Nocturnal Respiratory Disturbances Research Articles

Predictors of Increased Daytime Sleepiness in Patients with Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study.

Background. Patients with Chronic Obstructive Pulmonary Disease (COPD) suffer from increased daytime sleepiness. The aim of this study was to identify potential predictors of subjective daytime sleepiness with special regard to sleep-related breathing disorder and nocturnal activity. Methods. COPD patients were recruited at the University Hospital Basel, Switzerland. COPD risk groups A–D were determined according to spirometry and COPD Assessment Test (CAT). Breathing disorder evaluation was performed with the ApneaLink device. Nocturnal energy expenditure was measured with the SenseWear Mini Armband. Subjective daytime sleepiness was recorded using the Epworth Sleepiness Scale (ESS). Results. Twenty-two patients (36%) were in COPD risk group A, 28 patients (45%) in risk group B, and 12 patients (19%) in risk groups C + D (n = 62). Eleven patients (18%) had a pathological ESS ≥ 10/24. ESS correlated positively with CAT (r = 0.386, p < 0.01) and inversely with age (r = −0.347, p < 0.01). In multiple linear regression age (β = −0.254, p < 0.05), AHI (β = 0.287, p < 0.05) and CAT score (β = 0.380, p < 0.01) were independent predictors of ESS, while nocturnal energy expenditure showed no significant association (p = 0.619). Conclusion. These findings provide evidence that daytime sleepiness in COPD patients may partly be attributable to nocturnal respiratory disturbances and it seems to mostly affect younger patients with more severe COPD symptoms.

Efficacy of Bilevel-auto Treatment in Patients with Obstructive Sleep Apnea Not Responsive to or Intolerant of Continuous Positive Airway Pressure Ventilation.

Ventilation with continuous positive airway pressure (CPAP) is the gold standard therapy for obstructive sleep apnea (OSA). However, it was recently suggested that a novel mode of ventilation, Bilevel-auto, could be equally effective in treating patients unable to tolerate CPAP. The aim of this study was to investigate the ability of Bilevel-auto to treat OSA patients whose nocturnal ventilatory disturbances are not completely corrected by CPAP. We enrolled 66 consecutive OSA patients, not responsive to (group A) or intolerant of (group B) CPAP treatment, after a full night of manual CPAP titration in a laboratory. Full polysomnography data and daytime sleepiness score were compared for each group in the three different conditions: basal, during CPAP, and during Bilevel-auto. The apnea-hypopnea index decreased significantly during CPAP in both groups; however, in the group A, there was a further significant improvement during Bilevel-auto. The same trend was observed for oxygenation indices, while the distribution and the efficiency of sleep did not differ following the switch from CPAP to Bilevel-auto. This study confirmed the role of Bilevel-auto as an effective therapeutic alternative to CPAP in patients intolerant of this latter mode of ventilation. Moreover, extending the use of Bilevel-auto to those OSA patients not responsive to CPAP, we showed a significantly better correction of nocturnal respiratory disturbances.

Obstructive sleep apnea in a clinical setting of epilepsy patients: Prevalence and polysomnographic features of 100 consecutive cases

Both Obstructive Sleep Apnea Syndrome (OSAS) and epilepsy are prevalent conditions in general population. Recent publications have reported a higher prevalence of OSAS in clinical series of epileptic patients,suggesting that untreated OSAS may contribute to a worse control of epilepsy.Since OSAS is often underdiagnosed in general population,the aim of our study was to determine OSAS prevalence and severity in a large clinical setting of unselected epileptic patients referred for polysomnographic (PSG) evaluation. We evaluated 100 consecutive epileptic patients (mean age 43.4, 55 men),referred to Sleep Unit for PSG recording due to the following reasons: epileptic syndrome diagnosis (47%), nocturnal seizures (19%), OSAS suspicion (12%), drug resistant epilepsy (9%),isolated convulsive seizure (7%), and parasomnia (6%). All patients underwent attended video-PSG. Patients with an Apnea–Hypopnea Index (AHI ) ⩾ 5 were classified as having OSA. Prior to PSG evaluation demographic and clinical data were recorded (epileptic syndrome and number and type of antiepileptic drugs). The overall prevalence of OSAS in our series was 51%, with a mean AHI of 22.4 (SD 17.4). Among OSAS patients, 49,1% had mild OSAS, 23.5% moderate OSAS and 27% severe OSAS,with significant worse nocturnal saturation indices when compared with no-OSAS group. OSAS was confirmed in all patients with previous clinical suspicion, and was also diagnosed in 39 patients with no suspected OSA prior to the PSG evaluation (21 mild, 9 moderate and 9 patients with severe OSAS).Compared with no-OSAS group, OSAS patients were older (mean age 51.8 vs 34.7), with a higher BMI (28.1 vs 23.8) and mostly men (36% vs 19%, p < 0.05). Sleep architecture showed a higher percentage of non-REM sleep in OSAS patients ( p < 0.05), with no differences in the efficiency or REM sleep. No significant differences were observed in the Epworth Sleepiness Scale (ESS) or number of AEDs at the time of PSG. A high prevalence of OSAS was observed in our clinical setting of epilepsy patients, especially among older men with a higher BMI. A large number of patients (39%) were diagnosed of OSAS with no prior clinical suspicion of nocturnal respiratory disturbance. Clinical screening of OSAS in settings of epileptic patients may be needed in order to diagnose maybe a potential and modifiable risk factor for epilepsy. We thank Dr. Romero, Dr. Sampol, Dr. Jurado and Dr. Ferré for their support.

Insomnia symptoms, objectively measured sleep, and disease severity in chronic obstructive pulmonary disease outpatients

BackgroundSleep disturbances are known to have a negative impact on a range of clinical outcomes in chronic obstructive pulmonary disease (COPD). We examined the associations of insomnia symptoms and objectively measured sleep parameters to a composite score for body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index (a multidimensional index of COPD severity), arterial blood gases, nocturnal respiratory disturbances, periodic limb movements (PLM), psychologic distress, pain, age, and sex. MethodsThe sample comprised 73 COPD outpatients (mean age, 63.6years; standard deviation {SD}, 7.5; range 47–85years; 41.1% women). Insomnia symptoms were measured with the Bergen Insomnia Scale (BIS) and sleep efficiency (SE), slow-wave sleep (SWS), and total sleep time (TST) were assessed with clinical polysomnography (PSG). ResultsBODE index was positively associated with composite BIS score (P=.040). Patients with more severe COPD presented more complaints of nonrestorative sleep compared to patients with less severe COPD (P=.010). In multivariate analysis, the composite BIS score was independently associated with PLM (P<.001), nocturnal respiratory disturbances (P=.001), pain (P=.031), and psychologic distress (P=.044) but not with the BODE index. Objectively measured sleep variables were not associated with any of the health-related variables. ConclusionInsomnia symptoms in COPD patients result from a wide range of health-related factors. More severe COPD may be associated with a subjective experience of nonrestorative sleep but not with objectively measured sleep variables.

Sleep apnoea and metabolic dysfunction.

Obstructive sleep apnoea (OSA) is a highly prevalent condition often associated with central obesity. In the past few years, several studies have analysed the potential independent contribution of OSA to the pathogenesis of metabolic abnormalities, including type 2 diabetes, the metabolic syndrome and non-alcoholic fatty liver disease. New perspectives in OSA patient care have been opened by the promotion of lifestyle interventions, such as diet and exercise programmes that could improve both OSA and the metabolic profile. The rich clinical literature on this subject, together with the growing amount of data on pathophysiological mechanisms provided by animal studies using the chronic intermittent hypoxia model, urged the organising Committee of the Sleep and Breathing meeting to organise a session on sleep apnoea and metabolic dysfunction, in collaboration with the European Association for the Study of Diabetes. This review summarises the state-of-the-art lectures presented in the session, more specifically the relationship between OSA and diabetes, the role of OSA in the metabolic consequences of obesity, and the effects of lifestyle interventions on nocturnal respiratory disturbances and the metabolic profile in OSA patients.

Sleep apnoea syndrome: how will physiologic knowledge position personalised medicine?

The sleep apnoea field is no longer only a matter of nocturnal choking and noise-related partner sleep disturbances. There is now a body of literature demonstrating the huge impact of these nocturnal respiratory disturbances on tissular and systemic inflammatory processes, oxidative stress and endothelial dysfunction, as well as imbalance in sympathetic/parasympathetic activities. These factors interact to favour the development of systemic impairments that include alterations in vigilance/cognition, metabolic disturbances, vascular remodelling and atherosclerosis, making way for hypertension, ischaemic heart disease, heart failure, glucose intolerance/diabetes and non-alcoholic steatohepatitis. In the present issue of the European Respiratory Review, the article by Levy et al. [1] perfectly illustrates the need for a multi-dimensional approach in the management of this disease by piecing together the up-to-date parts of the puzzle represented by the knowledge on pathophysiology, investigations, mechanisms of comorbidity and treatment alternatives. The authors clearly demonstrate that investigating and treating sleep apnoea patients is not only a way to provide silent and quiet nights to patients and their environment, but that the investigation and treatment must be integrated into strategies aimed at preventing the development of comorbid conditions that, nowadays, are recognised as being independently associated with sleep apnoea phenotype. This article also highlights the fact that the mechanisms responsible for the occurrence of sleep apnoea, as well as for the metabolic consequences of the disease, may be individually modulated so that treatment strategies and expected benefits from a sleep apnoea cure may be heterogeneous. From a mechanical point of view, Wellman et al. [2] recently reported that different physiological traits (pharyngeal anatomy/collapsibility, ventilatory loop gain, mechanical effectiveness of upper airway muscles recruitment and arousal threshold) may separately account for the occurrence of upper airway instability. Identifying the factor(s) responsible for upper airway closure in a given …

A Two-Year Weight Reduction Program in Obese Sleep Apnea Patients

To evaluate the effects of a 2-year weight reduction program on respiratory disturbances, arousal index, daytime sleepiness, metabolic status, and quality of life in obese patients with obstructive sleep apnea syndrome (OSAS). Prospective intervention study of 33 consecutive obese OSAS patients (24 men, 9 women); 19 subjects used continuous positive airway pressure and 4 used mandibular retaining device, except during nights with sleep recording. The program consisted of 8 weeks of low calorie diet followed by group meetings with behavioral change support. Seventy percent of the patients completed the program; 67% completed the sleep recordings. The success rate for the apnea-hypopnea index (AHI) (< 20 and reduction > or = 50%) was 15% in the intention to treat (ITT) analysis. The AHI showed a nonsignificant decrease in mean values, from 43 to 28. The oxygen desaturation index (ODI) decreased from 42 to 23 (p = 0.010), arousal index from 24 to 11 (p = 0.019), body mass index from 40 to 35 (p = 0.003) and the Epworth Sleepiness Scale (ESS) from 9 to 5 (p = 0.026), all ITT. Metabolic status, physical functioning, and vitality evaluations improved only in the per protocol analysis. Reduction in weight correlated significantly to reductions in ESS (p = 0.038) and insulin levels (p = 0.002), respectively. There were no differences based on gender or use/non-use of OSAS treatment device. Our weight reduction program showed a limited success in reducing AHI. However, there were significant improvements in weight, ODI, arousal index, and subjective symptoms. We recommend the program as an adjunct treatment for well-motivated obese OSAS patients.

Sleep Patterns in Patients With Huntington's Disease and Their Unaffected First-Degree Relatives: A Brief Report

Polysomnographic sleep patterns in Huntington's disease (HD) have been studied sporadically in small groups of patients, providing variable results. In this study, by comparing the polysomnographic sleep patterns of HD patients and their unaffected relatives, identifying sleep traits more specifically related to the HD gene was attempted. The results corroborated previously reported findings of prolonged sleep latency and the virtual absence of nocturnal respiratory disturbances in early HD. Sleep latency in the HD patients positively correlated with the results of a screening test for frontal lobe dysfunction. Larger, more standardized studies will be needed to correlate genetic markers and sleep patterns in HD.

Endothelial dysfunction and inflammatory reactions of elderly and middle-aged men with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is considered to be associated with cardiovascular complications, and atherosclerosis could mediate this relationship. Cardiovascular risk factors of OSAS still need to be elucidated in elderly patients, since studies about the association between OSAS and cardiovascular diseases have been done mainly in middle-aged adults. To investigate whether endothelial dysfunction, as an early marker of atherosclerosis, and inflammatory responses in OSAS were affected by age, we studied flow-mediated dilatation (FMD) and C-reactive protein (CRP) in elderly and middle-aged patients with OSAS. This study enrolled 161 male subjects of 117 middle-aged (35-59 years old) and 44 elderly (>or=60 years old) patients with OSAS. After they finished nocturnal polysomnography (NPSG), FMD was measured on the brachial artery and blood samples were obtained to determine serum CRP levels. FMD was significantly lower in the elderly patients (p = 0.04), but no difference was observed between two age groups in body mass index (BMI), neck circumference, waist-to-hip ratio, apnea hypopnea index (AHI), serum CRP level, or NPSG findings related with nocturnal hypoxemia such as average O(2) saturation, percentage of time below 90% O(2) saturation, and oxygen desaturation index (ODI). From the results of stepwise multiple linear regression analysis, the lowest oxygen saturation was a significant determinant of FMD (beta = 0.25, p < 0.01, adjusted R (2) = 6%), and BMI (beta = 0.22, p < 0.05) and waist-to-hip ratio (beta = 0.21, p < 0.05) were significant variables to explain CRP (adjusted R (2) = 11%, p < 0.01) in the middle aged patients. In the elderly patients, no variable was significant for predicting FMD, but AHI was significant determinant of CRP (beta = 0.46, p < 0.01, adjusted R (2) = 19%, p < 0.01). In predicting cardiovascular risks of OSAS, both hypoxia and obesity should be considered in the middle-aged group, whereas nocturnal respiratory disturbances are important in the elderly group.

ERS School Course Sleep Medicine: Non-respiratory causes of excessive daytime sleepiness

<h3>Educational aims</h3> To present the symptoms, methods of assessment and the different causes of excessive daytime sleepiness when nocturnal respiratory disturbances have been excluded. To enable physicians to confirm a diagnosis of sleepiness and recognise the pathology. <h3>Summary</h3> Excessive daytime sleepiness (EDS) is defined as an inability to stay awake and alert during the major waking episodes of the day, resulting in unintended drowsiness or sleep episodes almost daily for at least 3 months. This review will examine the assessment of sleepiness and different causes of EDS.

Night-to-night variability in sleep in cystic fibrosis

Objectives: The impact of night-to-night variability (NNV) on polysomnography (PSG) has been reported mainly in normal subjects, the elderly and patients with obstructive sleep apnea with focus on changes in the apnea/hypopnea index, rather than measures of nocturnal oxygenation. There is very limited data on NNV in patients with cystic fibrosis (CF). The goal of this study was to assess for first-night effect and reliability of PSG measurements on nocturnal oxygenation and respiratory disturbance in CF. Methods: A prospective observational study was performed in patients with CF who consented to PSG on two consecutive nights. Paired t-tests and intra-class correlation coefficients (ICCs) were calculated for repeated measures of sleep stage time, sleep efficiency, arousal indices, measures of nocturnal oxygenation, and respiratory events in all sleep stages. Results: Thirty-one patients with CF were studied, aged 27±8 (mean±1SD) years and forced expiratory volume in 1 s (FEV 1) of 37±11% of predicted. Relative to the first-night PSG, on the second PSG, we observed the following: shorter latency to rapid eye movement (REM) sleep ( P<0.001), increased sleep efficiency ( P<0.01), decreased wake after sleep onset (WASO) time ( P<0.01), decreased percentage of non-REM time with oxyhemoglobin saturation by pulse oximetry (SpO 2)≤90% ( P<0.05), decreased number of central apneas per hour ( P<0.05) and reduced respiratory rate in stage 2 sleep on night 2 ( P<0.05). Despite these changes, the ICCs between night 1 and night 2 showed good repeatability/reliability for measures of nocturnal oxygenation and indices of respiratory disturbance, including the percentage of total sleep time with SpO 2≤90% (ICC=0.85) and apnea-hypopnea index (ICC=0.75). Likewise, the ICCs were extremely high for respiratory rate in stage 2 (ICC=0.94), slow wave sleep (ICC=0.97), and REM sleep (ICC=0.96). Conclusion: Although a first-night effect is seen with sleep efficiency, REM latency, and WASO, a single-night PSG in patients with CF yields reliable information on nocturnal oxygenation and respiratory disturbance.

Sleep disturbances and their correlates in elderly Japanese American men residing in Hawaii.

Elderly people frequently report the presence of chronically disturbed sleep. However, most data are derived from predominantly Caucasian populations. The current study is an investigation of the prevalence and correlates of sleep disturbances in a cohort of elderly Japanese American men residing in Hawaii. The importance of this population lies in its representation of an ethnic group living in a culture different from their ancestry. This study is a cross-sectional cohort analysis of data pertaining to sleep disturbances and their potential correlates from 3,845 elderly Japanese American men residing in Hawaii (mean age. 78 years; range, 71-93 years) who participated in the fourth survey of the Honolulu Heart Program (1991-1994), which is the baseline exam for the Honolulu-Asia Aging Study. Information collected included an extensive survey of medication use, medical history, and assessments of physical and mental function, quality of life, and sleep. The prevalence of insomnia (DIMS) was 32.6%, a rate similar to that reported in predominantly Caucasian populations. Depression, benzodiazepine use, and several chronic health problems were the most important factors associated with DIMS. In contrast, excessive daytime sleepiness (EDS) had a prevalence of 8.9%, a rate lower than that found in elderly Caucasian populations but close to that reported among native Japanese. Important factors related to EDS were symptoms of nocturnal respiratory disturbance, depression, perception of adverse quality of life, Parkinson's disease, and digitalis use. Elderly Japanese men are less likely than elderly Caucasian men to report excessive daytime sleepiness. However, their insomnia rates are similar.

Heavy Snorer's Disease: A Progressive Local Neuropathy

“Heavy snorer's disease” is defined as progression from heavy snoring to obstructive sleep apnoea syndrome (OSAS). Apart from significant weight gain, the aetiology underlying progression to a collapse of the upper airways during inspiration and sleep remains unclear. Previous studies have shown that nocturnal respiratory disturbances became worse, even in some OSAS patients who did not gain weight. The patency of the upper airways depends on the balance between the negative intrapharyngeal pressure developed during inspiration and its counteraction by dilating muscles. The reflexogenic dilation is probably mediated by afferent nerve endings in the pharyngeal mucosa. Chronic vibration of a tissue may cause neuronal damage. Therefore, the hypothesis that snoring per se might cause progressive pharyngeal nerve lesion has been tested in a series of studies from the Karolinska institute, Stockholm, which, along with other studies, will be reviewed here. In these studies it was found that a majority of patients with heavy snoring and different degrees of respiratory disturbance had signs of pharyngeal afferent and efferent (motor) nerve lesions. These lesions may cause the collapse of upper airways in OSAS. Since it is not known which “heavy snorer” will develop OSAS, early effective prevention and/or treatment of snoring is called for.

Heavy Snorer's Disease: A Progressive Local Neuropathy

?Heavy snorer's disease? is defined as progression from heavy snoring to obstructive sleep apnoea syndrome (OSAS). Apart from significant weight gain, the aetiology underlying progression to a collapse of the upper airways during inspiration and sleep remains unclear. Previous studies have shown that nocturnal respiratory disturbances became worse, even in some OSAS patients who did not gain weight. The patency of the upper airways depends on the balance between the negative intrapharyngeal pressure developed during inspiration and its counteraction by dilating muscles. The reflexogenic dilation is probably mediated by afferent nerve endings in the pharyngeal mucosa. Chronic vibration of a tissue may cause neuronal damage. Therefore, the hypothesis that snoring per se might cause progressive pharyngeal nerve lesion has been tested in a series of studies from the Karolinska Institute, Stockholm, which, along with other studies, will be reviewed here. In these studies it was found that a majority of patients with heavy snoring and different degrees of respiratory disturbance had signs of pharyngeal afferent and efferent (motor) nerve lesions. These lesions may cause the collapse of upper airways in OSAS. Since it is not known which ?heavy snorer? will develop OSAS, early effective prevention and/or treatment of snoring is called for.

Short-Term Antihypertensive Medication Does Not Exacerbate Sleep-Disordered Breathing in Newly Diagnosed Hypertensive Patients

It has been speculated for some time that various antihypertensive medications may have a deleterious effect on respiration during sleep and thereby enhance the apparent association between hypertension and sleep apnea/hypopnea (SAH). However, there are few data to support this contention. The present study used a double-blind, randomized, cross-over design to contrast the effects of 6 weeks treatment with α-methyldopa and the combination of hydrochlorothiazide and amiloride with that of amlodipine and the combined diuretics in a group of 24 newly diagnosed patients with primary hypertension. All-night polysomnography was performed before the initiation of therapy (baseline) and at the end of the two treatment periods. Respiratory variables failed to reveal any significant differences between the treatments and baseline, or between the two different treatment regimens. The two treatment regimens achieved similar reductions in blood pressure. The prevalence of SAH was 25% before treatment, which is comparable to a prevalence of 20% in a similar group drawn from the same population but receiving various antihypertensive medications. The findings of this study are in agreement with previous reports using other classes of antihypertensive drugs that also failed to detect any tendency for increases in nocturnal respiratory disturbance indices over assessment periods of 8 weeks or shorter.

Neuropsychological functioning and determinants of morning alertness in patients with obstructive sleep apnea syndrome.

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions are divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea.

Four‐year follow‐up after uvulopalatopharyngoplasty in 50 unselected patients with obstructive sleep apnea syndrome

Fifty unselected consecutive patients with obstructive sleep apnea syndrome (OSAS) diagnosed by nocturnal recordings of respiration movements by a static charge sensitive bed (SCSB) and oximetry, alone or combined with polysomnography, were studied. Renewed SCSB-oximetry recordings evaluated treatment. Six months after surgery, 30 of 50 were classified as responders. Twenty-one months after surgery, 19 of 49 were responders. Patients who relapsed showed a significant increase in mean body mass index (BMI). Four years after surgery, 24 of 48 patients were responders. Preoperative BMI was significantly lower in the responder group. Subsequent treatment was required in 15 nonresponders. There was no correlation between patients' subjective improvement and objective results. The study resulted in the following conclusions: 1. The responder rate to UPPP in unselected patients is low. 2. Obesity and high indices of nocturnal respiratory disturbance are negative predictors. 3. The patients' subjective recovery alone must not be used for postoperative evaluation. 4. With regular follow-up and the use of the treatment alternatives available today, the majority of OSAS patients can receive effective treatment.

Natural evolution of sleep apnoea syndrome: a five year longitudinal study.

We wanted to investigate the natural evolution of Obstructive Sleep Apnoea Syndrome (OSAS). We therefore followed 58 patients who refused any treatment at the time of diagnosis. Of the eligible patients 32 subjects enrolled in instrumental follow-up. The effects on daytime somnolence, daytime lung function and nocturnal respiratory disturbances were retrospectively evaluated by repeating Multiple Sleep Latency Test (MSLT), spirometry and polysomnography after a follow-up period of at least 5 years (5.7 +/- 0.2 SEM yrs). In the patient group as a whole the mean Apnoea+Hypopnoea Index (AHI), the mean low arterial oxygen saturation (Sao2) and the mean Body Mass Index (BMI) did not change over time. The only significant differences were the increase in mean duration of apnoeas (21.0 vs 23.5 s) and hypopneas (13.5 vs 16.3 s) and the decrease in AHI < 80% (13.3 vs 7.9). No correlations were found between the changes in AHI or mean low Sao2 and age, BMI, AHI, mean low Sao2, pulmonary function tests or arterial blood gases at baseline. No significant changes were observed in systemic blood pressure, pulmonary function tests, blood gases analysis or MSLT. "Improved" (n = 6) and "worsened" (n = 7) groups were defined by a reduction or increase in AHI over 35% of baseline value. At baseline the "worsened" group tended to have lower AHI and higher mean low Sao2 compared with the "improved" group. In the "worsened" group the BMI rose significantly from 26.0 to 29.2, AHI rose significantly from 14.1 to 51.3 and mean low Sao2 decreased from 92 to 90 (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Development of Nocturnal Respiratory Disturbance in Untreated Patients With Obstructive Sleep Apnea Syndrome

Patient histories suggest that obstructive sleep apnea syndrome (OSAS) is a progressive condition. To investigate whether this could be shown in data from sleep recordings, 42 patients with OSAS were retrospectively studied. All had undergone a screening recording of respiration movements and oximetry at least 6 months (average, 16 months) prior to a diagnostic polysomnogram including these parameters. No treatment was given in the meantime. In the first recording, mean oxygen desaturation index (ODI, average number of desaturations of > 4 percent per sleeping hour) was 10; periodic, obstructive respiration movements occurred during (average) 36 percent of total estimated sleeping time, and mean nadir SaO2 was 85 percent. In the second recording, mean ODI was 21 (significant change, p = 0.0002), periodic respiration time was 61 percent, and nadir SaO2 was 80 percent (p = 0.0001, respectively). In 26 of 42 patients (62 percent), ODI had increased by > 50 percent. Increases in ODIs and periodic breathing were significantly correlated to increases in body weight. There were, however, exceptional patients with considerable increases in respiratory disturbance despite weight loss. The greatest changes were found in the patients who had the highest apnea indices in the polysomnograms. Early treatment may therefore be justified, since a borderline case may change to severe OSAS in 1 to 2 years' time. Follow-up recordings of untreated patients are important.

Recovery of Alertness After CPAP in Apnea

Excessive daytime sleepiness is the most common symptom in OSAS. Administering CPAP improves breathing during sleep. We evaluated the time course of the recovery of alertness following CPAP therapy in OSAS patients. Thirty-nine patients with OSAS were treated with CPAP and evaluated after one, 14, or 42 nights of treatment, 13 patients being randomly assigned to each group. All received a diagnostic polysomnogram and MSLT before treatment. The three groups had similar baseline values for nocturnal respiratory disturbance, oxygenation during sleep, fragmentation of sleep, and level of EDS. CPAP treatment was associated with a significant improvement in sleep-related respiration, oxygenation, and sleep fragmentation. The EDS showed significant improvement after one night, and further significant improvement after 14 nights, but no further significant improvement after 42 nights. The differential rate of improvement in nocturnal parameters compared with that of primary complaint of EDS suggests that OSAS patients experience a chronic functional sleep loss. As with sleep deprivation, recovery of alertness in OSAS requires several nights of normal sleep.