Obstructive sleep apnea and blood pressure. Interaction between the blood pressure-lowering effects of positive airway pressure therapy and antihypertensive drugs.
ABSTRACT There is increasing evidence that obstructive sleep apnea is an independent risk factor for arterial hypertension. Previous studies on the antihypertensive effects of positive airway pressure therapy on daytime blood pressure (BP) revealed inconsistent results.
The relations between the apnea/hypopnea index (AHI) and BP or heart rate (HR) were investigated in a cohort of 540 consecutive patients (age, 55.4 +/-11.1 years) with moderate or severe obstructive sleep apnea (OSA). The mean AHI was 28.2 +/- 22.0 events/h before OSA therapy. A group of 196 patients in whom antihypertensive medication was kept unchanged was followed for 6 months during bilevel or continuous positive airway pressure (Bi-/CPAP) therapy.
Significant associations were found between AHI and systolic BP (beta = 0.078, P = .014), diastolic BP (beta = 0.056, P = .003), HR (beta = 0.096, P < .001), and the prevalence of arterial hypertension (odds ratio = 0.015, P = .003), independent of age, body mass index, and gender. During the follow-up period with effective Bi-/CPAP therapy, the mean daytime systolic BP decreased from 130.7 +/- 15.5 mm Hg to 128.6 +/- 15.9 mm Hg (P = .051), diastolic BP from 80.2 +/- 9.3 mm Hg to 77.5 +/- 9.5 mm Hg (P = .001), and HR from 77.7 +/- 8.8 to 75.7 +/- 8.1 beats/min (P = .001). Multiple linear regression analysis revealed that the absence of antihypertensive drugs and the level of the initial BP are significant and independent predictors for the lowering effect of Bi-/CPAP therapy on systolic and diastolic BP.
This study confirms an independent relationship between the severity of OSA and BP/HR. Absence of BP-lowering medication and BP values before treatment are independent predictors for the reduction of BP with Bi-/CPAP therapy.
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- "Blood pressure Bixler et al. (2000), Suzuki et al. (1996), Borgel et al. (2004), Heitmann et al. (2004), Dhillon et al. (2005), Pepperell et al. (2002), Faccenda et al. (2001), Dernaika et al. (2009), Robinson et al. (2008), Patruno et al. (2007), Wilcox et al. (1993), Hui et al. (2006), Duran-Cantolla et al. (2010), Marrone et al. (2011) OSA is associated with elevated blood pressure that is attenuated by CPAP therapy; differences emerge regarding the level of reduction in BP after treatment , the circadian time at which reduction occurs (sleep/wakefulness), and whether the systolic or diastolic component is more affected Urine and blood catecholamine levels Fletcher et al. (1987), Baruzzi et al. (1991), Ziegler et al. (1997), Minemura et al. (1998), Loredo et al. (1999), Elmasry et al. (2002), Sukegawa et al. (2005), Drager et al. (2007), Kohler et al. (2008), Comondore et al. (2009), Zhang et al. (2011), Bao et al. (2002), Ziegler et al. (2001), Kohler et al. (2011) OSA patients demonstrate sustained elevation in catecholamine levels that are attenuated by treatment , and are elevated again by treatment "
ABSTRACT: Sleep is involved in the regulation of major organ functions in the human body, and disruption of sleep potentially can elicit organ dysfunction. Obstructive sleep apnea (OSA) is the most prevalent sleep disorder of breathing in adults and children, and its manifestations reflect the interactions between intermittent hypoxia, intermittent hypercapnia, increased intra-thoracic pressure swings, and sleep fragmentation, as elicited by the episodic changes in upper airway resistance during sleep. The sympathetic nervous system is an important modulator of the cardiovascular, immune, endocrine and metabolic systems, and alterations in autonomic activity may lead to metabolic imbalance and organ dysfunction. Here we review how OSA and its constitutive components can lead to perturbation of the autonomic nervous system in general, and to altered regulation of catecholamines, both of which then playing an important role in some of the mechanisms underlying OSA-induced morbidities.Frontiers in Neurology 01/2012; 3:7. DOI:10.3389/fneur.2012.00007
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ABSTRACT: Background: Epworth Sleepiness Scale (EES) and Berlin Questionnaire (BQ) are widely used, short, self administered questionnaires for the screening of patients with sleep disordered breathing (SDB). Whereas the ESS is asking for symptoms of daytime sleepiness and fatigue only, the BQ asks for symptoms of snoring and apneas, daytime sleepiness and the risk factors of extreme obesity and high arterial blood pressure. Objective: We wanted to investigate the sensitivity and specificity of both questionnaires for the pretest probability of sleep disordered breathing in a group of patients with highly suspected SDB. Methods: 1085 consecutives patients of our sleeplaboratory were asked to answer the ESS and BQ parallel before testing (polysomnography/PSG). The questionnaire scores were compared with PSG-results. Results: 1. BQ showed positiv risk in 870/994 SDB patients (sensitivity 87.53 %) and negative risk in 52/86 non SDB patients (specificity 60.47 %); ESS in 605/983 (sensitivity 61.55 %) and in 42/84 (specificity 50.00 %). 2. False negative results were generated by the BQ in 124 out of 994 SDB cases (12.5 %) and by the ESS in 378 out of 983 (38.5 %). 3. Obesity was not a specific marker for SDB. Depending on stature and weight a Body Mass Index over 30 kg/m2 was defined as obesity. Only 51,5 % of all 999 SDB patients were obese. 4. As one more result, high blood pressure has not pointed at SDB. In our study 52.2 % of all SDB patients had no high blood pressure. Conclusions: In comparison between the BQ and the ESS, the BQ has shown a much higher sensitivity (87.53 %) and a higher specificity (60.47 %) than the ESS (sensitivity: 61.53 %, specificity: 50.00 %) regarding the pretest probability of this selected patient group. Neither the BMI nor high blood pressure seemed to be relevant in the diagnosis of SDB in our selected patient group. Based on these results the combination of irregular snoring and daytime sleepiness questioned by the BQ pre-defines SDB best.