Microarousal Index Research Articles

Sleep Quality, Psychologic Profiles, Cardiac Activity, and Salivary Biomarkers in Young Subjects with Different Degrees of Rhythmic Masticatory Muscle Activity: A Polysomnography Study.

To investigate the objective and subjective characteristics of sleep and psychosomatic and physiologic variables in young subjects with different frequencies of rhythmic masticatory muscle activity (RMMA) during sleep. A total of 54 young (mean age 23.8 ± 2.1 years), healthy subjects underwent polysomnographic (PSG) recordings for 2 nights. Sleep and psychosomatic states were assessed prior to PSG using validated questionnaires, and the following PSG variables were assessed before and after sleep: subjective sleep quality, physical symptoms, anxiety level, and salivary biomarkers. Second-night sleep and oromotor variables were scored according to standard criteria as well as the quantitative autonomic activity during the night. These variables were compared among the high- (H-RMMA, n = 21, mean RMMA index: 5.7 times/hour) and low- (L-RMMA, n = 13, 2.6 times/hour) frequency RMMA and control (CTL, n = 20 subjects, 1.0 time/hour) groups. Sleep and psychosomatic states did not differ among the three groups. No group differences were noted for nonrhythmic oromotor events. Sleep architecture did not differ among the three groups except for sleep latency being shorter (P = .008) and microarousal index being higher (P = .013) in the H-RMMA group. Mean heart rate during sleep was lower (Stage N2, P = .008; Stage N3, P = .036; Stage R, P = .045) in the H-RMMA group, but the heart rate variability did not differ among the three groups. Sleep quality and anxiety level before and after sleep did not differ among the three groups. Cortisol did not differ among the three groups, while chromogranin A in the morning was slightly lower in the L-RMMA group (median: 9.1 pmol/mg) than in the H-RMMA group (12.3 pmol/mg) (P = .049). In otherwise healthy subjects presenting normal physiologic variables, neither significant nor consistent differences in sleep architecture, psychologic states, heart rate variability, or salivary biomarkers in relation to the frequency of RMMA were found.

Exploration of cardiac sympathetic adrenergic nerve activity in narcolepsy

ObjectiveTo compare cardiac sympathetic adrenergic nerve activity in patients with narcolepsy type 1 (NT1) and controls using 123I-MIBG myocardial scintigraphy, and to determine the clinical and neurophysiological variables associated with 123I-MIBG scintigraphy results in NT1. MethodsFifty-six NT1 patients and 91 controls without neurological diseases underwent a cardiac scintigraphy. MIBG uptake was quantified by delayed heart/mediastinum (H/M) ratio. Clinical, neurophysiological and biological determinants of a low H/M were assessed in NT1. ResultsMIBG uptake did not differ between NT1 and controls in crude and adjusted associations. Five patients had low MIBG uptake (<1.42, first decile of controls), often with advanced age, cardiovascular (CV) diseases, stimulants intake, and REM sleep behavior disorder. Patients with H/M <1.62 (lowest tertile) were older, with higher BMI, microarousal index and CV comorbidities. A three-fold increase of phasic/tonic REM sleep motor activities was found in those patients, confirmed in a subanalysis of 40 drug-free patients. No association was found with CSF hypocretin levels. ConclusionA direct measure of the heart adrenergic nerve activity revealed no sympathetic denervation in NT1. SignificanceOur results indicate normal cardiac sympathetic innervation in NT1. However, few patients with low MIBG uptake also presented CV comorbidities and REM sleep motor deregulation, potentially at high CV risk, requiring a careful follow-up.

Interrelationships Among Apolipoprotein B/Apolipoprotein A-I Ratio, Insulin Resistance and Obstructive Sleep Apnea: A Large-Scale Observational Study

Background: The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) ratio has been recognized as a new predictor of cardiovascular diseases (CVD). However, the interrelationships between the ApoB/ApoA-I ratio and common CVD risk factor [insulin resistance, obstructive sleep apnea (OSA)] remain unclear. Methods: A total of 6,433 suspected OSA consecutively admitted to our sleep center were screened and 4,813 were included. Anthropometric, fasting biochemical, and polysomnographic parameters were collected. The relationships between insulin resistance, OSA risk, and the ApoB/ApoA-I ratio were evaluated through logistic regressions analysis and restricted cubic spline (RCS) analysis. Mediation analyses were qualified to assess the interrelationships. Results: Patients with OSA had a lower level of ApoA-I and a higher ApoB and ApoB/ApoA-I ratio. The fully adjusted odds ratios (95% confidence intervals) for both OSA [1 (reference), 1.406 (1.129-1.751), 1.556 (1.236-1.958), and 1.943 (1.508-2.505)] and insulin resistance [1 (reference), 1.424 (1.176-1.725), 1.948 (1.359-1.998), 2.019(1.658-2.459)] increased from the first to the fourth quartiles of the ApoB/ApoA-I ratio. Finally, the RCS mapped a nonlinear dose-effect relationship between the ApoB/ApoA-I ratio and risk of insulin resistance and OSA. OSA was also independently associated with insulin resistance. Mediation analyses showed insulin resistance explain 7.4%, 3.6% and 10.8% of the association between apnea-hypopnea index, oxygen desaturation index, micro-arousal index and ApoB/ApoA-I ratio, respectively. Conclusions: Our study revealed that ApoB/ApoA-I ratio was positively associated with an increased risk for insulin resistance and OSA severity. Insulin resistance may serve as a potential mediator in OSA-related lipoprotein disorders and further increase CVD risk. Funding Statement: This study was supported by grants-in-aid from National Key R&D Program of China (2017YFC0112500), National Natural Science Foundation of China (81770987), Shanghai Sailing Program (17YF1414300), multi-center clinical research project from school of medicine, Shanghai Jiao Tong University (DLY201502) and Shanghai Shen-Kang Hospital Management Center Project of Shanghai (SHDC12015101). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: The ethics committee of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital approved this study according to Helsinki Declaration II. All the participants have given the informed consent before taking part in the study.

Objective and Subjective Sleep Efficiency in Adult Patients with Cystic Fibrosis and Impact on Quality of Life.

Poor sleep quality and excessive daytime sleepiness are common in patients with cystic fibrosis (CF), and both are negatively correlated with health-related quality of life (HRQoL). The objective of our study was to evaluate subjective and objective sleep quality in adult CF patients and its effect on HRQoL. This was a descriptive, prospective, cross-sectional study of CF patients > 18years of age. Patients underwent nocturnal polysomnography (PSG) and were administered the Pittsburgh Sleep Quality Index questionnaire (PSQI) and the Cystic Fibrosis Quality of Life Questionnaire (CFQR 14 + Spain). The study included 23 patients, 14 women (61%). The mean age of the participants was 32 + 18years. The mean PSQI score was 5.57 + 3.55; 13 (56.5%) of the patients were poor sleepers, and 13% reported poor sleep quality; seven (30%) had sleep latency > 30min, 10 (43.5%) had sleep efficiency < 85%. Nineteen underwent polysomnography. According to PSG measurements, sleep efficiency was less than 90% in 61% of the patients. Pathological values were found for the following parameters: intra-sleep wakefulness in 12 patients (63%); microarousal index in 12 patients (63%); and apnea-hypopnea index (AHI) in 2 patients. The desaturation time with SpO2 < 90% (T90) was > 30% in 3 patients. We observed a significant correlation between PSQI and all dimensions of CFQR 14. Subjective and objective sleep efficiency decreases in adult CF patients. Sleep quality has an impact on HRQoL. The PSQI questionnaire was able to discriminate sleep quality.

Independent relationships between cardinal features of obstructive sleep apnea and glycometabolism: a cross-sectional study

BackgroundObstructive sleep apnea (OSA) is associated with abnormal glycometabolism; however, the cardinal features of OSA, such as sleep fragmentation (SF) and intermittent hypoxia (IH), have yet to show clear, independent associations with glycometabolism. MethodsWe enrolled 1834 participants with suspected OSA from July 2008 to July 2013 to participate in this study. Polysomnographic variables, biochemical indicators, and physical measurements were collected for each participant. Multiple linear regression analyses were used to evaluate independent associations between cardinal features of OSA and glycometabolism. Logistic regressions were used to determine the odds ratios (ORs) for abnormal glucose metabolism across microarousal index (MAI) and oxygen desaturation index (ODI) quartiles. The effect of the interaction between MAI and ODI on glycometabolism was also evaluated. ResultsThe MAI was independently associated with fasting insulin levels (β = 0.024, p = 0.001) and the homeostasis model assessment of insulin resistance (HOMA-IR; β = 0.006, p = 0.002) after multiple adjustments of confounding factors. In addition, the ORs for hyperinsulinemia across higher MAI quartiles were 1.081, 1.349, and 1.656, compared with the lowest quartile (p = 0.015 for a linear trend). Similarly, the ODI was independently associated with fasting glucose levels (β = 0.003, p < 0.001), fasting insulin levels (β = 0.037, p < 0.001), and the HOMA-IR (β = 0.010, p < 0.001) after adjusting for multiple factors. The ORs for hyperglycemia across higher ODI quartiles were 1.362, 1.231, and 2.184, compared with the lowest quartile (p < 0.05 for a linear trend). In addition, the ORs for hyperinsulinemia and abnormal HOMA-IR across ODI quartiles had the same trends. There was no interaction between MAI and ODI with respect to glycometabolism. ConclusionSF was independently associated with hyperinsulinemia, and IH was independently associated with hyperglycemia, hyperinsulinemia, and an abnormal HOMA-IR. We found no interaction between SF and IH with respect to OSA-related abnormal glycometabolism.

Impact of Mandibular Advancement Therapy on Endothelial Function in Severe Obstructive Sleep Apnea.

Endothelial dysfunction, a major predictor of late cardiovascular events, is linked to the severity of obstructive sleep apnea (OSA). To determine whether treatment with mandibular advancement device, the main alternative to continuous positive airway pressure, improves endothelial function in patients with severe OSA. In this trial, we randomized patients with severe OSA and no overt cardiovascular disease to receive 2 months of treatment with either effective mandibular advancement device or a sham device. The primary outcome, change in reactive hyperemia index, a validated measurement of endothelial function, was assessed on an intention-to-treat basis. An embedded microsensor objectively measured treatment compliance. A total of 150 patients (86% males; mean [SD] age, 54 [10] yr; median [interquartile range] apnea-hypopnea index, 41 [35-53]; mean [SD] Epworth sleepiness scale, 9.3 [4.2]) were randomized to effective mandibular advancement device (n = 75) or sham device (n = 75). On intention-to-treat analysis, effective mandibular advancement device therapy was not associated with improvement of endothelial function compared with the sham device. Office and ambulatory blood pressure outcomes did not differ between the two groups. Effective mandibular advancement device therapy was associated with significant improvements in apnea-hypopnea index (P < 0.001); microarousal index (P = 0.008); and symptoms of snoring, fatigue, and sleepiness (P < 0.001). Mean (SD) objective compliance was 6.6 (1.4) h/night with the effective mandibular advancement device versus 5.6 (2.3) h/night with the sham device (P = 0.006). In moderately sleepy patients with severe OSA, mandibular advancement therapy reduced OSA severity and related symptoms but had no effect on endothelial function and blood pressure despite high treatment compliance. Clinical trial registered with www.clinicaltrials.gov (NCT 01426607).

Obstructive sleep apnea exaggerates cognitive dysfunction in stroke patients

BackgroundObstructive sleep apnea (OSA) is very common in stroke survivors. It potentially worsens the cognitive dysfunction and inhibits their functional recovery. However, whether OSA independently damages the cognitive function in stroke patients is unclear. A simple method for evaluating OSA-induced cognitive impairment is also missing. MethodsForty-four stroke patients six weeks after onset and 24 non-stroke patients with snoring were recruited for the polysomnographic study of OSA and sleep architecture. Their cognitive status was evaluated with a validated Chinese version of Cambridge Prospective Memory Test. The relationship between memory deficits and respiratory, sleeping, and dementia-related clinical variables were analyzed with correlation and multiple linear regression tests. ResultsOSA significantly and independently damaged time- and event-based prospective memory in stroke patients, although it had less power than the stroke itself. The impairment of prospective memory was correlated with increased apnea–hypopnea index, decreased minimal and mean levels of peripheral oxygen saturation, and disrupted sleeping continuity (reduced sleep efficiency and increased microarousal index). The further regression analysis identified minimal levels of peripheral oxygen saturation and sleep efficiency to be the two most important predictors for the decreased time-based prospective memory in stroke patients. ConclusionsOSA independently contributes to the cognitive dysfunction in stroke patients, potentially through OSA-caused hypoxemia and sleeping discontinuity. The prospective memory test is a simple but sensitive method to detect OSA-induced cognitive impairment in stroke patients. Proper therapies of OSA might improve the cognitive function and increase the life quality of stroke patients.

Correlation Analysis between Polysomnography Diagnostic Indices and Heart Rate Variability Parameters among Patients with Obstructive Sleep Apnea Hypopnea Syndrome

Heart rate variability (HRV) can reflect the changes in the autonomic nervous system (ANS) that are affected by apnea or hypopnea events among patients with obstructive sleep apnea hypopnea syndrome (OSAHS). To evaluate the possibility of using HRV to screen for OSAHS, we investigated the relationship between HRV and polysomnography (PSG) diagnostic indices using electrocardiography (ECG) and PSG data from 25 patients with OSAHS and 27 healthy participants. We evaluated the relationship between various PSG diagnostic indices (including the apnea hypopnea index [AHI], micro-arousal index [MI], oxygen desaturation index [ODI]) and heart rate variability (HRV) parameters using Spearman’s correlation analysis. Moreover, we used multiple linear regression analyses to construct linear models for the AHI, MI, and ODI. In our analysis, the AHI was significantly associated with relative powers of very low frequency (VLF [%]) (r = 0.641, P = 0.001), relative powers of high frequency (HF [%]) (r = -0.586, P = 0.002), ratio between low frequency and high frequency powers (LF/HF) (r = 0.545, P = 0.049), normalized powers of low frequency (LF [n.u.]) (r = 0.506, P = 0.004), and normalized powers of high frequency (HF [n.u.]) (r = -0.506, P = 0.010) among patients with OSAHS. The MI was significantly related to standard deviation of RR intervals (SDNN) (r = 0.550, P = 0.031), VLF [%] (r = 0.626, P = 0.001), HF [%] (r = -0.632, P = 0.001), LF/HF (r = 0.591, P = 0.011), LF [n.u.] (r = 0.553, P = 0.004), HF [n.u.] (r = -0.553, P = 0.004), and absolute powers of very low frequency (VLF [abs]) (r = 0.525, P = 0.007) among patients with OSAHS. The ODI was significantly correlated with VLF [%] (r = 0.617, P = 0.001), HF [%] (r = -0.574, P = 0.003), LF [n.u.] (r = 0.510, P = 0.012), and HF [n.u.] (r = -0.510, P = 0.012) among patients with OSAHS. The linear models for the PSG diagnostic indices were AHI = -38.357+1.318VLF [%], MI = -13.389+11.297LF/HF+0.266SDNN, and ODI = -55.588+1.715VLF [%]. However, the PSG diagnostic indices were not related to the HRV parameters among healthy participants. Our analysis suggests that HRV parameters are powerful tools to screen for OSAHS patients in place of PSG monitoring.

Independent Association between Sleep Fragmentation and Dyslipidemia in Patients with Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is independently associated with dyslipidemia. Previous studies have demonstrated that sleep fragmentation can impair lipid metabolism. The present study aimed to identify whether sleep fragmentation is independently associated with dyslipidemia, in a large-scale, clinic-based consecutive OSA sample. This cross-sectional study was conducted among 2,686 patients who underwent polysomnography (PSG) for suspicion of OSA from January 2008 to January 2013 at the sleep laboratory. Multivariate regression analyses were performed to evaluate the independent associations between the microarousal index (MAI) and lipid profiles adjusting for potential confounders, including metabolic syndrome components and nocturnal intermittent hypoxia. The adjusted odds ratios (ORs) for various types of dyslipidemia according to MAI quartiles, as determined by logistic regression were also evaluated. MAI was found positively associated with low-density lipoprotein cholesterol (LDL-c) but not with total cholesterol (TC), triglyceride (TG) or high-density lipoprotein cholesterol (HDL-c). Furthermore, the adjusted ORs (95% confidence interval) for hyper-LDL cholesterolemia increased across MAI quartiles, as follows: 1 (reference), 1.3 (1.1–1.7), 1.6 (1.2–2.0), and 1.6 (1.2–2.1) (p = 0.001, linear trend). Sleep fragmentation in OSA is independently associated with hyper-LDL cholesterolemia, which may predispose patients with OSA to a higher risk of cardiovascular disease.

Nocturnal Hypoxemia Causes Hyperglycemia in Patients With Obstructive Sleep Apnea and Type 2 Diabetes Mellitus

BackgroundOur purpose was to investigate the relationship between oxygen saturation (SpO2) and dynamic interstitial glucose level (IGL) in patients with obstructive sleep apnea (OSA) along with type 2 diabetes mellitus (T2DM), and to investigate the potential mechanisms thereof. Materials and MethodsA total of 130 patients with OSA and T2DM underwent polysomnography and oral glucose tolerance tests at the Sleep Medicine Center. Using the lowest (L) SpO2% tested, patients were divided into mild, moderate and severe LSpO2 groups. Polysomnography and continuous glucose monitoring systems were used to analyze the altered pattern of SpO2 and dynamic IGL in the 3 groups. ResultsLSpO2 during sleep in patients with OSA and T2DM stimulated an increase in IGL. The moderate and severe levels were represented by IGL45 and IGL30, respectively. The average nocturnal and peak IGL after LSpO2 in the severe group were significantly higher than in the mild and moderate groups. Stepwise multiple regression analysis showed that the body mass index (β = 0.301, P < 0.001), homeostatic model assessment of insulin resistance (β = 0.260, P < 0.001), apnea-hypopnea index (β = 0.309, P < 0.001), average SpO2 (β = −0.423, P = 0.008), LSpO2 (β = −0.369, P < 0.001) and microarousal index (β = 0.335, P = 0.044) were probably related to nocturnal IGL in patients with OSA along with T2DM. ConclusionsSevere and moderate OSA with T2DM is marked by a delayed IGL peak following LSpO2. Nocturnal hypoxemia causes hyperglycemia in patients with OSA along with T2DM.

Evaluating the clinical value of oscillatory cardiopulmonary coupling in patients with obstructive sleep apnea hypopnea syndrome by impedance cardiogram

ObjectivesFor patients with obstructive sleep apnea hypopnea syndrome (OSAHS), chronic inflammation and hemodynamic oscillations caused by respiratory events contribute to cardiovascular disease (CVD). In this study, a physiological marker named oscillatory coupling factor (OCF) exacted from cardiac output (CO) was introduced. This study aimed to evaluate the clinical value of OCF and tentatively explore its predictive value of cardiovascular prognosis in OSAHS patients. MethodsAn impedance cardiogram (ICG) was used to continuously obtain the participants' CO with simultaneous polysomnography. Participants were divided into three groups: an OSAHS–CVD– group (n = 19); an OSAHS + CVD– group (n = 34); and an OSAHS + CVD + group (n = 36). The OCF was exacted from the CO by using empirical mode decompensation-based detrended fluctuation analysis (EMD–DFA). ResultsThe OCF values were: OSAHS + CVD + group [1.20 (0.98–1.78)] > OSAHS + CVD– group [1.14 (1.02–1.94)] > OSAHS–CVD– group [0.95 (0.56–1.16)], (p = 0.001). A Spearman test showed that OCF was positively correlated with age, apnea/hypopnea index (AHI), microarousal index (MAI), oxygen desaturation index (ODI), and negatively correlated with the lowest SpO2. Ten participants were treated by one-night continuous positive airway pressure (CPAP): their AHI decreased from 44.9 (18.0–72.9)/hour to 1.25 (0.0–7.5)/hour, and their OCF fell from 1.17 (1.10–1.69) to 1.08 (0.96–1.23) (p = 0.038). Seventy-seven participants were effectively followed up. Seven participants developed CVD events or newly diagnosed CVD; their OCFs were distributed on a relatively high level [1.18 (1.01–1.56)]. ConclusionThe OSAHS participants had higher OCFs than those without OSAHS, while CVD made the OCFs even higher; CPAP could rectify this change. Oscillatory coupling factor may be a physiological marker of cardiopulmonary coupling and have potential cardiovascular prognostic value for people with OSAHS.

Relationship Between Nocturnal Intraocular Pressure Variations and Sleep Macrostructure.

The purpose of this study was to characterize the relationships between nocturnal intraocular pressure (IOP) variations and sleep macrostructure in healthy subjects. This was a cross-sectional study conducted in a center with shared expertise in chronobiology. Twelve healthy volunteers (22.3 ± 2.3 years) underwent a 24-hour IOP measurement session. The IOP variations of one eye were continuously estimated using a contact lens sensor (CLS) measuring the changes in corneal curvature related to the IOP and not requiring nocturnal awakening for measurements. The CLS measurement characteristics (mean, maximum, minimum, and amplitude) were evaluated across sleep stages (non-rapid eye movement [NREM] sleep [N1, N2, N3], REM) and assessed using polysomnography. The CLS signal measurement changes during sleep stage changes were calculated to evaluate the effects of sleep on IOP. A 24-hour IOP nyctohemeral rhythm was found in all subjects. During the nocturnal period, IOP signal values were significantly lower during wake stages than during REM and NREM N1, N2, and N3 sleep stages (P ≤ 0.04). The IOP signal values were significantly higher during the REM stage than during the NREM stages (P ≤ 0.03) and progressively decreased as NREM sleep deepened (P ≤ 0.04). We found a positive relationship between the micro-arousal index and the nocturnal period CLS signal SD (r = 0.76; P = 0.024) and a negative relationship between sleep efficiency and the nocturnal period CLS signal SD (r = -0.69; P = 0.041). Sleep micro- and macrostructure and nocturnal IOP variations are closely related in young subjects without sleep disorders. Across sleep stages, IOP is highest during REM sleep and progressively decreases as NREM sleep deepens.

Investigation of the relationship between arterial stiffness and sleep architecture in patients with essential hypertension

A change in sleep architecture might increase the risk of hypertension and worsen target organs. This study thus aimed to study the features of sleep architecture and examine its relationship with pulse wave velocity (PWV), a measure of arterial stiffness, in patients with essential hypertension and healthy people aged 45–65 years (n = 106). We collected data on demographics, the serum index, overnight polysomnography, vascular testing and ambulatory blood pressure in addition to measuring arterial stiffness and monitoring sleep respiration. We found that patients with hypertension had longer sleep latency and shorter duration. Their sleep efficiency and the ratio of N3 in non-rapid eye movement (NREM) and rapid eye movement were lower, while the micro-arousal index (MI), N1 and N2 in NREM, and the apnea-hypopnea index were higher than normal people in controls. PWV raised with a decrease in N3 and an increase in the MI. In summary, there were notable changes in sleep architecture and with a decrease in N3 and increase in MI can accelerate arterial stiffness and then worsen target organ damage in patients with hypertension.

Obstructive sleep apnea: acute effects of CPAP on polyssonographic variables

Introduction The use of non-invasive ventilation in the form of continuous positive airway pressure (CPAP) is among the main therapeutic options for patients with obstructive sleep apnea (OSA). Yet the effects of CPAP obtained on the first night of use are underreported. Objective To evaluate the acute effects of CPAP on polysomnographic variables in patients with OSA. Materials and methods This study is a case series with 31 patients (55.8 ± 11.4 years; 22 men) in the initial phase of CPAP treatment. The subjects were evaluated by means of polysomnography with and without CPAP (10.2 ± 3.1 cmH2O) and without CPAP, on different days, by means of the following variables: sleep stages 1, 2 and 3 (N1, N2 and N3), rapid eye movement (REM) sleep, apnea and hypopnea index (AHI), AHI in REM sleep (AHIREM) and the micro-arousal index (MAI). Results The use of CPAP resulted in a reduction of N2 (p &lt; 0.001), AHI (p &lt; 0.001), AHIREM (p &lt; 0.001) and MAI (p = 0.001). There was an increase in N3 (p = 0.006) and REM sleep (p &lt; 0.001) during the night with use of CPAP. Conclusion This study demonstrated that, from the first night of use by patients with OSA, CPAP promotes greater balance between sleep phases, and improves sleep quality. These results should be presented to patients and their families in order to encourage greater adherence in the initial phase of treatment with CPAP.

Electrical Stimulation of the Genioglossus in Patients with Residual Obstructive Sleep Apnea Post-UPPP Surgery

Objective: Genioglossus is a major upper-airway dilator muscle, which leads to upper-airway obstruction when its activity is decreased. We evaluated the effect and safety of genioglossus stimulation for patients with residual mild-to-moderate obstructive sleep apnea (OSA) after uvulopalatopharyngoplasty (UPPP). Methods: We enrolled 23 patients diagnosed with OSA by polysomnography (PSG) 6 months after UPPP, who underwent nightly transcutaneous genioglossus stimulation (TGS) therapy. Apnea hypopnea index (AHI), microarousal index (MAI), the ratio of duration of SpO2 < 90% to total sleep time (T90) and Epworth sleepiness scale (ESS) before and during TGS treatment were compared. We first observed the overall effect of TGS, and then compared its influence on patients with mild and moderate sleep apnea. Results: Compared with non-TGS therapy, there was a significant decrease in AHI, MAI, T90, and ESS (9.15 ± 4.21 vs. 17.90 ± 6.85, p < 0.0001; 6.33 ± 3.75 vs. 10.93 ± 4.90, p < 0.0001; 4.87 ± 4.02 vs. 9.13 ± 4.24, p < 0.0001; 8.65 ± 3.35 vs. 9.30 ± 3.10, p = 0.002, respectively), and a significant increase in mean SpO2 and minimal SpO2 (mini SpO2) (95.52% ± 0.95% vs. 94.43% ± 1.12%, p < 0.0001; 88.74% ± 2.94% vs. 85.17% ± 4.67%, p < 0.0001, respectively) during TGS treatment. Patients in the mild and moderate groups had the same variation trend between TGS and non-TGS therapy nights. However, the moderate group had a higher absolute value of changed AHI (△AHI; 11.12 ± 3.95 vs. 5.66 ± 1.70, p < 0.05) and MAI (△MAI; 5.8 (3.3, 8.6) vs. 2.5 (1.05, 5.6), p < 0.05) than the mild group. There were no significant differences in absolute changed mean SpO2 (△mean SpO2), absolute changed miniSpO2 (△miniSpO2), changed T90 (△T90) and absolute changed ESS (△ESS) between the two groups. Moreover, the percentage of △AHI was not different between the two groups (47.89% ± 13.79% vs. 51.04% ± 13.32%, p = 0.587). There was no perceived discomfort during TGS therapy and no procedure-related adverse events. Conclusion: Submental transcutaneous electrical stimulation of the genioglossus led to a significant reduction in AHI and improvement of daytime sleepiness for existing mild-to-moderate OSA patient’s post-UPPP surgery.

Efficacies of stimulation of genioglossus in mild-to-moderate obstructive sleep apnea syndrome patients after uvulopalatopharyngoplasty

To evaluate the efficacies of transcutaneous stimulation of genioglossus on remaining mild-to-moderate obstructive sleep apnea syndrome (OSAS) after uvulopalatopharyngoplasty (UPPP). A total of 22 patients diagnosed with mild-to-moderate OSAS by polysomnography (PSG) after UPPP were recruited from Sleep Center of First Affiliated Hospital, Nanjing Medical University from February 2013 to October 2013 and underwent transcutaneous stimulation of genioglossus therapy at night. Prior to and during treatment overnight polysomnography examination was performed. Moreover, the sleepiness of patients was assessed according to the Epworth sleepiness scale (ESS) before and after treatment. Comparison was made to observe the effects of treatment on PSG parameters and daytime ESS. Compared with pre-treatment, nocturnal apnea hypopnea index (AHI) (9.3 ± 4.2 vs 18.3 ± 6.8), microarousal index (MAI) (6.5 ± 3.8 vs 11.2 ± 4.8), radio of duration pulse oxygen saturation (SpO2) < 90% to total sleep time (T90) ((5.1 ± 4.0)% vs (9.5 ± 4.0)%) and score of daytime ESS (8.8 ± 3.3 vs 9.4 ± 3.1) all significantly decreased (all P < 0.01) while mean SpO2 ((95.5 ± 1.0)% vs (94.4 ± 1.1)%) and minimal SpO2 ((88.6 ± 2.9)% vs (84.9 ± 4.6)%) were both significantly elevated (both P < 0.001). None of them experienced obvious discomforts during treatment. Submental transcutaneous electrical stimulation of genioglossus is an effective treatment for remaining mild-to-moderate OSAS after UPPP surgery.

The Association between the Phenotype of Excessive Daytime Sleepiness and Blood Pressure in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

Objective Investigate the clinical features and the blood pressure (BP) pattern of the phenotype of excessive daytime sleepiness (EDS) in OSAHS.Methods A total of 508 Chinese adults with suspected OSAHS were referred to our sleep laboratory from October 2009 to May 2012. On the same night of polysomnography (PSG), the levels of blood pressure were measured before sleeping (bedtime BP) and immediately after waking up in the next morning (morning BP). EDS was recognized as Epworth Sleepiness Scale (ESS)≥9. Subjects were classified into four groups based on the apnea-hypopnea index (AHI) from PSG as follows: control (simple snoring) group (control, n=104) with AHI<5; mild group (mild, n=89) with AHI≥5 and <15; moderate group (moderate, n=70) with AHI≥15 and<30; and severe group (severe, n=245) with AHI ≥30. The differences and correlations between BP and PSG parameters in EDS and non-EDS group of OSAHS patients were analyzed.Results In all subjects, ESS was positively correlated with morning diastolic blood pressure (DBP), Mean arterial pressure (MAP) and bedtime DBP (r=0.144, 0.102 and 0.114, respectively, each P value<0.05). In OSAHS patients, ESS was only positively correlated with morning DBP (r=0.137, P<0.05). OSAHS patients with EDS phenotype were younger and were more likely to have the symptom of waking up feeling tired (36.1% vs. 23.2%, p=0.023), who had lower MSaO2, longer SIT90 (the ratio of time of SpO2 below 90% in total sleep time) and higher DBP (bedtime as well as morning). In patients with AHI≥15, ESS was correlated positively with both bedtime and morning DBP after controlling the confounding effects of age, sex, BMI, AHI and nadir nocturnal oxygen saturation( r=0.126,0.143, respectively, both P values<0.05). And in OSAHS patients of EDS phenotype, the bedtime DBP, bedtime MAP, morning DBP, and morning MAP were 3~5 mm Hg higher than that in patients of non-EDS phenotype(P<0.05). In the moderate and severe OSAHS group, patients with EDS phenotype were younger and had a lower mean blood oxygen saturation (MSaO2), longer time of SpO2 below 90% and higher SIT90 than patients with non-EDS phenotype (P<0.05). In hypertensive OSAHS patients, patients with EDS were also younger and had higher micro-arousal index (MiI), as well as higher morning DBP, morning MAP and bedtime DBP than that in non-EDS group (P<0.05).Conclusions EDS in OSAHS patients is a special phenotype, which was characterized by younger age, higher DBP and more severe hypoxic load. This feature is mainly manifested in moderate and severe OSAHS patients. It is very important to identify the phenotype of EDS in patients with OSAHS, who may meet more benefits from effective treatment of OSAHS by correcting the intermittent nocturnal hypoxia and sleep fragmentation.

Sleep characteristics in children with specific language impairment: macrostructure and microstrucrure analysis

Introduction Sleep is important for learning, memory and underlying neural plasticity. Studies support that children utilize a dual memory system when acquiring and integrating new vocabulary, and sleep (especially sleep spindles, slow waves sleep and REM sleep) is important for this process. We aimed to describe sleep characteristics in children with diagnosis of Specific Language Impairment because sleep disruption, especially of the microstructure, could have an important role in the development and evolution in these patients. Materials and methods 30 children (24 boys and 6 girls) with 3–5 years old, diagnosed of specific language impairment (development quotient ⩾ 70 in Brunet-Lezine Scale), normal MRI, without epileptiform discharges in EEG, no hearing impairment, no other disorders and with parents in medium–high sociocultural level. Children participated in a polysomnographic (PSG) sleep recording. Sleep disorders like Obstructive Sleep Apnea Pediatric (OSAP), Periodic Limb Movement Disorder (PLMD) and parasomnias, and sleep characteristics like sleep stages percentage, spindles characteristics, presence of significant alpha rhythm during sleep (alpha-delta sleep), microarousal index, sleep efficiency and awakenings episodes were analyzed. Results In our sample, we found OSAP only in one patient, and parasomnias in 2 patients. However, data about PLMD was relevant, 93.3% present this disorder with an average index of 9.316 ± 6.11 . We found an average of 4.073 % ± 3.41 of stage 1, 40.76 ± 8.89 of stage 2, 25.381 ± 6.91 of stage 3, 25.587 ± 6.91 of stage REM, 112.76 ± 25.65 of body movements, 3.10 ± 1.6 awakening episodes ⩾ 5 min, 85.14 ± 9.07 of sleep efficiency, 37.556 ± 9.6 of microarousal index (83.4% with microarousal index ⩾ 30 ), 80% present significant percentage of alpha rhythm during sleep and 66.7% presented unsuitable spindles. Conclusion We observed that although the sleep architecture in terms of the macrostructure, like time spent in the different stage of sleep, appears to not be consistently altered in relation with normal values, it is very important the analysis of sleep microstructure because specific features would be altered in these patients and could be related to the problem of language skills. Treatment for specific sleep disorders and treatment to stabilize sleep structure, could improve the symptomatology in these patients.

Nocturnal hypoxemia in children and adolescents with cystic fibrosis

OBJECTIVE: To determine the prevalence of nocturnal hypoxemia and its association with pulmonary function, nutritional status, sleep macrostructure, and obstructive respiratory events during sleep in a population of clinically stable children and adolescents with cystic fibrosis (CF). METHODS: This was a cross-sectional study involving 67 children and adolescents with CF between 2 and 14 years of age. All of the participants underwent polysomnography, and SpO2 was measured by pulse oximetry. We also evaluated the Shwachman-Kulczycki (S-K) scores, spirometry findings, and nutritional status of the patients. RESULTS: The study involved 67 patients. The mean age of the patients was 8 years. The S-K scores differed significantly between the patients with and without nocturnal hypoxemia, which was defined as an SpO2 < 90% for more than 5% of the total sleep time (73.75 ± 6.29 vs. 86.38 ± 8.70; p < 0.01). Nocturnal hypoxemia correlated with the severity of lung disease, FEV1 (rs = −0.42; p = 0.01), FVC (rs = −0.46; p = 0.01), microarousal index (rs = 0.32; p = 0.01), and apnea-hypopnea index (rs = 0.56; p = 0.01). CONCLUSIONS: In this sample of patients with CF and mild-to-moderate lung disease, nocturnal oxygenation correlated with the S-K score, spirometry variables, sleep macrostructure variables, and the apnea-hypopnea index.

Effects of real vs simulated altitude on sleep and sleep disordered breathing

“Real altitude” (e.g. hypobaric hypoxia) has been reported to impair sleep and induce sleep disordered breathing (SDB). It is however not clear whether for the same ambient Oxygen pressure (PO2) “simulated altitude” in a hypoxic chamber (e.g. normobaric hypoxia;) generates similar sleep alterations. Full polysomnography was performed on 13 healthy volunteers (33.9 ± 9.1 y.o, BMI: 23.5 ± 2.2 kg/m 2 ) under three conditions: Hypobaric hypoxia (HH, Junfraujoch Switzerland, 3454 m), normobaric hypoxia (NH, Sion, Switzerland, 500 m, FiO 2 = 0.138 ) and Normobaric normoxia (NN, control night, Sion). NN and NH recordings were performed in a hypoxic chamber (randomized order, double blind). Polysomnography recordings were performed and scored according to the AASM recommendations. For SDB, compared to NN condition, apnea hypopnea index (AHI) increased significantly in both hypoxic conditions (ANOVA): NN 7.1 ± 1.2/h, NH 35.9 ± 11.2/h ( p = 0.04), HH 38.0 ± 9.7/h (p = 0.02). The same was found for hypopnea: NN 6.7 ± 1.2, NH 18.3 ± 4.4 ( p = 0.04), HH 25.3 ± 5.2 ( p = 0.004), oxygen desaturation index (ODI3%): NN 3.8 ± 0.5/h, NH 43.9 ± 10.9/h ( p = 0.008), HH 53.3 ± 9.9/h ( p = 0.0009) and mean oxygen saturation (SaO 2 ): NN 96.5 ± 0.2%, NH 83.6 ± 05% ( p < 0.0001); HH 81.2 ± 0.87 ( p < 0.0001). Despite the same ambient PO2 (105 mmHg), there was a significant difference between HH and NH in mean SpO 2 : −2.4% ( p = 0.04), and an increase in hypopnea index: +7/h ( p = 0.04) but no difference in AHI or central sleep apnea. Regarding sleep, compared to NN, there was in NH and HH a significant decrease in total sleep time: NN 388 ± 13 min, NH 317 ± 18 min ( p = 0.01), HH 351 ± 17 min ( p = 0.05), a significant increase in microarousal index: NN 17.3 ± 1.8/h, NH 26.2 ± 3.9/h ( p = 0.03), HH 24.6 ± 3.8 ( p = 0.05) and a decrease in sleep efficiency between NN and HH: 8.4% ( p = 0.027). We also observed a significant increase in heart rate in hypoxic condition: NN 48.1 ± 1.5, NH 54.7 ± 1.6 ( p = 0.001), HH 61.2 ± 2.7 ( p = 0.002). HR in HH was significantly higher (+6.5 bpm, p = 0.018) than in NH. Compared to NN, both HH and NH conditions increased AHI, hypopnea index, ODI 3%, heart rate and decreased total sleep time and mean SaO2. There was a further decrease in mean SpO 2 and increase in HR and hypopnea in HH compared to NH, suggesting that HH and NH may have different physiological effect despite the same PO2. Swiss national science foundation.