A prospective study of nocturia and the quality of life of elderly patients with obstructive sleep apnea or sleep onset insomnia

OBJECTIVE: To prospectively evaluate the relationship between obstructive sleep apnea syndrome (OSAS), nocturia and quality of life in elderly patients free of the urologic and medical conditions that lead to increased nocturia. METHODS: Prospective study of nocturia in men 65 years and older with isolated OSAS or sleep onset insomnia. After a 7-day nocturia evaluation and nocturnal polysomnography, Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), Quality of Life (SF-36) were administered. RESULTS: OSAS patients with frequent nocturia had significantly greater body mass index (BMI), greater apnea-hypopnea index (AHI), lower lowest oxygen saturation and lower SF-36 subscale scores. Treatment with nasal continuous positive airway pressure (CPAP) for OSAS and behavioral techniques for insomnia improved ESS and BDI scores for all three groups. SF-36 subscale scores improved more in subjects with multiple nocturia. AHI and BMI explain 38% of the variance for nocturia. CONCLUSION: Nasal CPAP reduces OSA and nocturia and improves quality of life of elderly patients.     

Residual subjective daytime sleepiness under CPAP treatment in initially somnolent apnea patients: a pilot study using data mining methods

BACKGROUND AND PURPOSE: Despite correct treatment with positive airway pressure (PAP), obstructive sleep apnea (OSA) patients sometimes remain subjectively somnolent. The reliability of the Epworth Sleepiness Scale (ESS) has been established for healthy subjects and patients under stable conditions; the ESS may eventually vary among treated OSA patients, biasing the results of a cross-sectional analysis of persisting sleepiness. The objective of this study was to depict the evolution of subjective vigilance under treatment using an index of ESS variability (DeltaESS). METHODS: In 80 OSA patients (apnea-hypopnea index [AHI]=54+/-26/h), initially somnolent (ESS=15+/-3) and treated with auto-titrating PAP (APAP) (oxyhaemoglobin desaturation index 3% [ODIapap]=3.4+/-2.2/h; daily APAP use=5.3+/-1.5 h) during 434+/-73 days, ESS scores were regularly collected four times every 109+/-36 days. DESS was calculated and data mining methods (Segmentation and Decision Tree) were used to determine homogeneous groups according to the evolution of ESS scores. RESULTS: When assessed cross-sectionally, 14-25% of the subjects were recognized as somnolent, depending on the moment when ESS was administered. Using data mining methods, three groups were clearly identifiable: two without residual somnolence - group 1, n=38 (47%), with high DeltaESS=-2.9+/-0.8, baseline ESS=16.3+/-3.3, AHI=58.5+/-26.1/h, mean ESSapap=5.1+/-2.4 and group 2, n=31 (39%), with low DeltaESS=-1.1+/-0.5, baseline ESS=13.2+/-1.4, AHI=53+/-27.3/h, mean ESSapap=8.8+/-1.9; and one with persisting sleepiness; group 3, n=11 (14%), with low DeltaESS=-0.3+/-0.8, baseline ESS=16.3+/-3, AHI=38.7+/-10.8/h, mean ESSapap=14.1+/-1.9. Compliance to PAP was high and comparable in the three groups. Age and body mass index (BMI) did not differ. CONCLUSION: Data mining methods helped to identify 14% of subjects with persisting sleepiness. Validation needs to be done on a larger population in order to determine predictive rules.     

The impact of obstructive sleep apnea and daytime sleepiness on work limitation

BACKGROUND: Many patients with obstructive sleep apnea (OSA) participate in the work force. However, the impact of OSA and sleepiness on work performance is unclear. METHODS: To address this issue, we administered the Epworth Sleepiness Scale (ESS), the Work Limitations Questionnaire (WLQ), and an occupational survey to patients undergoing full-night polysomnography for the investigation of sleep-disordered breathing. Of 498 patients enrolled in the study, 428 (86.0%) completed the questionnaires. Their mean age+/-standard deviation (SD) was 49+/-12 years, mean body mass index (BMI) was 31+/-7 kg/m(2) mean apnea hypopnea index (AHI) was 21+/-22 events/h, and mean ESS score was 10+/-5. Subjects worked a mean of 39+/-18 h per week. The first 100 patients to complete the survey were followed up at two years. RESULTS: In the group as a whole, there was no significant relationship between severity of OSA and the four dimensions of work limitation. However, in blue-collar workers, significant differences were detected between patients with mild OSA (AHI 5-15/h) and those with severe OSA (AHI>30/h) with respect to time management (limited 23.1% of the time vs. 43.8%, p=0.05) and mental/personnel interactions (17.9% vs. 33.0%, p=0.05). In contrast, there were strong associations between subjective sleepiness (as assessed by the ESS) and three of the four scales of work limitation. That is, patients with an ESS of 5 had much less work limitation compared to those with an ESS 18 in terms of time management (19.7% vs. 38.6 %, p<0.001), mental-interpersonal relationships (15.5% vs. 36.0%, p<0.001) and work output (16.8% vs. 36.0%; p<0.001). Of the group followed up, 49 returned surveys and 33 who were using continuous positive airway pressure (CPAP) showed significant improvements between the initial and second follow-up in time management (26% vs. 9%, p=0.0005), mental-interpersonal relationships (16% vs. 11.0%, p=0.014) and work output (18% vs. 10%; p<0.009). CONCLUSION: We have demonstrated a clear relationship between excessive sleepiness and decreased work productivity in a population referred for suspected sleep-disordered breathing. Screening for sleepiness and sleep-disordered breathing in the workplace has the potential to identify a reversible cause of low work productivity.     

Effect of CPAP on QT interval dispersion in obstructive sleep apnea patients without hypertension

OBJECTIVES: Delayed cardiac repolarization leading to prolongation of the QT interval is a well-characterised precursor of arrhythmias. Obstructive sleep apnea (OSA) might cause arrhythmias, since QT corrected interval dispersion (QTcd) is increased in these patients. We aimed to determine the effect of nasal continuous positive airway pressure (CPAP) therapy on QTcd in OSA patients without hypertension. METHODS: An overnight polysomnography (PSG) and a standard 12-lead electrocardiogram (ECG) were performed on 49 subjects without hypertension, diabetes mellitus, cardiac or pulmonary disease or any hormonal, hepatic, renal or electrolyte disorders. In 29 moderate-severe OSA (apnea-hypopnea index: AHI15) patients, QTd (defined as the difference between the maximum and minimum QT interval) and QTcd were calculated using the Bazzet formula at baseline and after six months of CPAP therapy. RESULTS: Eighteen patients were compliant with nasal CPAP, and mean age was 46.5+/-4.9 years. Patients had high body mass index (BMI: 30.6+/-4.0 kg/m(2)), but there was no change in either BMI or blood pressure after six months. A strong positive correlation was shown between QTcd and AHI (p<0.001, r=0.913). The QTcd at baseline (54.5+/-8.7 ms) significantly decreased after CPAP therapy (35.5+/-4.2 ms, p<0.001), although it did not significantly change in 11 non-compliant patients. CONCLUSION: In OSA patients without hypertension, CPAP therapy improves the inhomogeneity of repolarization via a significant decrease in QTcd.     

Cognitive dysfunction in patients with obstructive sleep apnea (OSA): partial reversibility after continuous positive airway pressure (CPAP)

The aims of this study were to assess cognitive function in obstructive sleep apnea (OSA) patients and to evaluate the effect of short- and long-term treatment with continuous positive airway pressure treatment (CPAP). A battery of neuropsychological tests, the Epworth Sleepiness Scale (ESS), and the Beck Inventory Scale were administered to 23 patients with severe OSA (age: 56.5+/-6.13; AHI: 54.9+/-13.37) and to 23 age- and education-matched controls. The OSA patients were evaluated in a baseline condition and in two follow-up treatment sessions (after 15 days and 4 months of CPAP, respectively). At baseline, OSA patients had a significant impairment, compared to controls, in tests of sustained attention, visuospatial learning, executive function, motor performance, and constructional abilities. The longitudinal evaluation showed that after a 15-days CPAP treatment attentive, visuospatial learning, and motor performances returned to normal levels. A 4-months CPAP treatment did not result in any further improvement in cognitive tests. Performance on tests evaluating executive functions and constructional abilities was not affected by short- and long-term treatment with CPAP. The findings of this study confirm the hypothesis of partial reversibility of cognitive dysfunction in OSA patients after CPAP.     

Use of the Epworth Sleepiness Scale in Chinese patients with obstructive sleep apnea and normal hospital employees

OBJECTIVE: To determine the use of the Epworth Sleepiness Scale (ESS) in Chinese patients with obstructive sleep apnea syndrome (OSA) and normal hospital employees. METHODS: Our sample consisted of 61 healthy controls and 100 patients with OSA. The test-retest reliability, internal consistency, and concurrent validity of the Chinese version of the ESS were analyzed. We also compared the ESS scores between controls and patients, studied the association between the ESS score and the apnea-hypopnea index (AHI) and minimum oxygen saturation (mO(2)), and examined to what extent the ESS score was predictive of mean sleep latency of the Multiple Sleep Latency Test (MSLT). RESULTS: The Chinese version of the ESS was found to have satisfactory reliability and validity. The mean+/-S.D. of ESS scores in normals was 7.5+/-3.0; in patients, it was 13.2+/-4.7. The ESS score had a negative association with mean sleep latency of the MSLT (rho=-0.42, P=0.0001) but no correlation with the AHI and mO(2). ESS scores of 14 and above significantly predicted a low mean sleep latency of the MSLT. CONCLUSION: The ESS should be included as one of the methods for assessing sleepiness in clinic samples of patients with OSA. Our data showed that the ESS was useful to separate patients with and without pathological degree of objective daytime sleepiness as determined by the MSLT.     

Prospective randomized comparison of impedance-controlled auto-continuous positive airway pressure (APAP(FOT)) with constant CPAP

Background: The measurement of impedance permits reliable detection of obstructive apneas, hypopneas and upper airways resistance syndrome.Objective: To establish whether impedance-controlled self-adjusting positive airway pressure therapy (APAP(FOT)) is equally as good as constant continuous positive airway pressure (CPAP) in the treatment of sleep apnea syndrome (OSAS).Methods: Twenty men and five women with OSAS (age 52.8+/-9.0 years, body mass index (BMI) 31.4+/-5.0 kg/m(2), AHI 32.2+/-18.1/h (mean+/-SD)) underwent baseline polysomnography, manual CPAP titration and two nights of treatment, one with APAP(FOT), one with constant CPAP.Results: With both modes, a significant reduction in respiratory disturbances was seen (apnea/hypopnea index (AHI) baseline 32.2+/-18.1/h, constant CPAP 6.6+/-8.7, APAP(FOT) 5.5+/-3.8/h, P<0.001 baseline vs. each treatment mode). Under APAP(FOT), the sleep profile was normalized (S3/4 baseline 16.3+/-13.9% total sleep time (TST), APAP(FOT) 21.6+/-10.9% TST, P<0.05, rapid eye movement (REM) 14.2+/-6.7% TST vs. 20.3+/-7.3% TST, P<0.01), while with constant CPAP, a tendency towards improvement was found. The mean treatment pressure with APAP(FOT) was significantly lower than the constant CPAP (5.7+/-2.1 vs. 8.3+/-1.6 mbar, P<0.001).Conclusion: We conclude that APAP(FOT) is at least as effective as constant CPAP in normalizing sleep and breathing in OSAS.     

Factors influencing subjective sleepiness in patients with obstructive sleep apnea syndrome

The aim of the present paper was to clarify the factors influencing subjective daytime sleepiness in patients with obstructive sleep apnea syndrome (OSAS). Subjects included 230 adult male OSAS patients aged 20-73 years. Single and multiple linear regression analyses were performed to estimate the association between the Epworth Sleepiness Scale (ESS) and the following variables: Minnesota Multiphasic Personality Inventory (MMPI), Self-Rating Depression Scale (SDS), age, body mass index (BMI), sleep duration during the preceding month and apnea-hypopnea index (AHI). Single linear regression analysis showed that age had a negative association with ESS score, while BMI, AHI, SDS, hypochondriasis (Hs), hysteria, psychopathic deviant, psychasthenia, schizophrenia and hypomania on the MMPI had a positive association with ESS score. However, the other remaining parameters such as nocturnal sleep duration during the preceding month, depression, masculinity-femininity, paranoia, social introversion on the MMPI had no statistical association with ESS score. Multiple linear regression analysis with stepwise elimination method was applied to choose the significant factors associated with ESS. It was found that three variables including age, AHI and Hs scores were independent factors influencing ESS score. The R(2) for the model was 0.14, suggesting that these factors account for 14% of possible variance of subjective daytime sleepiness of OSAS patients. These results suggest that subjective daytime sleepiness in patients with OSAS may be influenced not only by the severity of respiratory disorder indices but also by certain personality characteristics affecting Hs score and by age.     

Nocturnal cardiac arrhythmia in patients with obstructive sleep apnea

BACKGROUND AND PURPOSE: Nocturnal cardiac arrhythmias occur in patients with obstructive sleep apnea (OSA), reportedly as a consequence of the autonomic effects of recurrent apnea with subsequent oxygen desaturation. We have investigated whether different patterns of OSA are associated with specific arrhythmia during sleep. PATIENTS AND METHODS: Electrocardiographic (ECG) data recorded during polysomnography (PSG) were analysed in 257 consecutive OSA patients to determine the prevalence of cardiac rhythm disturbances, and to relate these to breathing pattern (normal, apnea/hypopnea, recovering ventilation, snoring) and oxygen saturation. RESULTS: Arrhythmias were found in 18.5% of patients. Patients with nocturnal bradyarrhythmia (BA) had higher values of ventilatory disturbance (apnea-hypopnea index [AHI] 58.8+/-36.8 vs 37.2+/-30.3, p=0.02), mean desaturation amplitude (8.9+/-4 vs 5.9+/-3.4%, p=0.03), and a lower SaO(2) nadir (69% vs 77%, p=0.003) than those without arrhythmia. The prevalence of BA in patients with AHI>or=30/h was significantly higher than that observed in those with AHI<30/h (7.8% vs 1.5%, respectively; chi(2)=5.61, p=0.01). In contrast, patients with tachyarrhythmia (TA) had no significant differences in AHI, mean desaturation amplitude or SaO(2) nadir than those without arrhythmia. No associations were found between arrhythmia and the presence of comorbidity or concomitant medical therapy, except for an association between tachyarrhythmia and chronic obstructive pulmonary disease (COPD) (odds ratio 2.53; 95% confidence intervals 1.1-5.8, p=0.03). CONCLUSIONS: We conclude that while BA during sleep is associated with OSA severity, concomitant COPD or beta(2)-treatment may play a role in the development of TA during sleep.     

Periodic limb movements and sleepiness in obstructive sleep apnea patients

BACKGROUND AND PURPOSE: The aim of this study was to assess the possibility that periodic limb movements during sleep (PLMS) could play an additive role in the sleepiness associated with obstructive sleep apnea syndrome (OSAS) before treatment, or could account for residual sleepiness in successfully CPAP-treated patients. PATIENTS AND METHODS: In order to test this hypothesis, we compared objective sleepiness, assessed by the Multiple Sleep Latency Test (MSLT) and subjective sleep propensity, assessed by the Epworth Sleepiness Scale (ESS), in a clinical series of 57 patients consecutively diagnosed with OSAS (apnea/hypopnea index, 53.3+/-26.15), before and after 1 year of treatment with CPAP. RESULTS: Twenty-two patients (38.5%) had significant PLMS (at least 5 PLMS/h of sleep; mean 52.9+/-53.9) in absence of apneas (with CPAP). The two groups (with and without PLMS) were similar in gender distribution, BMI, apnea/hypopnea index or CPAP level. Patients with PLMS were older than those without PLMS. Sleepiness measurements following OSAS diagnosis and after 1 year of CPAP treatment were similar in patients PLMS compared to those without significant PLMS. There was no correlation in the PLMS patient group between the PLM index, Epworth Sleepiness Scale score and mean latency in the MSLT. CONCLUSION: In this study we did not find a link between PLMS and increased objective or self-evaluated sleepiness in OSAS patients, before or after treatment with CPAP.     

Gender differences on polysomnographic findings in Greek subjects with obstructive sleep apnea syndrome

BACKGROUND AND PURPOSE: Studies from North American clinics have reported that females with obstructive sleep apnea syndrome (OSAS) are about the same age as males but are heavier, have less severe apnea and make up a much smaller proportion of cases. We examined polysomnographic differences between Greek men and women with OSAS in order to study the influence of gender on clinical presentation and laboratory findings. PATIENTS AND METHODS: This retrospective study included a cohort of 1,010 Greek patients (844 males, 166 females) diagnosed with OSAS by overnight polysomnography (PSG), who were referred to the Sleep Disorders Center of Evangelismos Hospital, Athens Medical School, University of Athens. All patients were studied over a period of three consecutive years, during which time clinical and polysomnography (PSG) findings were compared. RESULTS: Body mass index (BMI) was similar in men and women with OSAS (BMI=31.6+/-5.5kg/m(2) in men versus BMI=32.5+/-8.1 (SD) kg/m(2) in women). Female patients were significantly older than male patients (56.9+/-10.6 versus 50.6+/-11.7 year, P=0.001). The mean apnea-hypopnea index (AHI) during total sleep time was higher in men than in women (42.4+/-28.2 versus 33.2+/-27.7 events/h, P<0.001). The AHI in non-rapid eye movement (NREM) sleep was higher in men than in women (42.9+/-28.9 versus 32.6+/-28.7 events/h, P<0.001), but in rapid eye movement (REM) sleep AHI was similar in men and women (36.0+/-23.3 versus 34.9+/-25.4 events/h). Forty percent of men had AHI-REM sleep >AHI-NREM compared to 62% of women, and the difference between REM and NREM-AHI was significantly less in men than in women (14.21+/-11.18 versus 19.76+/-13.43 events/h, P<0.001)). Several aspects of sleep were worse in women versus men: sleep efficiency index was lower (79.4+/-16.1% versus 85.1+/-12.5%, P<0.001); sleep onset latency (27.7+/-27.7 versus 17.9+/-18.1min, P<0.001), and REM onset latency (161.5+/-76.2 versus 145.7+/-71.4min, P<0.018) were longer; wake time after sleep onset (WASO) was also greater in women (42.6+/-46.5 versus 30.7+/-34.9min, P<0.003). CONCLUSIONS: In Greek subjects with OSAS, there was no difference in BMI, and female patients were significantly older than male patients. OSAS was diagnosed in men five times more often than in women. AHI was greater in men than in women, but women are more likely than men to have a higher AHI in REM than NREM. Sleep quality is worse in female than in male patients.     

Effects of CPAP on left ventricular structure and myocardial performance index in male patients with obstructive sleep apnoea

BACKGROUND: Obstructive sleep apnoea (OSA) has the potential to cause heart failure. We aimed to determine the effects of nasal continuous positive airway pressure (CPAP) therapy on left ventricular structure and myocardial performance index (MPI) in severe OSA patients. METHODS: Sixty-seven subjects without any cardiac or pulmonary disease had overnight polysomnography and echocardiography. In 33 males with severe OSA, thickness of interventricular septum (IVS) and posterior wall (LVPW) were measured by M-mode. Left ventricular MPI was calculated as (isovolumic contraction time+isovolumic relaxation time)/aortic ejection time by Doppler. RESULTS: Eight males were non-compliant with CPAP. Mean age was 47.9+/-8.2 years, and 20 of 25 patients (80.0%) were hypertensive. Patients had high body mass index (BMI: 31.0+/-3.9 kg/m(2)), but there was no change in BMI from baseline after 6 months. Thickness of IVS (11.0+/-1.1mm) and LVPW (11.0+/-1.0mm) at baseline were significantly decreased after 6 months of CPAP therapy (10.5+/-0.9 mm, P<0.001 and 10.4+/-0.7 mm, P<0.0001, respectively). Left ventricular MPI (60.1+/-13.8%) significantly decreased (53.0+/-10.7%, P<0.0001) after CPAP usage. CONCLUSIONS: In male patients with severe OSA, CPAP therapy significantly decreases left ventricular wall thickness and improves global function even with 6 months of usage.     

Effect of atrial overdrive pacing on obstructive sleep apnea in patients with systolic heart failure

BACKGROUND AND PURPOSE: Obstructive sleep apnea (OSA) is associated with cardiovascular disease. Preliminary studies suggested breathing improvement in patients with apnea and heart disease when atrial overdrive pacing was applied during sleep. However, more recent studies do not show significant beneficial effect for atrial overdrive pacing in OSA. To further investigate this relationship, we conducted a randomized clinical trial evaluating the effect of atrial overdrive pacing on sleep-related breathing events in subjects with OSA and systolic heart failure. PATIENTS AND METHODS: We screened 33 subjects with symptoms consistent with OSA. On a screening overnight polysomnography (PSG), 15 subjects with mean age of 74 years (standard deviation (SD) 6.6) and ejection fraction of 38% (SD 14.4%) had OSA defined as having an apnea/hypopnea index (AHI) of > or =15 per hour of sleep. These subjects underwent additional PSGs including a night with atrial overdrive pacing (O), a night with pacemaker rate set at 40-50 beats per minutes (N), and a positive airway pressure titration night. The O and N nights were consecutive and the order was randomized. For O, the pacemaker rate was set at 15 beats higher than the average nightly heart rate (determined from the screening night). RESULTS: At baseline, mean AHI was 34.8 (15.5) and mean SaO(2) nadir was 85% (3.2%). Average heart rate was significantly higher on O nights compared to N nights (p<0.005). The apnea index (AI) was statistically lower on O nights compared to N nights (18+/-16.6 vs. 24+/-18.9, p<0.05). However, AHI and minimum and average O(2) saturations did not differ significantly between O and N nights. Interestingly, AHI improved statistically significantly on O nights in younger subjects. CONCLUSIONS: While statistically reliable, the small pacing-related reduction in sleep-disordered breathing (SDB) events is of unknown clinical significance. By contrast, continuous positive airway pressure (CPAP) dramatically improved AHI, AI, respiratory arousal index, and O(2) saturation. Thus our data suggest that overdrive pacing exerts a mild effect on respiratory events in some heart failure patients with OSA; however, atrial overdrive pacing was not therapeutically effective for improving airway patency and sleep-related respiratory function.     

Residual sleep apnea on polysomnography after 3 months of CPAP therapy: Clinical implications,predictors and patterns

ObjectiveWe sought to determine the clinical implications, predictors and patterns of residual sleep apnea on continuous positive airway pressure (CPAP) treatment in patients with moderate-to-severe obstructive sleep apnea (OSA).MethodsWe performed a post hoc secondary analysis of data from a previously reported randomized trial. Sleepy patients with a high risk of moderate-to-severe OSA identified by a diagnostic algorithm were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. We observed them for 3 months and measured apnea–hypopnea index (AHI) on CPAP, Epworth sleepiness scale (ESS), sleep apnea quality of life index (SAQLI), CPAP pressure and objective CPAP compliance.ResultsSixty-one patients were randomized, 30 to the PSG group and 31 to the ambulatory group. Fifteen patients (25%) had residual sleep apnea (AHI >10/h on CPAP) with similar proportions in the PSG (7/30) and ambulatory (8/31) groups. Baseline variables including age, body mass index (BMI), ESS, SAQLI, respiratory disturbance index (RDI) and CPAP pressure did not differ between the groups. Outcomes including compliance were worse in patients with residual sleep apnea. Periodic breathing was prevalent among patients with residual sleep apnea.ConclusionsResidual sleep apnea is common in patients with moderate-to-severe OSA, despite careful CPAP titration, and is associated with worse outcomes.     

Evening and morning blood gases in patients with obstructive sleep apnea

BACKGROUND AND PURPOSE: The purpose of this study was to see if blood oxygen levels deteriorate overnight during obstructive sleep apnea (OSA). Before and after sleep, arterial blood gases (ABGs) in OSA subjects and controls were drawn during a diagnostic night, as well as during a continuous positive airway pressure (CPAP) night for the OSA subjects. PATIENTS AND METHODS: Subjects, both male and female, were referred to our sleep laboratory for symptoms of daytime somnolence. Subjects consisted of a control group (N=13) with a mean apnea hypopnea index (AHI) of 3.3 events/h and a study group (N=22) with a mean baseline AHI of 57 events/h. RESULTS: With the subject supine, resting room air ABGs were drawn at 'lights out' on the evening before (PM) nocturnal polysomnography and in the morning (AM) at discontinuation ('lights on') of the sleep study. In controls, PM PaO(2) (79.4+/-9.7 mmHg) was not significantly different from AM PaO(2) (80.2+/-8.9 mmHg, P=0.5). In apneic subjects, the PM PaO(2) was 78.7+/-7.2 mmHg compared to an AM PaO(2) of 72.6+/-8.3 mmHg (P<0.05). The AM PaO(2) after a night of CPAP treatment in the OSA subjects was 77.5+/-10.2 mmHg compared to the PM PaO(2) of 76.0+/-6.0 mmHg (NS). The PM and AM PaCO(2)s were not different in controls or in study subjects under baseline conditions. However, during titration with nasal CPAP, the PaCO(2) was significantly higher in the morning after CPAP treatment [43.1+/-4.8 vs. 46.1+/-4.8 mmHg, respectively (P<0.05)]. CONCLUSIONS: OSA subjects showed a fall in overnight resting oxygenation. This could be accounted for by overnight deterioration of gas exchange and is ameliorated by CPAP.     

Obstructive sleep apnoea: a case-control study

INTRODUCTION: Obstructive sleep apnoea (OSA), is characterized by loud snoring and excessive daytime sleepiness. Though the gold standard for diagnosis is overnight polysomnography (PSG), sleep questionnaires have also been used to diagnose this with good predictive value. MATERIAL AND METHODS: A pre-designed proforma with clinical details, symptom-specific questions for diagnosis of OSA, and Epworth Sleepiness Scale (ESS) was administered to 20 patients presenting to the Sleep Disorder Clinic of our hospital and to 40 age and sex-matched relatives (control group). The students 't-test' and chi-square were used as the statistical tests. RESULTS: There were 20 patients with a mean age of 41+/- 8 years, and 40 controls with a mean age of 41 +/- 6 years (P=>0.05). Seven had family history of snoring in the study group and 3 in the control group (P=0.02). Four had met with road traffic accidents in the study group and none in the control group (P=0.001). The body mass index (BMI) was 29.9 (SD 4.4) in the study group and 24.5 (SD3.5) in the controls (P=0.001). The mean ESS was 13.3 +/- 6 in the patients and 4.2+ 4 in the controls (P=0.001). A larger number of patients with OSA had hypertension: 5/20 vs. 3/40 (P=0.01). CONCLUSION: Patients with OSA had significantly higher BMI and ESS score, and were more likely to have hypertension and road traffic accidents. Increased awareness of this entity is essential.     

Predictors of symptoms of anxiety and depression in obstructive sleep apnea

BACKGROUND AND PURPOSE: To assess factors associated with anxiety and depression in patients with obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS: The study was comprised of a postal survey with a hospital chart review. Questionnaires were mailed to 242 previously hospitalised patients with OSAS. We assessed anxiety and depression with the Hospital Anxiety and Depression scale (HAD). Scores on the two HAD scales (0-21 scale, higher scores represent poor health) were categorized as normal/borderline (< or =10), and corresponding to a clinical diagnosis of anxiety or depression (> or =11). In logistic regression analysis, we assessed the association with HAD scores > or =11, using variables from the chart review and self-reported data on demographics, disease history, smoking status, CPAP/BiPAP use, and daytime sleepiness as assessed with the Epworth Sleepiness Scale (ESS), as potential predictors. RESULTS: One hundred and seventy-eight patients (74%) with mean (SD) age 55 (11) years and body mass index (BMI) of 31 (5) kgm(-2) responded to the questionnaire. In multivariate logistic regression analysis, only low compliance with CPAP therapy (odds ratio (OR) 5.60, P=0.005) predicted high level of anxiety, and low compliance with CPAP therapy (OR 3.59, P=0.03) and daytime sleepiness (OR 1.14 per unit increase in ESS score, P=0.02) were the only predictors of high level of depression. CONCLUSIONS: High anxiety score was associated with non-compliance with CPAP therapy. High depression score was associated with daytime sleepiness and non-compliance with CPAP therapy.     

Effect of CPAP treatment on residual depressive symptoms in patients with major depression and coexisting sleep apnea: Contribution of daytime sleepiness to residual depressive symptoms

BackgroundAlthough extensive studies have indicated a relationship between obstructive sleep apnea (OSA) and depressive symptoms, the effect of continuous positive airway pressure (CPAP) treatment on residual depressive symptoms in patients with both major depressive disorder (MDD) and coexisting OSA has not been examined.MethodsSeventeen patients with continued MDD despite pharmacotherapy such as antidepressants and/or benzodiazepines, who also had comorbid OSA, were required to complete the Beck Depression Inventory (BDI), Hamilton Rating Scale for Depression (HRSD), and Epworth sleepiness scale (ESS) at the commencement of the study and then again after 2 months of CPAP treatment.ResultsBDI and HRSD scores decreased from 19.7 to 10.8 and 16.7 to 8.0 after 2 months of CPAP treatment (both p < 0.01). We also found significant correlations among the improvement rates in BDI, HRSD and ESS scores (R = 0.86 and 0.75, both p < 0.01). The mixed effect model demonstrated a significant ESS effect on BDI and HRSD.ConclusionsThe results suggest that MDD patients with residual depressive symptoms despite pharmacotherapy who also have symptoms of suspected OSA, such as loud snoring, obesity, and daytime sleepiness, should be evaluated for sleep apnea by polysomnography and treated with an appropriate treatment such as CPAP. CPAP treatment may result in a significant improvement of residual depressive symptoms due to the improvement of daytime sleepiness in these patients.     

Long-term adherence to continuous positive airway pressure therapy in non-sleepy sleep apnea patients

ObjectiveThe effectiveness of continuous positive airway pressure (CPAP) therapy greatly depends on consistent use. However, data regarding adherence in non-sleepy obstructive sleep apnea (OSA) patients are scarce. The aim of this study was to assess long-term adherence and predictors of CPAP compliance in a large sample of non-sleepy OSA patients.MethodsWe conducted a prospective, multicenter study comprising 357 non-sleepy patients (Epworth Sleepiness Scale score <11) with moderate-to-severe OSA (apnea–hypopnea index [AHI] of ≥20) who began CPAP therapy between May 2004 and May 2006; follow-up ended in May 2009. Non-compliance was scored as CPAP dropout or average cumulative CPAP use of <4 hours per night. Multivariate Cox regression analysis was performed to identify independent predictors of poor CPAP adherence.ResultsPatients were followed up for a median of four years (interquartile range [IQR] = 3.0–4.4). At the end of the study period, 230 patients (64.4%) fulfilled the criteria for good CPAP compliance, whereas 127 patients (35.6%) were considered non-compliant. The median CPAP use was five hours per night (interquartile range = 2.18–6.25). Multivariate analysis showed that interactions between the AHI and the percentage of nighttime spent with an O₂ saturation of <90% (TC90) (p = 0.010) and between the AHI and hypertension at baseline (p = 0.029) predicted long-term compliance with CPAP.ConclusionThis study demonstrates that CPAP treatment is feasible in non-sleepy, moderate-to-severe OSA patients. Good CPAP adherence was predicted by greater OSA severity as measured by both the AHI and TC90 and by the presence of hypertension at baseline in patients with higher AHI levels.