Respiratory Disturbance Index Scores Research Articles

Comparative evaluation of the efficacy of customized maxillary oral appliance with mandibular advancement appliance as a treatment modality for moderate obstructive sleep apnea patients—a randomized controlled trial

BackgroundObstructive sleep apnea (OSA) is quite common among the adult population, according to recent epidemiological studies. The most frequently suggested alternate treatment for mild to moderate OSA is oral appliances (OA). The purpose of the present study was to assess as well as compare the effectiveness of custom-made maxillary oral appliances against mandibular advancement appliances in the care of individuals suffering from moderate obstructive sleep apnea.MethodsA prospective interventional research was carried out with 40 participants. Polysomnography (PSG) was done and the participants with an apnea-hypopnea index (AHI) >15–30 were involved in the research. Study participants were randomly split up into two test groups: group I was the “Control Group” (group treated with a mandibular advancement device (MAD), n=20), while group II was exposed to a “customized maxillary oral appliance” (CMOA, n=20). Both groups had reference measures for AHI, blood oxygen saturation (SpO2), oro-nasal airflow via respiratory disturbance index (RDI), and the Epworth Sleepiness Scale (ESS). Appliances were fabricated and delivered to the respective study group participants. PSG was again conducted after a period of 1 and 3 months of appliance delivery and re-evaluation was done for all the parameters and was compared with reference measurements. The facts were analyzed using descriptive and analytical statistical methods. The statistical program utilized in the study was “SPSS (Statistical Package for Social Sciences) Version 20.1.” After 1 and 3 months, the statistical significance between the two study groups was assessed at P<0.05.ResultsThe analysis of mean AHI, SPO2, RDI, and ESS for both test groups manifested statistically significant measures (P<0.001). The study results revealed a statistically significant depletion in mean AHI scores, improvement in mean SPO2 scores, and reduction in mean RDI scores and ESS scores when compared with reference measurements to 1 month, 1 to 3 months, and between reference measurements and 3 months.ConclusionThe CMOA was effective in managing moderate OSA and has great therapeutic potential. It can be an option for the MAD for treating patients suffering from moderate obstructive sleep apnea.Trial registrationThe study was registered under Clinical Trials Registry-India and the registration number is CTRI/2020/07/026936. Registered on 31 July 2020

Objective sleep hypoxia measures are associated with subjective quality of life ratings in amnestic MCI subjects

AbstractBackgroundSleep disturbances are common in individuals with Mild Cognitive Impairment (MCI); and sleep disturbances increase the risk of Alzheimer’s disease (AD). Lower ratings of quality of life (QoL) are also found in MCI. We examined the association between sleep disturbances and QoL ratings among participants with MCI.MethodsBaseline in‐home sleep assessments using the WatchPAT (Itamar Medical) and the QoL in AD questionnaire were collected from amnestic MCI (aMCI) participants from the diet intervention trial, Brain Energy for Amyloid Transformation in Alzheimer’s Disease (BEAT‐AD) at the Wake Forest ADRC. The WatchPAT assessed sleep time, efficiency, and sleep‐related hypoxemia measures including the apnea‐hypopnea index (AHI), oxygen desaturation index (ODI) and respiratory disturbance index (RDI), where higher values indicate greater disturbances in sleep. The QoL in AD scale ranged from 13–52 with lower scores indicating poorer QoL ratings. We assessed the association between total sleep time and sleep efficiency with QoL. Pearson correlations and regression models measured the association of sleep metrics with QoL scores.ResultsForty‐two aMCI participants (mean age =69.0 ± 7.4 years; N=23 female; mean BMI =27.6) were studied. Disturbed sleep indicated by the average number of apneas and hypopneas (AHI, mean = 18.6 ± 14.6) and respiratory events or related arousals (RDI, mean = 20.7 ± 14.2) was negatively associated with lower subjective measures of QoL. Higher AHI and RDI scores, indicating greater intermittent hypoxia and respiratory burden, were associated with lower QoL (AHI: r= ‐0.359, p=0.027; RDI: r= ‐0.340, p=0.037). There was a trend toward a negative association of ODI and QoL scores (r= ‐0.309, p=0.059). Regression models including age, sex, and BMI did not significantly predict QoL scores with AHI (F(4,35)=1.95, p&gt;.1) or RDI (F(4,34)=1.76, p&gt;.15), however, AHI and RDI individually added significantly to the prediction of QoL scores (AHI: B=‐.136, t=‐2.4,P&lt;.05; RDI: B=‐.162, t=‐2.4, p&lt;.05).ConclusionsGreater sleep disturbances related to hypoxic and respiratory events were associated with lower self‐ratings of QoL in MCI participants. Further research will increase the sample, investigate the impact of hypoxic and respiratory events on brain function, and whether longitudinal changes in diet influence the relationship of sleep‐related hypoxemia and QoL.

The Effects of Obstructive Sleep Apnea on Risk factors for Cardiovascular diseases.

Obstructive sleep apnea (OSA) is known to cause variety of cardiovascular diseases. The aim of this study was to examine the correlation between polysomnography (PSG) and risks factor for coronary heart disease in patients suspected to have OSA. A total of 108 consecutive adult habitual snorers underwent PSG. We assessed patients using the respiratory disturbance index (RDI), the Epworth sleepiness scale (ESS), body mass index (BMI), fasting serum total cholesterol, triglycerides (TGs), and C-reactive protein (CRP). Mean RDI scores were 0.53, 10.6, 27.3, and 45.1 in the control group (n = 21), mild (n = 29), moderate (n = 31), and severe (n = 27), respectively. Partial correlation analysis showed that patients' RDI score was significantly correlated with CRP after adjustment for BMI. Partial correlation analysis showed that the mean ESS score correlated significantly with the CRP level after adjustment for BMI. Partial correlation analysis showed that the mean least oxygen saturation was significantly correlated with CRP after adjustment for BMI Pearson's correlation coefficients examining the relationship between BMI and total cholesterol; TG and CRP were found to be 0.531, 0.401, and 0.321. The correlation of CRP levels with disease severity as assessed by RDI, ESS, and least oxygen saturation was significant after adjustment for BMI. Patients with OSA have elevated serum levels of high-sensitivity-CRP, a marker for inflammation and an independent risk predictor for cardiovascular morbidity.

Impact of sleep disordered breathing on performance in judo players

ObjectivePrevious studies have suggested that young sports players may suffer from sleep disordered breathing (SDB). It was hypothesised that SDB in heavy-class judo players was far more prevalent than expected...

Incidence of Obstructive Sleep Apnea in Elderly Edentulous Patients and the Possible Correlation of Serum Serotonin and Apnea-Hypopnea Index.

To estimate the incidence of obstructive sleep apnea (OSA) in elderly edentulous patients (aged 60-65 years) and investigate a correlation of serum serotonin levels with the apnea-hypopnea index (AHI), respiratory effort-related arousal (RERA), and respiratory disturbance index (RDI). 381 elderly completely edentulous patients (307 male, 74 female) aged 60 to 65 years with a history of edentulism of 12 to 15 months, seeking oral rehabilitation at the prosthodontic clinic at Saraswati Dental College & Hospital, Lucknow, India, between January 2014 and January 2016 were enrolled for the present study. After application of the inclusion and exclusion criteria of this study, 183 patients (162 male, 21 female) who were found susceptible, were subjected to the BERLIN questionnaire and Epworth Sleepiness Scale (ESS) to assess sleep disordered breathing (SDB) and then put through all-night polysomnography (PSG). On the basis of AHI, RERA, and RDI scores, 156 patients (143 male, 13 female) who tested positive for OSA were classified according to its intensity. All 156 patients underwent body-mass index (BMI) estimation, cephalometry, and intraoral examination for skeletal and soft tissue profile record. Serum serotonin was estimated from whole blood samples for the 156 OSA and the 27 normal patients. The 156 (147 nonobese, 9 obese) OSA-positive patients were provided with complete dentures and were trained to use the same as a modified mandibular advancement device (MAD) during sleep at night. These patients were kept on a quarterly follow-up for 9 months. Data collected was subjected to statistical analysis, and inferences drawn. The incidence of OSA in elderly edentulous subjects was found to be 32.03% in males and 8.91% in females. A mere 9 out of 156 (5.76%) elderly edentulous OSA patients were found to be obese (Class I) on the basis of BMI estimation. Cephalometry of the patients showed that they had a skeletal class I maxillomandibular relationship. AHI scores of nonobese patients revealed that most of the patients had moderate OSA, followed by mild OSA and severe OSA. Serum serotonin levels ranged from 53 to 83 ng/dL. AHI score of the 9 obese patients were in the moderate to severe range, and their serum serotonin levels were 60 to 70 ng/dL. A correlation between severity of OSA and serum serotonin level was validated in this study. OSA was found to be prevalent in edentulous subjects due to pharyngeal collapse and decreased neuromuscular control. An inverse relationship of serum serotonin levels and AHI scores was established.

Neck Circumference Is a Predictor of Metabolic Syndrome and Obstructive Sleep Apnea in Short-Sleeping Obese Men and Women

The constellation of metabolic syndrome, although controversial with regard to its clinical usefulness, is epidemiologically related to increased diabetes risk and cardiovascular mortality. Our goal was to investigate the associations among neck circumference (NC), obstructive sleep apnea syndromes (OSAS), and metabolic syndrome in obese men and women sleeping less than 6.5 hr per night. This was a cross-sectional study of obese men and premenopausal obese women sleeping less than 6.5 hr per night. We enrolled 120 individuals (92 women), age 40.5±6.9 years and body mass index (BMI) 38.6±6.5 kg/m(2). Metabolic syndrome severity was assessed by a score and OSAS was defined as a respiratory disturbance index (RDI) ≥5. Metabolic end endocrine parameters were measured, and sleep duration was determined by actigraphy and validated questionnaires. Metabolic syndrome was found in 41% and OSAS in 58% (28% had both). Subjects with metabolic syndrome were 3 years older and more often Caucasian; they had higher RDI scores, larger NC, more visceral fat, lower serum adiponectin, higher 24-hr urinary norepinephrine (NE) excretion, and lower growth hormone concentrations. A NC of ≥38 cm had a sensitivity of 54% and 58% and a specificity of 70% and 79% in predicting the presence of metabolic syndrome and OSAS, respectively. RDI, adiponectin, and NC accounted for approximately 30% of the variability in the metabolic syndrome score, as estimated by an age-, gender-, and race-corrected multivariate model (R(2)=0.376, P<0.001). Greater NC is associated with OSAS and metabolic syndrome in short-sleeping obese men and premenopausal obese women. Addition of NC to the definition of metabolic syndrome should be considered and needs to be validated in future studies.

Poor Sleep Quality and Sleep Apnea Are Associated with Higher Resting Energy Expenditure in Obese Individuals with Short Sleep Duration

Epidemiological studies reported an inverse or U-shaped relationship between sleep duration and weight. The relationship between sleep and resting energy expenditure (REE) has not been well characterized. The aim of the study was to determine the relationship between sleep, REE, and stress hormones. We conducted a cross-sectional evaluation of a prospective cohort study at a tertiary referral research clinical center. Subjects included 126 obese individuals (30 males, 96 females; age, 40.5 ± 6.9 yr; body mass index, 38.6 ± 6.5 kg/m(2); sleep duration, 360 ± 50 min/night; and sleep efficiency, 79.5 ± 7.5%). REE and respiratory quotient (RQ) were assessed by indirect calorimetry. Sleep duration and sleep efficiency were assessed by actigraphy. Sleep quality was estimated by questionnaires, and sleep apnea was evaluated by respiratory disturbance index (RDI). Morning plasma ACTH, serum cortisol, and 24-h urinary free cortisol and catecholamines were also measured. RDI was positively correlated with REE adjusted by fat-free mass (r = 0.307; P = 0.003) and RQ (r = 0.377; P < 0.001). Sleep efficiency was inversely correlated with RQ (r = -0.200; P = 0.033). The relationship of RDI score and REE was stronger in men than women (P = 0.03). In women, serum cortisol was positively correlated (r = 0.407; P < 0.001), and Epworth sleepiness score tended to be inversely (r = -0.190; P = 0.086) correlated with adjusted REE. The RQ was positively related to RDI in women, whereas subjective sleep time was related to RQ in men. In a multiple regression model, RDI, serum cortisol, and urinary norepinephrine were directly related to REE, whereas serum cortisol also directly related to adjusted REE. Poor sleep quality was associated with increased REE, a higher RQ indicating a shift from fat toward carbohydrate oxidation, and activation of the stress system.

Hyoid advancement to the mandible (hyo-mandibular advancement)

Hyoid advancement to the mandible was first described in 1984, but was later abandoned by most surgeons for the easier to perform advancement to the laryngeal cartilage. New modifications of the hyo-mandibular advancement technique has made this approach easier to perform and are described in this paper. The hyo-mandibular advancement technique has a higher success rate for the treatment of sleep apnea, especially in women.

Depression, sleepiness, and disease severity in patients with obstructive sleep apnea

To determine if a relationship exists between depression, disease severity, and sleepiness in patients with obstructive sleep apnea (OSA). Case control study. Fifty-three consecutive patients with suspected OSA were evaluated before treatment and compared with controls by using the Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), and polysomnography. OSA was associated with an increased risk of depression in the study group compared to the control group (odds ratio = 6.3, 95% confidence interval: 1.9-20.6, P = .002); depression was seen in 35% of OSA patients and 8% of controls (P < .001). There was a significant correlation between BDI and ESS scores (r = 0.342, P = .012). In addition, ESS was significantly associated (P = .039) with depression in a linear regression model that controlled for race, sex, age, and respiratory disturbance index (RDI). RDI and depression were weakly associated (P = .056) in this model, and there was no correlation found between BDI scores and OSA disease severity (RDI)(r = 0.446). Patients with OSA and daytime sleepiness are more likely to have depressive symptoms as compared with controls. OSA disease severity, as measured with the RDI score, is a weak predictor of BDI score, and no correlation was seen between the severity of OSA and BDI scores after controlling for other factors. However, there was a strong correlation between sleepiness (ESS) and disease severity (BDI). These data suggest that OSA patients with symptoms of excessive sleepiness have the highest risk of associated depressive symptoms and may benefit most from depression screening.

Sleep apnea in patients with oral cavity and oropharyngeal cancer after surgery and chemoradiation therapy

Objective To determine the point prevalence of sleep apnea in patients following oral and oropharyngeal cancer treatment at a major tertiary care referral center. Study Design A retrospective cross-sectional survey. Subjects and Methods Twenty-four patients with established oral or oropharyngeal cancer were submitted to overnight polysomnography. The surgical group consisted of 15 patients (11 male, 4 female; average age 64.2 yrs) having undergone primary surgery with radial forearm free flap reconstruction. The remaining patients (5 male, 4 female; average age 54.8 yrs) were treated nonsurgically with chemoradiation therapy. The fatigue-related daytime sleepiness was measured with the Epworth sleepiness scale (ESS). Results Eleven patients in the surgical group and three in the nonsurgical group had a respiratory disturbance index (RDI) greater than 15 (odds ratio = 5.5, P = 0.092). Twelve patients in the surgical group and five in the nonsurgical group had significant oxygen desaturation during sleep hours (odds ratio = 3.3, P = 0.356). There was no observed significant correlation between RDI and oxygen desaturation (r 2 = 0.28), nor was there any observed association between the RDI and ESS score (r 2 = 0.18). Conclusion This preliminary study has suggested that surgical patients in our cohort have a higher prevalence of moderate to severe obstructive sleep apnea in the postoperative period, when tested, compared with a nonsurgical group. A small sample size and incomplete matching on important cofactors of interest, such as primary site location, body mass index, and thyroid function, limit this study. A pretreatment and post-treatment analysis is obviously required to demonstrate any significant level of association between treatment type and sleep apnea status.

Sexual dysfunction in women with obstructive sleep apnea

Female sexual dysfunction is vastly under-recognized but has been previously described in chronic disease states. Sexual dysfunction in male patients with obstructive sleep apnea (OSA) is well described, but not in females. The objective of this study was to assess the prevalence of sexual dysfunction in women with OSA. We studied 21 consecutive pre-menopausal women with OSA, referred to our sleep lab, and who had a positive study for sleep apnea (respiratory disturbance index (RDI) > 5), and 11 healthy pre-menopausal women were included as the control group. Subjects were administered the Female Sexual Function Index (FSFI) questionnaire and a mood scale-Profile of Mood States. Of the study group, 11 women (52.4%) had FSFI scores in the poor range (<23) as compared to the control group, in which none of the women (0%) had FSFI scores in the poor range (<23). Negative mood domain scores were not different in patients with poor FSFI compared to patients with normal FSFI scores. There was no correlation between obesity, severity of sleep apnea, or mood disorders on overall scores of sexual dysfunction. Among individual domains, there was a correlation between RDI and arousal scores. In our study, we have found that prevalence of sexual dysfunction is high among women with OSA. Physicians should routinely screen and evaluate women with OSA for sexual dysfunction.

Relationship between obstructive sleep apnea and abnormal male hormone levels in morbidly obese men

OBJECTIVE: Obstructive sleep apnea is a common, yet under-diagnosed disorder associated with a sequele of co-morbidities including hypertension, myocardial infarctions, stroke, obesity, diabetes and impotentcy. The purpose of this study is to evaluate the reproductive hormonal profile in males with obstructive sleep apnea. DESIGN: Population hormone profile. MATERIALS AND METHODS: A cohort of obese males with BMI ≥ 30 kg/m2 were recruited as for the Utah Obesity Study. At the time of recruitment, questionnaires, anthropometric measurements, blood samples for serologic analysis were obtained from patients. Among others, the following tests were performed, total and free testosterone, sex hormone binding globulin, and estradiol. Sleep studies were preformed in a subgroup of these patients, evaluating parameters including Obstructive Sleep Apnea Index (OAI), Respiratory Disturbance Index (RDI), Hypoapnea Index (HI), Average Oxygen Saturation (AOS), and time spent with an average oxygen saturation below 80% (O2:80) and 90% (O2:90). RESULTS: 64 patients met the inclusion criteria. A sub-group of 38 patients consented to standard polysomnograms at the University of Utah Clinical Research Center. The patients mean age was 48.9 ± 1.24 (mean±SE) years old, the mean BMI was 46.3± 0.91 kg/m2. The distribution of the following BMI groups was as follows: 30-40 kg/m2 (20.3%), 40-50 kg/m2 (53.1%), and >50 kg/m2 (26.6%). The mean RDI score was 34.58 ± 5.12, with a diagnosis of sleep apnea recognized as an RDI >5. Several markers for sleep apnea were inversely correlated with total and free testosterone levels including RDI, OAI, HI, and O2:80 and O2:90. Free and total testosterone levels correlated positively to AOS.Table 1Correlation Between Testosterone and Sleep Apnea MarkersTotal TestosteroneFree TestosteroneSpearman's correlation coefficient2 tailed p valueSpearman's correlation coefficient2 tailed p valueRDI-0.5100.001-0.4630.003OAI-0.4270.007-0.4880.002HI-0.4080.011-0.3890.016AOS0.4520.0040.5190.001O2 : 80-0.2820.086-0.4970.001O2 : 90-0.4150.009-0.3590.027 Open table in a new tab The correlation between total and free testosterone levels and markers for sleep apnea remained significant after correction for BMI. CONCLUSIONS: Sleep apnea, independent of BMI, is a risk factor for abnormal male hormone levels.

Microdebrider-Assisted Extended Uvulopalatoplasty

To assess subjective and objective outcomes in selected patients with obstructive sleep apnea syndrome who underwent microdebrider-assisted extended uvulopalatoplasty (MEUP). Prospective study. Tertiary referral center. Fifty patients with obstructive sleep apnea syndrome who had substantial retropalatal obstruction and more than 10 events per hour on the respiratory disturbance index (RDI) and who underwent MEUP with 6 months of follow-up. Patients with a Friedman palate position of grade 4 and a tonsil size of grade 3 or 4 were excluded. MEUP was performed in each patient under general anesthesia. The procedure consisted of removal of the redundant mucosa, tissue above the muscular layer of the soft palate, and upper poles of the tonsils using a powered microdebrider. Postoperative pain was evaluated using a visual analog scale. Before surgery and at 6 months after surgery, subjective outcomes were assessed using the Epworth Sleepiness Scale and the snoring scale, and objective outcomes were assessed using overnight polysomnography variables (RDI, snoring index, and minimal oxygen saturation). Surgical success was defined as achieving a postoperative RDI score of fewer than 20 events per hour and a greater than 50% reduction in the preoperative RDI score. The mean (SD) visual analog scale scores were 3.9 (1.8) on the first postoperative day and 1.3 (0.9) on the seventh postoperative day. Compared with preoperative scores, postoperative scores statistically significantly improved on the Epworth Sleepiness Scale and on the snoring scale (P < .01 for both). The median RDI score decreased from 37.9 events per hour before surgery to 6.1 events per hour at 6 months after surgery, a statistically significant difference (P < .001). The median minimal oxygen saturation and snoring index scores also improved statistically significantly (P < .001 for both). The surgical success rate was 80% (40 of 50 patients). No postoperative bleeding or long-term velopharyngeal insufficiency was observed in any patient. MEUP is an effective and safe surgical procedure to improve sleep apnea and snoring in selected patients with obstructive sleep apnea syndrome. The use of the microdebrider in extended uvulopalatoplasty is addressed herein for the first time (to our knowledge).

Mandibular advancement splints for sleep apnoea

Objectives This study assessed the effectiveness of a mandibular advancement splint (MAS) in subjects with sleep-related breathing disorders using both objective and subjective outcome measures. Design The study was carried out as a retrospective analysis. Setting The study was conducted within the Sleep Studies Unit at the Queen Victoria Hospital, East Grinstead, between May 1997 and March 2000. Subjects and methods Twenty subjects with obstructive sleep apnoea (OSA) and six with non-apnoeic snoring, diagnosed by overnight polysomnography, were fitted with a monobloc appliance between May 1997 and March 2000. Main outcome measures The subjects were analysed for changes in the respiratory disturbance index (RDI) and Epworth Sleepiness Scale (ESS) scores. In addition each subject completed an outcome questionnaire following fitting of the appliance. Results Variability in response measured by the change in the respiratory disturbance index was found with no correlation to the baseline recording. Although median RDI values improved in both groups, significantly so in the obstructive sleep apnoea group (p<0.05), seven subjects exhibited an increased RDI score following mandibular advancement splint therapy. The median Epworth Sleepiness Scale scores decreased in both the OSA group and the non-apnoeic snorers although not significantly. Twenty-one of the 26 subjects completed the outcome questionnaire revealing an 81% reduction in snoring. Side-effects were generally transient and minor. Eighty-six per cent of the subjects' partners reported better quality of sleep as a result of MAS therapy. Conclusions The monobloc appliance significantly improved the Respiratory Disturbance Index in the obstructive sleep apnoea group. Some subjects had increased RDI scores following splint therapy. This supports the need for an objective assessment in the follow-up of patients treated with mandibular advancement splints.

The effect of a mandibular advancement splint in subjects with sleep-related breathing disorders

This study assessed the effectiveness of a mandibular advancement splint (MAS) in subjects with sleep-related breathing disorders using both objective and subjective outcome measures. The study was carried out as a retrospective analysis. The study was conducted within the Sleep Studies Unit at the Queen Victoria Hospital, East Grinstead, between May 1997 and March 2000. Twenty subjects with obstructive sleep apnoea (OSA) and six with non-apnoeic snoring, diagnosed by overnight polysomnography, were fitted with a monobloc appliance between May 1997 and March 2000. The subjects were analysed for changes in the respiratory disturbance index (RDI) and Epworth Sleepiness Scale (ESS) scores. In addition each subject completed an outcome questionnaire following fitting of the appliance. Variability in response measured by the change in the respiratory disturbance index was found with no correlation to the baseline recording. Although median RDI values improved in both groups, significantly so in the obstructive sleep apnoea group (p<0.05), seven subjects exhibited an increased RDI score following mandibular advancement splint therapy. The median Epworth Sleepiness Scale scores decreased in both the OSA group and the non-apnoeic snorers although not significantly. Twenty-one of the 26 subjects completed the outcome questionnaire revealing an 81% reduction in snoring. Side-effects were generally transient and minor. Eighty-six per cent of the subjects' partners reported better quality of sleep as a result of MAS therapy. The monobloc appliance significantly improved the Respiratory Disturbance Index in the obstructive sleep apnoea group. Some subjects had increased RDI scores following splint therapy. This supports the need for an objective assessment in the follow-up of patients treated with mandibular advancement splints.

Clinically significant but unsuspected restless legs syndrome in patients with sleep apnea

In this prospective study, the prevalence of clinically significant restless legs syndrome (RLS) with symptoms at least 2 to 3 days per week was 8.3% in 60 sequentially polysomnographically studied patients with clinically significant sleep apnea (Apnea Index score > 5 or Respiratory Disturbance Index score > 10). Age-matched spouses were used as a control group and showed a comparable prevalence of RLS at 2.5% (not significant). Although RLS appears to be only slightly more common in sleep apnea patients than in controls, the importance of this study lies in the fact that clinically significant RLS occurred in 1 of every 12 patients with sleep apnea and, in every case, the RLS was unsuspected before polysomnography. We recommend that all patients undergoing polysomnography to rule out sleep apnea be screened for the symptoms of RLS. We have found the MEMO-NIH consensus conference questionnaire administered at the time of polysomnography to be useful in this regard.

Measures of cognitive function in persons with varying degrees of sleep-disordered breathing: the Sleep Heart Health Study.

Epidemiologic literature suggests that persons with clinically diagnosed sleep apnoea frequently have impaired cognitive function, but whether milder degrees of sleep-disordered breathing (SDB) are associated with cognitive dysfunction in the general population is largely unknown. Approximately 1700 subjects free of clinically diagnosed SDB underwent at-home polysomnography (PSG) as part of the Sleep Heart Health Study (SHHS) and completed three cognitive function tests within 1-2 years of their PSG: the Delayed Word Recall Test (DWR), the WAIS-R Digit Symbol Subtest (DSS), and the Word Fluency test (WF). A respiratory disturbance index (RDI) was calculated as the number of apnoeas and hypopnoeas per hour of sleep. After adjustment for age, education, occupation, field centre, diabetes, hypertension, body-mass index, use of CNS medications, and alcohol drinking status, there was no consistent association between the RDI and any of the three cognitive function measures. There was no evidence of a dose-response relation between the RDI and cognitive function scores and the adjusted mean scores by quartiles of RDI never differed from one another by more than 5% for any of the tests. In this sample of free-living individuals with mostly mild to moderate levels of SDB, the degree of SDB appeared to be unrelated to three measures of cognitive performance.

Clinical predictors of sleep apnea in patients undergoing bariatric surgery.

Sleep apnea is a frequent and unappreciated condition of morbidly obese patients. If unrecognized it could lead to significant postoperative complications. A clinical tool to assess the severity of sleep apnea is not available. We prospectively determined whether the Epworth Sleepiness Scale (ESS) or body mass index (BMI) predict the severity of sleep apnea in morbidly obese patients. 66 consecutive patients evaluated for bariatric surgery from June to November 1999 were examined and prospectively administered a health questionnaire including the ESS. Patients with an ESS > or =6 were referred for polysomnography with calculation of Respiratory Disturbance Index (RDI). Sleep apnea was graded as mild (RDI 6-20), moderate (RDI 21-40) and severe (RDI>40). Clinical variables such as BMI and ESS score were compared using regression analysis. Data are mean +/- SEM. 4 men and 23 women (27/66) who scored >6 on the ESS completed a sleep study. Mean ESS was 13+/-4.5. Sleep apnea was mild in 13 patients, moderate in 7, severe in 6, and absent in 1. Mean age was 43+/-9.5 years. BMI was 52+/-10 kg/m2. Linear regression analysis did not demonstrate correlation between ESS score and severity of sleep apnea (r2=0.03, p>0.05). Multiple regression analysis demonstrated no correlation between BMI, patient snoring, and RDI score. Sleep apnea is frequent in candidates screened for bariatric surgery. ESS is a useful tool to investigate daytime sleepiness and other manifestations of sleep apnea. However, the ESS does not predict the severity of sleep apnea. Clinical suspicion of sleep apnea should prompt polysomnography.

Depression in sleep disorders clinics

The purpose of this paper was to determine the incidence of depression in our sleep disorders clinics (and it's relation to patient characteristics) and to determine whether the incidence of depression varies in patients with and without sleep apnea. The Beck Depression Inventory (BDI) was administered to evaluate patients for depression. We reviewed records of all new patients between November, 1995 and May, 1996 and determined their BDI scores and polysomnogram (PSC) results. Patients were divided based on their respiratory disturbance index (RDI); a cut off value of 15 was chosen. Patients were re-divided based on the BDI score (13 or greater suggestive of depression). The age, sex, body mass index (BMI), BDI or RDI (as appropriate) and arousal indices were compared. Sixty-three patients were enrolled; 29% were depressed. BDI scores and PSG data were available in 42 patients. Those with a high RDI had significantly lower BDI scores and higher arousal indices. Those with a high and low BDI scores were not significantly different in any of the parameters evaluated. Symptoms of depression are commonly seen in a sleep clinic. In patients with symptoms suggestive of SA but with low RDI scores, a diagnosis of depression should be entertained. The presence of depression, however, should not negatively influence a decision to perform PSG.

Comparison of two dental devices for treatment of obstructive sleep apnea syndrome (OSAS)

Previous case reports have indicated dental devices can be an effective nonsurgical treatment for snoring and obstructive sleep apnea. This pilot study evaluated the effectiveness of two intraoral devices in reducing the Respiratory Disturbance Index (RDI) and Epworth Sleepiness Scale (ESS) scores in a group of 24 adult volunteers with a history of loud snoring. Subjects were randomly assigned to two groups. Twelve subjects were fitted with a dental device designed to increase vertical dimension and protrude the mandible (device A). The other 12 subjects received a different device designed to minimally increase vertical opening without protruding the mandible (device B). Unattended home sleep monitoring (Edentrace II Digital Recorder, Edentech Corp.) was used to compute RDI at two time periods: (T0) before using any dental device and (T1) while using a dental device 2 weeks after the initial delivery date. The mean RDI and ESS scores at T0 for subjects in the device A group were 35.6 ± 28.4 and 12.0 ± 3.9, respectively. Means for the same measures at T1 were 21.1 ± 21.4 and 8.2 ± 4.0. For subjects in the device B group, means for RDI and ESS scores at T0 were 36.5 ± 43.7 and 13.0 ± 4.5, the means at T1 were 46.8 ± 47.0 and 12.5 ± 5.7. The effectiveness of the two devices was estimated by comparing the difference in RDI scores from T0 to T1 for the 10 subjects who were using device A and completed the study and the 8 subjects who were using device B and completed the study. Six subjects withdrew for various reasons. From T0 to T1, device A reduced RDI scores in 9 of 10 subjects, with a mean reduction in RDI of 14.5 ( p ≤ 0.05) and in ESS score of 3.8 ( p ≤ 0.005). Device B showed no change or an increased RDI score in 8 of 8 subjects. Seven of the eight subjects who showed no improvement in RDI with device B were then fitted with device A. Four of these seven subjects showed a reduction in RDI and five showed a reduction in ESS after using device A for 2 weeks. The mean reduction in RDI and ESS was 2.4 ± 19.8 and 2.4 ± 3.0, respectively. Hence, we conclude that a dental device that advances the mandible and increases the vertical dimension to open the upper airway is more effective in reducing the number of apneic and snoring events during sleep than one which does not.