Under reporting of sleepiness and driving impairment in patients with sleep apnoea/hypopnoea syndrome

SUMMARY Under reporting of symptoms by patients with sleep apnoeal/hypopnoea syndrome (SAHS) has been reported anecdotally, but investigation of the prevalence or determinants of this is limited. To assess this, repeated ratings in 99 patients with sleep apnoea/hypopnoea syndrome of pre-treatment Epworth sleepiness score, unintended napping, driving impairment and mood were obtained, first at presentation and then after treatment with continuous positive airway pressure (CPAP) therapy of median 22 (range 2-70) weeks duration. Median Epworth score for pre-treatment sleepiness rose from 12 (range 0-24) initially to 14 (range 5-24) retrospectively (P<0.0001). More patients initially under-rated Epworth score (67%) than over-rated (29%; P0.001). ‘False negative’ cases with an initially ‘normal’ (≤ 10) and retrospectively ‘sleepy’ (≥ 11) Epworth score comprised 24% of all patients and 62% of initially ‘normal’ scorers. Unintended napping behaviour also was rated as significantly more severe on retrospective assessment (P<0.001). Driving impairment due to sleepiness was initially reported by 23% of all drivers and retrospectively by 37% (P=0.01), with 25% of initial deniers retrospectively admitting compromised driving ability before continuous positive airway pressure. No polysomnographic predictors of symptom under reporting were found (P 0.1). These results suggest a high prevalence of symptom minimization before treatment in patients with sleep apnoea/hypopnoea syndrome.     

Prevalence of sleepiness and its relation to autonomic evidence of arousals and increased inspiratory effort in a community based population of men and women

Degrees of sleep apnoea and daytime sleepiness are quite common in community populations. However the relationship between the two is poor, although sleepiness does correlate better with a history of snoring. It has been suggested that sleep can be fragmented by upper airways obstructive events, short of full apnoeas or hypopnoeas, and that these events may not provoke full cortical arousal, but be detectable through activation of the autonomic system. Failure to detect both these could mask a relationship between 'sleep apnoea' and daytime sleepiness. We have therefore measured sleepiness (Epworth Sleepiness Scale) in addition to both autonomic 'arousals' and inspiratory effort (using pulse transit time) in 473 men and women at home. Although sleepiness was related to a history of snoring, it was not significantly predicted by the measures of autonomic 'arousal', or inspiratory effort. Reported snoring and objectively measured snoring correlated poorly. As in other studies, nocturnal hypoxic dips were correlated with obesity, age, alcohol consumption, drug usage and a history of snoring. These data make it unlikely that sleep fragmentation from subtle variants of sleep apnoea and 'autonomic' (or 'subcortical') arousals are an important source of daytime sleepiness in the community.     

Sleep apnoea in the Prader-Willi syndrome

SUMMARY  Seventeen children and young adults with the Prader-Willi syndrome were investigated. Twelve of 17 subjects had excessive daytime sleepiness as determined by their own or parental report, a high Epworth Sleepiness Scale score or a short mean sleep latency. Night sleep disturbances were reported in seven subjects with snoring, mouth-breathing, breath-holding and occasional nocturnal enuresis. Polysomnography showed abnormalities of sleep structure with rapid eye movements without reduction in muscle tone at sleep onset in 12 subjects, and a high respiratory event index with frequent brief apnoeas, particularly in REM sleep, in 16 subjects. Most apnoeas were not accompanied by arousals. Seven subjects, all of whom were obese, were considered to have symptomatic sleep apnoea and were treated with continuous positive airway pressure (CPAP) but this was poorly tolerated in two. Five subjects continued CPAP over a 6-month period resulting in subjective improvement in excessive daytime sleepiness in 3.
Excessive daytime sleepiness occurs in approximately two-thirds of subjects with the Prader-Willi syndrome. It is mainly of central origin but obstructive sleep apnoea may increase sleepiness, particularly in obese subjects.     

Psychomotor vigilance performance predicted by Epworth Sleepiness Scale scores in an operational setting with the United States Navy

It is critical in operational environments to identify individuals who are at higher risk of psychomotor performance impairments. This study assesses the utility of the Epworth Sleepiness Scale for predicting degraded psychomotor vigilance performance in an operational environment. Active duty crewmembers of a USA Navy destroyer (N = 69, age 21–54 years) completed the Epworth Sleepiness Scale at the beginning of the data collection period. Participants wore actigraphs and completed sleep diaries for 11 days. Psychomotor vigilance tests were administered throughout the data collection period using a 3‐min version of the psychomotor vigilance test on the actigraphs. Crewmembers with elevated scores on the Epworth Sleepiness Scale (i.e. Epworth Sleepiness Scale >10) had 60% slower reaction times on average, and experienced at least 60% more lapses and false starts compared with individuals with normal Epworth Sleepiness Scale scores (i.e. Epworth Sleepiness Scale ≤10). Epworth Sleepiness Scale scores were correlated with daily time in bed (P < 0.01), sleep (P < 0.05), mean reaction time (P < 0.001), response speed 1/reaction time (P < 0.05), slowest 10% of response speed (P < 0.001), lapses (P < 0.01), and the sum of lapses and false starts (P < 0.001). In this chronically sleep‐deprived population, elevated Epworth Sleepiness Scale scores identified that subset of the population who experienced degraded psychomotor vigilance performance. We theorize that Epworth Sleepiness Scale scores are an indication of personal sleep debt that varies depending on one's individual sleep requirement. In the absence of direct performance metrics, we also advocate that the Epworth Sleepiness Scale can be used to determine the prevalence of excessive sleepiness (and thereby assess the risk of performance decrements).     

The human leucocyte antigen DQB1*0602 allele is associated with electroencephelograph differences in individuals with obstructive sleep apnoea syndrome

Human leucocyte antigen (HLA) DQB1*0602 allele, a well‐known genetic risk factor for narcolepsy, has been associated with sleep parameters in healthy subjects. We aimed to assess the association of this allele with daytime sleepiness and altered sleep electroencephalogram characteristics in the general population and in patients with obstructive sleep apnoea syndrome (OSAS). Eight hundred and ninety‐four individuals from the Epidemiologic Study of Sleep were genotyped for the HLA DQB1*0602 allele. Full‐night polysomnography was performed, and daytime sleepiness was analysed according to the Epworth Sleepiness Scale. HLA‐DQB1*0602 allele‐positive and ‐negative subjects in the general population, as well as in patients with OSAS, exhibited similar sleep parameters and levels of daytime sleepiness. However, spectral analysis showed that allele‐positive individuals with OSAS exhibited higher theta power during sleep Stage 1 (P < 0.05) in occipital derivations, and lower delta power during sleep Stages 1 and 2 (P < 0.01) compared with individuals negative for the allele, even after correction for potential confounders as age, sex, body mass index and European ancestry. No significant differences in the electroencephalogram variables were found in individuals without OSAS. The data highlight the HLA‐DQB1*0602 as a potential genetic factor influencing sleep physiology in individuals diagnosed with OSAS.     

Associations of Subjective Sleep Quality and Daytime Sleepiness With Cognitive Impairment in Adults and Elders With Heart Failure

This study examined the association of subjective nighttime sleep quality and daytime sleepiness with cognitive impairment in 105 adults (< 60 years old) and 167 elders (≥ 60 years old) with heart failure. Nighttime sleep quality and daytime sleepiness were measured by the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Cognitive impairment was assessed using a neuropsychological battery measuring attention, memory, and processing speed. Multivariate logistic regression was used. In adults, daytime sleepiness was associated with cognitive impairment, whereas poor nighttime sleep quality was associated with cognitive impairment in elders. Age may play an important role in how sleep impacts cognition in persons with heart failure. Improving nighttime sleep quality and daytime sleepiness in this population may improve cognition.     

Sleepiness in obstructive sleep apnea: a harbinger of impaired cardiac function?

STUDY OBJECTIVES: Daytime sleepiness is a common clinical presentation in both obstructive sleep apnea (OSA) and cardiovascular diseases. The purpose of this study was to assess the relationship between degree of subjective daytime sleepiness and cardiac performance in patients with obstructive sleep apnea. DESIGN: Observational study. SETTING: General Clinical Research Center. PATIENTS: The study sample was comprised of 86 patients (68 men and 18 women) with an average age of 47 years. All were suspected of having obstructive sleep apnea and underwent confirmatory diagnostic polysomnography (respiratory disturbance index > or = 15). MEASUREMENTS AND RESULTS: Stroke volume and cardiac output were measured using impedance cardiography and corrected for body surface area to yield stroke index and cardiac index. Daytime sleepiness was quantified using the Epworth Sleepiness Scale. A higher Epworth Sleepiness Scale score, suggesting more daytime sleepiness, was significantly related to lower stroke index and cardiac index. In multiple regression analyses, the relationships of Epworth Sleepiness Scale score with both stroke index and cardiac index were significant (p < .05), even after controlling for age, sex, ethnicity, respiratory disturbance index, and mean sleep oxygen saturation. CONCLUSIONS: These results suggest that daytime sleepiness is independently associated with decreases in cardiac function as assessed by impedance cardiography in patients with obstructive sleep apnea.     

The effect of clustered versus regular sleep fragmentation on daytime function

Previously, we found that regular sleep fragmentation, similar to that found in patients with sleep apnoea/hypopnoea syndrome (SAHS), impairs daytime function. Apnoeas and hypopnoeas occur in groups in patients with REM or posture related SAHS. Thus, we hypothesised that clustered sleep fragmentation would have a similar impact on daytime function as regular sleep fragmentation. We studied 16 subjects over two pairs of 2 nights and 2 days. The first night of each pair was for acclimatisation. On the second night, subjects either had their sleep fragmented regularly every 90 s, or fragmented every 30 s for 30 min every 90 min, the remaining 60 min being undisturbed. We fragmented sleep with tones to produce a minimum 3 s increase in EEG frequency. During the days following each pair of nights we tested subjects daytime function. Total sleep time (TST) and microarousal frequency were similar no both study nights. We found significantly less stage 2 (55 SD 4, 62 +/- 7%; P = 0.001) and more slow wave sleep (21 SD 3, 12 +/- 6%; P < 0.001) on the clustered night. Mean sleep onset latency was similar on MSLT (clustered 10 SD 5, regular 9 +/- 4 min; P = 0.7) and MWT (clustered 32 SD 7, regular 30 +/- 7 min; P = 0.2). There was no difference in subjects mood or cognitive function after either study night. These results suggest that although there is more slow wave sleep (SWS) on the clustered night, similar numbers of sleep fragmenting events produced similar daytime function whether the events were evenly spaced or clustered.     

Assessment of sleep and sleepiness in Parkinson disease

STUDY OBJECTIVES: To develop a short and practical scale (SCOPA-SLEEP) that evaluates nighttime sleep and daytime sleepiness. The scale is developed for research in Parkinson disease but may be of value for other somatic diseases. DESIGN: Postal survey including 4 instruments, the SCOPA-SLEEP nighttime sleep (5 items) and daytime sleepiness (6 items), the Pittsburgh Sleep Quality Index, and the Epworth Sleepiness Scale. SETTING: Movement Disorders Center, Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. PARTICIPANTS: 143 patients with Parkinson disease and 104 controls. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Reliability of the scale was high: internal consistency of the nighttime sleep and daytime sleepiness scales were 0.88 and 0.91, respectively (Cronbach alpha), and test-retest reliabilities were 0.94 and 0.89, respectively (intraclass correlation coefficient). Scale scores differed significantly between patients and controls (P < .001). Construct validity was assessed by correlations with scales that addressed similar constructs. Correlation between the nighttime sleep scale and the Pittsburgh Sleep Quality Index was 0.83 (P < .001), and the correlation between the daytime sleepiness scale and the Epworth Sleepiness Scale was 0.81 (P < .001). Factor analysis revealed 1 factor each for both scales, indicating that the scales measure 1 construct, which justifies the calculation of sumscores. The coefficient of variation of both the nighttime sleep and the daytime sleepiness scale was higher than that of the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale, indicating a better ability to detect differences between individuals. CONCLUSIONS: The SCOPA-SLEEP is a reliable and valid instrument for assessing nighttime sleep and daytime sleepiness in patients with Parkinson disease.     

Sleep habits and accident risk among truck drivers: a cross-sectional study in Argentina

Road accidents are a major cause of death, and sleep deprivation affects driving skills. We conducted a cross-sectional study to evaluate sleep habits and accident risk in long-haul truck drivers in Buenos Aires, Argentina. Questionnaires regarding sleep habits, snoring, and daytime sleepiness were administered, and a limited physical examination was performed. We obtained 738 complete answers (response rate 85%). Mean sleep hours during working days was 3.76 (SD 2.40). Mean driving hours was 15.9 (SD 5.60) per day. Frequent sleepiness while driving was reported by 43.7% of responders. Sleepiness while driving was associated with Epworth Sleepiness Scale values >10 (odds ratio 1.85, 95% confidence interval = 1.20-2.85). Snoring was reportea by 71% of drivers and was frequent in 43.8%. Snoring more than 3 times a week (odds ratio 1.73, 95% confidence interval = 1.23-2.44), sleepiness while driving (OR 1.92, 95% confidence interval = 1.08-1.96), and Epworth Sleepiness Scale score > 10 (odds ratio 2.53, 95% confidence interval = 1.61-3.97) were independently associated with reporting of accidents or near accidents. Sleep deprivation and long driving shifts were prevalent in our study. Accident risk was associated with frequent snoring, daytime sleepiness, and reporting of sleepiness at the wheel. This study highlights the need of improving working conditions in this highly exposed population.     

Sleep Disordered Breathing and Hypertension: Does Self-Reported Sleepiness Modify the Association?

STUDY OBJECTIVES: Epidemiologic studies that demonstrate increased risk of hypertension in persons with sleep disordered breathing indicate that only a minority of these persons report significant subjective sleepiness. Studies also suggest that presence of self-reported sleepiness may identify a subset of persons with sleep disordered breathing who are at greatest risk of cardiovascular sequelae, including hypertension. We explore whether self-reported sleepiness modifies the relationship between sleep disordered breathing and prevalent hypertension. DESIGN: Cross-sectional. SETTING: Multicenter study. PARTICIPANTS: 6046 subjects from the Sleep Heart Health Study. MEASUREMENTS: Polysomnography, systolic and diastolic blood pressure, antihypertensive medication use, questionnaire determined excessive sleepiness and Epworth Sleepiness Scale, and covariates. RESULTS: The odds of hypertension at higher apnea hypopnea index categories were larger in participants identified as sleepy based on responses to a frequency of sleepiness question or the Epworth score. For example, for those with AHI > or =30 compared to AHI <1.5, the adjusted odds ratio for hypertension was 2.83 (1.33-6.04) among those reporting sleepiness > or =5 days per month, but only 1.22 (0.89-1.68) among those reporting less frequent daytime sleepiness. In adjusted logistic regression models, there was statistical evidence for effect modification by frequency of sleepiness (P = 0.033) of the association between apnea hypopnea index and hypertension. In adjusted models that included the Epworth score as a continuous variable, the interaction term fell slightly short of statistical significance (beta = 0.010, P = 0.07). CONCLUSION: This study finds that the association of sleep disordered breathing with hypertension is stronger in individuals who report daytime sleepiness than in those who do not.     

Subjective daytime sleepiness: dimensions and correlates in the general population

STUDY OBJECTIVE: Discrepancies between several widely used assessment tools suggest that subjective daytime sleepiness is not a unitary phenomenon. Most research, however, has been based on patients. The aim of this study was to examine whether qualitatively different facets of subjective daytime sleepiness exist in the general population and to assess how different aspects of subjective sleepiness varied by age, gender, education status, body mass index, sleep debt, Stanford Sleepiness Scale, and objectively measured sleepiness (Multiple Sleep Latency Test). DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Population-based sample of 1562 women and 1351 men, mean age of 46.6 +/- 7.9 years, including a subset of 145 participants who underwent an Multiple Sleep Latency Test. MEASUREMENTS: Self-reported sleepiness problems, Epworth Sleepiness Scale items, sleep habits, Multiple Sleep Latency Test, and Stanford Sleepiness Scale. RESULTS: Principal-axis factor analysis of 13 self-reported daytime-sleepiness measures yielded 3 factors, labeled perceived daytime sleepiness (Cronbach's alpha = 0.74), subjective sleep propensity in active situations (alpha = 0.82), and subjective sleep propensity in passive situations (alpha = 0.63). The factor-based scores were all related to increased body mass index and lower education status, but the associations of scores for perceived and subjective propensity factors differed with gender, age, sleep debt, MSLT, and Stanford Sleepiness Scale. Worse perceived sleepiness factor-based score was significantly related to female gender, younger age, higher sleep debt, and worse Stanford Sleepiness Scale scores. Worse factor-based scores for subjective sleep propensity in both active and passive situations were significantly associated with male gender, older age, and worse Multiple Sleep Latency Test scores. CONCLUSION: Findings from the present analysis on a general population sample support the hypothesis that subjective daytime sleepiness has multiple dimensions.     

Does the physiological success of CPAP titration predict clinical success?

Patients commencing continuous positive airway pressure therapy (CPAP) undergo overnight airway pressure titration in sleep centres to optimize breathing and sleep patterns. We tested the hypothesis that data from formal scoring of the sleep and breathing patterns observed at the best achievable pressure during titration can predict CPAP use and effectiveness, as our clinical experience suggested otherwise. The relationship between CPAP titration scores (apnoea/hypopnoea frequency, arousal frequency and sleep staging) and subsequent CPAP use was examined in 150 sleep apnoea/hypopnoea syndrome patients. One hundred patients were continuing CPAP therapy and 50 were randomly selected patients who had discontinued CPAP. Within the CPAP group, titration scores were compared with CPAP machine use, subjective daytime sleepiness and requirements for airway pressure adjustment. Respiratory irregularities and arousals during titration did not relate to outcome. Sleep-stage analysis revealed a weak relationship between more wakefulness during titration and CPAP discontinuation (P=0.02). There was a correlation between more prolonged Stage 4 sleep during titration and reduced sleepiness on established therapy (P=0.002), but this explained less than 12% of the variance. The absence of rapid eye movement sleep during titration was not associated with poorer outcomes. We conclude that routine scoring of breathing and sleep patterns observed during CPAP titration is of little clinical value, as the results do not predict outcome for individual patients. Satisfactory CPAP therapy may be established even if significant numbers of apnoeas/hypopnoeas or arousals are observed at the optimal pressure during titration.     

Intermittent fasting during Ramadan: does it affect sleep?

Islamic intermittent fasting is distinct from regular voluntary or experimental fasting. We hypothesised that if a regimen of a fixed sleep–wake schedule and a fixed caloric intake is followed during intermittent fasting, the effects of fasting on sleep architecture and daytime sleepiness will be minimal. Therefore, we designed this study to objectively assess the effects of Islamic intermittent fasting on sleep architecture and daytime sleepiness. Eight healthy volunteers reported to the Sleep Disorders Centre on five occasions for polysomnography and multiple sleep latency tests: (1) during adaptation; (2) 3 weeks before Ramadan, after having performed Islamic fasting for 1 week (baseline fasting); (3) 1 week before Ramadan (non‐fasting baseline); (4) 2 weeks into Ramadan (Ramadan); and (5) 2 weeks after Ramadan (non‐fasting; Recovery). Daytime sleepiness was assessed using the Epworth Sleepiness Scale and the multiple sleep latency test. The participants had a mean age of 26.6 ± 4.9 years, a body mass index of 23.7 ± 3.5 kg m^?2 and an Epworth Sleepiness Scale score of 7.3 ± 2.7. There was no change in weight or the Epworth Sleepiness Scale in the four study periods. The rapid eye movement sleep percentage was significantly lower during fasting. There was no difference in sleep latency, non‐rapid eye movement sleep percentage, arousal index and sleep efficiency. The multiple sleep latency test analysis revealed no difference in the sleep latency between the ‘non‐fasting baseline’, ‘baseline fasting’, ‘Ramadan’ and ‘Recovery’ time points. Under conditions of a fixed sleep–wake schedule and a fixed caloric intake, Islamic intermittent fasting results in decreased rapid eye movement sleep with no impact on other sleep stages, the arousal index or daytime sleepiness.     

The effect of CPAP treatment on excessive daytime somnolence in patients with obstructive sleep apnea

The study was undertaken to investigate whether a CPAP therapy improves symptoms of excessive daytime sleepiness (EDS) in patients with obstructive sleep apnoea (OSA). In seventy six patients (66 M and 10 F) with AHI = 50 +/- 3.3, BMI = 34 +/- 0.9 kg/m2 and mean age = 50.4 +/- 1 years OSA was diagnosed using standard polysomnography. EDS was assessed using Epworth Sleepiness Scale (ESS). Each patient was examined two or three times, before, after 1 and/or 2-15 months of CPAP treatment. Significant reduction of EDS within 1 month of CPAP therapy was found. Mean ESS was reduced from 14.3 +/- 0.9 to 7.0 +/- 0.7 after 1 month therapy (p < 0.001). Continuation of treatment had no further effect on decrease of symptoms of daytime sleepiness. There was a correlation between percent of sleep spent with CPAP and improvement in ESS.     

Actual and perceived sleep: associations with daytime functioning among postpartum women

Sleep and wake have a homeostatic relation that influences most aspects of physiology and waking behavior. Sleep disturbance has a detrimental effect on sleepiness and psychomotor vigilance. The purpose of this study was to identify which actual or perceived sleep characteristics accounted for the most variance in daytime functioning among postpartum mothers. Seventy first-time postpartum mothers' actual sleep (actigraphically estimated: total sleep time, number of wake bouts, length of nocturnal wake, and sleep efficiency) and perceived sleep (self-reported: number of awakenings, wake time, and sleep quality) were measured along with their daytime functioning (Stanford Sleepiness Scale [SSS], Epworth Sleepiness Scale [ESS], Visual Analogue of Fatigue Scale [VAFS], and morning Psychomotor Vigilance Test [PVT]). Data were repeatedly collected from the same sample during postpartum weeks 2, 7, and 13. Four stepwise linear regressions were calculated for each postpartum week to examine which objective and/or subjective variable(s) accounted for the most variance in daytime functioning. The SSS and VAFS were both most consistently associated with perceived sleep quality. The ESS was most consistently associated with actual total sleep time. PVT performance was most consistently associated with estimates of actual and perceived sleep efficiency. Actual and perceived sleep profiles were differentially associated with specific daytime functions. These results from postpartum mothers may indicate that populations who experience specific forms of sleep disturbance (e.g. fragmentation and/or deprivation) may also experience specific daytime conditions.     

Effects of continuous positive airway pressure on neurocognitive and neuropsychiatric function in obstructive sleep apnea

The aim of this study was to determine the neurocognitive and neuropsychiatric effects of continuous positive airway pressure treatment on patients with obstructive sleep apnea. This cross‐sectional, prospective, observational study included 126 patients with sleep apnea. The following tests were performed: the Montreal Cognitive Assessment for the evaluation of cognitive impairment, the Beck Depression Inventory, and the State‐Trait Anxiety Inventory, together with the Epworth Sleepiness Scale for the evaluation of neuropsychiatric symptoms and a person's general level of daytime sleepiness. The first measurement did not show neurocognitive impairment or a higher level of depressive and anxiety symptoms in 126 patients with obstructive sleep apnea in comparison to normative standards. After the 3‐month treatment indicated for 43 patients with obstructive sleep apnea, we did not find any significant improvement in cognitive performance (p = .213). However, patients with sleep apnea with continuous positive airway pressure treatment did show significantly less daytime sleepiness, anxiety and depressive symptoms (all p < .001). In conclusion, short‐term (3 months) treatment of patients with obstructive sleep apnea can substantially alleviate their daytime sleepiness, as well as depressive and anxiety symptoms.     

A survey of subjective sleepiness and consequences in attending physicians

This article surveyed attending physicians on their work hours, sleep schedule, daytime sleepiness, and the perceived relation of these factors to patient safety, quality of care, and personal well-being. Physicians answered demographic and workload questions and attitudinal questions regarding work-hour limitations; the Epworth Sleepiness Scale (ESS) was used to measure subjective sleepiness, and an 18-item Impact Questionnaire was also used. Of 180 participants, 41 (23%) attending physicians manifested abnormal ESS scores (11 or greater). Private practice- and surgically-based subspecialties had higher ESS scores. Reduced sleep, but not hours worked, was associated with increased sleepiness. Sleepy physicians were more likely to associate sleep loss with medical errors and driving impairment. Sleepiness may be attenuated by education regarding consequences of insufficient sleep and institution of effective countermeasures.     

Polysomnographic and actigraphic evidence of sleep fragmentation in patients with irritable bowel syndrome

STUDY OBJECTIVE: To characterize the function and quality of sleep in patients with irritable bowel syndrome (IBS). DESIGN: A prospective study with a historic comparison group. SETTING: A regional hospital that also serves as a tertiary referral center. PATIENTS: Eighteen patients with IBS and a comparison group of 20 matched adults with mild benign snoring. INTERVENTIONS: A polysomnography study and a wrist actigraphy study. MEASUREMENTS: All subjects underwent sleep studies and completed self-report questionnaires (IBS severity, psychosocial variables, sleep function, and Epworth Sleepiness Scale). Fourteen IBS and 11 comparison patients underwent actigraphy. RESULTS: The IBS patients had more than 70% less slow-wave stage sleep (4.5 +/- 7.3% vs 19.3 +/- 12.9%; P = 0.006), compensated by increased stage 2 sleep (72.2 +/- 6.6% vs 60.1 +/- 16.8%; P = 0.01). The IBS group had significant sleep fragmentation with a significantly higher arousal and awakening index (P < 0.001), a longer wake period after sleep onset (P = 0.02), and more downward shifts to lighter sleep stages (P = 0.01). The 4-night actigraphy study supported the polysomnography findings. The sleep fragmentation index was significantly higher (P = 0.008) in the IBS group. The IBS patients reported greater daytime sleepiness (9.0 +/- 4.8 vs 6.4 +/- 4.8, Epworth Sleepiness Scale score, P < 0.01) and greater impairment in quality of life, which correlated significantly with the sleep fragmentation indexes. The difference between the groups was not due to differences in baseline anxiety/depression levels. CONCLUSIONS: Patients with IBS have impaired sleep quality, reduced slow-wave sleep activity, and significant sleep fragmentation. The cause-and-effect relationship of these findings with patients' daytime symptoms should be studied further.     

Effect of sodium oxybate on disrupted nighttime sleep in patients with narcolepsy

This post hoc analysis evaluated the dose‐related effects of sodium oxybate on sleep continuity and nocturnal sleep quality in patients with narcolepsy–cataplexy. Polysomnography data, including shifts to Stage N1/Wake, were from a randomized, placebo‐controlled trial of sodium oxybate. Patients were ≥16 years old with a diagnosis of narcolepsy including symptoms of cataplexy and excessive daytime sleepiness. Treatment was for 8 weeks with placebo or sodium oxybate 4.5, 6 or 9 g administered as two equally divided nightly doses. Relative to baseline, significant dose‐dependent reductions in the number of shifts per hour from Stages N2/3/rapid eye movement and Stages N2/3 to Stage N1/Wake were observed at week 8 with sodium oxybate (P < 0.05); sodium oxybate 6‐ and 9‐g doses also resulted in similar reductions in shifts per hour of rapid eye movement to Stage N1/Wake (both P < 0.05). Across all shift categories, the shift reductions with sodium oxybate 9 g were significantly greater than those observed with placebo (P < 0.05). Improvements from baseline in reported sleep quality were significantly greater with sodium oxybate 4.5 and 9 g at week 8 (P < 0.05). Correlations between change from baseline in number of shifts per hour to Stage N1/Wake and cataplexy frequency, patient‐reported nocturnal sleep quality, and excessive daytime sleepiness assessed using the Epworth Sleepiness Scale were numerically highest for the sodium oxybate 9‐g dose across all sleep stage shift categories. In these patients with narcolepsy, sodium oxybate showed improvements in the sleep continuity and nocturnal sleep quality that are characteristic of disrupted nighttime sleep ( ClinicalTrials.gov identifier NCT00049803).