Clinical, anthropometric and upper airway anatomic characteristics of obese patients with obstructive sleep apnea syndrome

Perceptual, Aerodynamic and Acoustic Evaluation of Vocal Characteristics in Subjects With Obesity

INTRODUCTION

Obesity has tripled since 1975 and affects health across many domains. Increasing body mass index increases the risk to the obese subject of many non-communicable diseases. The study evaluated the perceptive, aerodynamic, and acoustic parameters that characterize the voice of the obese population.

METHODOLOGY

Eighty adult subjects (40 participants in each obese and control group) aged 18-50 years were enrolled. The perceptual voice analysis was performed using the Consensus Auditory Perceptual Evaluation of Voice. The aerodynamic and acoustic voice analyses were performed using the MIR Spiro lab instrument and Doctor's Speech software. A digital stopwatch was also used to measure maximum phonation time.

RESULTS

Statistical analysis revealed a significant difference (P-value <0.05 and t value >2) between two groups on acoustic parameters, specifically Normalized noise energy and fundamental frequency tremor (F0 tremor). Normalized noise energy and fundamental frequency tremor were greater in the obese group. Moreover, maximum phonation time and expiratory reserve volume were significantly reduced in the obese group.

DISCUSSION AND CONCLUSION

Results of the present study showed poor voice quality and reduced expiratory reserve volume in obese individuals. This could be credited to the adverse effects of accrued adipose on the functioning of the laryngeal and respiratory systems. Increasing body mass index escalates the risk to the obese subjects of many non-communicable diseases.

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

A pilot observation using ultrasonography and vowel articulation to investigate the influence of suspected obstructive sleep apnea on upper airway

Failure to employ suitable measures before administering full anesthesia to patients with obstructive sleep apnea (OSA) who are undergoing surgery may lead to developing complications after surgery. Therefore, it is very important to screen OSA before performing a surgery, which is currently done by subjective questionnaires such as STOP-Bang, Berlin scores. These questionnaires have 10-36% specificity in detecting sleep apnea, along with no information given on anatomy of upper airway, which is important for intubation. To address these challenges, we performed a pilot study to understand the utility of ultrasonography and vowel articulation in screening OSA. Our objective was to investigate the influence of OSA risk factors in vowel articulation through ultrasonography and acoustic features analysis. To accomplish this, we recruited 18 individuals with no risk of OSA and 13 individuals with high risk of OSA and asked them to utter vowels, such as /a/ (as in "Sah"), /e/ (as in "See"). An expert ultra-sonographer measured the parasagittal anterior-posterior (PAP) and transverse diameter of the upper airway. From the recorded vowel sounds, we extracted 106 features, including power, pitch, formant, and Mel frequency cepstral coefficients (MFCC). We analyzed the variation of the PAP diameters and vowel features from "See: /i/" to "Sah /a/" between control and OSA groups by two-way repeated measures ANOVA. We found that, there was a variation of upper airway diameter from "See" to "Sah" was significantly smaller in OSA group than control group (OSA: ∆12.8 ± 5.3 mm vs. control: ∆22.5 ± 3.9 mm OSA, p < 0.01). Moreover, we found several vowel features showed the exact same or opposite trend as PAP diameter variation, which led us to build a machine learning model to estimate PAP diameter from vowel features. We found a correlation coefficient of 0.75 between the estimated and measured PAP diameter after applying four estimation models and combining their output with a random forest model, which showed the feasibility of using acoustic features of vowel sounds to monitor upper airway diameter. Overall, this study has proven the concept that ultrasonography and vowel sounds analysis may be useful as an easily accessible imaging tool of upper airway.

Correlation of Medical Comorbidities and Upper Airway Measurements among Dental Patients at Risk of Developing Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a partial or total upper airway collapse resulting in sleep-breathing disturbances. There are many medical comorbidities associated with OSA; hence, this study is important as the prevalence of patients with medical comorbidities associated with OSA is increasing. The study aimed to correlate medical comorbidities and OSA symptoms of the patients along with their upper airway dimensions using Cone Beam Computed Tomography (CBCT) scans to identify patients at risk of developing OSA. This cross-sectional study included patients who had CBCT imaging taken between 2014 and 2020. A questionnaire was used to gather information on patients’ medical history and OSA symptoms. The upper airway dimensions of the CBCT scans were evaluated before logistic regression and Fisher’s exact test were carried out to determine the relationships between the variables. p ≤ 0.05 was considered statistically significant. Logistic regression revealed an association of longer length (p = 0.016), smaller total volume (p = 0.017) and width (p = 0.010) of upper airways with hypertension. Furthermore, loud snoring was seen in patients with hypertension, heart disease and obesity whereas difficulty concentrating during the day was present in subjects with deviated nasal septum, tonsillitis and depression. For upper airway dimensions, a smaller average volume was associated with loud snoring (p = 0.037), difficulty concentrating during the day (p = 0.002) and mood changes (p = 0.036). A larger anterior-posterior dimension was also associated with excessive daytime sleepiness (p = 0.042), difficulty concentrating during the day (p < 0.001) and mood changes (p = 0.009). Longer airway length was additionally found to be associated with loud snoring (p = 0.021). CBCT taken for dental investigations could be correlated with patients’ medical history and OSA symptoms to screen patients at risk of OSA.

Acoustic parameter changes after bariatric surgery

OBJECTIVE

To investigate the acoustic parameter changes after weight loss in bariatric surgery patients.

MATERIALS AND METHODS

This prospective, longitudinal study was conducted with 15 patients with planned bariatric surgery, who were evaluated pre-operatively and at 6 months post-operatively. Fundamental frequency (F0), Formant frequency (F1, F2, F3, and F4), Frequency perturbation (Jitter), Amplitude perturbation (Shimmer) and Noise-to-Harmonics Ratio (NHR) parameters were evaluated for /a/, /e/, /i/, /o/, and /u/ vowels. Changes in the acoustic analysis parameters for each vowel were compared. The study group was separated into two groups according to whether the Mallampati score had not changed (Group 1) or had decreased (Group 2) and changes in the formant frequencies were compared between these groups.

RESULTS

A total of 15 patients with a median age of 40 ± 11 years completed the study. The median weight of the patients was 122 ± 14 kg pre-operatively and 80 ± 15 kg, post-operatively. BMI declined from 46 ± 4 to 31 ± 5 kg/m². The Mallampati score decreased by one point in six patients and remained stable in nine. Of the acoustic voice analysis parameters of vowels, in general, fundamental frequency tended to decrease, and shimmer and jitter values tended to increase. Some of the formant frequencies were specifically affected by the weight loss and this showed statistical significance between Group 1 and Group 2.

CONCLUSION

The present study reveals that some specific voice characteristics might be affected by successful weight loss after bariatric surgery.HighlightsObesity reduces the size of the pharyngeal lumen at different levels.The supralaryngeal vocal tract size and configuration is a determinative factor in the features of the voice.Changes in the length and shape of the vocal tract, or height and position of the tongue can result in changes especially in formant frequencies in acoustic analysis.

Ultrasonographic Measurement of Pharyngeal-Airway Dimension and Its Relationship with Obesity and Sleep-Disordered Breathing

Previous studies based on magnetic resonance imaging (MRI) or computed tomography (CT) have shown that pharyngeal airway diameter during wakefulness is different between healthy controls and patients with a high risk of sleep-disordered breathing (SDB). However, MRI and CT are expensive and not easily accessible. Conversely, ultrasonography is more accessible and is getting more attention as a point-of-care technology to assess physiologic systems, such as the pharynx. Thus, we aimed to evaluate the feasibility of ultrasonography in estimating the pharyngeal airway dimension. To evaluate the pharyngeal airway with ultrasonography, we measured the parasagittal anterior-posterior (PAP) diameter and transverse diameter. For PAP diameter measurements, the transducer probe was placed in a submandibular lateral oblique position, with its superior margin abutting the angle of the left mandible. For the transverse measurement, the ultrasound probe was positioned in a submandibular location, in a near-coronal plane, just above the hyoid bone so that the tongue could be seen in cross-section. The diameter measurements were performed manually by two technicians. The reliability of these measurements was assessed by the intra-class correlation coefficient (ICC). To validate our measurements, we compared the measured PAP diameter with the average pharyngeal airway cross-sectional area from vellum to glottis measured by acoustic pharyngometry. Furthermore, we compared the influence of obesity and SDB in the measured pharyngeal diameters. Eighteen controls and 13 individuals with a high risk of SDB participated in this study. Reliability analysis of the PAP measurements yielded an ICC of 0.97 (95% confidence interval: 0.94-0.98). Furthermore, measured PAP diameters were significantly correlated with the pharyngeal airway cross-sectional area (r = 0.76, p < 0.01). Moreover, obesity and SDB were associated with decreases in PAP diameter. Our study shows that ultrasonography measurement of the PAP diameter may provide a quantitative assessment of the pharyngeal airway and may be useful for screening of SDB.

Three-dimensional assessment of pharyngeal volume and cross-sectional area in Chinese infants and preschool children

OBJECTIVE

The cross-sectional area (CSA) and the volume of the pharyngeal airway normative reference data aren't established, although they are closely associated with the pathogenesis of obstructive sleep apnea syndrome (OSAS) in infants and preschool children. Our objective is to measure the cross-sectional area (CSA) and volume of pharyngeal airway subregions and investigate the effects of age and sex in infants and preschool children using computerized tomography (CT).

METHODS

After applying strict inclusion criteria, 57 infants and preschool children (27 females, 30 males) aged from 1 day to 72 months who underwent maxillofacial CT scans due to trauma were selected. The sample was stratified into three age groups (1 day-24 months, 25-48 months, and 49-72 months). The CSA and the volume of the naso-, palato-, glosso-, and laryngopharyngeal airway were calculated using a 3-dimensional image processing software. Linear regression analysis was performed to express the effect of age, height, and weight. One-way analysis of covariance with height as a covariate was used to analyze the statistical significance of the difference between males and females within each age group.

RESULTS

The CSA and volume of all pharyngeal airway subregions increased with age, height, and weight (P < 0.05) in children under 6 years old. Multiple linear regression analysis showed an age effect, identified in all measurements (P < 0.001), whereas no height or weight effect were found. There were no differences in any measurements between males and females within each age group.

CONCLUSION

The normative reference data of CSA and volume of pharyngeal airway subregions were established after applying strict inclusion and exclusion criteria in infants and preschool children. Results may be useful in screening and assist in the timely diagnosis and management of pediatric OSAS.

Association between Loss of Sleep-specific Waves and Age, Sleep Efficiency, Body Mass Index, and Apnea-Hypopnea Index in Human N3 Sleep

Sleep spindles (SS) and K-complexes (KC) play important roles in human sleep. It has been reported that age, body mass index (BMI), and apnea-hypopnea index (AHI) may influence the number of SS or KC in non-rapid-eye-movement (NREM) 2 (N2) sleep. In this study, we investigated whether the loss of SS or KC is associated with the above factors in NREM 3 (N3) sleep. A total of 152 cases were enrolled from 2013 to 2017. The correlations between the number of SS or KC in N3 sleep and participants’ characteristics were analyzed using Spearman rank correlation. Chi-squared test was used to assess the effects of age, sleep efficiency, and BMI on the loss of N3 sleep, N3 spindle and N3 KC. Our results showed that there were negative correlations between the number of SS in N3 sleep with age, BMI, and AHI (P < 0.001), and similar trends were found for KC as well. The loss of SS and KC in N3 sleep was related with age, BMI, and AHI (P < 0.01), as was the loss of N3 sleep (P < 0.01). However, sleep efficiency was not related with the loss of N3 sleep, SS and KC in N3 sleep (P > 0.05). The present study supports that age, BMI, and AHI are all influencing factors of SS and KC loss in human N3 sleep, but sleep efficiency was not an influencing factor in the loss of N3 sleep and the loss of SS and KC in N3 sleep.

Craniofacial and upper airway profile assessment in North Indian patients with obstructive sleep apnea

Introduction

Upper airway imaging can often identify the anatomical risk factors for sleep apnea and provide sufficient insight into the pathophysiology of obstructive sleep apnea (OSA).

Materials and Methods

We conducted a case-control, observational study at a tertiary care hospital in North India. All cases and controls underwent lateral cephalometry and magnetic resonance imaging (MRI) for craniofacial and upper airway evaluation. Only the cases had polysomnography testing for confirmation of OSA and assessing the severity of disease.

Results

Forty cases and an equal number of matched controls were recruited. On X-ray cephalometry, it was observed that the cases had a significantly larger hyoid mandibular distance and soft palate length; and shorter mandibular length. The MRI cephalometric variables were significantly different, the soft palate length, tongue length, and submental fat were longer while the retropalatal and retroglossal distance was shorter amongst the cases. A statistically significant positive correlation was found between the cephalometric parameters and the indices of severity of OSA. An increased hyoid mandibular distance and soft palate length, and a decrease in the lower anterior facial height were found to be predictive of severe OSA (Apnea-Hypopnea Index ->30/h). An increased hyoid mandibular distance, soft palate length, and the tongue length and a reduced mandibular length were found to be predictive of need for continuous positive airway pressure (CPAP) pressures of ≥15 cm H₂O. There were significant differences between the cephalometric parameters of the Indian OSA patients and patients from other ethnicities reported in the literature.

Conclusions

OSA patients had a significantly smaller upper airway compared to age-, sex-, and body mass index-matched controls and cephalometric variables correlated with the indices of OSA severity. The cephalometric assessment was also predictive of severe OSA and the need for higher pressures of CPAP. This indicates the important role of upper airway anatomy in the pathogenesis of OSA.

Maximum Phonation Time in People with Obesity Not Submitted or Submitted to Bariatric Surgery

BACKGROUND

Our aim in this investigation was to evaluate maximum phonation time in people with obesity not submitted to surgery and in people with obesity submitted to bariatric surgery and compare it with maximum phonation time of healthy volunteers. The hypothesis was that the reduced maximum phonation time in people with obesity would be corrected after surgery due to weight loss.

METHOD

Maximum phonation time was evaluated in 52 class III patients (Group A), 62 class III patients who were treated by surgery 3 to 115 months before (Group B), 20 controls (Group C), and 15 class III patients whose maximum phonation time was evaluated before and two to six months after surgery (Group D). Maximum phonation time was measured in the sitting position with the vowels /A/, /I/, and /U/.

RESULTS

Maximal phonation time was shorter in groups A and B compared with that of controls. There was an increase in maximal phonation time after surgery (Group B); however, the difference was not significant when compared with that in group A. In group D, maximal phonation time for /A/ increased after the surgery. In group A, there was a negative correlation between maximal phonation time and weight or body mass index and a positive correlation between maximal phonation time and height. In group B, there was an almost significant positive relation between percentage of weight loss and maximal phonation time for /A/ (p=0.08) and /I/ (p=0.07). Mean values of spirometry testing (FEV₁, FVC, and FEV₁/FVC) in people with obesity (groups A and B), expressed as percentage of the predicted value, were within the normal range.

CONCLUSION

Compared with healthy controls, maximal phonation time is shorter in people with obesity, with a tendency to increase after bariatric surgery, as a possible consequence of weight loss.

Evaluation of the oropharynx in class I and II skeletal patterns by CBCT

PURPOSE

This study aimed to evaluate the dimensions of the oropharynx and its shape in the minimum cross-sectional area, in individuals with Class I and Class II skeletal patterns, using three-dimensional CBCT images.

METHODS

Forty-two cone-beam computed tomography images of grown individuals were evaluated. The images were divided according to the patient's skeletal patterns. The dimensions of the oropharyngeal airway space were determined using the Dolphin Imaging software.

RESULTS

The volume and the minimum cross-sectional area were greater in patients with a Class I skeletal pattern, with a median difference of 5379 mm³ and 86.8 mm², respectively. The anteroposterior and lateral diameters in the minimum cross-sectional area were also higher in Class I individuals (2.3 and 6.0 mm, respectively), but the ratio between them was not different.

CONCLUSIONS

The volume and the minimum cross-sectional area of the oropharynx, as well as the anteroposterior and lateral diameters, are lower in individuals with a class II skeletal pattern than in individuals with a class I skeletal pattern. There was no difference in the shape of the oropharynx in healthy individuals with different skeletal patterns.

Assessment by airway ellipticity on cine-MRI to differentiate severe obstructive sleep apnea

INTRODUCTION

The severity of obstructive sleep apnea (OSA) is assessed by the apnea-hypopnea index (AHI) determined from polysomnography (PSG). However, PSG requires a specialized facility with well-trained specialists and takes overnight. Therefore, simple tools, which could distinguish severe OSA, have been needed before performing PSG.

OBJECTIVES

We propose the new index using cine-MRI as a screening test to differentiate severe OSA patients, who would need PSG and proper treatment.

METHODS

Thirty-six patients with suspected OSA (mean age 54.6 y, mean AHI 52.6 events/h, 33 males) underwent airway cine-MRI at the fourth cervical vertebra level during 30 s of free breathing and PSG. The minimum airway ellipticity (AE) in 30 s duration was measured, and was defined as the severity of OSA. Patients were divided into severe OSA, not-severe OSA, and normal groups, according to PSG results. The comparison of AE between any two of the three groups was performed by Wilcoxon rank-sum test. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off of AE for identifying severe OSA patients.

RESULTS

The minimum AE for severe OSA was significantly lower than that for not-severe OSA and normal (severe, 0.17 ± 0.16; not severe, 0.31 ± 0.17; normal, 0.38 ± 0.19, P < .05). ROC analysis revealed that the optimal cutoff of the minimum AE 0.21 identified severe OSA patients, with an area under the curve of 0.75, 68% sensitivity, and 83% specificity.

CONCLUSION

AE is a feasible quantitative index, and a promising screening test for detecting severe OSA patients.

Clinicals And Upper Airway Characteristics in Obese Children with Obstructive Sleep Apnea

Introduction

Obesity is a factor that is strongly related to the occurrence of obstructive sleep apnea (OSA) in adults, although this association remains controversial for children.

Objective

The aim of this study was to compare the clinical and upper airway charactheristics, obtained by questionnaires, physical examination and laboratory tests, among obese children with and without OSA.

Method

This was aprospective cohort study. 44 obese children (body mass index above the 95th percentile) were included in the study. Questionnaires, physical examination of the upper airway, nasofibrolaryngoscopy, polysomnography, and laboratory allergic tests were performed.

Results

There were 22 male patients (50%), and the mean age was 7.6±2.5 years. OSA was present in 19 (43%) patients. There were no statistically significant differences between the groups with and without OSA, in relation to clinical or laboratory allergic parameters. For the upper airway assessments, hypertrophy of the pharyngeal (p=0.001) and palatine (p=0.049) tonsils were the only parameters associated with OSA, and a modified Mallampati index of class III/IV also demonstrated a tendency towards being statistically associated with OSA (p=0.081). Moreover, these findings were confirmed to be factors associated with OSA in this group of children according to a logistic regression analysis.

Conclusions

The occurrence rate of OSA in this obese pediatric population was high. Adenotonsillar hypertrophy and a modified Mallampati index of class III/IV were the factors associated with OSA.

Obstructive sleep apnoea pathogenesis from mild to severe: Is it all the same?

Obstructive sleep apnoea (OSA) is a common disorder caused by not only an impaired upper airway anatomy (i.e. anatomically narrow/collapsible airway), but also by several non-anatomical factors. In this review, we summarise what is known about how each of the pathological factors that cause OSA vary according to disease severity as measured by the apnoea-hypopnoea index. Our synthesis of the available literature indicates that most of the key factors that cause OSA vary with disease severity. However, there is substantial heterogeneity such that the relative contribution of each of these traits varies both between patients and within different severities of disease. These differences likely contribute to variable efficacy of many non-continuous positive airway pressure treatments and inconsistencies in responses with regard to different OSA severities at baseline.

Three-dimensional imaging of the upper airway anatomy in obstructive sleep apnea: a systematic review

INTRODUCTION

The pathogenesis of upper airway collapse in people with obstructive sleep apnea (OSA) is not fully understood. The aim of this study was to systematically review the literature in order to assess the most relevant anatomical characteristics of the upper airway related to the pathogenesis of OSA by analyzing the three-dimensional upper airway anatomy.

METHOD

A PICO (population/patient, intervention, comparison, outcome) search strategy, focusing on the upper airway anatomy of people with OSA, was conducted using the following databases: MEDLINE (PubMed), Excerpta Medica database (EMBASE), Web of Science, and Cochrane Library. The studies in which three-dimensional images were made from the participants who were awake and in the supine position during quiet breathing were selected in this systematic review.

RESULTS

Of the 758 unique retrieved studies, eight fulfilled the criteria for this systematic review. The minimum cross-sectional area of the upper airways of people with OSA, which is influenced by many factors such as hard and soft tissues surrounding the upper airway, was significantly smaller than that of those without OSA.

CONCLUSION

Within the limitation of the selected studies, this systematic review suggested that a small minimum cross-sectional area is the most relevant anatomical characteristic of the upper airway related to the pathogenesis of OSA.

Cone-beam CT analysis of patients with obstructive sleep apnea compared to normal controls

Purpose

To evaluate the upper airway dimensions of obstructive sleep apnea (OSA) and control subjects using a cone-beam computed tomography (CBCT) unit commonly applied in clinical practice in order to assess airway dimensions in the same fashion as that routinely employed in a clinical setting.

Materials and Methods

This was a retrospective analysis utilizing existing CBCT scans to evaluate the dimensions of the upper airway in OSA and control subjects. The CBCT data of sixteen OSA and sixteen control subjects were compared. The average area, average volume, total volume, and total length of the upper airway were computed. Width and anterior-posterior (AP) measurements were obtained on the smallest axial slice.

Results

OSA subjects had a significantly smaller average airway area, average airway volume, total airway volume, and mean airway width. OSA subjects had a significantly larger airway length measurement. The mean A-P distance was not significantly different between groups.

Conclusion

OSA subjects have a smaller upper airway compared to controls with the exception of airway length. The lack of a significant difference in the mean A-P distance may indicate that patient position during imaging (upright vs. supine) can affect this measurement. Comparison of this study with a future prospective study design will allow for validation of these results.

Correlation of cephalometric and anthropometric measures with obstructive sleep apnea severity

Introduction: Patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) often have associated changes in craniofacial morphology and distribution of body fat, either alone or in combination.

Aim: To correlate cephalometric and anthropometric measures with OSAHS severity by using the apnea-hypopnea index (AHI).

Method: A retrospective cephalometry study of 93 patients with OSAHS was conducted from July 2010 to July 2012. The following measurements were evaluated: body mass index (BMI), neck circumference (NC), waist circumference (WC), hip circumference (HC), the angles formed by the cranial base and the maxilla (SNA) and the mandible (SNB), the difference between SNA and SNB (ANB), the distance from the mandibular plane to the hyoid bone (MP-H), the space between the base of the tongue and the posterior pharyngeal wall (PAS), and the distance between the posterior nasal spine and the tip of the uvula (PNS-P). Means, standard deviations, and Pearson's correlation coefficients were calculated and analyzed.

Results: AHI correlated significantly with BMI (r = 0.207, p = 0.047), NC (r = 0.365, p = 0.000), WC (r = 0.337, p = 0.001), PNS-P (r = 0.282, p = 0.006), and MP-H (r = 0.235, p = 0.023).

Conclusion: Anthropometric measurements (BMI, NC, and WC) and cephalometric measurements (MP-H and PNS-P) can be used as predictors of OSAHS severity.

Sex-specific characteristics of anthropometry in patients with obstructive sleep apnea: neck circumference and waist-hip ratio

OBJECTIVE

This study aimed to investigate the sex-specific effects of anthropometric profiles on the occurrence and severity of obstructive sleep apnea (OSA).

METHODS

We evaluated 151 patients with suspected OSA undergoing polysomnography and anthropometric measurements such as body mass index (BMI), neck and waist circumference (NC and WC), and waist-hip ratio (WHR).

RESULTS

In men, NC (P = .006), WC (P = .035), and WHR (P = .003) were significantly increased in OSA and all were significantly correlated with apnea hypopnea index (AHI). However, in female OSA patients, BMI (P = .05), WC (P = .008), and WHR (P = .001) were elevated, but only WHR was significantly correlated with AHI. Correlation analyses showed significant correlations between NC and other anthropometric indexes in men but not in women. The receiver operating characteristic curves revealed that NC and WHR in men, and WHR in women, were significant in both model I (AHI > or = 5) and model 2 (AHI > or = 15).

CONCLUSION

Waist-hip ratio is the most reliable correlate of OSA in both sexes. Neck circumference is an independent risk factor for male, but not for female, OSA patients. These different aspects of obesity may contribute to the pathogenesis of OSA and provide helpful guidance in the screening of OSA.

Current knowledge and impressions of speech-language pathologists of the swallow of persons who are obese

PURPOSE

The overall goal of this study was to provide insight on the topic of dysphagia in the obese population. More specifically, the purpose of this study was to obtain preliminary descriptive data on the knowledge and impressions of speech-language pathologists (SLPs) working in the field of dysphagia on the swallow of persons who are obese.

METHODS

One hundred seventy-seven SLPs responded to a web-based survey that was posted on two popular listserves that serve the dysphagia community.

RESULTS

Descriptive results showed that nearly all SLPs have assessed and treated patients who are obese for dysphagia, that there is little consensus as to how the obese swallow compares to the normal swallow, and that there is a consensus that dysphagia observed in the obese population is most likely related to other concomitant disorders.

CONCLUSIONS

Results provide preliminary insight into the knowledge and impressions of SLPs working with dysphagia and highlight the need for future research to determine (1) if there is an increased incidence of dysphagia in the obese population, and (2) if obesity itself constitutes a risk factor for dysphagia or if any dysphagia observed in this population is related to other comorbidities.

Velopharyngeal anatomy in patients with obstructive sleep apnea versus normal subjects

PURPOSE

Obesity can cause disturbed breathing and is one of the most significant risk factors for obstructive sleep apnea (OSA). However, the anatomic basis of OSA and, specifically, the anatomic mechanisms leading from obesity to OSA are still unclear. We examined the anatomic features of the velopharynx in patients with OSA versus those without in correlation with the body mass index (BMI), age, history of snoring, and OSA severity and re-evaluated the contribution of adding a frontal view to the cephalometric analysis of patients with OSA.

MATERIALS AND METHODS

Lateral and frontal cephalometric measurements were taken to assess the velopharyngeal anatomic features of 306 men with various degrees of OSA and 64 men without OSA and without a history of snoring. The demographic, polysomnographic, and cephalometric features were compared.

RESULTS

The patients with OSA had an increased pharyngeal length, thicker velum, a thicker posterior pharyngeal wall, a reduced pharyngeal width, and a consequent narrowing of the pharyngeal lumen. As the BMI increased, the OSA severity increased. Also, in parallel, the velum and posterior pharyngeal wall thickness increased and the pharyngeal width decreased. Three types of velopharyngeal narrowing, with an increased occurrence in severe degrees of OSA, were identified: bottle shape, hourglass shape, and tube shape. These aerodynamically unfavorable changes might cause increased upper airway resistance, explaining the development of both OSA and hypoventilation syndrome in obese patients.

CONCLUSIONS

Velopharyngeal thickening and lumen narrowing were shown to be features of obese men with OSA. However, these features developed only above a threshold BMI value. The combination of frontal and lateral cephalometry is important for comprehensive evaluation of patients with OSA.

Acoustic, perceptual and aerodynamic voice evaluation in an obese population

Objective:

To investigate perceptual, acoustic and aerodynamic voice parameters in obese individuals.

Methods:

Twenty obese and 20 normal-weight volunteers underwent voice evaluation by laryngoscopy, acoustic analysis, aerodynamic measurement and perceptual analysis (using the grade-roughness-breathiness-asthenia-strain (‘GRBAS') scale and the Voice Handicap Index 10 scale). Data from both subject groups were compared.

Results:

No difference was found in acoustic analysis parameters between the two groups (p > 0.05). Maximum phonation time in the obese group (mean ± standard deviation, 19.6 ± 4.9 seconds) was significantly shorter than in controls (26.4 ± 4.1 seconds) (p < 0.001), although the s/z ratio was very similar between the two groups. In the obese and control groups, the mean ± standard deviation grade-roughness-breathiness-asthenia-strain scores were 1 ± 1.3 and 0.2 ± 0.6 (p = 0.002) and the mean ± standard deviation Voice Handicap Index 10 scores were 0.5 ± 1.2 and 1.2 ± 1.7 (p = 0.27), respectively.

Conclusion:

Obese individuals had poorer vocal quality as judged by the grade-roughness-breathiness-asthenia-strain scale, and reduced maximum phonation time. However, there was no change in voice quality as assessed by acoustic analysis and Vocal Handicap Index 10 score, compared with controls.

Gender-specific anthropometric markers of adiposity, metabolic syndrome and visceral adiposity index (VAI) in patients with obstructive sleep apnea

Obstructive sleep apnea often coexists with visceral adiposity and metabolic syndrome. In this study, we analysed gender-related differences in anthropometrics according to sleep apnea severity and metabolic abnormalities. In addition, the visceral adiposity index, a recently introduced marker of cardiometabolic risk, was analysed. Consecutive subjects with suspected obstructive sleep apnea (n = 528, 423 males, mean age ± standard deviation: 51.3 ± 12.8 years, body mass index: 31.0 ± 6.2 kg m(-2) ) were studied by full polysomnography (apnea-hypopnea index 43.4 ± 27.6 h(-1) ). Variables of general and visceral adiposity were measured (body mass index, neck, waist and hip circumferences, waist-to-hip ratio). The visceral adiposity index was calculated, and metabolic syndrome was assessed (NCEP-ATP III criteria). The sample included controls (apnea-hypopnea index <10 h(-1) , n = 55), and patients with mild-moderate (apnea-hypopnea index 10-30 h(-1) , n = 144) and severe sleep apnea (apnea-hypopnea index >30 h(-1) , n = 329). When anthropometric variables were entered in stepwise multiple regression, body mass index, waist circumference and diagnosis of metabolic syndrome were associated with the apnea-hypopnea index in men (adjusted R(2)  = 0.308); by contrast, only hip circumference and height-normalized neck circumference were associated with sleep apnea severity in women (adjusted R(2)  = 0.339). These results changed little in patients without metabolic syndrome; conversely, waist circumference was the only correlate of apnea-hypopnea index in men and women with metabolic syndrome. The visceral adiposity index increased with insulin resistance, but did not predict sleep apnea severity. These data suggest gender-related interactions between obstructive sleep apnea, obesity and metabolic abnormalities. The visceral adiposity index was a good marker of metabolic syndrome, but not of obstructive sleep apnea.

Magnetic resonance imaging in the evaluation of anatomical risk factors for pediatric obstructive sleep apnoea-hypopnoea: a pilot study

OBJECTIVE

Aim of our study was to identify anatomical risk factors involved in the development of pediatric OSAHS through a MRI-based case-control pilot study.

METHODS

MRI exams of the head and neck of 40 children affected by OSAHS were retrospectively evaluated. 25 indices referring to the air lumen, soft tissues and craniofacial skeleton were measured. Subsequently, the same process of measurement of indices was performed on MRI exams of 40 controls. For each index, then, we calculated in both groups mean, standard deviation, standard error and t value. Comparing the two series we finally calculated the degree of significance of each difference between children with OSAHS and controls through the Student's t-test.

RESULTS

Besides the expected and previously described differences of minimum retropharyngeal cross-sectional area (CSA), nasopharyngeal airway, combined upper airway volume, tonsillar and adenoid cross-sectional and volumetric indices, we found a higher midsagittal CSA of the soft palate and lower position of the hyoid bone, SNB angle and mandibular volume.

CONCLUSIONS

Results from our study population, certainly limited in terms of number of patients and considered age range, showed that not only adeno-tonsillar hypertrophy is important in determining the clinical syndrome: soft palate enlargement and certain skeletal pattern can even assume greater importance in the genesis and in the progression of the obstruction. MRI proved to be an accurate technique in the evaluation of the prevalent risk factor in children affected by OSAHS, leading to the most appropriate surgical approach.

Obesity and craniofacial structure as risk factors for obstructive sleep apnoea: impact of ethnicity

OSA is the result of structural and functional abnormalities that promote the repetitive collapse of the upper airway during sleep. This common disorder is estimated to occur in approximately 4% of men and 2% of women, with prevalence studies from North America, Australia, Europe and Asia indicating that occurrence is relatively similar across the globe. Anatomical factors, such as obesity and craniofacial morphology, are key determinants of the predisposition to airway collapse; however, their relative importance for OSA risk likely varies between ethnicities. Direct inter-ethnic studies comparing craniofacial phenotypes in OSA are limited. However, available data suggest that Asian OSA populations primarily display features of craniofacial skeletal restriction, African Americans display more obesity and enlarged upper airway soft tissues, while Caucasians show evidence of both bony and soft tissue abnormalities. Our recent comparison of Chinese and Caucasian OSA patients found for the same degree of OSA severity. Caucasians were more obese, and Chinese had more skeletal restriction. However, the ratio of obesity to craniofacial bony size (or anatomical balance, an important determinant of upper airway volume and OSA risk) was similar between Caucasians and Chinese OSA patients. Ethnicity appears to influence OSA craniofacial phenotype but furthermore the relative contribution of the anatomical factors underlying OSA risk. The skeletal restriction craniofacial phenotype may be particularly vulnerable to increasing obesity rates. Better understanding of craniofacial phenotypes encompassing ethnicity may help improve OSA recognition and treatment; however, further studies are needed to elucidate ethnic differences in OSA anatomical risk factors.

Clinical features and polysomnographic findings in greek male patients with obstructive sleep apnea syndrome: differences regarding the age

Background-Aim. Although sleep disturbance is a common complaint among patients of all ages, research suggests that older adults are particularly vulnerable. The aim of this retrospective study was to elucidate the influence of age on clinical characteristics and polysomnographic findings of obstructive sleep apnea syndrome (OSAS) between elderly and younger male patients in a Greek population. Methods. 697 male patients with OSAS were examined from December 2001 to August 2011. All subjects underwent an attended overnight polysomnography (PSG). They were divided into two groups: young and middle-aged (<65 years old) and elderly (≥65 years old). We evaluated the severity of OSAS, based on apnea-hypopnea index (AHI), and the duration of apnea-hypopnea events, the duration of hypoxemia during total sleep time (TST) and during REM and NREM sleep, and the oxygen saturation in REM and in NREM sleep. Results. PSG studies showed that elderly group had significant higher duration of apnea-hypopnea events, longer hypoxemia in TST and in NREM sleep, as well as lower oxygen saturation in REM and NREM sleep than the younger group. Otherwise, significant correlation between BMI and neck circumference with AHI was observed in both groups. Conclusions. The higher percentages of hypoxemia during sleep and longer duration of apnea-hypopnea events that were observed in the elderly group might be explained by increased propensity for pharyngeal collapse and increased deposition of parapharyngeal fat, which are associated with aging. Another factor that could explain these findings might be a decreased partial arterial pressure of oxygen (PaO₂) due to age-related changes in the respiratory system.

Sedation considerations for the nonintubated obese patient in critical care

Sedation of the obese critical care patient presents unique challenges that include altered respiratory function and a predisposition to respiratory suppression and airway obstruction. Sedative drugs have pronounced effects on obese patients. Knowledge of the anatomic and physiologic changes associated with obesity, airway management, and sedation agents better prepares one to care for these patients safely and effectively.

História clínica e exame físico em SAOS: clinical history and physical examination

Embora SAOS seja uma patologia comum, é frequentemente subdiagnosticada. Seus sinais e sintomas são, na sua maioria, subjetivos e, portanto, deve haver suspeição diagnóstica quando existir roncos, sonolência diurna, cansaço, desânimo e alteração de humor. Escalas e tabelas com boa sensibilidade, que incluem os sintomas clínicos mais relevantes e dados do exame físico, podem indicar o diagnóstico de SAOS. A confirmação diagnóstica é realizada através de polissonografia, considerada o método padrão ouro.

Sex differences in the association of regional fat distribution with the severity of obstructive sleep apnea

STUDY OBJECTIVES

To describe sex differences in the associations between severity of obstructive sleep apnea (OSA) and measures of obesity in body regions defined using both dual-energy absorptiometry and traditional anthropometric measures in a sleep-clinic sample.

DESIGN

A prospective case-series observational study.

SETTING

The Western Australian Sleep Health Study operating out of the Sir Charles Gairdner Hospital Sleep Clinic, Perth, Western Australia.

PARTICIPANTS

Newly referred clinic patients (60 men, 36 women) suspected of having OSA.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Obstructive sleep apnea severity was defined by apnea-hypopnoea index from laboratory-based overnight polysomnography. Body mass index, neck, waist and hip circumference, neck-to-waist ratio, and waist-to-hip ratio were measured. Dual energy absorptiometry measurements included percentage fat and lean tissue. Multivariate regression models for each sex were developed. In women, percentage of fat in the neck region and body mass index together explained 33% of the variance in apnea-hypopnea index. In men, percentage of fat in the abdominal region and neck-to-waist ratio together accounted for 37% of the variance in apnea-hypopnea index.

CONCLUSIONS

Regional obesity is associated with obstructive sleep apnea severity, although differently in men and women. In women, a direct influence of neck fat on the upper airway patency is implicated. In men, abdominal obesity appears to be the predominant influence. The apnea-hypopnea index was best predicted by a combination of Dual Energy Absorptiometry-measured mass and traditional anthropometric measurements.

Comparison of cone-beam CT parameters and sleep questionnaires in sleep apnea patients and control subjects

OBJECTIVE

The aim of this work was to compare the cone-beam computerized tomography (CBCT) scan measurements between patients with obstructive sleep apnea (OSA) and snorers to develop a prediction model for OSA based on CBCT imaging and the Berlin questionnaire.

STUDY DESIGN

Eighty subjects (46 OSA patients with apnea-hypoapnea index [AHI] >or= 10 and 34 snorers with AHI <10 based on ambulatory somnographic assessment) were recruited through flyers and mail at the University of Southern California School of Dentistry and at a private practice. Each patient answered the Berlin questionnaire, and was imaged with CBCT in supine position. Linear and volumetric measurements of the upper airway were performed by one blinded operator, and multivariate logistic regression analysis was used to identify risk factors for OSA.

RESULTS

The OSA patients were predominantly male and older and had a larger neck size and larger body mass index than the snorers. The minimum cross-sectional area of the upper airway and its lateral dimension were significantly smaller in the OSA patients. Airway uniformity defined as the minimum cross-sectional area divided by the average area was significantly smaller in the OSA patients.

CONCLUSIONS

Age >57 years, male gender, "high risk" on the Berlin questionnaire, and narrow upper airway lateral dimension (<17 mm) were identified as significant risk factors for OSA. The results of this study indicate that 3-dimensional CBCT airway analysis could be used as a tool to assess the presence and severity of OSA. The presence and severity (as measured by the respiratory disturbance index) of OSA is associated with a narrow lateral dimension of the airway, increasing age, male gender, and high-risk Berlin questionnaire.

Risk factors and treatment for obstructive sleep apnea amongst obese children and adults

PURPOSE OF REVIEW

The purpose of this review is to summarize the evidence for the association between obesity and obstructive sleep apnea (OSA), as well as predisposing risk factors and treatment strategies for OSA amongst obese patients.

RECENT FINDINGS

Recent findings highlight a number of factors including sex, age, upper airway structure and ethnicity, which may predispose patients to OSA when obese. Both invasive and noninvasive weight-reduction strategies also show positive signs of being an effective means to reduce or remediate OSA amongst obese adults and children.

SUMMARY

In view of recent findings, a direct association between body mass and upper airway obstruction should be viewed with caution. Obesity may play a more significant role in the predisposition to OSA amongst particular subgroups of the population, such as adults, and those with particular craniofacial and upper airway morphology. Healthcare prioritization and requirements may be more substantial for such groups. Further, commonly used treatment methods for OSA (such as adenotonsillectomy for children and continuous positive airway pressure for adults) may be less effective for obese individuals. Weight-reduction strategies appear important for an optimal outcome, and such strategies may be more or less invasive depending on the severity of obesity, OSA or both, and other patient complications.

Cervical CT derived neck fat tissue distribution differences in Japanese males and females and its effect on retroglossal and retropalatal airway volume

OBJECTIVE

The objective of this study was to investigate the difference of neck fat tissue distribution by sex and its correlation with retropalatal and retroglossal airway.

STUDY DESIGN

A total of 38 consecutive patients (male: 19; female: 19) who received a CT scan were compared in the retroglossal region and at the narrowest cross section of the airway. Retroglossal fat tissue volume (FV) was segmented with Amira software and separated into subcutaneous and internal fat volume (SFV, IFV). These volumes were normalized by retroglossal neck volume (NV).

RESULTS

Men had 51.9% more IFV/NV and 64.4% less SFV/NV compared with women. Age-adjusted BMI was negatively correlated with retroglossal airway volume (normalized by NV) and with the lateral width of the smallest cross-section airway (LW) in females. In males the IFV/NV was negatively correlated with LW, after adjusting for BMI and age.

CONCLUSION

Upper airway collapsibility analysis is needed to rule out whether increased BMI or IFV causes an increase in airway collapsibility.

Self-Reported Snoring, Maternal Obesity and Neck Circumference as Risk Factors for Pregnancy-Induced Hypertension and Preeclampsia

BACKGROUND

Physical and hormonal changes during pregnancy alter breathing patterns of pregnant women. It is possible that occult disordered breathing during sleep may be a risk factor for the development of pregnancy-induced hypertension (PIH) and preeclampsia.

OBJECTIVE

Our aim was to determine the incidence of self-reported snoring in pregnant women, and to investigate the relationship of snoring, obesity and neck circumference to PIH and preeclampsia.

METHODS

469 pregnant women and 208 age-matched nonpregnant women were included in the study. Both groups were asked to complete a questionnaire. Maternal complications were retrieved from the medical records.

RESULTS

Habitual snoring was reported from 1.9% of nonpregnant women, 2.5% of pregnant women prior to pregnancy and 11.9% of those same women during the third trimester of pregnancy (p < 0.001). Age, smoking during pregnancy, and weight before delivery were independent risk factors for habitual snoring in pregnancy. PIH and preeclampsia developed in 20 and 10.9% of pregnant women with habitual snoring, as compared to 11 and 5.8% of non-snoring pregnant women (p = 0.045, p = 0.125, p = 0.415), respectively. In women who developed preeclampsia, weight before pregnancy, weight before delivery and neck circumference were significantly higher in univariate analysis. Neck circumference was an independent risk factor for PIH and preeclampsia according to logistic regression analysis.

CONCLUSION

The incidence of snoring is significantly higher in pregnant women than in nonpregnant women. Snoring may indicate a risk of PIH. Neck circumference was an independent risk factor for both PIH and preeclampsia.