Moderate Obstructive Sleep Apnea Patients Research Articles

Association between Serum Homocysteine Level and Obstructive Sleep Apnea: A Meta-Analysis.

Background Obstructive sleep apnea (OSA) is a common problem that affects human health. Researches have reported a variety of results with reference to the association between OSA and serum homocysteine (Hcy) level. This meta-analysis is proposed to figure out the association between serum Hcy level and OSA. Methods Eligible studies were identified via searching PubMed, Embase, and China National Knowledge Infrastructure (CNKI). Two independent reviewers reviewed studies. The Newcastle-Ottawa Quality Assessment Scale (NOS) was employed for quality assessment of included studies. RevMan (5.1) software and STATA (12.0) software were applied to data analyses. Results 10 studies containing 839 subjects were included in the present meta-analysis; results revealed that Hcy levels in OSA group were 2.40 μmol/l higher than that in control group (95% confidence interval: 0.6 to 4.20, P < 0.01; I2 = 96%). Subgroup analysis showed a significant increase of serum Hcy level in OSA patients compared with healthy controls when apnea hyperpnoea index (AHI) >= 30. Conclusions Serum Hcy levels and OSA have close-knit and significant association. Analyses demonstrated that patients with OSA had a higher serum Hcy level than healthy controls. In addition, this difference is more significant in moderate or severe OSA patients.

A systematic review on the effectiveness of titratable over nontitratable mandibular advancement appliances for sleep apnea.

Background:Mandibular advancement appliances are being tested for use in patients with obstructive sleep apnea (OSA). However, the effectiveness of titration of these appliances does not have conclusive evidence. Systematic reviews help us to compile all available clinical evidence using statistical principles. Hence, the aim of this systematic review is to identify the effectiveness of titratable over nontitratable mandibular advancement appliances in patients with mild to moderate OSA. This review objective is to identify if titration of these appliances produce significant benefits over fixed appliances.Materials and Methodology:Electronic databases were searched to identify eligible studies based on set inclusion criteria. Data extraction form was created and the data were extracted. The participants were mild to moderate OSA patients who received mandibular advancement appliances. Studies included a comparison between titratable and nontitratable mandibular advancement appliance.Results:Of the five included studies, three were observational and two were a randomized trial. All these studies were conducted in adults. The outcome attributes were polysomnographic readings and apnea-hypopnea index (AHI). A significant heterogeneity was seen between the eligible studies and hence a meta-analysis could not be performed.Conclusion:The results from this systematic review did not show significant advantages of titratable appliances, although titratable appliances performed better from individual studies as regards to reduction in AHI and polysomnography. The reason is the lack of sufficient clinical trials on the same. More high quality randomized controlled trials comparing titratable and fixed appliances have to be initiated to get to conclusive evidence.

Effect of oral appliance therapy on blood pressure in Japanese patients with obstructive sleep apnea

ABSTRACTObjective: Obstructive sleep apnea (OSA) treatment in patients with OSA and hypertension reduces blood pressure (BP). Oral appliance (OA) therapy is nowadays prescribed for patients with mild to moderate OSA. This study aimed to clarify the effect of OA therapy on BP reduction in Japanese patients with mild to moderate OSA. Methods: Polysomnography was employed to detect sleep-disordered breathing. Totally, 237 patients without cardiac and/or cerebrovascular diseases and those with apnea-hypopnea index (AHI) ≥ 5/h–< 30/h were enrolled. Office BP change after receiving 8–12 weeks of OA therapy was assessed and the factors related to the degree of BP reduction were analyzed. Results: The study patients consisted of 188 men and 49 women, the mean age was 54.7 ± 13.2 years old, and the body mass index (BMI) was 24.6 ± 3.4 kg/m2. The antihypertensive effect of OA therapy resulted in systolic BP (SBP) −2.4 ± 14.8 (p = 0.078) and diastolic BP (DBP) −2.0 ± 11.7 mm Hg (p = 0.045) in all patients. SBP before OA therapy played a significant role in the degree of SBP reduction (β = −0.597, p < 0.001), whereas DBP before OA therapy was a significant factor of the degree of DBP reduction (β = −0.522, p < 0.001). Conclusion: A certain time period of OA therapy effected BP reduction in mild to moderate OSA patients without cardiac and/or cerebrovascular diseases. Its antihypertensive effect was greater in OSA patients whose BP was higher before receiving OA therapy.

The expression of serum endoplasmic reticulum stress protein-78 in obstructive sleep apnea patients

This study aimed to detect serum level of glucose regulated protein 78(GRP78) in patients with obstructive sleep apnea(OSA) and explore the relationship between endoplasmic reticulum stress and the pathophysiology of OSA. A total of 91 patients with OSA were enrolled in this study, including 30 mild, 28 moderate and 33 severe. The other 27 obese subjects were of age, gender and BMI matched group. Eleven moderate or severe OSA patients were administrated with continuous positive airway pressure (CPAP) treatment for 24 hours. Polysomnography, apnea hypopnea index (AHI), lowest arterial oxygen saturation(SaO2) and percentage of time spent at SaO2 below 90% (SIT90) were measured before and after sleep. Serum GRP78 was measured by ELISA. The expression of GRP78 in mild(3.42±0.97)μg/L, moderate(2.67±1.14)μg/L and severe(2.62±1.11)μg/L OSA groups was significantly higher than in control group(1.75±0.41)μg/L (P<0.05). The GRP78 level in mild OSA group was significantly higher than either moderate or severe OSA group (P<0.05). After 24 h treatment of CPAP, serum GRP78 level decreased significantly [(1.77±0.39)μg/L vs(2.84±0.39)μg/L; P<0.05]. Endoplasmic reticulum stress involves in the pathophysiology of patients with OSA. Higher GRP78 level in mild OSA patients suggests that endoplasmic reticulum related protein GRP 78 might rise then fall during exacerbation of OSA.

Morning cortisol levels and glucose metabolism parameters in moderate and severe obstructive sleep apnea patients.

Obstructive sleep apnea (OSA) has been associated with dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in glucose metabolism with increased risk for type 2 diabetes. The aim of the current study was to compare morning plasma cortisol levels and glucose metabolism parameters between moderate (apnea-hypopnea index (AHI): 15-30events/h) and severe OSA patients (AHI >30events/h), with respective controls. A total of 56 male OSA patients, 24 moderate (AHI=21.1±5.3) and 32 severe (AHI=49.7±18.1), underwent a full-night polysomnography, oral glucose tolerance test (OGTT), and measurement of morning plasma cortisol levels. These groups were compared to 20 matched subjects in a control group. Morning plasma cortisol levels were statistically lower in severe OSA group than in moderate OSA and control groups (303.7±93.5 vs. 423.9±145.1 vs. 417.5±99.8pmol/L, P<0.001). Significant negative correlations were found between morning plasma cortisol levels and AHI (r=-0.444, P=0.002), as well as oxygen desaturation index (r=-0.381, P=0.011). Fasting plasma glucose (5.0±0.5 vs. 5.4±0.7 vs. 4.9±0.6mmol/L, P=0.009) was higher in the severe OSA group compared to moderate OSA and controls. Homeostasis model assessment insulin resistance (HOMA-IR) was higher in the severe OSA group compared to moderate OSA and controls (4.6±3.7 vs. 2.7±2.0 and 2.2±1.8, respectively, P=0.006). In conclusion, our study showed that morning plasma cortisol levels measured at 8a.m. were significantly lower in severe OSA patients than those in moderate OSA group and controls. Morning plasma cortisol levels showed a negative correlation with AHI and oxygen desaturation index. Additionally, this study confirmed the evidence of glucose metabolism impairment in moderate and severe OSA patients, with more pronounced effect in the severe OSA patients group.

A novel method for sensitive determination of subclinical right ventricular systolic dysfunction in patients with obstructive sleep apnea.

The aim of this study was to evaluate right ventricular (RV) regional systolic function and dyssynchrony in patients with newly diagnosed obstructive sleep apnea using real-time three-dimensional (3D) echocardiography. Eighty-two subjects without hypertension, diabetes mellitus or any cardiac or pulmonary disease referred for evaluation of obstructive sleep apnea (OSA) had overnight polysomnography and complete echocardiographic assessment. According to the apnea hypopnea index (AHI), subjects were divided into four groups: group 1: control subjects (AHI < 5, n = 19), group 2: patients with mild OSA (AHI: 5-14, n = 21), group 3: moderate OSA (AHI: 15-30, n = 18), group 4: severe OSA (AHI > 30, n = 24). Real-time three-dimensional echocardiographic images were acquired to obtain RV regional (inflow, body and outflow) ejection fraction (EF) and time to minimum systolic volume in all subjects. Body weight and body mass index were greater in the severe and moderate OSA group than those of mild and controls group (P < 0.05). There was a significant decrease in mean SaO2 and the lowest SaO2 in severe OSA when compared to other groups (P < 0.001). Inflow EF and global EF were significantly lower in moderate and severe OSA patients than in controls (P < 0.05). Inflow EF and global EF were negatively correlated with AHI (r = -0.534 and r = -0.479, respectively, P < 0.001). In patients with OSA, RV inflow and global systolic function were impaired and were in inverse relationship with AHI. Evaluation of RV regional systolic function using real-time three-dimensional echocardiography may play a potential role in the noninvasive assessment of the severity of OSA.

Effect of CPAP Therapy in Improving Daytime Sleepiness in Indian Patients with Moderate and Severe OSA

Obstructive Sleep Apnoea (OSA) is a highly prevalent disease and a major public health issue in India. Excessive daytime sleepiness is an almost ubiquitous symptom of OSA. Epworth Sleepiness Scale (ESS) score is a validated objective score to measure the degree of daytime sleepiness. Continuous Positive Airway Pressure (CPAP) therapy has been established as the gold standard treatment modality for OSA patients. A few Indian studies have reported the effectiveness of CPAP therapy in improving ESS scores after 1st month of CPAP use. To observe both, short-term (one month) and long-term (three month) effects of CPAP therapy on ESS scores in moderate to severe OSA patients. The patients complaining of excessive day-time sleepiness, snoring and choking episodes during sleep, consecutively presenting to medicine OPD over a period of 2 years, were subjected to Polysomnography (PSG). Seventy-three patients with apnoea-hypopnea index (AHI) ≥15 were categorised as having moderate to severe forms of OSA (moderate OSA with AHI=15-30 and severe OSA with AHI >30), and were scheduled for an initial trial of CPAP therapy. Forty-seven patients reported good tolerance to CPAP therapy after a trial period of 2 weeks and comprised the final study group. ESS scores in these patients were recorded at the baseline, and after 1st and 3rd month of CPAP therapy, and statistically analysed for significance. Mean ESS score at the baseline among moderate and severe OSA patients were 13.67±2.29 and 16.56 ±1.87, respectively. ESS score in both these subgroups improved significantly to 11.63±3.79, p=0.022, CI (0.3293-4.0106)} and 14.13 ±3.74, p < 0.001, CI (1.2991-4.5408), respectively after one month of CPAP therapy. Likewise, mean ESS scores among moderate and severe OSA patients improved significantly to 9.84 ±2.97, p = 0.022, CI (0.3293-4.0106) and 12.29 ±3.97, p <0.001, CI (2.9414-6.1385), respectively after three months of CPAP therapy. The result of the present study shows that CPAP therapy is significantly effective in improving ESS scores in Indian patients having moderate to severe OSA. Benefits in daytime sleepiness were observed after short-term as well as long-term use of CPAP therapy.

Usefulness of the SAME-TT2R2 score to predict anticoagulation control on VKA in patients with atrial fibrillation and obstructive sleep apnea

BackgroundOral anticoagulation is crucial for the prevention of stroke and thromboembolism in atrial fibrillation (AF). One of the comorbidities potentially affecting thromboembolic risk and anticoagulation effectiveness is obstructive sleep apnea (OSA). The objective of this study was to establish if presence of OSA is associated with poor expected benefit from vitamin K antagonist (VKA) therapy as assessed using the SAMe-TT2R2 score. MethodsWe studied AF patients planned for invasive electrophysiological procedures. All patients had a whole night polygraphy performed for the diagnosis of OSA, and their SAMe-TT2R2 score was calculated. ResultsWe studied 211 AF patients (mean age=57.1±10.2years, 62.6% males). OSA with apnea–hypopnea index (AHI) ≥15/h was found in 48 (22.7%) patients. Mean SAMe-TT2R2 score in non-OSA patients was 1.4±0.9, compared to mild OSA patients, 1.5±0.9; moderate OSA patients, 1.9±1.1; and severe OSA patients, 2.8±0.6. A significantly higher percentage of patients with SAMe-TT2R2≥2, indicating poor predicted INR control on VKAs, was found with increasing AHI category (37% vs. 41% vs. 57% vs. 100%, respectively). Patients with poor predicted anticoagulation control (SAMe-TT2R2≥2) had a higher prevalence of OSA. There was a lower proportion of patients with TTR>70% among patients with moderate/severe OSA compared to no/mild OSA (13.6% vs. 29.6%, p=0.03). ConclusionSAMe-TT2R2 scores in patients with OSA are substantially higher than in those without sleep-disordered breathing. The mean SAMe-TT2R2 score, as well as the percentage of patients with SAMe-TT2R2 score≥2, suggests poor predicted anticoagulation control on VKA rises along with the AHI. There was a lower proportion of patients with TTR>70% among patients with moderate/severe OSA, compared to no/mild OSA.

Decision tree based diagnostic system for moderate to severe obstructive sleep apnea.

One of the major modern medical issues, obstructive sleep apnea (OSA), particularly at moderate to severe levels, may potentially cause cardiovascular morbidity and mortality. However, polysomnography (PSG), a gold standard tool in diagnosing OSA, is cumbersome, has limited availability, and is costly and time-consuming. Clinical prediction models thus are absolutely necessary in screening patients with OSA. Furthermore, the performance of the published prediction formulas is not satisfactory for Chinese populations. The aim of this study was to develop and validate a simple and accurate prediction system for the diagnosis of moderate to severe OSA by integrating an expert-based feature extraction technique with decision tree algorithms which have automatic feature selection capability in screening the moderate to severe OSA cases in Taiwan. Moreover, the backward stepwise multivariable logistic regression model and four other decision tree algorithms were also employed for comparison. The results showed that the proposed best prediction formula, with an overall accuracy reaching to 96.9 % in sensitivity = 98.2 % and specificity = 93.2 %, could present a good tool for screening moderate and severe Taiwanese OSA patients who require further PSG evaluation and medical intervention. Results also indicate that the proposed best prediction formula is simple, accurate, and reliable, and outperforms all the other prediction formulae considered in the present study. The proposed clinical prediction formula derived from three non-invasive features (Sex, Age, and AveSBP) may help prioritize patients for PSG studies as well as avoid a diagnosis of PSG in subjects who have a low probability of having the disease.

Drug Induced Sleep Endoscopy for Poor-Responder to Uvulopalatopharyngoplasty in Patient with Obstructive Sleep Apnea Patients

*Dong-Kyu Kim and Jung Woo Lee equally contributed to the work. Background and ObjectivesZZThe purpose of this study is to evaluate drug-induced sleep endoscopy (DISE) findings in patients with persistent obstructive sleep apnea (OSA) after uvulopalatopharyngoplasty (UPPP) surgery. Subjects and MethodZZPatients were included in this study if they had a postoperative DISE evaluation as well as preand postoperative polysomnography. DISE findings included the obstructive sites (velum, oropharyngeal lateral walls, tongue base, and epiglottis), and the obstructive patterns of velopharynx (anteroposterior, lateral, and concentric). ResultsZZA total of 77 patients were included in this study. Poor-responder patients to UPPP (n=50) and well-responder patients to UPPP (n=27) were similar with regard to age, gender, body mass index, preoperative AHI, and minimal O2 saturation. In our analysis of DISE findings on poor-responder, velopharynx was the most common obstruction site (100%), followed by oropharynx (88%), tongue base (70%), and epiglottis (44%). Results showed that most patients (n=49) had multiple obstructive sites. No significant differences according to position dependency and REM dependency were found in obstructive sites. However, severe OSA patients had tongue base obstruction more frequently than the moderate OSA patients did. The obstructive pattern of velopharynx usually showed concentric configuration (70%, 35 of 50). ConclusionZZOur results suggest that the preoperative DISE may be a useful method for determination of the personalized surgery to OSA patients because of its more precise information to upper airway obstruction. Korean J Otorhinolaryngol-Head Neck Surg 2014;57:96-102

Determining the efficacy of temporary mandibular advancement splint in mild to moderate obstructive sleep apnea patients at baseline polysomnography

Introduction Mandibular advancement splint (MAS) have become increasingly popular as alternatives to continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea (OSA). However,the acceptance of MAS is limited to the efficacy rate of 50–70% and inability to predict which patients will respond to this treatment. To overcome this limitation,the temporary mandibular advancement titration was performed in mild to moderate OSA patients dsuring baseline polysomnography (PSG) Objective: To determine the efficacy of temporary mandibular advancement splint in mild to moderate OSA patients during baseline polysomnography (PSG). Materials and methods This pilot study consisted of ten undiagnosed subjects with OSA symptoms. The Temporary mandibular advancement splint,fabricated at 50% and 70% of maximum jaw protrusion, had been delivered to all subjects before each subject underwent baseline PSG. After the first half of the night,five subjects had severe OSA (AHI > 30) and CPAP titration was performed in this group,four subjects had mild to moderate OSA (AHI 5–30) and temporary mandibular advancement splint titration was performed in this group, one subjects was normal (AHI Results Mean apnea–hypopnea index (AHI) was significantly reduced from 20.60(SD ± 8.28) to 5.65(SD ± 4.49) after treatment with Temporary mandibular advancement splint ( p Conclusion This pilot study shows that it is possible to utilize temporary mandibular advancement splint titration in mild to moderate OSA patients during baseline PSG and these results suggest that temporary mandibular advancement splint can be used as a tool in predicting treatment response in terms of efficacy piro to oral appliance therapy by means of using mandibular advancement splint in treating OSA. Acknowledgements This study is granted by dental department,Phramongkutklao hospital, Bangkok, Thailand.

Anterior palatoplasty for selected mild and moderate obstructive sleep apnea: preliminary results

The aim of this prospective study was to evaluate the long-term efficacy anterior palatoplasty (AP) technique in treatment of patients with mild to moderate obstructive sleep apnea (OSA). Forty-two patients were diagnosed with mild to moderate OSA. Participants were treated with AP for mild or moderate OSA. Patients were evaluated with one night polysomnography before the surgery and 24 months after the surgery. Patients completed Epworth sleepiness scale (ESS), snoring VAS (visual analog scale) before and 24 months after the surgery. Forty two patients with a mean age of 39.2 ± 7.6 were included study. Success rate was 57.1%. Total apnea-hypopnea index (AHI) values significantly decreased after 2 years (p < 0.025). Non-REM AHI and supine AHI values significantly decreased after 2 years (p < 0.025). The oxygen desaturation index changes significantly decreased after AP (p < 0.025). Snoring VAS values significantly decreased after AP (p < 0.025). ESS scores of patients significantly decreased (p < 0.001). We believe that AP is an effective, inexpensive technique for mild and moderate OSA patients.

Are we missing a simple treatment for most adult sleep apnea patients? The avoidance of the supine sleep position

Obstructive sleep apnea (OSA) is a sleep disorder which has been gradually accepted as an important cause of increased morbidity and mortality. The treatment of moderate-severe OSA has improved dramatically since the introduction of continuous positive airway pressure (CPAP) devices; however, the adherence of patients to CPAP treatment is relatively low. Adherence appears to be even worse in patients with mild or asymptomatic OSA. The failure to identify and treat mildly symptomatic or asymptomatic OSA patients may be costly, as such patients comprise about 20% of the general adult population. OSA patients could be divided into positional and non-positional patients. Positional patients show most of their breathing abnormalities while sleeping in the supine position. Simply, by sleeping in the lateral postures, they eliminate or reduce significantly the number of apneas and hypopneas. On the contrary, non-positional patients suffer from breathing abnormalities in the supine and lateral postures, and as a consequence those are the most severe OSA patients for whom CPAP is the treatment of choice. In this paper we intend to argue that positional therapy, i.e., avoidance of the supine posture during sleep, could represent a valuable therapy mainly for mild-moderate OSA. Considering the fact that the vast majority of mild-moderate OSA patients are positional patients (between 65 and 87%), positional therapy may be a simple, cheap and effective solution for them. High-quality research regarding this issue is needed to evaluate the real effectiveness of this mode of therapy.

Topography-specific spindle frequency changes in Obstructive Sleep Apnea

BackgroundSleep spindles, as detected on scalp electroencephalography (EEG), are considered to be markers of thalamo-cortical network integrity. Since obstructive sleep apnea (OSA) is a known cause of brain dysfunction, the aim of this study was to investigate sleep spindle frequency distribution in OSA. Seven non-OSA subjects and 21 patients with OSA (11 mild and 10 moderate) were studied. A matching pursuit procedure was used for automatic detection of fast (≥13Hz) and slow (<13Hz) spindles obtained from 30min samples of NREM sleep stage 2 taken from initial, middle and final night thirds (sections I, II and III) of frontal, central and parietal scalp regions.ResultsCompared to non-OSA subjects, Moderate OSA patients had higher central and parietal slow spindle percentage (SSP) in all night sections studied, and higher frontal SSP in sections II and III. As the night progressed, there was a reduction in central and parietal SSP, while frontal SSP remained high. Frontal slow spindle percentage in night section III predicted OSA with good accuracy, with OSA likelihood increased by 12.1%for every SSP unit increase (OR 1.121, 95% CI 1.013 - 1.239, p=0.027).ConclusionsThese results are consistent with diffuse, predominantly frontal thalamo-cortical dysfunction during sleep in OSA, as more posterior brain regions appear to maintain some physiological spindle frequency modulation across the night. Displaying changes in an opposite direction to what is expected from the aging process itself, spindle frequency appears to be informative in OSA even with small sample sizes, and to represent a sensitive electrophysiological marker of brain dysfunction in OSA.

Tp‐e Interval, Tp‐e/QT Ratio, and Tp‐e/QTc Ratio are Prolonged in Patients with Moderate and Severe Obstructive Sleep Apnea

Prolongation of the peak and the end of T wave (Tp-e) has been reported to be associated with ventricular arrhythmias. Tp-e/QT ratio and Tp-e/QTc ratio are used as an index of ventricular arrhythmogenesis. An increased incidence of ventricular arrhythmias has been reported in patients with obstructive sleep apnea (OSA). The aim of this study was to assess ventricular repolarization in patients with OSA by using Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. We have studied 72 patients who underwent overnight polysomnography (PSG) between the years 2010-2011 at our institution. Patients with moderate and severe OSA (23 patients; mean age: 45±10), according to the apnea-hypopnea index, constituted the study group. Patients with normal PSG (23 patients; mean age: 42±11) were used as the control group. In all patients, Tp-e interval, Tp-e/QT ratio, Tp-e/QTc ratio, as well as some other electrocardiogram intervals were measured. Independent samples t-tests were used for comparison of continuous and categorical variables and correlations were calculated by Spearman rank correlation. Although QT and QTc intervals were not different between the groups, mean Tp-e interval (81.6±11.1 msn; 63.9±7.3 msn; respectively; P < 0.001), Tp-e/QT ratio (0.21±0.03; 0.17±0.02; respectively; P < 0.001), and Tp-e/QTc ratio (0.20±0.03; 0.16±0.02; respectively; P < 0.001) were prolonged in the study group compared to the control group. Correlation analysis showed a significant positive correlation between the presence of moderate and severe OSA and Tp-e interval (r = 0.72; P < 0.001), Tpe/QT ratio (r = 0.70; P < 0.001), and Tp-e/QTc ratio (r = 0.70; P < 0.001). Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio are prolonged in patients with moderate and severe OSA patients. There is a positive correlation between the presence of OSA and Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio.

Evaluation of subclinical left ventricular systolic dysfunction in patients with obstructive sleep apnea by automated function imaging method; an observational study

We aimed to evaluate the subclinical left ventricular (LV) systolic dysfunction with the automated function imaging method (AFI) based on speckle tracking echocardiography (STE) in obstructive sleep apnea patients (OSA) with normal left ventricular ejection fraction (LVEF) and without any confounding disease that can cause myocardial dysfunction. Twenty-one healthy individuals and 58 OSA patients were included in this observational cross-sectional study. According to the severity of disease, OSA patients were examined in three groups; mild, moderate and severe OSA. Apical 2-, 3- and 4- chamber images were obtained for AFI evaluation. The global systolic longitudinal strain (GLS) values were determined for each view, and averages of these were used in comparison of the patient groups. One-way ANOVA, Kruskal-Wallis, Pearson correlation tests and linear regression analysis were used for statistical analysis. The GLS values of the OSA patients were lower than of the healthy individuals and these values were decreased along with the OSA severity (Healthy:-25.58±-2.16%, Mild:-23.93±-3.96%, Moderate:-21.27±-2.60%, Severe:-16.94±-2.66%, respectively). The difference was significant between moderate OSA patients and healthy individuals, and significant between severe OSA patients and all other groups (p<0.03). The apnea-hypopnea index was found to be correlated with the GLS (β=-0.659, 95% CI: 0.09-0.17, p<0.001). Longitudinal LV mechanics in OSA patients with normal LVEF are deteriorated in the subclinical stage being associated with the severity of disease. AFI can be used as an effective and safe method in the determination of subclinical myocardial dysfunction in OSA patients, because it is semi-automated and easy to use with a short analysis time.

Relocation pharyngoplasty

Relocation pharyngoplasty

Phenotyping interindividual variability in obstructive sleep apnoea response to temazepam using ventilatory chemoreflexes during wakefulness

Centrally active agents have a variable impact in patients with obstructive sleep apnoea (OSA) that is unexplained. How to phenotype the individual OSA response is clinically important, as it may help to identify who will be at risk of respiratory depression and who will benefit from a centrally active agent. Based on loop gain theory, we hypothesized that OSA patients with higher central chemosensitivity have higher breathing instability following the use of a hypnosedative, temazepam. In 20 men with OSA in a double-blind, placebo-controlled cross-over trial we tested the polysomnographically (PSG) measured effects of temazepam 10 mg versus placebo on sleep apnoea. Treatment nights were at least 1 week apart. Ventilatory chemoreflexes were also measured during wakefulness in each subject. The patients (mean ± standard deviation; 44 ± 12 years) had predominantly mild-to-moderate OSA [baseline apnoea-hypopnoea index (AHI) = 16.8 ± 14.1]. Patients' baseline awake central chemosensitivity correlated significantly with both the change of SpO₂ nadir between temazepam and placebo (r = -0.468, P = 0.038) and oxygen desaturation index (ODI; r = 0.485, P = 0.03), but not with the change of AHI (r = 0.18, P = 0.44). Peripheral chemosensitivity and ventilatory recruitment threshold were not correlated with the change of SpO₂ nadir, ODI or AHI (all P > 0.05). Mild-moderate OSA patients with higher awake central chemosensitivity had greater respiratory impairment during sleep with temazepam. Relatively simple daytime tests of respiratory control may provide a method of determining the effect of sedative-hypnotic medication on breathing during sleep in OSA patients.

Comparison of Titratable Oral Appliance and Mandibular Advancement Splint in the Treatment of Patients with Obstructive Sleep Apnea

Objective. To compare the effect of two intraoral devices (titratable oral appliance-Klearway (KW) and mandibular advancement splint (MAS)) in mild and moderate obstructive sleep apnea (OSA) patients. Method and Materials. The study group was comprised of twenty-four adult volunteer patients with OSA. Twelve subjects were fitted with a titratable oral appliance (group KW) protruding the mandible (85% of maximum protrusion). The other 12 subjects received MAS with 75% protrusion of the mandible (group MAS). Baseline, (“0.PSG”), first week (K1.PSG for KW group and M1.PSG for MAS group), and after the first month (K2.PSG for KW group and M2′. PSG for MAS group). Results. Both groups produced similar reduction in apnea-hypopnea index (AHI) from baseline till the end of the first week and first month (P < .05). However, the success rate of both groups at the end of the first month was found to be statistically different from the success rate of the first week (P < .05). The reduction in mean AHI of group KW-moderate (KW-mo) was significantly different from the mean AHI of group MAS-moderate (MAS-mo) at the end of the first month (P < .05). Conclusion. This study suggests that Klearway appliance was more effective in treating moderate OSA patients than MAS appliance. It was concluded that an appliance that provides 85% mandibular advancement to open the upper airway was more effective in reducing the number of high apneic events during sleep in comparison to the one which provides 75%.

New Index for Analysis of Polysomnography, ‘Integrated Area of Desaturation’, Is Associated with High Cardiovascular Risk in Patients with Mild to Moderate Obstructive Sleep Apnea

Background: Although obstructive sleep apnea (OSA) severity is evaluated by the apnea-hypopnea index (AHI), the value of AHI in evaluating cardiovascular risks, especially in mild to moderate OSA, is unclear. Objectives: The purpose of this study is to evaluate the validity of a new index, the integrated area of desaturation (IAD), to detect the incidence of cardiovascular events (CVEs) in such patients. Methods: We enrolled 230 consecutive patients with mild to moderate OSA and 354 with severe OSA diagnosed by polysomnography, of whom 53 and 112, respectively, had CVEs. The IAD was calculated by dividing the area of desaturation by total sleep time in polysomnography. C-reactive protein (CRP) was also measured for all patients. Results: In the mild to moderate OSA patients, the mean IAD of the CVEs group was significantly higher than that of the non-CVE group (94.4 ± 82.7 vs. 62.3 ± 50.8, p = 0.001), whereas mean AHI and 3% oxygen desaturation index were similar in both groups. Multivariate analysis demonstrated that the IAD was an independent variable for CVEs (OR 1.006, 95% confidence interval 1.001–1.012, p = 0.031). Moreover, the IAD level of the high CRP group was significantly higher than that of the low CRP group (92.9 ± 84.8 vs. 63.9 ± 54.5, p = 0.009). There was no significant difference in AHI, IAD or other polysomnographic parameters in the severe OSA patients. Conclusions: IAD might be superior to AHI alone in the evaluation of the history of CVEs in mild to moderate OSA patients, and it deserves attention as a possible predictor of future CVEs.