Bojan Gavrilovic1, T Douglas Bradley2, Daniel Vena1, Owen D Lyons3, Joseph M Gabriel3, Milos R Popovic1, Azadeh Yadollahi4. 1. Toronto Rehabilitation Institute, University Health Network, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada. 2. Toronto Rehabilitation Institute, University Health Network, Toronto, Canada; Department of Medicine, University of Toronto, Toronto, Canada. 3. Toronto Rehabilitation Institute, University Health Network, Toronto, Canada. 4. Toronto Rehabilitation Institute, University Health Network, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada. Electronic address: Azadeh.Yadollahi@uhn.ca.
Abstract
OBJECTIVES:Obstructive sleep apnea (OSA) is highly prevalent in patients with fluid-retaining conditions. Using bioimpedance measurements, previous studies have shown that the greater the amount of fluid redistributed from the legs to the neck overnight, the greater the severity of OSA. Our objective was to investigate factors that predispose the development or worsening of OSA in response to experimental fluid overload. METHODS:Fifteen normotensive and non-obese adult men with and without OSA underwent polysomnography (PSG) during whichnormal saline was infused intravenously at a minimal rate to keep the vein open (control) or as a bolus of 22 ml/kg body weight (approximately 2 L) in a random order and crossed over after a week. RESULTS AND CONCLUSIONS: Before and after sleep, neck circumference and bioimpedance were measured to calculate neck resistance, reactance, phase angle, and fluid volume. Subjects who experienced more than a twofold increase in apnea-hypopnea index (AHI) or obstructive AHI from control to intervention and had an AHI>10 during intervention were considered susceptible to the development or worsening of OSA. Baseline neck circumference and phase angle before saline infusion were independently associated with increased susceptibility to developing or worsening OSA in response to saline infusion. In non-obese men, a larger neck circumference and bioimpedance phase angle of the neck, which may be associated with larger pharyngeal tissue content, is associated with increased susceptibility for worsening of OSA in response to fluid overloading.
RCT Entities:
OBJECTIVES: Obstructive sleep apnea (OSA) is highly prevalent in patients with fluid-retaining conditions. Using bioimpedance measurements, previous studies have shown that the greater the amount of fluid redistributed from the legs to the neck overnight, the greater the severity of OSA. Our objective was to investigate factors that predispose the development or worsening of OSA in response to experimental fluid overload. METHODS: Fifteen normotensive and non-obese adult men with and without OSA underwent polysomnography (PSG) during which normal saline was infused intravenously at a minimal rate to keep the vein open (control) or as a bolus of 22 ml/kg body weight (approximately 2 L) in a random order and crossed over after a week. RESULTS AND CONCLUSIONS: Before and after sleep, neck circumference and bioimpedance were measured to calculate neck resistance, reactance, phase angle, and fluid volume. Subjects who experienced more than a twofold increase in apnea-hypopnea index (AHI) or obstructive AHI from control to intervention and had an AHI>10 during intervention were considered susceptible to the development or worsening of OSA. Baseline neck circumference and phase angle before saline infusion were independently associated with increased susceptibility to developing or worsening OSA in response to saline infusion. In non-obesemen, a larger neck circumference and bioimpedance phase angle of the neck, which may be associated with larger pharyngeal tissue content, is associated with increased susceptibility for worsening of OSA in response to fluid overloading.
Authors: Daniel Vena; T Douglas Bradley; Philip J Millar; John S Floras; Jonathan Rubianto; Bojan Gavrilovic; Elisa Perger; Azadeh Yadollahi Journal: J Clin Sleep Med Date: 2018-04-15 Impact factor: 4.062