Mandibular advancement splint titration in obstructive sleep apnoea

Introduction  Mandibular advancement splints (MAS) allowing self-adjustment may be better tolerated, but the optimum titration protocol needs systematic study. Aim  The aims of the study are to assess the effectiveness of a titratable MAS device in consecutive patients with body mass index (BMI) < 35 kg/m² and obstructive sleep apnoea [OSA, apnoea–hypopnoea index (AHI) 10–40/h] and compare two methods of adjustment [self-adjustment or adjustment after polysomnographic (PSG) feedback]. Materials and methods  Twenty-eight patients (24 M, mean age 49 years, mean BMI 27.6 kg/m²) with symptomatic (Epworth Sleepiness score > 8/24, snoring, choking or poor sleep quality) OSA (mean AHI 25.7/h, range 10–46/h) had a MAS set at 70% maximal protrusion and were randomised to subjective self-adjustment for 6 weeks (n = 16) or objective adjustment (n = 12; fixed position for 3 weeks, then PSG based feedback at 3 weeks with self-adjustment instructions). Primary outcome variable (AHI) and OSA symptoms were compared by t tests and chi-squared tests at baseline and after 6 weeks. Resolution of apnoea was defined as AHI < 5/h; improvement was defined as AHI decreased by >50% but still >5/h. Results  The groups had similar baseline demographics, OSA severity and occlusal type. MAS therapy improved or resolved OSA in 20 out of 28 (71%) and was reportedly used nightly by 91% of the objective group and 63% of the subjective group (p = 0.04). MAS were used all night by 75% of the objective group and 69% of the subjective group (p > 0.05). MAS adjustment following PSG feedback did not lower AHI further from 3 weeks (baseline 26.5 ± 12.0/h, 3 weeks 15.3 ± 13.5/h p = 0.01, 6 weeks 11.7 ± 10.0/h, p = 0.11). The overall improvement was similar to that achieved with subjective adjustment (baseline AHI 25.4 ± 7.4/h, 6 weeks 14.3 ± 10.7/h, p = 0.0002). Symptomatic benefit was reported by both groups. Conclusion  In selected patients, titratable MAS improved or resolved OSA in the majority of patients and was well tolerated. PSG-based feedback at 3 weeks allowed objective confirmation of efficacy and increased device use but did not result in greater improvement in AHI or symptoms. Neither titration method was significantly superior for us to provide firm endorsement. However, we recommend a follow-up sleep study to confirm MAS efficacy.     

Randomised trial of compliance with flexible (C-Flex) and standard continuous positive airway pressure for severe obstructive sleep apnea

Introduction  Obstructive sleep apnea (OSA) is often treated with continuous positive airway pressure (CPAP) but the effectiveness of treatment is probably limited by poor compliance. CPAP manufacturers are thus attempting to devise more comfortable PAP devices in an effort to improve compliance. An example of such a novel device is Flexible expiratory-modulated PAP (C-Flex mode Respironics REMstar Pro, Murraysville, PA, USA). Materials and methods  We aimed to compare compliance between C-Flex and standard CPAP in patients with severe OSA in a randomised controlled trial. Nineteen patients with severe OSA (mean ± SD Apnea Hypopnea Index = 78 ± 33/h, Epworth 14 ± 4, PAP 8–17 cm H₂O, BMI = 39 ± 10 kg/m²) and aged 20–63 years were randomly assigned to 4 weeks of either C-Flex (setting II, n = 9) or CPAP (n = 10). Results  Patients treated with C-Flex exhibited a trend toward higher compliance with their PAP devices compared to patients treated with standard CPAP (4.7 ± 2.9 vs. 3.0 ± 2.1 h/night, p = 0.15, effect size = 0.68). Paradoxically, improvements in subjective sleepiness (Epworth Sleepiness Scale) were greater in those who received CPAP than C-Flex (8.1 + 4.9 vs. 2.1 + 4.0 points, p = 0.014, effect size = 1.46). Improvements in objective wakefulness (Modified Maintenance of Wakefulness Test) and simple reaction times (Psychomotor Vigilance Task) were not significantly different between treatments. This randomised trial provides some evidence that C-Flex might increase initial treatment compliance, compared to CPAP, in patients with severe OSA. However, this trend toward greater compliance was not associated with better short-term treatment outcomes for patients. These findings need to be confirmed in a larger, longer-term trial. Stipend from Massey University (to NSM). None of the authors have had any financial relationships with Respironics Inc., who are the manufacturers of the device tested. Respironics International Inc., through their New Zealand suppliers Care Medical, provided six C-Flex machines for the purposes of this trial.     

Nasal nitric oxide improved by continuous positive airway pressure therapy for upper airway inflammation in obstructive sleep apnea

Purpose

In this report, we examined the association between obstructive sleep apnea (OSA) and upper and lower airway inflammation based on nitric oxide (NO) measurements.

Methods

Study subjects included 51 consecutive participants. Sleep-disordered breathing was evaluated by a type 3 portable monitor and quantified by respiratory disturbance index (RDI). Airway inflammation was noninvasively analyzed by the measurement of nasally and orally exhaled NO; nasal value was presented as nasally exhaled NO minus orally exhaled NO. In 15 patients prescribed nasal continuous positive airway pressure (nCPAP) therapy, exhaled NO was re-evaluated in 10.7 ± 6.3 months after nCPAP therapy.

Results

Nasal NO was significantly higher in patients with severe OSA (RDI ≥ 30/h) than those with non-OSA (RDI < 10/h) (76.9 ± 26.0 ppb vs. 47.9 ± 22.0 ppb, respectively, p = 0.016) and correlated with RDI (rho = 0.36, p = 0.0099), whereas orally exhaled NO did not differ between non-OSA and OSA patients and was not correlated with RDI. In 15 patients, nasal NO after nCPAP therapy was significantly decreased than that before nCPAP therapy (81.9 ± 31.2 ppb vs. 53.7 ± 27.2 ppb, respectively, p = 0.0046); in 11 patients having good compliance to nCPAP therapy (nCPAP use >4 h per night on more than 70% of nights), this association was more remarkable.

Conclusions

In OSA, upper but not lower airway inflammation can be increased by repetitive collapse of the upper airway. Future studies are required to determine the role of nasal NO in OSA.

     

Predictors of fatigue in obstructive sleep apnea

Objective  The objective of this study was to determine potential inflammatory predictors of fatigue in obstructive sleep apnea (OSA). Materials and methods  Fifty-six women and men untreated OSA patients had their sleep monitored with polysomnography. Fatigue was assessed by the Multidimensional Fatigue Symptom Inventory-Short Form. Depressed mood was assessed by the Center for Epidemiologic Studies-Depression Scale. Blood was drawn to assess circulating levels of Interleukin-6 (IL-6) and soluble tumor necrosis factor receptor I (sTNF-RI). Age, gender, body mass index (BMI), blood pressure, OSA severity, depressed mood, and inflammatory biomarkers were entered into a hierarchical multiple linear regression analysis predicting self-reported fatigue. Results  Approximately 42% of the patients reported significant amounts of fatigue. Higher BMI (p = 0.014), greater depressed mood (p = 0.004), and higher sTNF-RI levels (p = 0.033) were independent predictors of fatigue in the final model (full model R ² = .571; p = .003). Age, gender, blood pressure and apnea severity were unrelated to fatigue. Conclusion  The findings suggest that in addition to depressed mood, fatigue in OSA may be associated with increased body weight and elevated levels of the proinflammatory cytokine receptor sTNF-RI. The findings support a linkage between the widely reported fatigue in OSA and a sleep-related component of inflammation.     

Is the clinical presentation different between men and women admitting to the sleep laboratory?

Objectives  Sleep and sleep disorders are different in several important ways between men and women. We aimed to investigate gender differences in initial symptoms and associating medical diseases of patients admitting to our sleep clinic. Methods  Ninety-one patients, 20 women (22%) and 71 men (78%), admitting consecutively to the sleep clinic were studied. A detailed sleep and medical history of the patients was recorded. All patients were questioned for Epworth Sleepiness Scale (ESS) and underwent an entire night of diagnostic polysomnography. Apnea–hypopnea index (AHI) was identified as the total number of apnea and hypopnea per hour of sleep. Hypopnea was defined as a decrease of airflow by at least 50% and desaturations were defined as ≥4% decrease in oxygen saturation. Results  The mean values for age, body mass index, blood pressures and ESS score did not significantly differ between men and women, but AHI (events/h) was significantly higher in men (29.1 ± 22.7) than women (17.9 ± 17.7, p < 0.05). Snoring was the most common symptom in both men (95%) and women (90%). Among the main presenting complaints, only morning headache (12 of women 60%, 31 of men 43%, p = 0.04) and dry mouth on awakening (ten of women 50%, 57 of men 80%, p = 0.02) showed a significant difference between the two genders, while among the medical diseases only hypothyroidism (four of women 20% and three of men 4%, p = 0.03) and depression (nine of women 45% and 16 of men 22%, p = 0.02) were seen as statistically higher in women than in men. Conclusions  Primary care physicians should be aware of obstructive sleep apnea (OSA) in women and the importance of referring women for sleep studies when they complain of symptoms associated with OSA, even if other non-specific symptoms such as morning headaches are reported. Also, hypothyroidism and depression are accompanied with sleep disorders especially in women.     

Effects of obstructive sleep apnea treatment on left atrial volume and left atrial volume index

Obstructive sleep apnea (OSA) and increased left atrial volume (LAV) both independently increase cardiovascular mortality. We hypothesized that treatment of OSA with continuous positive airway pressure (CPAP) may decrease LAV. We retrospectively identified 47 OSA patients receiving CPAP who had echocardiograms done before and after polysomnography. Compliance was defined as CPAP use at-least five nights weekly and 5 h per night. The compliant group (n = 23) had a significant decrease in diastolic blood pressure (DBP; 4.4 ± 8.9 mmHg, p < 0.05) and mean arterial pressure (MAP; 4.7 ± 10.3 mmHg, p < 0.05), while no significant changes were observed in the noncompliant group (n = 24). LAV data were available in 13 compliant and 20 noncompliant patients. LAV decreased nonsignificantly (3.54 ± 16.6 mL, n = 13, p = 0.65) in CPAP-compliant patients, while it increased (15.47 ± 22.3 mL, n = 20, p < 0.006) in noncompliant patients. Similar changes were seen in the LAV index. Untreated OSA was associated with an increase in LAV and LAV index without significant changes in blood pressure. Treatment of OSA was associated with a decrease in DBP and MAP with a nonsignificant decrease in LAV. Treatment of OSA may prevent adverse left atrial remodeling. There are no conflicts of interest or financial disclosures for any of the authors.     

Circulating endothelial cells in patients with chronic lymphocytic leukemia

Angiogenesis is increased in B-cell chronic lymphocytic leukemia (B-CLL). We wanted to quantify and characterize the circulating endothelial cells (CECs) in patients with B-CLL and correlate with plasma angiogenesis-related factors. Using a four-color flow cytometry, we prospectively analyzed the CEC in the whole blood of 20 healthy controls and 20 patients with B-CLL. We quantified (CD45−/CD31+/CD146+) and characterized the CECs according to whether they were apoptotic (annexin stain) or activated (CD106+). We also measured plasma levels of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and thrombospondin-1 (TSP-1). Most patients (90%) had Rai stages 0–2 at the time of diagnosis. As a group, B-CLL patients had higher number of CECs (median of 26.5 cells/ml) compared (P = 0.04) to healthy controls (18.5 cells/ml). However, only four (20%) patients had elevated CEC counts, defined as ≥2 SD of the control mean (≥53 cells/ml). The proportions of apoptotic (P = 0.83) and activated (P = 0.12) CECs were similar in both groups. B-CLL patients had higher FGF-2 (P < 0.001), lower TSP-1 (P = 0.004), and similar VEGF (P = 0.27) plasma levels. The number of CECs was not associated with Rai stage, absolute lymphocyte count, or levels of angiogenesis-related factors. CECs are increased in only a small fraction of B-CLL patients in our cohort with low rates of apoptosis and activation. While no correlation was found between CECs and clinical features, more studies in a larger patient sample size and advanced disease are necessary. Supported by the Gundersen Lutheran Center for Cancer and Blood Disorders and the Gundersen Lutheran Medical Foundation. The Greater Richland Area Cancer Elimination (GRACE), Inc. and the Gundersen Lutheran Medical Foundation funded this study.     

Evaluation of a portable recording device (ApneaLink?) for case selection of obstructive sleep apnea

Objective  This study was designed to assess the sensitivity and specificity of a portable sleep apnea recording device (ApneaLink™) using standard polysomnography (PSG) as a reference and to evaluate the possibility of using the ApneaLink™ as a case selection technique for patients with suspected obstructive sleep apnea (OSA). Materials and methods  Fifty patients (mean age 48.7 ± 12.6 years, 32 males) were recruited during a 4-week period. A simultaneous recording of both the standard in-laboratory PSG and an ambulatory level 4 sleep monitor (ApneaLink™) was performed during an overnight study for each patient. PSG sleep and respiratory events were scored manually according to standard criteria. ApneaLink™ data were analyzed either with the automated computerized algorithm provided by the manufacturer following the American Academy of Sleep Medicine standards (default setting DFAL) or The University of British Columbia Hospital sleep laboratory standards (alternative setting, ATAL). The ApneaLink respiratory disturbance indices (RDI), PSG apnea–hypopnea indices (AHI), and PSG oxygen desaturation index (ODI) were compared. Results  The mean PSG-AHI was 30.0 ± 25.8 events per hour. The means of DFAL-RDI and ATAL-RDI were 23.8 ± 21.9 events per hour and 29.5 ± 22.2 events per hour, respectively. Intraclass correlation coefficients were 0.958 between PSG-AHI and DFAL-RDI and 0.966 between PSG-AHI and ATAL-RDI. Receiver operator characteristic curves were constructed using a variety of PSG-AHI cutoff values (5, 10, 15, 20, and 30 events per hour). Optimal combinations of sensitivity and specificity for the various cutoffs were 97.7/66.7, 95.0/90.0, 87.5/88.9, 88.0/88.0, and 88.2/93.9, respectively for the default setting. The ApneaLink™ demonstrated the best agreement with laboratory PSG data at cutoffs of AHI ≥ 10. There were no significant differences among PSG-AHI, DFAL-RDI, and ATAL-RDI when all subjects were considered as one group. ODI at 2%, 3%, and 4% desaturation levels showed significant differences (p < 0.05) compared with PSG-AHI, DFAL-RDI, and ATAL-RDI for the entire group. Conclusion  The ApneaLink™ is an ambulatory sleep monitor that can detect OSA and/or hypopnea with acceptable reliability. The screening and diagnostic capability needs to be verified by further evaluation and manual scoring of the ApneaLink™. It could be a better choice than traditional oximetry in terms of recording respiratory events, although severity may be under- or overestimated.     

Automated detection of sleep disordered breathing using a nasal pressure monitoring device

To assess the accuracy of a single channel portable monitoring device (RUSleeping™ RTS, Respironics, Murrysville, PA) that measures nasal pressure (a surrogate for airflow) to detect sleep disordered breathing (SDB). Twenty-five adult patients referred to a community sleep laboratory with suspected obstructive sleep apnea (OSA) participated in this investigation. The portable monitoring device was used in the sleep laboratory to acquire data concurrently with a standard multi-channel polysomnogram (PSG) to assess SDB. Respiratory events were scored manually on the PSG using standard criteria for clinical research to quantify an apnea–hypopnea index (AHI) based on events during sleep. The portable monitoring device automatically calculated an unedited respiratory event index (REI) based on recording time. These data were then compared using the Pearson product–moment correlation coefficient, Bland–Altman analysis, receiver operating characteristic (ROC) curves, and likelihood ratios. All 25 subjects completed the study. Mean age of subjects was 42.4 ± 12.9 years and mean body mass index was 31.0 ± 7.4 kg m⁻². There was good agreement between the REI and the AHI (R = 0.77, p < 0.001, mean difference 2.6 events per hour [2 SD: 39.8] using a Bland–Altman plot). The area under the ROC curve for detecting SDB (PSG AHI greater than or equal to five events per hour) with the REI was 0.94 (95% CI 0.84–1.0). For an REI >11.9 events per hour, the sensitivity was 0.89 (95% CI 0.65–0.99) and the specificity was 0.86 (95% CI 0.42–1.0) with a likelihood ratio of 6.2 for a positive test (LR+) and 0.13 for a negative test (LR−). Similar results were observed for detecting moderate–severe SDB (PSG AHI ≥ 15 events h⁻¹) using REI >15.2 events h⁻¹. In a population of subjects with suspected OSA, this portable monitoring device can automatically quantify an REI that compares well to the AHI scored manually on a concurrent PSG. Such a device may prove useful to assess SDB in high risk populations with self-administered testing in ambulatory settings such as the home. This study was performed at the Sleep Center of Greater Pittsburgh Sleep Laboratory.     

Cardiologist’s knowledge and attitudes about obstructive sleep apnea: a survey study

Obstructive sleep apnea (OSA) is associated with cardiovascular diseases, yet available data suggests cardiologists underreport OSA. This study assessed whether cardiologists’ knowledge and attitudes about OSA contribute to this finding. A previously validated questionnaire, the “Obstructive Sleep Apnea Knowledge and Attitudes Questionnaire” (OSAKA), was modified by the addition of 20 knowledge items and one attitude question to include a total of 38 knowledge items and six attitude questions. The questionnaire was mailed to a random sampling of 420 cardiologists in the USA. Ninety-two cardiologists (22%) returned completed questionnaires. Mean age was 48 ± 10 years, 74% were male, and 52% were general cardiologists. Mean score on the original OSAKA portion of the questionnaire (76%) was similar to previously reported scores of primary care physicians (PCPs), while the total knowledge score was 77%. Scores did not differ by gender (p = 0.7) or subspecialty (p = 0.3), and there were no correlations between knowledge and age or years in practice. While 80% stated that identifying patients at risk for OSA was very or extremely important, only 68% felt confident identifying these patients, and only 18% felt confident managing OSA patients. There was no difference in mean total attitude score when analyzed by age, gender, years of practice, and subspecialty. Total knowledge scores correlated with attitude scores (r = 0.29, p = 0.004). Cardiologists’ knowledge about OSA is comparable to that of PCPs. Cardiologists may lack confidence identifying and managing patients with OSA, factors that may contribute to their low rate of reporting OSA. The institution at which the work was done: MetroHealth Medical Center at Case Western Reserve University.     

NREM-AHI greater than REM-AHI versus REM-AHI greater than NREM-AHI in patients with obstructive sleep apnea: clinical and polysomnographic features

Purpose  

Previous studies show a high prevalence of obstructive sleep apnea (OSA) patients with a higher non-rapid eye movement (NREM) apnea–hypopnea index (AHI) (NREM-AHI) than rapid eye movement (REM) AHI (REM-AHI). However, the clinical significance of this phenomenon in patients with OSA is unknown. This study aimed to investigate whether there were significant differences in clinical and polysomnographic features between the NREM-AHI > REM-AHI group and the REM-AHI > NREM-AHI group and to determine whether NREM-AHI > REM-AHI or REM-AHI > NREM-AHI is a specific clinical entity.     

CPAP compliance in patients with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is characterized by repeated cessations of breathing during sleep. Major symptoms of this disease are excessive daytime sleepiness, snoring, and witnessed apnea. Most of the patients are treated with CPAP. In this study, we aimed to evaluate the factors affecting adherence to the CPAP treatment. Seventy-one patients were enrolled to this study. Patients were divided into three groups according to CPAP usage. Group I consisted of patients who had never used CPAP, group II consisted of patients who had used CPAP occasionally, and group-III patients had used CPAP treatment regularly. Group-III patients had higher apnea–hypopnea index (AHI) than groups I and II (respectively, 56.6 ± 27.7, 26.3 ± 7.5, and 32.3 ± 7.06; p < 0.000 for both). Oxygen desaturation index was significantly higher in group-III patients comparing to groups I and II (44.6 ± 22.3, 15.9 ± 8.3, and 25.6 ± 9.5; p < 0.000 for all). Our findings have shown that only very severe patients use the CPAP device regularly (mean AHI 56.6 ± 27.7). Compliance to CPAP treatment seemed to be poor in patients with moderate to severe, AHI about 30, OSAS. Considering the well-established benefits of CPAP treatment in patients with true indications, patients should be encouraged to use CPAP regularly, and complications of OSAS should be keynoted.     

Gender differences in clinical and polysomnographic features of obstructive sleep apnea: a clinical study of 2827 patients

Purpose

Obstructive sleep apnea (OSA) is underdiagnosed in females due to different clinical presentation. We aimed to determine the effect of gender on clinical and polysomnographic features and identify predictors of OSA in women.

Methods

Differences in demographic, clinical, and polysomnographic parameters between 2052 male and 775 female OSA patients were compared.

Results

In female OSA patients, age (56.1 ± 9.7 vs. 50.4 ± 11.6 years, p < 0.0001) and body mass index (36.3 ± 8.6 vs. 31.8 ± 5.9 kg/m², p < 0.0001) were increased, whereas men had higher waist-to-hip ratio and neck circumference (p < 0.0001). Hypertension, diabetes mellitus, thyroid disease, and asthma were more common in females (p < 0.0001). Men reported more witnessed apnea (p < 0.0001), but nocturnal choking, morning headache, fatigue, insomnia symptoms, impaired memory, mood disturbance, reflux, nocturia, and enuresis were more frequent in women (p < 0.0001).

The indicators of OSA severity including apnea-hypopnea index (AHI) (p < 0.0001) and oxygen desaturation index (p = 0.007) were lower in women. REM AHI (p < 0.0001) was higher, and supine AHI (p < 0.0001) was lower in females. Besides, women had decreased total sleep time (p = 0.028) and sleep efficiency (p = 0.003) and increased sleep latency (p < 0.0001). In multivariate logistic regression analysis, increased REM AHI, N3 sleep, obesity, age, morning headache, and lower supine AHI were independently associated with female gender.

Conclusions

These data suggest that frequency and severity of sleep apnea is lower in female OSA patients, and they are presenting with female-specific symptoms and increased medical comorbidities. Therefore, female-specific questionnaires should be developed and used for preventing underdiagnosis of OSA.

     

Assessment of the test–retest reliability of laboratory polysomnography

Statement of the problem  When conducting a treatment intervention study, it is assumed that a level of reliability can be obtained from the measurement tool such that the outcome can be reasonably assessed. Purpose of study  Investigate the reliability of laboratory polysomnography, the gold standard for assessment of treatment outcomes for obstructive sleep apnea, at a 1-month interval. Materials and Methods  In a clinical trial of 118 patients recruited to assess the effects of a pharmaceutical treatment intervention, a subset of 20 patients designated as placebo controls completed two polysomnography studies, one at baseline and one at least one month later. Results  The correlation between the overall Apnea/Hypopnea indices from the two polysomnography (PSG) studies was poor (r = 0.44) and the results were biased, with a mean increase of seven events per hour on night 2. Twenty-five percent of the subjects had an increase greater than 20 events/hour on night 2 and only 45% of participants had a night-to-night difference of ≤5 events/hour. The correlation between overall apnea indexes for nights 1 and 2 (r = 0.61) was improved, compared to the overall apnea/hypopnea indexes. The correlation in sleep efficiency across the two nights was relatively week (r = 0.52) but significant. The correlations between nights 1 and 2 for the percentage of time supine (r = 0.70) and the supine apnea–hypopnea index (AHI) (r = 0.69) were similar and highly significant. The correlation for the non-supine AHI was only 0.25 Conclusions  In this study, the reliability of a single-night PSG in measuring treatment outcome was compromised as a result of the large night-to-night variability of subjects’ obstructive sleep apnea (OSA). Studies employing the AHI as an outcome need to be adequately powered with respect to the inherent night-to-night variability in the measurement. When assessing treatment intervention outcomes, there may be benefit from the acquisition and averaging of multiple nights of data in order to mitigate the inherent night-to-night variability of OSA and improve the accuracy of the outcome assessment.     

Prevalence of sleep apnea and cardiovascular risk factors in patients with hypertension in a day hospital model

Introduction: To identify patients at risk for obstructive sleep apnea (OSA) syndrome at a specialized hypertension center, we administered questionnaires and used respiratory polygraphy (RP). Results: We studied 168 patients (64.8% men and 35.2% women). Patients’ body mass index (BMI) was 34.7 ± 6.79 and Epworth Sleepiness Scale (ESS) scores were 8.01 for male and 8.92 for women (p = 0.69). RP recordings revealed AHI (Apnea-Hypopnea Index) of 18.03 ± 15.7, an ODI (Oxygen Desaturation Index) of 18.6 ± 15.2, and a time oxygen saturation <90% (%) of 20.8 ± 24.3. Around 44% of patients had an AHI of >15 events/h, and continuous positive airway pressure (CPAP) was recommended to 69 patients (41.07%). Pulse wave velocity (PWV) showed high values in AHI > 15/h (p = 0.050), and carotid intima-media thickness (IMT) did not correlate with AHI > 15; right IMT: 0.83 ± 1.3 versus 0.78 ± 0.13 mm (p = 0.41) and 0.82 ± 0.16 versus 0.78 ± 0.19 mm (p = 0.40). However, we find correlation with carotid plaque (p = 0.046). The ACC/AHA calculator revealed a gradual increase in the risk of cardiovascular events: 8.7% with AHI < 5/h, and 30.3% in severe OSA. Conclusions: In hypertension (HT) patients, RP revealed a high prevalence of OSA associated with carotid artery disease, high PWV, and increased cardiovascular risk.     

Gender differences in Saudi patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) remains under-recognized in women possibly due to differences in clinical presentation, difference in tolerance to symptoms, and rate of usage and referral to sleep services. No reports have addressed OSA in women in the Middle Eastern (Arab) population. Therefore, we conducted this study to assess the differences in demographics, clinical presentation, and polysomnographic (PSG) findings between Saudi women and men diagnosed to have (OSA). The study group comprised 191 consecutive Saudi women and 193 consecutive men who were referred to the Sleep Disorders Centre and were found by in-laboratory PSG to have OSA. Demographic and clinical data were obtained by personal interviews. Women were significantly older than men (53.9 and 43.0 years, respectively; p < 0.001). Similarly, their body mass index was significantly higher than men (p < 0.001). Insomnia was more common among women (39.8%) compared to men (25.9%; p = 0.005). Other sleep symptoms including witnessed apnea, and excessive daytime sleepiness did not show any statistical difference between the two groups. Women were more likely than men to be diagnosed with hypothyroidism, diabetes, hypertension, cardiac disease, and asthma. Apnea–hypopnea index (AHI) was statistically higher in men compared to women; however, most of apnea/hypopnea events in women occurred during rapid eye movement sleep, and the mean duration of hypopnea and apnea was significantly lower in women (p = 0.004). Sleep efficiency was lower in women (71.5% vs. 77.7%) in men (p < 0.001). The desaturation index was higher in men (p = 0.01), but no difference was found in lowest SaO₂ or time with SaO₂ less than 90%. The present study showed important clinical and PSG differences between Saudi women and men with OSA. Clinicians need to be aware of these differences when assessing women for the possibility of OSA as they may be symptomatic at a lower AHI and have significant comorbid conditions that can be adversely affected if their OSA was not timely managed.     

Risk factors for cardiovascular disease and endothelin-1 levels in Takayasu arteritis patients

The objective of this study was to evaluate traditional risk factors for cardiovascular disease (CVD) and endothelin-1 (ET-1) levels in Takayasu arteritis (TA) patients. Twenty-two TA patients and 37 controls were evaluated. TA patients had a higher prevalence of hypertension (63.6% vs. 21.6%, p = 0.001) and higher levels of triglycerides (129.5 mg/dL ± 70.8 vs. 88.4 mg/dL ± 60.8, p = 0.017) than controls. Mean number of CVD risk factors was 1.64 ± 1.22 in TA patients and 1.03 ± 1.44 among controls, p = 0.030. More TA patients presented at least one CVD risk factor when compared to controls (77.2% vs. 51.3%, p = 0.048). ET-1 levels were higher in patients than in controls (1.49 pg/mL ± 0.45 vs. 1.27 pg/mL ± 0.32, p = 0.034), however no significant difference was found between patients with active and inactive disease. In this study, TA patients presented a higher prevalence of hypertension, higher levels of triglycerides, and ET-1 than controls.     

Previously Unrecognized Obstructive Sleep Apnea in Chinese Subjects With Essential Hypertension

Obstructive sleep apnea (OSA) is found to affect 2–4% of the middle-aged population in several Caucasian studies, whereas the prevalence among other ethnic groups have not been clearly documented. It has been reported that OSA and systemic hypertension are highly associated; we therefore conducted a study on Chinese subjects who were receiving treatment for essential hypertension to assess the prevalence of OSA among this group. Ninety-two consecutive patients being followed up at a hypertension clinic were recruited for a questionnaire survey. The entire study group was aged 54.7 ± 11.7 years, with 40 men. One male subject had a diagnosis of obstructive sleep apnea on nasal continuous positive airway pressure (nCPAP) treatment and 46 subjects agreed to an overnight sleep study. Those who underwent sleep study showed selection bias with a higher body mass index and more symptoms associated with OSA. Of the 46 who underwent sleep study, 16 (34.8%) had an obstructive apnea-hypopnea (AHI) score of ≥5 and excessive daytime sleepiness, with a median score of 26.2 (range, 8.3–64.9). Patients in the group with obstructive sleep apnea syndrome (OSAS) thus defined compared with those without OSAS had more men (64.7 vs 17.20%, p= 0.001) and an excess of smokers (31.5 vs 3.3%. p= 0.01) and had significantly more symptoms of excessive daytime sleepiness (p= 0.001), daytime fatigue (p= 0.007), and witnessed apneas (p= 0.008). Seven patients accepted treatment with nCPAP and reported improvement in symptoms, but there was no detectable change in clinic blood pressure measurements after 3 months of nCPAP treatment. This study demonstrated a high prevalence of previously unidentified OSAS among Chinese patients with essential hypertension. Increased awareness of both doctors and patients toward this potentially treatable problem is warranted. Accepted for publication: 16 August 1999     

Symptoms of obstructive sleep apnea in a Caribbean sample

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that disproportionately affects blacks. While clinical and epidemiologic data indicate intraethnic differences in several medical diseases, little is known about whether OSA symptoms differ within the black ethnic group. We estimated the rate of OSA symptoms in a community-based sample of Caribbean-born black men and women. We also ascertained which sociodemographic and/or medical factors were associated with OSA risk. A total of 554 patients (mean age = 48.17 ± 16.75 years) participated in the study; 55% were women. Data were collected in four primary-care clinics in Brooklyn, NY. A health educator explained the purpose of the study to interested patients and assisted consenting participants in completing questionnaires, which required 15 min to complete. Participants reporting habitual snoring, excessive daytime sleepiness, and sleep fragmentation were considered at high OSA risk. The rate of OSA symptoms was: snoring (45%), excessive daytime sleepiness (33%), and difficulty maintaining sleep (34%). Many reported falling asleep while watching television (47%) or while driving (14%). Based on logistic regression analysis, a history of heart disease was the most important predictor of the likelihood of expressing OSA symptoms, with a corresponding multivariate-adjusted odds ratio of 11 (95% confidence interval = 3.03–40.63). Findings suggest the need to investigate whether Caribbean-born blacks are at greater risk for developing OSA than African Americans and whites. Caribbean-born blacks with a history of heart disease should be a prime target for interventions that promote adequate screening and timely OSA diagnosis.     

Modified Epworth Sleepiness Scale in Chinese children with obstructive sleep apnea: a retrospective study

Background and objective  The purpose of this study is to assess whether Chinese children with high apnea–hypopnea index (AHI) are sleepier by a modified Epworth Sleepiness Scale (ESS). Materials and methods  Records were retrospectively reviewed. We included children who were between 3 and 12 years old, admitted for overnight polysomnogram because of suspected obstructive sleep apnea syndrome (OSAS). A modified ESS was used to assess excessive daytime sleepiness (EDS) of the children. Results  One hundred ninety-two Chinese children were included. Children with high AHI, defined as AHI > 5.0, were sleepier than children with AHI less than or equal to 5. After adjustment by age, gender, and obesity, children with high AHI remained significantly sleepier. Modified ESS was significantly correlated with AHI (rho = 0.124, 95% CI = 0.004–0.281). Modified ESS score of >8 was the best cutoff point with the sensitivity and specificity of 0.29 and 0.91, respectively. The odds ratio of children with modified ESS > 10 having high AHI was 4.231 (95%CI = 1.248 to 14.338) and children with modified ESS > 8 had the highest odds ratio, 4.295(95%CI = 1.66 to 11.1), of having high AHI. Conclusion   Chinese children with high AHI appear to be sleepier than children with low AHI. Children with suspected OSAS and high modified ESS, i.e., ESS > 8, had significantly higher odds ratio of having high AHI. Increased sleepiness is a specific but not a sensitive symptom in snoring children with high AHI. Screening for EDS in snoring children may help us identify those with high AHI and prioritize the management of those children. All authors worked and the study was carried out in Kwong Wah Hospital in Hong Kong. There was no conflict of interest and no specific source of funding for the study.