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Douglas T Bradley - One of the best experts on this subject based on the ideXlab platform.
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hypervolemia and sleep apnea in kidney disease
Seminars in Nephrology, 2015Co-Authors: Owen D. Lyons, Douglas T Bradley, Christopher T ChanAbstract:In end-stage renal disease (ESRD) and heart failure, conditions characterized by Fluid overload, both obstructive sleep apnea (OSA) and central sleep apnea (CSA) are highly prevalent. This observation suggests that Fluid overload may be a unifying mechanism in the pathogenesis of both OSA and CSA in these conditions. An overnight rostral Fluid Shift from the legs to the neck and lungs has been shown to contribute to the pathogenesis of OSA and CSA, respectively, in various different patient populations. This article reviews the evidence that supports a role for Fluid overload and overnight Fluid Shift in the pathogenesis of sleep apnea in ESRD. The diagnosis, epidemiology, and clinical features of sleep apnea in patients with ESRD also are considered.
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influence of rostral Fluid Shift on upper airway size and mucosal water content
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 2014Co-Authors: Takatoshi Kasai, Rosilene M Elias, Shveta S Motwani, Joseph M Gabriel, Luigi Taranto Montemurro, Naotake Yanagisawa, Neil Spiller, Narinder Paul, Douglas T BradleyAbstract:Study Objective:Fluid displacement from the legs during recumbency while in bed might narrow the upper airway (UA) in association with nuchal Fluid accumulation that may contribute to the pathogene...
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effect of intensified diuretic therapy on overnight rostral Fluid Shift and obstructive sleep apnoea in patients with uncontrolled hypertension
Journal of Hypertension, 2014Co-Authors: Takatoshi Kasai, Douglas T Bradley, Oded Friedman, Alexander G LoganAbstract:Objectives:Fluid displacement from the lower extremities to the upper body during sleep is strongly associated with obstructive sleep apnoea in hypertensive patients. The present pathophysiological study tests the hypothesis that intensified diuretic therapy will reduce the apnoea-hypopnoea index an
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rostral overnight Fluid Shift in end stage renal disease relationship with obstructive sleep apnea
Nephrology Dialysis Transplantation, 2012Co-Authors: Takatoshi Kasai, Rosilene M Elias, Douglas T Bradley, Shveta S Motwani, Christopher T ChanAbstract:Background. In both healthy male subjects and men with heart failure, the severity of obstructive sleep apnea (OSA) is related to the amount of Fluid displaced from their legs into the neck overnight. Whether overnight rostral Fluid Shift contributes to the pathogenesis of OSA in patients with end-stage renal disease (ESRD) is unknown. We hypothesized that the change in neck circumference (NC) and severity of OSA are related to the extent of overnight change in leg Fluid volume (LFV) in patients with ESRD. Methods. We studied 26 patients with ESRD (14 men) on conventional hemodialysis. All subjects underwent polysomnography. LFV was measured by bioelectric impedance at bedtime and repeated in the next morning on awakening. Results. Our cohort’s overall apnea–hypopnea index was 22.8 6 26.8 episodes/h of sleep. Their overnight change in LFV was � 243 6 278 mL. The change in LFV correlated with apnea–hypopnea time (AHT) (P ¼ 0.001) and NC (P ¼ 0.0016). Other independent factors associated with AHT included age (P ¼ 0.005), baseline neck (P ¼ 0.0002), sitting time (P ¼ 0.008) and male gender. Stepwise multiple regression analysis revealed that age, change in LFV and male gender remained independent related to AHT. Conclusions. Nocturnal rostral Fluid Shift is associated with the severity of OSA in ESRD. Prospective evaluation of the effect of reducing Fluid overload and severity of OSA in ESRD patients warrants further examination.
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effects of venous compression of the legs on overnight rostral Fluid Shift and obstructive sleep apnea
Respiratory Physiology & Neurobiology, 2011Co-Authors: Stefania Redolfi, Isabelle Arnulf, Douglas T Bradley, Michel Pottier, Thomas SimilowskiAbstract:Abstract The amount of Fluid displaced overnight from the legs into the neck as a consequence of lying recumbent correlates with the number of apneas and hypopneas per hour of sleep (AHI). Sedentary living promotes dependent Fluid accumulation in the legs that can be counteracted by venous compression of the legs (compression stockings). We hypothesized that, in non-obese sedentary men with obstructive sleep apnea (OSA), wearing compression stockings during daytime will reduce the AHI by reducing the amount of Fluid available for the displacement into the neck overnight. Polysomnography and measurement of overnight changes in leg Fluid volume and neck circumference were performed at baseline and after one day of legs venous compression. The median AHI decreased from 30.9 (interquartile range 19.6–60.4) to 23.4 (12.9–31.8) (P = 0.016) in association with a median 40% reduction in the change in leg Fluid volume (P = 0.016) and a median 42% reduction in the increase in neck circumference (P = 0.016). These results provide proof-of-principle that overnight Fluid displacement into the neck plays a causative role in OSA.
Stefania Redolfi - One of the best experts on this subject based on the ideXlab platform.
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Subjects with venous insufficiency have high risk of obstructive sleep apnea in relationship to Fluid Shift.
Sleep medicine, 2020Co-Authors: Elisa Perger, Stefania Redolfi, Sophie Blaise, Céline Vermorel, G. Böge, Jean-louis Pépin, Jean Luc BossonAbstract:Abstract Background Obstructive sleep apnea (OSA) is highly prevalent in conditions characterized by Fluid overload. Chronic venous insufficiency (CVI) is associated to Fluid overload that might interfere with OSA occurrence and severity. Methods A total of 180 patients with symptomatic CVI completed the Berlin questionnaire and were assessed for the presence of symptoms and signs of OSA and Fluid Shift. Results According to the Berlin questionnaire, 59 patients (33%) had high risk of OSA. The predictors of having a positive Berlin questionnaire were male sex, body mass index and symptoms possibly related to Fluid Shift. Conclusions Patients with CVI, a disease characterized by Fluid overload, present high risk of OSA, which might be related to Fluid Shift.
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postural preinspiratory cortical activity genioglossus activity and Fluid Shift in awake obstructive sleep apnoea patients
Experimental Physiology, 2020Co-Authors: Claire Launois, Isabelle Arnulf, Thomas Similowski, Valérie Attali, Marie-cécile Niérat, Mathieu Raux, Stefania RedolfiAbstract:NEW FINDING What is the central question of this study? Transition to supine posture induces an inspiratory load associated with cortical activation in awake healthy subjects. Some obstructive sleep apnoea patients exhibit this cortical activity in the sitting position contributing to the arousal-dependent compensation of their upper airway abnormalities. Does a transition to the supine posture in awake obstructive sleep apnoea patients increase this cortical activity? What is the main finding and its importance? The transition to supine posture induces a reduction in the cortical activity despite evidence of an increase in genioglossus activity, suggesting that genioglossus activation is not driven by cortical activity. ABSTRACT The anatomy and mechanical properties of the upper airway (UA) depend on posture. Lying in a supine position causes cephalad Fluid Shift to the neck, thus narrowing the UA and predisposing the individual to obstructive sleep apnoea (OSA). Increased UA dilator muscle activity during wakefulness prevents the UA collapse but the underlying mechanism has not yet been elucidated. In the sitting position during wakefulness, some OSA patients exhibit preinspiratory cortical activity (preinspiratory potential, PIP) probably related to UA abnormalities. The aim of this study was to investigate changes in the preinspiratory cortical activity and UA dilator muscle in OSA patients during postural challenge. An electroencephalogram was used to detect PIP, and the genioglossus electromyographic activity and ventilation were analysed in 17 awake, male OSA patients while they were sitting, just after lying down, and then in response to leg positive pressure to enhance cephalad Fluid Shift. The prevalence of PIP decreased from 53% (sitting) to 12% (supine) (P = 0.002) in association with increased genioglossus activity (tonic from median (25th, 75th centiles) 2.3 (1.8, 2.8)% to 3.6 (1.7, 5.0)% of voluntary deglutition, P = 0.019; phasic from 2.3 (1.9, 2.8)% to 3.7 (2.0, 6.1)%, P = 0.024), and with increased transcutaneous carbon dioxide pressure (from 43.0 (42.4, 44.2) to 44.6 (43.5, 45.2) mmHg). No change was observed during leg-positive-pressure application. Moving from the sitting position to the supine position reduces respiratory-related premotor cortical activity in awake OSA patients. The concomitant increase in genioglossus activity, therefore, is not driven by cortical respiratory activity.
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Evening sock marks as an adjunct to the clinical prediction of obstructive sleep apnea
Sleep and Breathing, 2019Co-Authors: Elisa Perger, Oumama Badarani, Carole Philippe, Isabelle Rivals, Isabelle Arnulf, Thomas Similowski, Stefania RedolfiAbstract:Study objectivesFluid overload Shifting from the legs to the upper airway during sleep promotes obstructive sleep apnea (OSA) and interventions targeting Fluid attenuate OSA. Fluid Shift has been previously measured by bioelectrical impedance, a complex and time-consuming technique not applicable in the daily clinical settings. The aim of this study is to evaluate the presence of clinically detectable Fluid overload and Shift and its association with OSA.MethodsPatients undergoing sleep study for suspected OSA were asked to report the presence of 11 signs/symptoms associated to excessive accumulation of Fluid in different parts of the body at different times of the day.ResultsAmong 392 patients (male: 53%, median [interquartile range] age: 56 years [ 1 ], body mass index, BMI: 29 kg/m^2 [ 2 ]) included in the study, 135 (34%) had moderate-to-severe OSA (apnea hypopnea index, AHI ≥ 15). Daytime Fluid accumulation and nocturnal Fluid Shift, clinically detectable by patient-reported “evening sock marks,” “heavy legs during the day,” and “morning stuffed nose,” were prevalent in the entire population (46%, 43%, and 33%, respectively). In multivariate analysis, evening sock marks was an independent correlate of having an AHI ≥ 15, together with male sex, older age, and self-reported snoring and apneas.ConclusionsClinically detectable Fluid overload and Shift are prevalent in patients addressed for suspected OSA, and evening sock marks, a marker for leg swelling, is an independent correlate of moderate-to-severe OSA. This sign might contribute to OSA diagnosis and identification of patients likely to be treated by interventions targeting Fluid overload and Shift.
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postural respiratory related cortical activation and rostral Fluid Shift in awake healthy humans
Experimental Physiology, 2019Co-Authors: Claire Launois, Elisa Perger, Isabelle Arnulf, Thomas Similowski, Valérie Attali, Marie-cécile Niérat, Mathieu Raux, Stefania RedolfiAbstract:NEW FINDINGS What is the central question of this study? Moving to supine induces upper airway modifications and a Fluid Shift to the neck, which represent inspiratory load that predisposes to upper airway collapse. Is there cortical participation in the response to the load induced by transition to a supine posture in awake healthy subjects? What is the main finding and its importance? Moving to supine induces transient cortical activation in awake healthy subjects, with greater Fluid Shift, supporting possible cortical participation in the response to upper airway load induced by transition to a supine posture. Our findings open new perspectives in the understanding of the pathogenesis of obstructive sleep apnoea. ABSTRACT Moving from sitting upright to lying supine causes anatomical modifications and a Fluid Shift to the neck, which represent inspiratory loads that predispose to upper airway collapse. The pre-inspiratory potential (PIP) corresponds to the cortical activity observed during inspiratory load. In the sitting position during wakefulness, some obstructive sleep apnoea patients exhibit PIP, probably in relationship to upper airway abnormalities. The aim of this study was to investigate whether moving to the supine position induces respiratory-related cortical activation (PIP) in awake healthy subjects. The ECG was analysed to detect PIP, and EMG activity of the genioglossus muscle and ventilation were measured in the sitting position, immediately after moving to the supine position, and during application of leg positive pressure in the supine position to promote Fluid Shift, which was measured by bioelectrical impedance. Twenty-four subjects were included. From sitting to lying, PIP prevalence increased from 1/24 to 11/24 (P = 0.002), and ventilation decreased with no change in genioglossus activity. The Fluid Shift from sitting to supine was higher in the subjects exhibiting PIP while supine compared with the subjects without PIP [median (25th; 75th centiles) 440 (430; 520) versus 320 (275; 385) ml, P = 0.018], without any other differences. From before to during leg positive pressure, PIP disappeared (P = 0.006). These results indicate that moving from sitting to lying induces transient respiratory-related cortical activity in awake healthy subjects with greater Fluid Shift, supporting possible cortical participation in the response to upper airway loading induced by moving from sitting upright to lying supine. This study offers new perspectives in the understanding of obstructive sleep apnoea pathogenesis.
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Postural respiratory‐related cortical activation and rostral Fluid Shift in awake healthy humans
Experimental physiology, 2019Co-Authors: Claire Launois, Elisa Perger, Isabelle Arnulf, Thomas Similowski, Valérie Attali, Marie-cécile Niérat, Mathieu Raux, Stefania RedolfiAbstract:NEW FINDINGS What is the central question of this study? Moving to supine induces upper airway modifications and a Fluid Shift to the neck, which represent inspiratory load that predisposes to upper airway collapse. Is there cortical participation in the response to the load induced by transition to a supine posture in awake healthy subjects? What is the main finding and its importance? Moving to supine induces transient cortical activation in awake healthy subjects, with greater Fluid Shift, supporting possible cortical participation in the response to upper airway load induced by transition to a supine posture. Our findings open new perspectives in the understanding of the pathogenesis of obstructive sleep apnoea. ABSTRACT Moving from sitting upright to lying supine causes anatomical modifications and a Fluid Shift to the neck, which represent inspiratory loads that predispose to upper airway collapse. The pre-inspiratory potential (PIP) corresponds to the cortical activity observed during inspiratory load. In the sitting position during wakefulness, some obstructive sleep apnoea patients exhibit PIP, probably in relationship to upper airway abnormalities. The aim of this study was to investigate whether moving to the supine position induces respiratory-related cortical activation (PIP) in awake healthy subjects. The ECG was analysed to detect PIP, and EMG activity of the genioglossus muscle and ventilation were measured in the sitting position, immediately after moving to the supine position, and during application of leg positive pressure in the supine position to promote Fluid Shift, which was measured by bioelectrical impedance. Twenty-four subjects were included. From sitting to lying, PIP prevalence increased from 1/24 to 11/24 (P = 0.002), and ventilation decreased with no change in genioglossus activity. The Fluid Shift from sitting to supine was higher in the subjects exhibiting PIP while supine compared with the subjects without PIP [median (25th; 75th centiles) 440 (430; 520) versus 320 (275; 385) ml, P = 0.018], without any other differences. From before to during leg positive pressure, PIP disappeared (P = 0.006). These results indicate that moving from sitting to lying induces transient respiratory-related cortical activity in awake healthy subjects with greater Fluid Shift, supporting possible cortical participation in the response to upper airway loading induced by moving from sitting upright to lying supine. This study offers new perspectives in the understanding of obstructive sleep apnoea pathogenesis.
Takatoshi Kasai - One of the best experts on this subject based on the ideXlab platform.
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Fluid Retention and Rostral Fluid Shift in Sleep-Disordered Breathing
Current Hypertension Reviews, 2016Co-Authors: Takatoshi KasaiAbstract:Sleep-disordered breathing (SDB) is common and adversely affects cardiovascular morbidity and mortality. Despite multifactorial pathogenesis, SDB is prevalent in patients with Fluid retention disorders, such as drug-resistant hypertension, end-stage renal disease, and heart failure, suggesting that Fluid retention may play a role in the pathogenesis of SDB. During the day, Fluid is likely to accumulate in the legs, and upon lying down at night is displaced from the legs. Many data suggest that some of this Fluid displaced from the legs may redistribute to the upper body and predispose to SDB. This review article will highlight evidence for a relationship between SDB and Fluid retention or rostral Fluid Shift, and discuss mechanisms that link them.
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influence of rostral Fluid Shift on upper airway size and mucosal water content
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 2014Co-Authors: Takatoshi Kasai, Rosilene M Elias, Shveta S Motwani, Joseph M Gabriel, Luigi Taranto Montemurro, Naotake Yanagisawa, Neil Spiller, Narinder Paul, Douglas T BradleyAbstract:Study Objective:Fluid displacement from the legs during recumbency while in bed might narrow the upper airway (UA) in association with nuchal Fluid accumulation that may contribute to the pathogene...
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effect of intensified diuretic therapy on overnight rostral Fluid Shift and obstructive sleep apnoea in patients with uncontrolled hypertension
Journal of Hypertension, 2014Co-Authors: Takatoshi Kasai, Douglas T Bradley, Oded Friedman, Alexander G LoganAbstract:Objectives:Fluid displacement from the lower extremities to the upper body during sleep is strongly associated with obstructive sleep apnoea in hypertensive patients. The present pathophysiological study tests the hypothesis that intensified diuretic therapy will reduce the apnoea-hypopnoea index an
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effect of rostral Fluid Shift on pharyngeal resistance in men with and without obstructive sleep apnea
Respiratory Physiology & Neurobiology, 2014Co-Authors: Takatoshi Kasai, Laura H. White, Shveta S Motwani, Dai Yumino, Vinoban AmirthalingamAbstract:Abstract Background Obstructive sleep apnea (OSA) relates to overnight rostral Fluid Shift, possibly because Fluid accumulation around the pharynx increases pharyngeal resistance (Rph). We hypothesised that Rph will increase more in men with than without OSA in response to rostral Fluid redistribution. Methods Seventeen men with, and 12 without OSA were randomized to lower body positive pressure (LBPP) for 15 min or control, then crossed over. Leg Fluid volume (LFV) and Rph were measured before and after each period. Results LBPP displaced similar amounts of Fluid from the legs in both groups. However, compared to the non-OSA group, Rph increased significantly more during LBPP in the OSA group (−0.38 ± 2.87 vs. 2.52 ± 2.94 cmH2O/l/s, p = 0.016). Change in Rph during LBPP correlated directly with baseline Rph in the OSA group, but inversely in the non-OSA group. Conclusion OSA patients have increased susceptibility to pharyngeal obstruction in response to rostral Fluid redistribution, which could predispose to pharyngeal collapse during sleep.
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rostral overnight Fluid Shift in end stage renal disease relationship with obstructive sleep apnea
Nephrology Dialysis Transplantation, 2012Co-Authors: Takatoshi Kasai, Rosilene M Elias, Douglas T Bradley, Shveta S Motwani, Christopher T ChanAbstract:Background. In both healthy male subjects and men with heart failure, the severity of obstructive sleep apnea (OSA) is related to the amount of Fluid displaced from their legs into the neck overnight. Whether overnight rostral Fluid Shift contributes to the pathogenesis of OSA in patients with end-stage renal disease (ESRD) is unknown. We hypothesized that the change in neck circumference (NC) and severity of OSA are related to the extent of overnight change in leg Fluid volume (LFV) in patients with ESRD. Methods. We studied 26 patients with ESRD (14 men) on conventional hemodialysis. All subjects underwent polysomnography. LFV was measured by bioelectric impedance at bedtime and repeated in the next morning on awakening. Results. Our cohort’s overall apnea–hypopnea index was 22.8 6 26.8 episodes/h of sleep. Their overnight change in LFV was � 243 6 278 mL. The change in LFV correlated with apnea–hypopnea time (AHT) (P ¼ 0.001) and NC (P ¼ 0.0016). Other independent factors associated with AHT included age (P ¼ 0.005), baseline neck (P ¼ 0.0002), sitting time (P ¼ 0.008) and male gender. Stepwise multiple regression analysis revealed that age, change in LFV and male gender remained independent related to AHT. Conclusions. Nocturnal rostral Fluid Shift is associated with the severity of OSA in ESRD. Prospective evaluation of the effect of reducing Fluid overload and severity of OSA in ESRD patients warrants further examination.
Alexander G Logan - One of the best experts on this subject based on the ideXlab platform.
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pathogenesis of obstructive sleep apnoea in hypertensive patients role of Fluid retention and nocturnal rostral Fluid Shift
Journal of Human Hypertension, 2015Co-Authors: Alexander G Logan, L H White, T D BradleyAbstract:Obstructive sleep apnoea (OSA) is highly prevalent in hypertensive patients, particularly those with drug resistance. Evidence from animal experiments, epidemiologic studies and clinical trials strongly suggest a causal link. Mechanistic studies argue for increased sympathetic neural activity and endothelial dysfunction. However, disturbances in Fluid volume regulation and distribution may also be involved in the pathogenesis of these two conditions. Several studies have shown a high prevalence of OSA in Fluid-retaining states including hypertension, a direct relationship between the severity of OSA and the volume of Fluid displaced from the legs to the neck during sleep, and a decrease in upper airway cross-sectional area in response to graded lower body positive pressure. Treatments targeting Fluid retention and redistribution, including diuretics, mineralocorticoid antagonists, exercise, and possibly renal denervation lower blood pressure and reduce the apnoea–hypopnoea index, a measure of OSA severity. From these observations, it has been postulated that during the daytime, excess Fluid collects in the lower extremities due to gravity, and on lying down overnight is redistributed rostrally to the neck, where it may narrow the upper airway and increase its collapsibility, predisposing to OSA when pharyngeal dilator muscle activity decreases during sleep. This article discusses the associations between OSA and hypertension and reviews the evidence for Fluid accumulation and its nocturnal rostral redistribution in the pathogenesis of OSA in hypertensive patients.
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effect of intensified diuretic therapy on overnight rostral Fluid Shift and obstructive sleep apnoea in patients with uncontrolled hypertension
Journal of Hypertension, 2014Co-Authors: Takatoshi Kasai, Douglas T Bradley, Oded Friedman, Alexander G LoganAbstract:Objectives:Fluid displacement from the lower extremities to the upper body during sleep is strongly associated with obstructive sleep apnoea in hypertensive patients. The present pathophysiological study tests the hypothesis that intensified diuretic therapy will reduce the apnoea-hypopnoea index an
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relationship between overnight rostral Fluid Shift and obstructive sleep apnea in drug resistant hypertension
Hypertension, 2010Co-Authors: Oded Friedman, Douglas T Bradley, Christopher T Chan, Robert Parkes, Alexander G LoganAbstract:Obstructive sleep apnea occurs frequently in patients with drug-resistant hypertension. The factors accounting for this observation, however, are unclear. Both conditions demonstrate clinical features suggestive of extracellular Fluid volume overload. The aims of this study were to examine whether the spontaneous overnight Fluid Shift from the legs to the upper body is associated with obstructive sleep apnea in hypertensive subjects and whether its magnitude is greater in drug-resistant hypertension. Leg Fluid volume and the circumference of the calf and neck were measured before and after sleep in drug-resistant hypertensive (n=25) and controlled hypertensive (n=15) subjects undergoing overnight polysomnography. The severity of obstructive sleep apnea was greater in the drug-resistant hypertensive group than in the controlled hypertensive group (apnea-hypopnea index: 43.0±5.4 versus 18.1±4.2 events per hour of sleep; P =0.02, case-mix adjusted). In both groups, the apnea-hypopnea index strongly related to the amount of leg Fluid volume displaced ( R 2 =0.56; P P =0.01, propensity-score adjusted). The overnight reduction in calf circumference and increase in neck circumference were also greater in drug-resistant hypertension (both P ≤0.02). In hypertensive subjects, rostral Fluid displacement strongly relates to the severity of obstructive sleep apnea with its magnitude being greater in drug-resistant hypertension. Our findings support the concept that Fluid redistribution centrally during sleep accounts for the high prevalence of obstructive sleep apnea in drug-resistant hypertension.
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relationship between overnight rostral Fluid Shift and obstructive sleep apnea in drug resistant hypertension
Hypertension, 2010Co-Authors: Oded Friedman, Douglas T Bradley, Christopher T Chan, Robert Parkes, Alexander G LoganAbstract:Obstructive sleep apnea occurs frequently in patients with drug-resistant hypertension. The factors accounting for this observation, however, are unclear. Both conditions demonstrate clinical features suggestive of extracellular Fluid volume overload. The aims of this study were to examine whether the spontaneous overnight Fluid Shift from the legs to the upper body is associated with obstructive sleep apnea in hypertensive subjects and whether its magnitude is greater in drug-resistant hypertension. Leg Fluid volume and the circumference of the calf and neck were measured before and after sleep in drug-resistant hypertensive (n = 25) and controlled hypertensive (n=15) subjects undergoing overnight polysomnography. The severity of obstructive sleep apnea was greater in the drug-resistant hypertensive group than in the controlled hypertensive group (apnea-hypopnea index: 43.0 ± 5.4 versus 18.1 ± 4.2 events per hour of sleep; P = 0.02, case-mix adjusted). In both groups, the apnea-hypopnea index strongly related to the amount of leg Fluid volume displaced (R² = 0.56; P < 0.0001), although the magnitude of change was greater in the drug-resistant hypertensive group (346.7 ± 24.1 versus 175.8 ± 31.3 mL; P = 0.01, propensity-score adjusted). The overnight reduction in calf circumference and increase in neck circumference were also greater in drug-resistant hypertension (both P ≤ 0.02). In hypertensive subjects, rostral Fluid displacement strongly relates to the severity of obstructive sleep apnea with its magnitude being greater in drug-resistant hypertension. Our findings support the concept that Fluid redistribution centrally during sleep accounts for the high prevalence of obstructive sleep apnea in drug-resistant hypertension.
Olga L Vinogradova - One of the best experts on this subject based on the ideXlab platform.
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Fluid Shift versus body size: changes of hematological parameters and body Fluid volume in hindlimb-unloaded mice, rats and rabbits.
The Journal of experimental biology, 2018Co-Authors: Alexander A Andreev-andrievskiy, Anfisa S Popova, Evgeniia A Lagereva, Olga L VinogradovaAbstract:The cardiovascular system is adapted to gravity, and reactions to the loss of gravity in space are presumably dependent on body size. The dependence of hematological parameters and body Fluid volume on simulated microgravity have never been studied as an allometric function before. Thus, we estimated red blood cell (RBC), blood and extracellular Fluid volume in hindlimb-unloaded (HLU) or control (attached) mice, rats and rabbits. RBC decrease was found to be size independent, and the allometric dependency for RBC loss in HLU and control animals shared a common power (-0.054±0.008) but a different Y0 coefficient (8.66±0.40 and 10.73±0.49, respectively, P
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Fluid Shift versus body size: changes of hematological parameters and body Fluid volume in hindlimb-unloaded mice, rats and rabbits.
The Journal of Experimental Biology, 2018Co-Authors: Alexander A Andreev-andrievskiy, Evgeniia A Lagereva, Anfisa Popova, Olga L VinogradovaAbstract:Cardiovascular system is adapted to gravity, and reactions to its vanishing in space are presumably dependent on body size. Dependency of hematological parameters and body Fluids reaction to simulated microgravity have never been studied as an allometric function before. Thus we estimated RBC, blood and extracellular Fluid volumes in hindlimb-unloaded (HLU) or control (ATT) mice, rats and rabbits. RBC decrease was found to be size-independent, and the allometric dependency for red blood loss in HLU and ATT animals shared a common power (−0.054±0.008) but differrent Y 0 (8.66±0.40 and 10.73±0.49 correspondingly, p 0 (1.02±0.09) but had different powers N (0.708±0.017 and 0.648±0.016 correspondingly, p Our data underscore the importance of size-independent mechanisms of cardiovascular adaptation to weightlessness. Despite use of mice hampers application of a straightforward translational approach, this species is useful for gravitational biology as a tool to investigate size-independent mechanisms of mammalian adaptation to microgravity.