Obstructive Sleep Apnea-hypopnea Syndrome In Patients Research Articles

#1543 Risk factors of obstructive sleep apnea-hypopnea syndrome in patients with chronic kidney disease

Abstract Background and Aims Both obstructive sleep apnea-hypopnea syndrome (OSAHS) and chronic kidney disease (CKD) are common disease. Patients with OSAHS were evidenced to have oxidative stress, increased albuminuria and renal injury. Previous reports show high prevalence of OSAHS among CKD patients, while its risk factors are hardly investigated. The objective of this study is to assess the risk factors of OSAHS in patients with CKD. Method We selected 181 patients with CKD who were hospitalized in department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital from September 2020 to February 2023. All participants underwent full-night standard nocturnal polysomnography (PSG) monitoring in the sleep center using Alice 4, 5 or 6 devices. An apnea hypopnea index (AHI)>5 events/h was consistent with the diagnosis of OSA. The 181 Patients are divided into three groups based on the level of AHI to studied the differences of clinical and biochemical characteristics. According to Kidney Disease Improving Global Outcomes (KDIGO) risk categories, all patients are divided into non very high risk and very high risk group, logistic regression is used for analyzing risk factors of OSAHS in patients with CKD. Results The prevalence of OSAHS was 86.7% (157 of 181), with 29.8% mild, 30.9% moderate and 25.9% severe respectively. The urea nitrogen (P=0.039) and cystatin C (P = 0.030) levels in patients of severe OSAHS group were significantly higher than those within non or mild OSAHS group. The eGFR in non or mild OSAHS group was significantly higher than moderate OSAHS group (P = 0.036). Pearson correlation analysis showed a significant negative correlation between AHI (p = 0.022), ODI (p = 0.033), and hypopnea index (p = 0.004) of sleep parameters and eGFR, while a significant positive correlation was found between LaSO2 (p = 0.005), MaSO2 (p = 0.030), and eGFR. Stepwise linear regression analysis showed that the hypopnea index was an independent risk factor for eGFR (p = 0.033, R2: 0.215), and CT90 was an independent risk factor for UACR (p < 0.001, R2: 0.105). Logistic regression analysis revealed that hypopnea index (OR = 1.058) was significantly correlated with very high risk in KDIGO risk categories (p < 0.05). Conclusion OSAHS is high prevalence in patients with CKD. Regression analysis shows that hypopnea index is not only an independent risk factor for eGFR but also a significant predictor associated with very high risk according to KDIGO risk category.

Protective Role of TRPC3 Gene Polymorphism (rs10518289) in Obstructive Sleep Apnea Hypopnea Syndrome Among Hypertensive Patients.

BACKGROUND Obstructive sleep apnea-hypopnea syndrome (OSAHS) presents a significant health concern, particularly among individuals with essential hypertension (EH). Understanding the genetic underpinnings of this association is crucial for effective management and intervention. We investigated the relationship between TRPC3 gene polymorphisms and susceptibility to OSAHS in patients with EH. MATERIAL AND METHODS We enrolled 373 patients with EH hospitalized at the First Affiliated Hospital of Xinjiang Medical University between April 2015 and November 2017. Patients were categorized into EH (n=74) and EH+OSAHS (n=299) groups according to the apnea-hypopnea index. Sequenom detection technology was used for TRPC3 gene single-nucleotide polymorphism genotyping, including genotypes at rs953691, rs10518289, rs2292232, rs4995894, rs951974, and rs4292355. RESULTS Sex, smoking history, alcohol history, hypertension duration, fasting blood glucose, urea, creatinine, total cholesterol, HDL-C, LDL-C, glycosylated hemoglobin, 24-h mean systolic BP, and 24-h mean diastolic BP were not significantly different between the 2 groups (P>0.05); however, age, BMI, triglyceride levels differed significantly (P<0.05). No significant difference was detected in distribution frequency of polymorphisms of TRPC3 gene between the 2 groups (P>0.05), while genotype, dominant genotype, and recessive genotype at rs10518289 and alleles at rs4292355 differed significantly (P<0.05). Logistic regression analysis showed age, BMI, and CG+GG genotypes at rs10518289 were risk factors for OSAHS in patients with EH. Interaction between TRPC3 (rs10518289) and obesity was not a risk of OSAHS with EH (P>0.05). CONCLUSIONS CC genotype of rs10518289 in the TRPC3 gene could be a protective genetic marker of OSAHS, and CG+GG genotype may be a risk genetic marker of OSAHS with EH.

Lack of associations between thyroid dysfunction and obstructive sleep apnea-hypopnea syndrome: A meta-analysis.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a comprehensive syndrome with endocrine and metabolic complications. This review aims to explore the correlation between thyroid hormone levels and the severity of OSAHS in patients. The protocol for this meta-analysis has been registered on PROSPERO. Searches were carried out from the inception of the databases to July 18, 2023, utilizing 6 databases (PubMed, CNKI, EMBASE, Web of Science, Cochrane Library, China Biology Medicine, and Wanfang). Standardized mean difference (SMD) and correlation coefficients were used as the effect size measures. Additionally, random effects or fixed effects models were used for pooled analysis. Moreover, data were statistically evaluated with the help of STATA 11.0 and R 4.1.3. This study included 23 articles that satisfied the pre-defined criteria. The prevalence of hypothyroidism and subclinical hypothyroidism in OSAHS patients was 6% and 8%, whereas hyperthyroidism had a prevalence of 2%. Moreover, thyroid hormone levels in OSAHS individuals exhibited no significant difference relative to healthy subjects. Subgroup analysis based on disease severity also established no significant changes in thyroid hormone levels between OSAHS individuals and controls. There was no significant correlation between the Apnea-Hypopnea Index (AHI) and free triiodothyronine (FT3), serum thyroid stimulating hormone (TSH), and free thyroxine (FT4) levels. The prevalence of thyroid dysfunction is relatively low in OSAHS individuals. Thyroid hormone levels show no significant difference between OSAHS patients and healthy subjects. Furthermore, there is no significant correlation between AHI and serum TSH, FT3, and FT4 levels. Based on existing data, the relationship between OSAHS and thyroid function remains controversial, and further in-depth research is warranted to validate the connection and elucidate the underlying mechanisms.

The Weighted Combination of the Epworth Sleepiness Scale and the STOP-Bang Questionnaire Improved the Predictive Value of for OSAHS in Hypertensive Patients.

PurposeHypertension interrelated with obstructive sleep apnea hypopnea syndrome (OSAHS), worsening morbidity and mortality. It is urgent to screening OSAHS from hypertensive patients. An ideal effective questionnaire screening approach for OSAHS is lacking. In this study, we aimed to explore a new OSAHS screening method via weighted combining the current used Epworth sleepiness scale (ESS) and STOP-Bang questionnaire (SBQ) upon calculation.Patients and MethodsThree hundred and sixteen hypertensive patients with suspicion of the OSAHS were enrolled and randomized in the study into ESS, SBQ and portable respiratory polysomnography (RP) tests. The predictive value of ESS, SBQ and weighted combination were evaluated by calculating the area under curve (AUC), sensitivity and specificity, positive and negative likelihood ratio.ResultsBoth the two scales alone and weighted combination were closely related with apnea hypopnea index (AHI), minimum oxygen saturation and average oxygen saturation at night (P < 0.05). The AUC, sensitivity and specificity, positive predictive value (PPV) and negative predictive value (NPV) of ESS in predicting OSAHS were 79.0%, 74.8%, 75.6%, 80.1% and 57.5%, respectively. For SBQ, they were 73.6%, 67.0%, 68.6%, 65.1% and 75.2%, respectively. In contrast, the AUC, sensitivity, and specificity of the combined approach were 82.5%, 73.9% and 82.6%.ConclusionThe weighted combination of ESS and SBQ could improve the diagnostic ability of OSAHS in patients with hypertension, not only in the accuracy and sensitivity, but also for its easy procedure and accessibility and in hospital. Therefore, the weighted combination approach of ESS and SBQ is promising for OSAHS screening.

Utility of the STOP-Bang and Epworth scales and the neck-to-height ratio to detect severe obstructive apnea-hypopnea syndrome in severe obesity.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is present in 80% of patients evaluated for bariatric surgery (BS). Extensive evaluation is not widely available, but treatment is mandatory for severe cases. The Snore, Tiredness, Observed apneas and Pressure - Body mass index, Age, Neck circumference and Gender (STOP-Bang) and Epworth questionnaires and neck-to-height ratio (NHtR) are accessible clinical tools to screen for sleep and metabolic disturbances, but their utility to detect severe OSAHS in patients with severe obesity has not been determined. To evaluate the cutoff point of those clinical tools that may predict severe OSAHS, confirmed by polysomnography in patients referred for BS. Tertiary referral center in Mexico City. We applied the STOP-Bang and Epworth questionnaires, evaluated anthropometric characteristics, and collected samples for arterial gasometry and metabolic parameters from 68 patients with severe obesity, who were then referred for polysomnography before their evaluation for BS. Of the 68 patients participating in the study, 67.7% were female, with a median age of 43 years (35-49 years) and a body mass index (BMI) of 45.5 kg/m2 (42.4-50.9 kg/m2; 28.3% had a BMI ≥ 50 kg/m2). A STOP-Bang cutoff >5 points had a sensitivity of 60% and specificity of 90% for detecting severe OSAHS (area under the curve [AUC] = .962); meanwhile, an NHtR >.25 had a sensitivity of 90% and specificity of 52.5% (AUC = .759). The Epworth scale score >11 points had a sensitivity of 57.1% and specificity of 83.3% (AUC = .802). Clinical data may be useful to detect severe sleep apnea in high-risk populations, allowing for rapid referral and better use of resources.

Diagnostic accuracy of the Berlin questionnaire and therapeutic effect of nasal continuous positive airway pressure in OSAHS patients with glucose metabolic dysfunction

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with alterations in glucose metabolism. TheBerlin questionnaire (BQ) is effective in identifying subjects with high risk of OSAHS. However, its validity in patients with glucose metabolic dysfunction remains unclear. Our study aims to examine the diagnostic efficacy ofthe BQ in detecting OSAHS in patients with glucose metabolic dysfunction and toexplore the effect of nasal CPAP on glucose metabolism. Patients with glucose metabolic dysregulation were first asked to complete theBQ and then recruited for polysomnogram (PSG). The diagnostic accuracy of theBQ and the relationships between groups withnormal glucose tolerance (NGT), elevated fasting blood glucose (IFG), impaired glucose tolerance (IGT), and diabetes mellitus (DM) were analyzed. Subjects with both OSAHS and glucose dysregulation received CPAP treatment and underwent an oral glucose tolerance test. Changes inapnea-hypopnea indices (AHI) and glycemic parameters were calculated to determine the efficacy of CPAP. Glycosylated hemoglobin and insulin levels were statistically different between the high-risk and low-risk groups according to theBQ. For diagnosis of subjects withOSAHS who also had glucose metabolic dysfunction, the sensitivity and specificity of theBQ using AHI cut-off values at 5events per hour were 73% and 67%. CPAP therapy effectively reduced the blood glucose, HOMA-IR, and insulin levels. TheBQ can be considered to bean effective and economical screening tool for patieints withOSAHS who also haveglucose metabolic dysfunction. Treatment with CPAP mayimprove glycemic parameters.

Роль полиморфизма Q223R гена LEPR как генетического предиктора синдрома перекрёста (синдром обструктивного апноэ/гипопноэ сна и хроническая обструктивная болезнь лёгких)

Comorbidity of obstructive sleep apnea / hypopnea syndrome (OSAHS) and chronic obstructive pulmonary disease (COPD) is defined as overlap syndrome and is a state of mutual aggravation characterized by an accelerated development of pulmonary hypertension and chronic respiratory failure, as well as a high risk of sudden death in sleep. At the same time, obesity is one of the most significant and independent risk factors for the development of OSAHS. The aim of the study was to identify the role of the leptin receptor gene LEPR single nucleotide polymorphism (SNP) Q223R (rs1137101) in the development of overlap syndrome. A total of 134 people (73,1% of men and 26,9% of women) aged 60 [53; 65] years were examined, 66 of them with OSAHS, 30 patients with a diagnosis of COPD, and 38 with comorbidity of both forms of pathology. It was shown that the carriage of both the polymorphic G allele and the GG genotype is not a risk factor for the development of OSAHS in patients with COPD (p = 0,92) and does not correlate with the severity of both nosologies, but is statistically significantly associated with the formation of obesity 2 degrees (p &lt; 0,05). The findings suggest that among the residents of the Krasnoyarsk Territory, the study of SNP Q223R of the LEPR gene cannot be used as a genetic predictor of the formation of overlap syndrome.

The No-apnea score vs. the other five questionnaires in screening for obstructive sleep apnea-hypopnea syndrome in patients with cerebral infarction.

Given the growing number of patients suspected of having obstructive sleep apnea-hypopnea syndrome (OSAHS), screening methods have become increasingly important for sleep clinics. We analyzed the clinical value of the No-apnea score which is used to diagnose OSAHS in patients with cerebral infarction, and compared the accuracy of the No-apnea score with the accuracy of the NoSAS score, the STOP-Bang questionnaire (SBQ), the Epworth Sleepiness Scale (ESS), the STOP questionnaire (STOP) and the Berlin questionnaire (BQ). Between January 2014 and December 2018, a total of 221 cerebral infarction patients, suspected of having OSAHS, underwent the polysomnography (PSG) for one night at the sleep medical center of Guangdong Medical University Affiliated Second Hospital. The PSG data were collected and analyzed with the NoSAS score, the SBQ, the ESS, the STOP, the BQ, and patients' demographic information. Based on the apnea-hypopnea index (AHI), the patients were classified into four groups: the normal group (<5 events/h), mild OSAHS group (5-15 events/h), moderate OSAHS group (15-30 events/h) and severe OSAHS group (≥30 events/h). The sensitivity, specificity, positive predictive value, negative predictive value and areas under the curve (AUC) of the Receiver Operating Curve (ROC) were calculated for the five questionnaires to compare their relative efficacies for diagnosing OSAHS. When using the standard of AHI ≥5 for diagnosing OSAHS, the NoSAS score had an AUC of 0.831; the SBQ had an AUC of 0.730; the BQ had an AUC of 0.698; and the STOP had an AUC of 0.735, so these techniques are relatively accurate in diagnosing OSAHS. On the other hand, the No-apnea score and the ESS score are relatively less accurate comparing to the rest: the No-apnea had an AUC of 0.626, and the ESS had an AUC of 0.650. Using the NoSAS score to predict AHI ≥5 events/h, AHI ≥15 events/h and AHI ≥30 events/h, the sensitivity and specificity were 0.867 and 0.731, 0.888 and 0.476, 0.889 and 0.369, respectively; Using the SBQ to predict AHI ≥5 events/h, AHI 15 events/h and AHI ≥30 events/h, the sensitivity and specificity were 0.903 and 0.268, 0.914 and 0.200, 0.903 and 0.268, respectively; Using the STOP to predict AHI ≥5 events/h, AHI ≥15 events/h and AHI ≥30 events/h, the values were 0.830 and 0.500, 0.871 and 0.390, 0.875 and 0.302, respectively; and using the BQ to predict AHI ≥5 events/h, AHI ≥15 events/h and AHI ≥30 events/h, the values were 0.758 and 0.482, 0.810 and 0.429, 0.819 and 0.362, respectively. The study concludes that the NoSAS score and the SBQ had a better predictive value for cerebral infarction patients suspected with OSAHS disease. These questionnaires can also effectively help clinicians quickly address nocturnal hypoxia in patients with cerebral infarction to control subsequent complications in patients with cerebral infarction. More studies are needed to evaluate the efficacy of the NoSAS score in screening for OSAHS in patients with cerebral infarction.

БИОХИМИЧЕСКИЕ АСПЕКТЫ МЕТАБОЛИЗМА КОЛЛАГЕНА IV ТИПА И ОСОБЕННОСТИ АМИНОКИСЛОТНОГО СОСТАВА ПЛАЗМЫ КРОВИ У ПАЦИЕНТОВ С ГАСТРОЭЗОФАГЕАЛЬНОЙ РЕФЛЮКСНОЙ БОЛЕЗНЬЮ И/ИЛИ СИНДРОМОМ ОБСТРУКТИВНОГО АПНОЭ/ГИПОПНОЭ СНА

Background. Gastroesophageal reflux disease (GERD) and obstructive sleep apnea/hypopnea syndrome (OSAHS) seem to be comorbid conditions. However, pathogenetic interactions between these conditions are not completely researched. Aim of the study. To determine the interrelation between plasma collagen type IV and cortisol levels and to investigate plasma amino acid composition in patients with GERD and OSAHS. Material and methods. A total of 143 patients have been examined. Esophagogastroduodenoscopy and respiratory monitoring were performed. The patients were divided into 4 groups: group 1 – patients with GERD, group 2 – those with GERD and OSAHS, group 3 – those with OSAHS, group 4 – the comparison group. The plasma levels of cortisol, collagen type IV and amino acids were estimated. Results. The patients with GERD and OSAHS had higher plasma levels of cortisol and collagen type IV and a low level of glycine in contrast to the comparison group. We revealed a positive correlation between plasma cortisol level and apnea/hypopnea index (AHI), between collagen type IV level and AHI as well as between the levels of cortisol and collagen type IV. Conclusions. The presence of OSAHS in patients with GERD is associated with high levels of cortisol and collagen type IV and low levels of glycine in blood plasma.

The posterior pharyngeal wall thickness is associated with OSAHS in patients with acromegaly and correlates with IGF-1 levels.

To evaluate the incidence of obstructive sleep apnea-hypopnea syndrome (OSAHS), explore the structural changes in pharyngeal soft tissue underlying OSAHS development and analyze the correlation between hormone levels and pharyngeal soft tissue changes in patients with untreated acromegaly. Twenty-five patients with untreated acromegaly were prospectively enrolled. Pituitary hormones were tested, sellar magnetic resonance imaging was confirmed, overnight polysomnography was conducted, and upper airway computed tomography was performed on these patients. Patients with untreated acromegaly had a high incidence of OSAHS (52.0%, 13/25). The average age of the patients with OSAHS was 12 years older than that of patients without OSAHS (47.0 ± 8.5 years vs. 35.1 ± 9.5 years, p = 0.003). The posterior pharyngeal soft tissues were thicker in four different planes, including the planes of the soft palate, uvula, tongue and epiglottis (p = 0.003, 0.008, 0.027, and 0.003, respectively), and the soft palate (p = 0.024) was more hypertrophic in patients with acromegaly presenting with OSAHS than patients without OSAHS. The posterior pharyngeal wall thickness (cm) positively correlated with the serum insulin-like growth factor 1 (IGF-1) level (ng/ml) in the planes of the soft palate (slope = 0.001, p = 0.006) and epiglottis (slope = 0.002, p = 0.039). OSAHS is a common complication in patients with untreated acromegaly, and advanced age is a risk factor. Posterior pharyngeal soft tissue thickening and soft palate hypertrophy are structural changes underlying OSAHS development in patients with acromegaly. Higher IGF-1 levels predict an increase in the posterior pharyngeal soft tissue thickness in patients with acromegaly.

Relationship between Chinese visceral adipose index and obstructive sleep apnea hypopnea syndrome in patients with type 2 diabetes mellitus

Sleep apnea hypopnea index(AHI) was evaluated in 304 patients with T2DM using a portable sleep apnea monitor. Patients were divided into 4 groups as T2DM without obstructive sleep apnea hypopnea syndrome(OSAHS) group, T2DM with mild, moderate and severe OSAHS groups according to AHI. Patients were divided into 4 groups according to CVAI. The results suggested that the prevalence of OSAHS was 61.8% among hospitalized T2DM patients. There were significant differences in body mass index, waist circumference, Chinese visceral adipose index(CVAI), high density lipoprotein cholesterol, triglyceride and alanine aminotransferase among groups(all P<0.05). There were significant positive correlations between CVAI and AHI, GGT, ALT, AST, HOMA-IR(all P<0.01). CVAI was a risk factor of AHI according to multivariable regression analysis. CVAI may reflect the severity of OSAHS in patients with T2DM and visceral adipose deposition is a risk factor of AHI. (Chin J Endocrinol Metab, 2018, 34: 141-143) Key words: Diabetes mellitus, type 2; Visceral adipose index; Obstructive sleep apnea hypopnea syndrome

Relationship between Prader-Willi syndrome and sleep related breathing disorders

Prader-Willi syndrome(PWS)is a type of genetic disease, which is associated with low muscle tone, growth and development, progressive fatal obesity and sleep related respiratory disorders(SRBD). Obstructive sleep apnea hypopnea syndrome(OSAHS)is the most common type of SRBD.The cause, influencing factors and treatment of OSAHS in patients with PWS are described in this paper.To understand the degree of OSAHS in children with PWS, the polysomnography is recommended. Key words: Prader-Willi syndrome; Sleep related respiratory disorders; Obstructive sleep apnea hypopnea syndrome; Polysomnography

Changes in Retinal Nerve Fiber Layer Thickness in Obstructive Sleep Apnea/Hypopnea Syndrome: A Meta-Analysis

Purpose: To evaluate and compare changes in retinal nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). Methods: The Cochrane Library, Medline, and Embase were screened using our key words. Results were carefully reviewed to ensure that the included studies met the inclusion/exclusion criteria, and the quality of the studies was assessed using the Newcastle-Ottawa Scale. All included studies categorized patients with OSAHS into 3 groups (mild, moderate, and severe), and measured average and 4-quadrant (temporal, superior, nasal, and inferior) RNFL thickness. All studies included a healthy control group. The weighted mean differences and 95% confidence intervals were calculated for the continuous outcomes. Results: Ten case-control studies were included in the meta-analysis, consisting of a total of 811 OSAHS group and 868 healthy eyes. A meta-analysis of the data showed that the average RNFL thicknesses in the mild, moderate, and severe OSAHS groups were significantly decreased compared to healthy controls. Additionally, RNFL thickness was significantly reduced in all but the temporal quadrant in the moderate and severe OSAHS groups when compared to healthy controls. Conclusions: On the basis of these results, we suggest that peripapillary RNFL thickness as measured by optical coherence tomography could be a useful tool to monitor and assess the severity of OSAHS in patients. Further studies are required in order to differentiate these RNFL changes from glaucomatous changes. This has not been properly examined in any of the studies we were able to identify.

Sleep disordered breathing in patients with acute coronary syndromes.

Although the prevalence of obstructive sleep apnea/hypopnea syndrome (OSAHS) is high in patients with acute coronary syndromes (ACS), there is little knowledge about the persistence of OSAHS in ACS patients after the acute event. We aimed to assess the prevalence and time course of OSAHS in patients with ACS during and after the acute cardiac event. Fifty-two patients with first-ever ACS, underwent attended overnight polysomnography (PSG) in our sleep center on the third day after the acute event. In patients with an apnea hypopnea index (AHI) > 10/h, we performed a follow up PSG 1 and 6 months later. Twenty-eight patients (54%) had an AHI > 10/h. There was a significant decrease in AHI 1 month after the acute event (13.9 vs. 19.7, p = 0.001), confirming the diagnosis of OSAHS in 22 of 28 patients (79%). At 6-month follow-up, the AHI had decreased further (7.5 vs. 19.7, p < 0.05), and at that time only 6 of the 28 patients (21%) were diagnosed as having OSAHS. Twelve of the 16 current smokers stopped smoking after the acute event. We have demonstrated a high prevalence of OSAHS in ACS patients, which did not persist 6 months later, indicating that, to some degree, OSAHS may be transient and related with the acute phase of the underlying disease or the reduction in the deleterious smoking habit.

Sleep Apnea in Morbidly Obese Patients: Prevalence and Clinical Predictivity

Background: Little is known about the prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in morbidly obese patients and whether such patients show peculiar clinical findings that may make it easier to suspect and diagnose OSAHS. Objectives: To investigate prevalence of OSAHS in patients with morbid obesity and find a simple structured model for predicting the results of polysomnography. Methods: The study enrolled a group of 101 consecutive inpatients (33 males, age range 20–80 years) with a body mass index ≥40, whose symptoms of OSAHS were not known, and a validation group of 45 patients. Results: Habitual snoring, nocturnal apneas or awakening as well as diurnal sleepiness were frequent findings (90.1, 40.6, 50.5 and 61.4%, respectively). Chronic obstructive pulmonary disease, hypertension, diabetes and myocardial ischemia were also frequently associated (22.8, 56.4, 30.7 and 6.9%, respectively). OSAHS was found in 61 (60.4%) patients, in 33.7% it was of severe degree. A multivariate logistic regression model allowed to select the independent predictors of OSAHS: age, male sex, diurnal sleepiness and the value of minimum nocturnal saturation. Sensitivity of 97%, specificity of 77% as well as positive and negative predictive values of 87% and 95%, respectively, were obtained; similar results were found in the validation group. When the best obtainable cutoff on the receiver operating characteristic curve is below 40%, the instrumental diagnosis might be excluded in as many as 33% of cases, since they are not affected by OSAHS or have OSAHS of mild degree. Conclusions: OSAHS is present in almost two thirds of morbidly obese patients. By applying the prediction model we propose, one may calculate the probability of a morbidly obese patient of being affected by OSAHS.

Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.