Is high and fluctuating muscle nerve sympathetic activity in the sleep apnoea syndrome of pathogenetic importance for the development of hypertension?

Hedner, Jan; Ejnell, Hasse; Sellgren, Johan; Hedner, Thomas; Wallin, Gunnar

doi:10.1097/00004872-198812040-00166

Cited by 325 publications

(165 citation statements)

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“…35,36 In contrast to blood pressure however, the overall changes in heart rate seen in the study were approximately twice those reported in other placebo-controlled trials. 21 This difference may relate to gender bias (all subjects in the current study were male) or enhanced sympathetic activity secondary to the combined effects of moderate-severe sleep apnoea 37 and sibutramine. However, the clinical significance of the small heart rate rise observed in this study is not clear despite the known cardiovascular risk associated with an elevated resting heart rate.…”

Section: Discussionmentioning

confidence: 91%

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

et al. 2006

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Objective: Obstructive sleep apnoea (OSA) occurs frequently in obese patients and may be reversible with weight loss. Obstructive sleep apnoea and obesity are both independent risk factors for hypertension and increased sympathetic activity. Sibutramine has been increasingly used in the management of obesity, but is relatively contraindicated in patients with hypertension. No studies have investigated the effect of sibutramine on OSA, blood pressure and heart rate. We aimed to assess the changes in OSA and cardiovascular parameters in obese men with OSA enrolled in a sibutramine-assisted weight loss programme (SIB-WL). Design: Open uncontrolled cohort study of obese male subjects with OSA in an SIB-WL. Subjects: Eighty-seven obese (body mass index ¼ 34.272.8 kg/m 2 ) middle-aged (46.379.3 years) male subjects with symptomatic OSA (Epworth score 13.473.6; respiratory disturbance index (RDI) 46.0723.1 events/h) completed the study. Results: At 6 months, there was significant weight loss (8.374.7 kg, Po0.0001), as well as a reduction in waist and neck circumference and sagittal height (all Po0.0001). These changes were accompanied by a reduction in OSA severity (RDI fell by 16.3719.4 events/h and Epworth score by 4.574.6), both Po0.0001). There was no significant change to systolic (P ¼ 0.07) or diastolic blood pressure (P ¼ 0.87); however, there was a mild rise in resting heart rate (Po0.0001). Conclusion: Moderate (B10%) weight loss with SIB-WL results in improvement in OSA severity without increase in blood pressure in closely monitored OSA subjects.

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Section: Discussionmentioning

confidence: 91%

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

et al. 2006

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“…Regardless of the method used, essentially all studies have reported that OSA is associated with increased sympathetic activity. 20,22,24,25 Furthermore, unlike the situation in normal subjects, blood pressure 26 and sympathetic activity remain high during sleep in OSA patients. These findings highlight the challenges of using autonomic signals to detect sleep stages in OSA patients.…”

Section: Light/deep Sleep Detectionmentioning

confidence: 98%

“…However, peak sympathetic activity usually is seen at the termination of respiratory events. 24 This enables a sophisticated algorithm that defines a local baseline and calculates changes over different time periods to detect both state specific and event specific changes. Indeed, despite the general increase of sympathetic tone and large respiratory event related sympathetic activations in OSA, the algorithm used in this study was found to detect specific autonomic changes associated with sleep and differentiate sleep stages with a reasonable accuracy.…”

Section: Light/deep Sleep Detectionmentioning

confidence: 99%

Sleep Staging Based on Autonomic Signals: A Multi-Center Validation Study

Hedner

White

Malhotra

et al. 2011

Journal of Clinical Sleep Medicine

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119

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Study Objectives: One of the most important caveats of ambulatory devices is the inability to record and stage sleep. We assessed an algorithm determining 4 different stages: wake, light sleep, deep sleep, and REM sleep using signals derived from the portable monitor Watch-PAT100 (PAT recorder). Methods: Participants (38 normal subjects and 189 patients with obstructive sleep apnea [OSA]) underwent simultaneous overnight recordings with polysomnography (PSG) and the PAT recorder in a study originally designed to assess the accuracy of the PAT recorder in diagnosing OSA. Light/deep sleep and REM sleep from the PAT recorder recording were automatically scored based on features extracted from time series of peripheral arterial tone amplitudes and inter pulse periods. The PSG scored sleep stages 1 and 2 were classified as light sleep for epoch-by-epoch comparisons. Results:The overall agreement in detecting light/deep and REM sleep were 88.6% ± 5.9% and 88.7% ± 5.5%, respectively. There was a good agreement between PSG and the PAT recorder in quantifying sleep efficiency (78.4% ± 9.9% vs. 78.8% ± 13.4%), REM latency (237 ± 148 vs. 225 ± 159 epochs), and REM percentage (14.4% ± 6.5% vs. 19.3% ± 8.7%). OSA severity did not affect the sensitivity and specificity of the algorithm. The Cohen κ coefficient for detecting all sleep stages: sleep from wake, REM from NREM sleep, and deep from light sleep were 0.48, 0.55, 0.59, and 0.46, respectively. Conclusions: Analysis of autonomic signals from the PAT recorder can detect sleep stages with moderate agreement to more standard techniques in normal subjects and OSA patients. This novel algorithm may provide insights on sleep and sleep architecture when applying the PAT recorder for OSA diagnosis.

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“…Reflex effects leading to changes in autonomic tone may be activated through 1) changes in thoracic mechanics from obstructed respiratory efforts (4), 2) changes in blood-gas tensions (hypoxia and/or hypercapnia) (12,18), and 3) postapneic arousals. These factors ultimately culminate in an increase in sympathoadrenal tone (9,13), which is associated with a pressor response during the apnea and postapnea periods. Studies to date have focused mainly on the relative effect of these physiological alterations with regard to the overall cardiovascular response to apneas.…”

mentioning

confidence: 99%

Effects of vagotomy on cardiovascular response to periodic apneas in sedated pigs

Slamowitz

Chen

Scharf

1999

Journal of Applied Physiology

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Slamowitz, D., L. Chen, and S. M. Scharf. Effects of vagotomy on cardiovascular response to periodic apneas in sedated pigs. J. Appl. Physiol. 86(6): 1890-1896, 1999There are few studies investigating the influence of vagally mediated reflexes on the cardiovascular response to apneas. In 12 sedated preinstrumented pigs, we studied the effects of vagotomy during apneas, controlling for apnea periodicity and thoracic mechanical effects. Nonobstructive apneas were produced by paralyzing and mechanically ventilating the animals, then turning the ventilator off and on every 30 s. Before vagotomy, relative to baseline, apnea caused increased mean arterial pressure (MAP; ϩ19 Ϯ 25%, P Ͻ 0.05), systemic vascular resistance (SVR; ϩ33 Ϯ 16%, P Ͻ 0.0005), and heart rate (HR; ϩ5 Ϯ 6%, P Ͻ 0.05) and decreased cardiac output (CO) and stroke volume (SV; Ϫ16 Ϯ 10% P Ͻ 0.001). After vagotomy, no significant change occurred in MAP, SVR, and SV during apneas, but CO and HR increased relative to baseline. HR was always greater (ϳ14%, P Ͻ 0.01) during the interapneic interval compared with during apnea. We conclude that vagally mediated reflexes are important mediators of the apneic pressor response. HR increases after apnea termination are related, at least in part, to nonvagally mediated reflexes. apnea; vagus; hemodynamics OBSTRUCTIVE SLEEP APNEA is a relatively common clinical condition in which upper airway collapse and cessation of airflow produce an acute cardiovascular response, including elevations in blood pressure as well as changes in heart rate and ventricular function (3,24,26). In general, cardiovascular variables fluctuate during the apnea-interapnea periods because of mechanical alterations and reflex changes in autonomic tone. Reflex effects leading to changes in autonomic tone may be activated through 1) changes in thoracic mechanics from obstructed respiratory efforts (4), 2) changes in blood-gas tensions (hypoxia and/or hypercapnia) (12, 18), and 3) postapneic arousals. These factors ultimately culminate in an increase in sympathoadrenal tone (9, 13), which is associated with a pressor response during the apnea and postapnea periods. Studies to date have focused mainly on the relative effect of these physiological alterations with regard to the overall cardiovascular response to apneas. However, few studies have examined specific autonomic pathways mediating this response. In particular, little is known about the relative contribution of vagal traffic in the modulation of the sympathetic response. The vagus nerve could play a prominent role in the cardiovascular response to apneas because of afferent and/or efferent autonomic signals carried within the nerve. Sensory afferent signals from aortic receptors (baroreceptors and/or chemoreceptors) or mechanoreceptors carried via the vagus could be responsible for the augmentation in sympathetic tone during apneas (1, 25). In addition, mechanoreceptor afferents carried via the vagus could increase sympathetically mediated responses through an arousal mechanism (11,14)....

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Is high and fluctuating muscle nerve sympathetic activity in the sleep apnoea syndrome of pathogenetic importance for the development of hypertension?

Cited by 325 publications

References 0 publications

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

Sleep Staging Based on Autonomic Signals: A Multi-Center Validation Study

Effects of vagotomy on cardiovascular response to periodic apneas in sedated pigs

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