Sleep fragmentation mimicking sleep apnea does not alter cardiac function in either control or heart failure mice

Background: Obstructive sleep apnea (OSA) has been associated with worsening heart failure. Sleep fragmentation (SF), one of the major hallmarks of OSA, induces inflammation, oxidative stress and sympathetic activation, and could potentially contribute to OSA-induced cardiovascular consequences. However, it remains unclear whether SF per se is deleterious to cardiac function.Aim: To evaluate the effect of SF mimicking OSA on echocardiographically-measured cardiac function (ECHO) in otherwise healthy mice and in a murine model of heart failure.Methods: Forty C57BL/6J male mice were randomized into 4 treatment groups: control sleep, sleep fragmentation (SF), isoproterenol-induced heart failure (HF), and SF+HF. ECHO was measured at baseline and after 30 days. Left ventricular end-diastolic diameter, end-systolic diameter, shortening fraction and left ventricular ejection fraction were recorded by a blinded investigator.Results: Isoproterenol treatment promoted significant left ventricular dilatation and reduced systolic function in HF and SF+HF groups (in all cases p
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Sleep and control of breathing Source Type: research

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Abstract Neural control of the heart is regulated by sympathetic and parasympathetic divisions of the autonomic nervous system, both opposing each other to maintain cardiac homeostasis via regulating heart rate, conduction velocity, force of contraction and coronary blood flow. Sympathetic hyperactivity and diminished parasympathetic activity are the characteristic features of many cardiovascular disease states including hypertension, myocardial ischemia, and arrhythmias that result in heart failure. Restoring parasympathetic activity to the heart has recently been identified as the promising approach to treat suc...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research
Abstract BACKGROUND: Obstructive sleep apnea (OSA) is characterized by augmented sympathetic nerve activity. In our previous study, patients with OSA and an apnea-hyperpnea index (AHI)>55events/h showed increased single-unit muscle sympathetic nerve activity compared to patients with OSA and AHI of 30-55events/h. However, the prognostic impact in these patients remains unclear. METHODS: Ninety-one OSA patients were included. All patients who had indication for continuous positive airway pressure (CPAP) were treated with CPAP. Patients were divided into three groups: mild/moderate OSA (S), AHI55events/h (n=...
Source: Journal of Cardiology - Category: Cardiology Authors: Tags: J Cardiol Source Type: research
Conclusion: Chronic SF mimicking OSA did not induce echocardiographic changes in cardiac structure and function in both healthy and HF mice. Thus, the deleterious cardiac consequences of OSA are likely induced by other perturbations associated with this prevalent condition, or result from interactions with underlying comorbidities in OSA patients.
Source: Frontiers in Neurology - Category: Neurology Source Type: research
CONCLUSION: Treatment of OSA in patients with systolic HF improves respiratory indices but does not have a favorable effect on sleep quality. While OSA per se was associated with an increase in sympathetic drive, APAP treatment was not associated with a reduction in sympathetic drive. After 6 months of treatment, there was even a trend towards additional increases in sympathetic drive in the APAP group. PMID: 31240541 [PubMed - as supplied by publisher]
Source: Sleep and Breathing - Category: Sleep Medicine Authors: Tags: Sleep Breath Source Type: research
ConclusionTreatment of OSA in patients with systolic HF improves respiratory indices but does not have a favorable effect on sleep quality. While OSA per se was associated with an increase in sympathetic drive, APAP treatment was not associated with a reduction in sympathetic drive. After 6  months of treatment, there was even a trend towards additional increases in sympathetic drive in the APAP group.
Source: Sleep and Breathing - Category: Respiratory Medicine Source Type: research
The objective of this review is to incorporate recent advances in the field into a phenotype-based approach to the management of OSA in HF. PMID: 31047953 [PubMed - as supplied by publisher]
Source: Chest - Category: Respiratory Medicine Authors: Tags: Chest Source Type: research
Conclusions Aging leads to a progressive decrease in androgen production that, in turn, leads to the development of LOH, defined by significant low T serum levels (in the lowest quartile) in the presence of signs and symptoms of hypogonadism (51). LOH could be due to both testicular and hypothalamic-pituitary dysfunction (32), and ED is one of its main symptoms. ED in LOH is linked to increased oxidative stress, subclinical inflammation, and subsequent endothelial dysfunction (101). In elderly men, it has been shown that LOH is also linked to lower cAMP pool and to an alteration of the cGMP signaling pathway. PDE5 gene l...
Source: Frontiers in Endocrinology - Category: Endocrinology Source Type: research
Introduction/Purpose We demonstrated that patients with obstructive sleep apnea (OSA) have reduced muscle metaboreflex control of muscle sympathetic nerve activity (MSNA). In addition, exercise training increased muscle metaboreflex control in heart failure patients. Objective We tested the hypothesis that exercise training would increase muscle metaboreflex control of MSNA in patients with OSA. Methods Forty-one patients with OSA were randomized into the following two groups: 1) nontrained (OSANT, n = 21) and 2) trained (OSAT, n = 20). Muscle sympathetic nerve activity was assessed by microneurography technique, m...
Source: Medicine and Science in Sports and Exercise - Category: Sports Medicine Tags: CLINICAL SCIENCES Source Type: research
AbstractPurpose of ReviewAn abnormal heightened carotid body (CB) chemoreflex, which produces autonomic dysfunction and sympathetic overactivation, is the common hallmark of obstructive sleep apnea (OSA), resistant hypertension, systolic heart failure (HF), and cardiometabolic diseases. Accordingly, it has been proposed that the elimination of the CB chemosensory input to the brainstem may reduce the autonomic and cardiorespiratory alterations in sympathetic-associated diseases in humans.Recent FindingsA growing body of evidence obtained in preclinical animal models support that an enhanced CB discharge produces sympatheti...
Source: Current Hypertension Reports - Category: Primary Care Source Type: research
AbstractRenal afferent and efferent sympathetic nerves are involved in the regulation of blood pressure and have a pathophysiological role in hypertension. Additionally, several conditions that frequently coexist with hypertension, such as heart failure, obstructive sleep apnea, atrial fibrillation, renal dysfunction, and metabolic syndrome, demonstrate enhanced sympathetic activity. Renal denervation (RDN) is an approach to reduce renal and whole body sympathetic activation. Experimental models indicate that RDN has the potential to lower blood pressure and prevent cardio-renal remodeling in chronic diseases associated wi...
Source: Clinical Autonomic Research - Category: Research Source Type: research
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