Nasal CPAP reduces systemic blood pressure in patients with Obstructive sleep apnea and mild sleepiness

Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
Thorax (Impact Factor: 8.29). 12/2006; 61(12):1083-90. DOI: 10.1136/thx.2006.064063
Source: PubMed


A randomised controlled study was undertaken to examine the effect of nasal continuous positive airway pressure (CPAP) on 24 hour systemic blood pressure (BP) in patients with obstructive sleep apnoea (OSA).
Patients were fitted with an ambulatory BP measuring device as outpatients during normal activities and recorded for 24 hours before starting therapeutic or subtherapeutic (4 cm H(2)O) CPAP treatment. BP monitoring was repeated before completion of 12 weeks of treatment. The primary end point was the change in 24 hour mean BP.
Twenty three of 28 participants in each treatment arm completed the study. There was no significant difference between the two groups in age, body mass index, Epworth Sleepiness Score, apnoea-hypopnoea index, arousal index, and minimum Sao(2). Twenty four patients were hypertensive. The pressure in the therapeutic CPAP group was 10.7 (0.4) cm H(2)O. CPAP usage was 5.1 (0.4) and 2.6 (0.4) hours/night for the therapeutic and subtherapeutic CPAP groups, respectively (p<0.001). After 12 weeks of treatment there were significant differences between the two CPAP groups in mean (SE) changes in 24 hour diastolic BP (-2.4 (1.2) v 1.1 (1.0) mm Hg (95% CI -6.6 to -0.5), p = 0.025); 24 hour mean BP (-2.5 (1.3) v 1.3 (1.1) mm Hg (95% CI -7.2 to -0.2), p = 0.037); sleep time systolic BP (-4.1 (2.1) v 2.2 (1.8) mm Hg (95% CI -11.8 to -0.7), p = 0.028); and sleep time mean BP (-3.6 (1.7) v 1.3 (1.4) mm Hg (95% CI -9.2 to -0.4), p = 0.033).
Compared with subtherapeutic CPAP, 12 weeks of treatment with therapeutic CPAP leads to reductions in 24 hour mean and diastolic BP by 3.8 mm Hg and 3.5 mm Hg, respectively, in mildly sleepy patients with OSA.

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    • "Mean net change in diurnal systolic blood pressure Engleman 1996 Barbé 2001 Faccenda 2001 Monasterio 2001 Barnes 2002 Pepperell 2002 Becker 2003 Barnes 2004 Ip 2004 Campos-Rodriguez 2006 Hui 2006 Mills 2006 Robinson 2006 Coughlin 2007 Drager 2007 Lam 2007 Cross 2008 Kohler 2008 Alonso-Fernández 2009 Oliveira 2009 Barbé 2010 Durán-Cantolla 2010 Lam 2010 Lozano 2010 Nguyen 2010 Drager 2011 Kohler 2011 Sharma 2011 "
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    ABSTRACT: We sought to provide an updated systematic review and meta-analysis of studies investigating the effect of positive airway pressure (PAP) treatment for obstructive sleep apnea (OSA) on systolic and diastolic blood pressure (SBP, DBP). Two independent investigators undertook a systematic search of the PubMed database (1980-2012) to identify randomized controlled trials comparing therapeutic PAP to sham-PAP, pill placebo, or standard care over at least one week in adult OSA patients without major comorbidities. The mean, variance, and sample size for diurnal and nocturnal SBP and DBP data were also extracted independently from each study. Random effects meta-analyses were conducted, followed by pre-specified subgroup and meta-regression analyses. 32 studies were identified, with data available from 28 studies representing n = 1,948 patients. The weighted mean difference in diurnal SBP (-2.58 mm Hg, 95% CI -3.57 to -1.59 mm Hg) and DBP (-2.01 mm Hg, 95% CI -2.84 to -1.18 mm Hg) both significantly favored PAP treatment over control arms, with similar results seen in nocturnal readings. Statistically significant reductions in BP were seen in studies whose patients were younger, sleepier, had more severe OSA, and exhibited greater PAP adherence. Meta-regression indicated that the reductions in DBP with PAP were predicted by mean baseline BP (β = -0.22, p = 0.02) and Epworth Sleepiness Scale scores (β = -0.27, p = 0.04). PAP treatment for OSA is associated with modest but significant reductions in diurnal and nocturnal SBP and DBP. Future research should be directed towards identifying subgroups likely to reap greater treatment benefits as well as other therapeutic benefits provided by PAP therapy. CITATION: Montesi SB; Edwards BA; Malhotra A; Bakker JP. The effect of continuous positive airway pressure treatment on blood pressure: a systematic review and meta-analysis of randomized controlled trials. J Clin Sleep Med 2012;8(5):587-596.
    Full-text · Article · Oct 2012 · Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine
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    • "Overnight diagnostic PSG (Healthdyne Alice 4, USA) was performed for every subject recording electroencephalogram(EEG), electro-oculogram, submental electromyogram (EMG), bilateral anterior tibial EMG, electrocardiogram, chest and abdominal wall movement by inductance plethysmography, airflow measured by a nasal pressure transducer [PTAF2, Pro-Tech, Woodinville, WA, USA] and supplemented by an oral thermister, and finger pulse oximetry as described in our previous studies [15,16]. Sleep stages were scored according to standard criteria by Rechtshaffen and Kales [17]. "
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    ABSTRACT: To examine the long-term effect of CPAP on carotid artery intima-media thickness (IMT) in patients with Obstructive sleep apnea syndrome(OSAS). A prospective observational study over 12 months at a teaching hospital on 50 patients newly diagnosed with OSAS who received CPAP or conservative treatment (CT). Carotid IMT was assessed with B-mode Doppler ultrasound from both carotid arteries using images of the far wall of the distal 10 mm of the common carotid arteries at baseline, 6 months and 12 months. MEASUREMENTS AND RESULTS [MEAN (SE)]: Altogether 28 and 22 patients received CPAP and CT respectively without significant differences in age 48.8(1.8) vs 50.5(2.0)yrs, BMI 28.2(0.7) vs 28.0(1.2)kg/m2, ESS 13.1(0.7) vs 12.7(0.6), AHI 38(3) vs 39(3)/hr, arousal index 29(2) vs 29(2)/hr, minimum SaO2 75(2) vs 77(2)% and existing co-morbidities. CPAP usage was 4.6(0.3) and 4.7(0.4)hrs/night over 6 months and 1 year respectively. Carotid artery IMT at baseline, 6 months, and 12 months were 758(30), 721(20), and 705(20)micron for the CPAP group versus 760(30), 770(30), and 778(30)micron respectively for the CT group, p = 0.002. Among those free of cardiovascular disease(n = 24), the carotid artery IMT at baseline, 6 months and 12 months were 722(40), 691(40), and 659(30)micron for the CPAP group (n = 12) with usage 4.5(0.7) and 4.7(0.7) hrs/night over 6 months and 12 months whereas the IMT data for the CT group(n = 12) were 660(20), 685(10), and 690(20)micron respectively, p = 0.006. Reduction of carotid artery IMT occurred mostly in the first 6 months and was sustained at 12 months in patients with reasonable CPAP compliance.
    Full-text · Article · Mar 2012 · Respiratory research
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    • ".The acute application of CPAP attenuates blood pressure elevations during sleep [91]. However, the long-term effects of CPAP on blood pressure are controversial, from studies reporting a significant decrease in blood pressure to studies reporting small or no effects [92] [93] [94] [95] [96] [97] [98] [99] [100] [101] [102] [103] [104] [105] [106]. Three meta-analyses have tried to overcome these discrepancies and revealed that the beneficial effect is modest, with reductions in systolic blood pressure ranging from 1.38 mmHg to 2.46 mmHg [107] [108] [109]. "
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    ABSTRACT: Resistant hypertension is defined as uncontrolled blood pressure despite the use of three antihypertensive drugs, including a diuretic, in optimal doses. Treatment resistance can be attributed to poor adherence to antihypertensive drugs, excessive salt intake, physician inertia, inappropriate or inadequate medication, and secondary hypertension. Drug-induced hypertension, obstructive sleep apnoea, primary aldosteronism, and chronic kidney disease represent the most common secondary causes of resistant hypertension. Several drugs can induce or exacerbate pre-existing hypertension, with non-steroidal anti-inflammatory drugs being the most common due to their wide use. Obstructive sleep apnoea and primary aldosteronism are frequently encountered in patients with resistant hypertension and require expert management. Hypertension is commonly found in patients with chronic kidney disease and is frequently resistant to treatment, while the management of renovascular hypertension remains controversial. A step-by-step approach of patients with resistant hypertension is proposed at the end of this review paper.
    Full-text · Article · Mar 2011
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