MRI evaluation of cerebral metabolic rate of oxygen (CMRO2) in obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) are at elevated risk of developing systemic vascular disease and cognitive dysfunction. Here, cerebral oxygen metabolism was assessed in patients with OSA by means of a magnetic resonance-based method involving simultaneous measurements of cerebral blood flow rate and venous oxygen saturation in the superior sagittal sinus for a period of 10 minutes at an effective temporal resolution of 1.3 seconds before, during, and after repeated 24-second breath-holds mimicking spontaneous apneas, yielding, along with pulse oximetry-derived arterial saturation, whole-brain CMRO2 via Fick’s Principle. Enrolled subjects were classified based on their apnea-hypopnea indices into OSA (N = 31) and non-sleep apnea reference subjects (NSA = 21), and further compared with young healthy subjects (YH, N = 10). OSA and NSA subjects were matched for age and body mass index. CMRO2 was lower in OSA than in the YH group during normal breathing (105.6 ± 14.1 versus 123.7 ± 22.8 μmol O2/min/100g, P = 0.01). Further, the fractional change in CMRO2 in response to a breath-hold challenge was larger in OSA than in the YH group (15.2 ± 9.2 versus 8.5 ± 3.4%, P = 0.04). However, there was no significant difference in CMRO2 between OSA and NSA subjects. The data suggest altered brain oxygen metabolism in OSA and possibly in NSA as well.

Download Full-text

0170 Association of HIF-1 Alpha and Beta Subunits with Clock and BMAL1 Proteins in Obstructive Sleep Apnea Patients

SLEEP ◽

10.1093/sleep/zsaa056.168 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A67-A67

Author(s):

A Gabryelska ◽

M Sochal ◽

S Turkiewicz ◽

P Bialasiewicz

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Circadian Clock ◽

Hypoxia Inducible Factor ◽

Study Groups ◽

Oxygen Metabolism ◽

Apnea Hypopnea Index ◽

Protein Levels ◽

Obstructive Sleep ◽

Significant Difference

Abstract Introduction Obstructive sleep apnea (OSA) is a chronic condition that is characterized by intermittent hypoxia. Key regulator of oxygen metabolism is hypoxia inducible factor (HIF), which consists of oxygen sensitive subunit and continuously produced subunit. Circadian clock is composed of set of genes, which function as activators - CLOCK and BMAL 1, who similarly to HIF are basic helix-loop-helix-PER-ARNT-SIM transcription factors. Therefore, the aim of the study was to assess the relationship between HIF-1alpha, HIF-1beta, CLOCK, BMAL1 and polysomnography (PSG) variables in healthy individuals and severe OSA patients. Methods The study included 20 individuals, who underwent PSG and based on apnea-hypopnea index (AHI) were divided into severe OSA group (n=10; AHI30; 90% male) and healthy control (n=10; AHI<5; 70% male). All participants had their peripheral blood collected in the evening (9:00-10:00 pm) before and in the morning (6:00-7:00 am) after the PSG. HIF-1alpha, HIF-1beta, CLOCK and BMAL1 protein concertation measurements were performed using ELISA. Results Significant difference was observed in the following protein measurements between study groups: evening and morning HIF-1 (p=0.020 and p=0.043, respectively), evening HIF-1alpha (p=0.047), evening and morning CLOCK (p=0.037 and p=0.019, respectively) and morning BMAL1 (p=0.016). No differences were observed between morning and evening protein levels in both groups. Evening HIF-1beta corraleted with evening CLOCK and morning BMAL1 (R=0.511, p=0.21 and R=0.594, p=0.006, respectively), while morning HIF-1 with evening BMAL1 (R=474, p=0.35). Furthermore, evening and morning HIF-1 correlated with evening BMAL1 (R=564, p=0.010 and R=0.689, p=0.001, respectively). Additionally, morning CLOCK and BMAL1 correlated with AHI (R=0.510, p=0.022 and R=0.560, p=0.010, respectively) and desaturation index (R=0.487, p=0.209 and R=0.570, p=0.009, respectively). Conclusion There is significant correlation between both subunits of HIF-1 protein and circadian clock proteins: CLOCK and BMAL1, which further correlate with increased disease severity. This suggests OSA patients are in risk of circadian clock disruption due to present hypoxia. Support The study was financed by Polish National Centre Grant no. 2018/31/N/NZ5/03931.

Download Full-text

MRI evaluation of cerebrovascular reactivity in obstructive sleep apnea

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x19862182 ◽

2019 ◽

Vol 40 (6) ◽

pp. 1328-1337 ◽

Cited By ~ 3

Author(s):

Pei-Hsin Wu ◽

Ana E Rodríguez-Soto ◽

Zachary B Rodgers ◽

Erin K Englund ◽

Andrew Wiemken ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Rate Of Change ◽

Cerebrovascular Reactivity ◽

Breath Hold ◽

High Temporal Resolution ◽

Compensatory Mechanism ◽

Whole Brain ◽

Sagittal Sinus ◽

Obstructive Sleep

Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during sleep. Cerebrovascular reactivity (CVR) is an index of cerebral vessels' ability to respond to a vasoactive stimulus, such as increased CO2. We hypothesized that OSA alters CVR, expressed as a breath-hold index (BHI) defined as the rate of change in CBF or BOLD signal during a controlled breath-hold stimulus mimicking spontaneous apneas by being both hypercapnic and hypoxic. In 37 OSA and 23 matched non sleep apnea (NSA) subjects, we obtained high temporal resolution CBF and BOLD MRI data before, during, and between five consecutive BH stimuli of 24 s, each averaged to yield a single BHI value. Greater BHI was observed in OSA relative to NSA as derived from whole-brain CBF (78.6 ± 29.6 vs. 60.0 ± 20.0 mL/min2/100 g, P = 0.010) as well as from flow velocity in the superior sagittal sinus (0.48 ± 0.18 vs. 0.36 ± 0.10 cm/s2, P = 0.014). Similarly, BOLD-based BHI was greater in OSA in whole brain (0.19 ± 0.08 vs. 0.15 ± 0.03%/s, P = 0.009), gray matter (0.22 ± 0.09 vs. 0.17 ± 0.03%/s, P = 0.011), and white matter (0.14 ± 0.06 vs. 0.10 ± 0.02%/s, P = 0.010). The greater CVR is not currently understood but may represent a compensatory mechanism of the brain to maintain oxygen supply during intermittent apneas.

Download Full-text

Postoperative monitoring of children with obstructive sleep apnea syndrome

Orvosi Hetilap ◽

10.1556/oh.2014.29879 ◽

2014 ◽

Vol 155 (18) ◽

pp. 703-707 ◽

Cited By ~ 1

Author(s):

Pálma Benedek ◽

Gabriella Kiss ◽

Eszter Csábi ◽

Gábor Katona

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Obstructive Sleep Apnea Syndrome ◽

Preoperative Evaluation ◽

Sleep Apnea Syndrome ◽

Study Patient ◽

Severe Obstructive Sleep Apnea ◽

Obstructive Sleep ◽

Significant Difference ◽

Apnea Syndrome

Introduction: Treatment of pediatric obstructive sleep apnea syndrome is surgical. The incidence of postoperative respiratory complications in this population is 5–25%. Aim: The aim of the authors was to present the preoperative evaluation and monitoring procedure elaborated in Heim Pál Children Hospital, Budapest. Method: 142 patients were involved in the study. Patient history was obtained and physical examination was performed in all cases. Thereafter, polysomnography was carried out, the severity of the obstructive sleep apnea syndrome was determined, and the patients underwent tonsilloadenotomy. Results: 45 patients with mild, 50 patients with moderate and 47 patients with severe obstructive sleep apnea syndrome were diagnosed. There was no complication in patients with mild disease, while complications were observed in 6 patients in the moderate group and 24 patients in the severe group (desaturation, apnea, stridor, stop breathing) (p<0.000). In patients with severe obstructive sleep apnea syndrome, no significant difference was noted in preoperative apnoea-hypapnea index (p = 0.23) and in nadir oxygen saturation values (p = 0.73) between patients with and without complication. Conclusions: Patients with severe obstructive sleep apnea syndrome should be treated in hospital where pediatric intensive care unit is available. Orv. Hetil., 2014, 155(18), 703–707.

Download Full-text

Aerodynamics Analysis of the Impact of Nasal Surgery on Patients with Obstructive Sleep Apnea and Nasal Obstruction

ORL ◽

10.1159/000516243 ◽

2021 ◽

pp. 1-8

Author(s):

Lifeng Li ◽

Demin Han ◽

Hongrui Zang ◽

Nyall R. London

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Nasal Obstruction ◽

Upper Airway ◽

Apnea Hypopnea Index ◽

Nasal Surgery ◽

Subjective Sleep Quality ◽

Obstructive Sleep ◽

Significant Difference ◽

The Impact

Objective: The purpose of this study was to evaluate the effects of nasal surgery on airflow characteristics in patients with obstructive sleep apnea (OSA) by comparing the alterations of airflow characteristics within the nasal and palatopharyngeal cavities. Methods: Thirty patients with OSA and nasal obstruction who underwent nasal surgery were enrolled. A pre- and postoperative 3-dimensional model was constructed, and alterations of airflow characteristics were assessed using the method of computational fluid dynamics. The other subjective and objective clinical indices were also assessed. Results: By comparison with the preoperative value, all postoperative subjective symptoms statistically improved (p < 0.05), while the Apnea-Hypopnea Index (AHI) changed little (p = 0.492); the postoperative airflow velocity and pressure in both nasal and palatopharyngeal cavities, nasal and palatopharyngeal pressure differences, and total upper airway resistance statistically decreased (all p < 0.01). A significant difference was derived for correlation between the alteration of simulation metrics with subjective improvements (p < 0.05), except with the AHI (p > 0.05). Conclusion: Nasal surgery can decrease the total resistance of the upper airway and increase the nasal airflow volume and subjective sleep quality in patients with OSA and nasal obstruction. The altered airflow characteristics might contribute to the postoperative reduction of pharyngeal collapse in a subset of OSA patients.

Download Full-text

Effect of Cooling Irrigating Saline in Tongue Base Ablation in Obstructive Sleep Apnea

OTO Open ◽

10.1177/2473974x21989599 ◽

2021 ◽

Vol 5 (1) ◽

pp. 2473974X2198959

Author(s):

Ahmed Yassin Bahgat

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Controlled Trial ◽

Tongue Base ◽

Control Group ◽

University Hospitals ◽

Energy Field ◽

Obstructive Sleep ◽

Prospective Randomized Controlled Trial ◽

Significant Difference

Objective Plasma is formed by creating a high-density energy field within an electrically conductive fluid such as saline. Sometimes ablated bits of tissue get stuck between the electrodes of the wand, obstructing the suction channel. The purpose of this study is to investigate the effect of cooling the irrigating saline during ablation of the hypertrophied tongue base in patients with obstructive sleep apnea. Study Design Prospective randomized controlled trial. Setting An otorhinolaryngology department in Main University hospitals. Methods Sixty adult patients with obstructive sleep apnea and tongue base hypertrophy underwent tongue base ablation surgery. Patients were randomly divided into 2 groups of 30 patients each: cooled saline and room temperature saline. The Coblation wand used was the EVac 70 Xtra HP (Smith & Nephew). Results In this study, a significant difference in operative time (mean ± SD) was seen between groups: 21.2 ± 5.5 minutes in the cold group and 47 ± 9.5 minutes in the control group ( P = .001). The wands in the cold group did not obstruct, while all the wands in the control group were obstructed by tissue clogs with variable degrees, hence wasting more time to clean the wands’ tips. Conclusion Cooling the irrigating saline overcame the problem of wand clogs, and the wand tip did not occlude at all during the procedures, thus saving time lost in wand cleaning and demonstrating a faster and safer surgical procedure. Further studies are needed to identify the hemostatic effect of the cooled saline over the regular one.

Download Full-text

Comparisons of Thyroid Hormone, Intelligence, Attention, and Quality of Life in Children with Obstructive Sleep Apnea Hypopnea Syndrome before and after Endoscopic Adenoidectomy

BioMed Research International ◽

10.1155/2015/523716 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

Hui-Wei Feng ◽

Tao Jiang ◽

Hong-Ping Zhang ◽

Zhe Wang ◽

Hai-Ling Zhang ◽

...

Keyword(s):

Quality Of Life ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Thyroid Hormone ◽

Intelligence Quotient ◽

Obstructive Sleep ◽

Significant Difference ◽

Before And After ◽

Hypopnea Syndrome

Objective. The aim of this study was to compare the differences in thyroid hormone, intelligence, attention, and quality of life (QoL) of children with obstructive sleep apnea hypopnea syndrome (OSAHS) before and after endoscopic adenoidectomy.Method. A total of 35 OSAHS children (21 males and 14 females with a mean age of6.81±1.08years) were included in this study for analyzing the levels of thyroid hormone, intelligence, attention, and QoL. There were 22 children underwent endoscopic adenoidectomy with bilateral tonsillectomy (BT), while the other 13 children who underwent endoscopic adenoidectomy without bilateral tonsillectomy without BT.Results. Our results revealed no significant difference in serum free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) levels in OSAHS children before and after endoscopic adenoidectomy (allP>0.05). However, there were significant differences in full-scale intelligence quotient (FIQ) (92.45±5.88versus106.23±7.39,P<0.001), verbal intelligence quotient (VIQ) (94.17±15.01versus103.91±9.74,P=0.006), and performance intelligence quotient (PIQ) (94.12±11.04versus104.31±10.05,P=0.001), attention (98.48±8.74versus106.87±8.58,P<0.001), and total OSA-18 scores (87.62±17.15versus46.61±10.15,P<0.001) between before and after endoscopic adenoidectomy in OSAHS children.Conclusion. Our findings provided evidence that the intelligence, attention, and QoL of OSAHS children may be significantly improved after endoscopic adenoidectomy.

Download Full-text

Evaluation of Respiratory Resistance as a Predictor for Oral Appliance Treatment Response in Obstructive Sleep Apnea: A Pilot Study

Journal of Clinical Medicine ◽

10.3390/jcm10061255 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1255

Author(s):

Hiroyuki Ishiyama ◽

Masayuki Hideshima ◽

Shusuke Inukai ◽

Meiyo Tamaoka ◽

Akira Nishiyama ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Pilot Study ◽

Reduction Rate ◽

Oral Appliance ◽

Respiratory Resistance ◽

Obstructive Sleep ◽

Respiratory Event ◽

Significant Difference ◽

Treatment Responses

The aim of this study was to determine the utility of respiratory resistance as a predictor of oral appliance (OA) response in obstructive sleep apnea (OSA). Twenty-seven patients with OSA (mean respiratory event index (REI): 17.5 ± 6.5 events/h) were recruited. At baseline, the respiratory resistance (R20) was measured by impulse oscillometry (IOS) with a fitted nasal mask in the supine position, and cephalometric radiographs were obtained to analyze the pharyngeal airway space (SPAS: superior posterior airway space, MAS: middle airway space, IAS: inferior airway space). The R20 and radiographs after the OA treatment were evaluated, and the changes from the baseline were analyzed. A sleep test with OA was carried out using a portable device. The subjects were divided into Responders and Non-responders based on an REI improvement ≥ 50% from the baseline, or REI < 5 after treatment, and the R20 reduction rate between the two groups were compared. The subjects comprised 20 responders and 7 non-responders. The R20 reduction rate with OA in responders was significantly greater than it was in non-responders (14.4 ± 7.9 % versus 2.4 ± 9.8 %, p < 0.05). In responders, SPAS, MAS, and IAS were significantly widened and R20 was significantly decreased with OA (p < 0.05). There was no significant difference in non-responders (p > 0.05). A logistic multiple regression analysis showed that the R20 reduction rate was predictive for OA treatment responses (2% incremental odds ratio (OR), 24.5; 95% CI, 21.5–28.0; p = 0.018). This pilot study confirmed that respiratory resistance may have significant clinical utility in predicting OA treatment responses.

Download Full-text

Impact of adenotonsillectomy on the quality of life of patients operated on at the Hospital de Clínicas, Paraguay

International Journal of Medical and Surgical Sciences ◽

10.32457/ijmss.v8i4.1650 ◽

2021 ◽

pp. 1-7

Author(s):

Carlos Mena Canata ◽

Rebeca Noemí Ruiz Vallejos

Keyword(s):

Quality Of Life ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Rural Areas ◽

Urban Areas ◽

Obstructive Sleep ◽

Significant Difference ◽

Before And After ◽

The Impact

The objective of this study is to determine the impact of adenotonsillectomy on the quality of life of postoperative patients.The study is observational, cross-sectional, and retrospective. The files of all postoperative adenotonsillectomy patients in Otorhinolaryngology Service, Hospital de Clínicas, San Lorenzo Paraguay. The Obstructive sleep apnea – 18 questionnaire (OSA 18) was applied, asking patients about symptoms before and after surgery. An effective sample of 143 postoperative patients was obtained. The average age was 6.05 ± 2.08 years, 55.10% (81) were male and 44.89% (66) were female, 65.30% (96) were from urban areas and 34.69% (51) from the rural areas. The t test was performed for means of two paired samples, comparing the results of the Obstructive sleep apnea – 18 questionnaire surveys before and after surgery which presented a significant difference (p <0.05) with a tendency to improve the quality of life after surgery. It has been shown that there is a significant difference, a considerable improvement in the quality of life of patients after adenotonsillectomy.

Download Full-text

Validation of the Spanish Version of the STOP-Bang Questionnaire: Usefulness as a Screening Tool for Obstructive Sleep Apnea in Adults

Ear Nose & Throat Journal ◽

10.1177/0145561320932334 ◽

2020 ◽

pp. 014556132093233

Author(s):

Beatriz Delgado-Vargas ◽

Leticia Acle-Cervera ◽

Gianmarco Narciso López

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Screening Tool ◽

Sleep Apnea Syndrome ◽

Spanish Version ◽

Obstructive Sleep ◽

Significant Difference ◽

Good Internal Consistency ◽

The Mean ◽

Apnea Syndrome

Objectives: Obstructive sleep apnea syndrome (OSAS) is an increasing health problem, the diagnosis of which is generally delayed due to long waiting lists for the tests used to identify it. Therefore, tools that help on classifying patients at higher risk of suffering this syndrome have been developed. Methods: One hundred ninety-three consecutive patients, with and without OSAS, filled in the Spanish version of the STOP-Bang questionnaire in Hospital Universitario de Torrejón (Spain). Polysomnographies were performed to diagnose the presence and severity of the OSAS. Statistics analysis of the demographic characteristics of the sample and the questionnaire results was performed. Results: Most patients were male (73%) and the mean age was 50.4 years (ranging from 19-77 years). Cronbach α coefficient in the sample was 0.8072. A statistically significant difference was noted in the questionnaire scores between patients with OSAS and those without the syndrome. Conclusions: The Spanish version of the STOP-Bang questionnaire possess a good internal consistency that allows us to rely on it as a screening tool for patients with OSAS. In our sample, a difference in the questionnaire score was appreciated between patients with and without the syndrome, which strongly supports the utility of the questionnaire for its purpose.

Download Full-text

Speech Outcomes after Tonsillectomy in Patients with Known Velopharyngeal Insufficiency

International Journal of Otolaryngology ◽

10.1155/2012/912767 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 7

Author(s):

L. M. Paulson ◽

C. J. MacArthur ◽

K. B. Beaulieu ◽

J. H. Brockman ◽

H. A. Milczuk

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Cleft Palate ◽

Speech Intelligibility ◽

Velopharyngeal Insufficiency ◽

Speech Evaluation ◽

Obstructive Sleep ◽

Significant Difference ◽

Before And After ◽

History Of

Introduction. Controversy exists over whether tonsillectomy will affect speech in patients with known velopharyngeal insufficiency (VPI), particularly in those with cleft palate.Methods. All patients seen at the OHSU Doernbecher Children's Hospital VPI clinic between 1997 and 2010 with VPI who underwent tonsillectomy were reviewed. Speech parameters were assessed before and after tonsillectomy. Wilcoxon rank-sum testing was used to evaluate for significance.Results. A total of 46 patients with VPI underwent tonsillectomy during this period. Twenty-three had pre- and postoperative speech evaluation sufficient for analysis. The majority (87%) had a history of cleft palate. Indications for tonsillectomy included obstructive sleep apnea in 11 (48%) and staged tonsillectomy prior to pharyngoplasty in 10 (43%). There was no significant difference between pre- and postoperative speech intelligibility or velopharyngeal competency in this population.Conclusion. In this study, tonsillectomy in patients with VPI did not significantly alter speech intelligibility or velopharyngeal competence.

Download Full-text