Rationale: Impaired endothelium-dependent vasodilation has been documented in patients with sleep apnea. This impairment may result in blood flow dysregulation during apnea-induced fluctuations in arterial blood gases.
Objectives: To test the hypothesis that hypoxic and hypercapnic vasodilation in the forearm and cerebral circulation are impaired in patients with sleep apnea.
Methods: We exposed 20 patients with moderate to severe sleep apnea and 20 control subjects, to isocapnic hypoxia and hyperoxic hypercapnia. A subset of 14 patients was restudied after treatment with continuous positive airway pressure.
Measurements And Main Results: Cerebral flow velocity (transcranial Doppler), forearm blood flow (venous occlusion plethysmography), arterial pressure (automated sphygmomanometry), oxygen saturation (pulse oximetry), ventilation (pneumotachograph), and end-tidal oxygen and carbon dioxide tensions (expired gas analysis) were measured during three levels of hypoxia and two levels of hypercapnia. Cerebral vasodilator responses to hypoxia (-0.65 +/- 0.44 vs. -1.02 +/- 0.72 [mean +/- SD] units/% saturation; P = 0.03) and hypercapnia (2.01 +/- 0.88 vs. 2.57 +/- 0.89 units/mm Hg; P = 0.03) were smaller in patients versus control subjects. Hypoxic vasodilation in the forearm was also attenuated (-0.05 +/- 0.09 vs. -0.10 +/- 0.09 unit/% saturation; P = 0.04). Hypercapnia did not elicit forearm vasodilation in either group. Twelve weeks of continuous positive airway pressure treatment enhanced hypoxic vasodilation in the cerebral circulation (-0.83 +/- 0.32 vs. -0.46 +/- 0.29 units/% saturation; P = 0.01) and forearm (-0.19 +/- 0.15 vs. -0.02 +/- 0.08 units/% saturation; P = 0.003), and hypercapnic vasodilation in the brain showed a trend toward improvement (2.24 +/- 0.78 vs. 1.76 +/- 0.64 units/mm Hg; P = 0.06).
Conclusions: Vasodilator responses to chemical stimuli in the cerebral circulation and the forearm are impaired in many patients with obstructive sleep apnea. Some of these impairments can be improved with continuous positive airway pressure.
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http://dx.doi.org/10.1164/rccm.200903-0393OC | DOI Listing |
Eur J Pediatr
January 2025
Service de Physiologie Pédiatrique-Centre du Sommeil-CRMR Hypoventilations Alvéolaires Rares, INSERM NeuroDiderot, Université Paris-Cité, AP-HP, Hôpital Robert Debré, Paris, France.
Unlabelled: It is known that in most cases of congenital central hypoventilation syndrome (CCHS), apnoeas and hypoventilation occur at birth. Nevertheless, a detailed description of initial symptoms, including pregnancy events and diagnostic tests performed, is warranted in infants with neonatal onset of CCHS, that is, in the first month of life. The European Central Hypoventilation Syndrome Consortium created an online patient registry from which 97 infants (44 females) with CCHS of neonatal onset and PHOX2B mutation from 10 countries were selected.
View Article and Find Full Text PDFSleep
January 2025
Division of Pulmonary, Critical Care and Sleep Medicine, University at Buffalo, NY, USA.
Nat Sci Sleep
January 2025
Department of Stomatology, Gongli Hospital of Shanghai Pudong New Area, Shanghai, People's Republic of China.
Objective: Patients with obstructive sleep apnea (OSA) frequently suffer from migraine, however the causal relationship between OSA and migraine is unknown. Investigating the causation will assist in understanding the etiology of OSA and migraine.
Methods: Bidirectional two-sample Mendelian randomization (MR) and multivariable MR (MVMR) approaches were carried out to investigate the causal link between OSA and migraine.
Nat Sci Sleep
January 2025
Sleep Center, Department of Geriatric Respiratory, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, People's Republic of China.
Purpose: Approximately 30% of patients with sleep-disordered breathing (SDB) present with masked hypertension, primarily characterized by elevated nighttime blood pressure. This study aimed to develop a hypertension prediction model tailored for primary care physicians, utilizing simple, readily available predictors derived from type IV sleep monitoring devices.
Patients And Methods: Participants were recruited from communities in Guangdong Province, China, between April and May 2021.
Brain Behav Immun Health
December 2024
Department of Systems Medicine, University of Rome "Tor Vergata", 00133, Rome, Italy.
Background: Interleukin-6 (IL-6) represents one of the main molecules involved in inflammatory responses, which can be altered in either patients with cognitive impairment or obstructive sleep apnea (OSA). The present study aimed to evaluate serum IL-6 levels and cognitive performance in patients with severe OSA (Apnea-Hypopnea Index - AHI >30/h).
Methods: Thirty patients with severe OSA were compared to 15 controls similar in age, sex, and Body Mass Index.
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