAM-1 from baseline to follow-up among all participants after 4 months (0.027 ng/ml, p=0.52). There were no statistically significant associations between the change in ICAM-1 and change in sleepiness measures (all p>0.05) or 24-hour MAP (1.124 mm Hg, p=0.07). A nominal association between increased ICAM-1 and increased daytime MAP after 4 months was observed (1.39 mm Hg, p=0.033), although this result was not significant after correction for multiple comparisons. Conclusion Our results do not support changes in ICAM-1 as the biological pathway linking changes in sleepiness or ABPM following CPAP treatment of adults with OSA. Support P01-HL094307 (NHLBI, PI: Pack AI)

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Effects of nasal continuous positive airway pressure and oxygen supplementation on norepinephrine kinetics and cardiovascular responses in obstructive sleep apnea

Journal of Applied Physiology ◽

10.1152/japplphysiol.00494.2005 ◽

2006 ◽

Vol 100 (1) ◽

pp. 343-348 ◽

Cited By ~ 83

Author(s):

Paul J. Mills ◽

Brian P. Kennedy ◽

Jose S. Loredo ◽

Joel E. Dimsdale ◽

Michael G. Ziegler

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Continuous Positive Airway Pressure ◽

Release Rate ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Oxygen Supplementation ◽

Obstructive Sleep

Obstructive sleep apnea (OSA) is characterized by noradrenergic activation. Nasal continuous positive airway pressure (CPAP) is the treatment of choice and has been shown to effectively reduce elevated norepinephrine (NE) levels. This study examined whether the reduction in NE after CPAP is due to an increase in NE clearance and/or a decrease of NE release rate. Fifty CPAP-naive OSA patients with an apnea-hypopnea index >15 were studied. NE clearance and release rates, circulating NE levels, urinary NE excretion, and blood pressure and heart rate were determined before and after 14 days of CPAP, placebo CPAP (CPAP administered at ineffective pressure), or oxygen supplementation. CPAP led to a significant increase in NE clearance ( P ≤ 0.01), as well as decreases in plasma NE levels ( P ≤ 0.018) and daytime ( P < 0.001) and nighttime ( P < 0.05) NE excretion. NE release rate was unchanged with treatment. Systolic ( P ≤ 0.013) and diastolic ( P ≤ 0.026) blood pressure and heart rate ( P ≤ 0.014) were decreased in response to CPAP but not in response to oxygen or placebo CPAP treatment. Posttreatment systolic blood pressure was best predicted by pretreatment systolic blood pressure and posttreatment NE clearance and release rate ( P < 0.01). The findings indicate that one of the mechanisms through which CPAP reduces NE levels is through an increase in the clearance of NE from the circulation.

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Blood pressure increase detected by ambulatory monitoring correlates with hypoxemia reflecting sleep apnea severity

Open Medicine ◽

10.2478/s11536-009-0011-z ◽

2009 ◽

Vol 4 (2) ◽

pp. 222-232 ◽

Cited By ~ 2

Author(s):

Soňa Grešová ◽

Zoltán Tomori ◽

Martin Kurpas ◽

Alexander Marossy ◽

Adela Vrbenská ◽

...

Keyword(s):

Blood Pressure ◽

Sleep Apnea ◽

Continuous Positive Airway Pressure ◽

Arterial Hypertension ◽

Oxygen Saturation ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Arterial Oxygen Saturation ◽

Secondary Component ◽

Arterial Oxygen

AbstractAmbulatory blood pressure monitoring and parallel polysomnographic study were performed in 116 adult males divided into 6 groups. Thirty blood-pressure (BP) and polysomnographic variables were measured to test their usefulness for screening for both arterial hypertension and sleep apnea-hypopnea syndrome (SAHS). The development of severe breathing disorders and hypoxemia during sleep was attributed to SAHS, when compared with measurements in healthy controls and in patients with arterial hypertension. Such disorders manifested as an increased apnea-hypopnea index, apnea index, duration of arterial oxygen saturation of less than 85%, and decrease of average arterial oxygen saturation that correlated with nocturnal average diastolic BP (p=0.0049, p=0.0027, p=0.049 and p=0.0457, respectively). These respiratory disorders resulted in various nocturnal, rather than diurnal, and diastolic and systolic BP variables. The acute antihypertensive effect of continuous positive airway pressure therapy for SAHS significantly reduced the episodes of apnea and hypopnea and the secondary component of hypertension caused by excessive sympathetic stimulation. For the SAHS-induced, dose-dependent component of hypertension that responded to continuous positive airway pressure, the following variables, in decreasing significance, were useful: nocturnal average systolic and diastolic BP and 24-hour average systolic and diastolic BP, as well as percent time elevation and mean blood pressure load. The monitoring of these variables could contribute to early diagnostic and prognostic stratification of complications and adequate therapy of the secondary component of hypertension caused by SAHS.

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