Showing papers on "Sleep disorder published in 1997"

Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women.

Abstract: The proportion of sleep apnea syndrome (SAS) in the general adult population that goes undiagnosed was estimated from a sample of 4,925 employed adults. Questionnaire data on doctor-diagnosed sleep apnea were followed up to ascertain the prevalence of diagnosed sleep apnea. In-laboratory polysomnography on a subset of 1,090 participants was used to estimate screen-detected sleep apnea. In this population, without obvious barriers to health care for sleep disorders, we estimate that 93% of women and 82% of men with moderate to severe SAS have not been clinically diagnosed. These findings provide a baseline for assessing health care resource needs for sleep apnea.

The Sleep Heart Health Study: design, rationale, and methods.

Abstract: The Sleep Heart Health Study (SHHS) is a prospective cohort study designed to investigate obstructive sleep apnea (OSA) and other sleep-disordered breathing (SDB) as risk factors for the development of cardiovascular disease. The study is designed to enroll 6,600 adult participants aged 40 years and older who will undergo a home polysomnogram to assess the presence of OSA and other SDB. Participants in SHHS have been recruited from cohort studies in progress. Therefore, SHHS adds the assessment of OSA to the protocols of these studies and will use already collected data on the principal risk factors for cardiovascular disease as well as follow-up and outcome information pertaining to cardiovascular disease. Parent cohort studies and recruitment targets for these cohorts are the following: Atherosclerosis Risk in Communities Study (1,750 participants), Cardiovascular Health Study (1,350 participants), Framingham Heart Study (1,000 participants), Strong Heart Study (600 participants), New York Hypertension Cohorts (1,000 participants), and Tucson Epidemiologic Study of Airways Obstructive Diseases and the Health and Environment Study (900 participants). As part of the parent study follow-up procedures, participants will be surveyed at periodic intervals for the incidence and recurrence of cardiovascular disease events. The study provides sufficient statistical power for assessing OSA and other SDB as risk factors for major cardiovascular events, including myocardial infarction and stroke.

Elevation of Plasma Cytokines in Disorders of Excessive Daytime Sleepiness: Role of Sleep Disturbance and Obesity

Abstract: Excessive daytime sleepiness (EDS) and fatigue are frequent symptoms in the general population and the chief complaint of the majority of patients at Sleep Disorders Centers. There is evidence that the inflammatory cytokines tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 are involved in physiological sleep regulation and that their administration to humans is associated with sleepiness and fatigue. To explore whether plasma levels of TNFα, IL-1β, and IL-6 are elevated in patients with EDS, we measured morning plasma levels of TNFα, IL-1β, and IL-6 in 12 sleep apneics, 11 narcoleptics, 8 idiopathic hypersomniacs, and 10 normal controls. TNFα was significantly elevated in sleep apneics and narcoleptics compared to that in normal controls (P< 0.001 and P = 0.001, respectively). Plasma IL-1β concentrations were not different between sleep disorder patients and controls, whereas IL-6 was markedly and significantly elevated in sleep apneics compared to that in normal controls (P = 0.028). The ...

Population-Based Study of Sleep-Disordered Breathing as a Risk Factor for Hypertension

Abstract: Background: Clinical observations have linked sleepdisordered breathing, a condition of repeated apneas and hypopneas during sleep, with hypertension but evidence for an independent association has been lacking. Understanding this relationship is important because the prevalence of sleep-disordered breathing is high in adults. Objective: To test the hypothesis that sleep-disordered breathing is related to elevated blood pressure independent of confounding factors. Methods: The sample included 1060 employed women and men aged 30 through 60 years who had completed an overnight protocol as part of the Wisconsin Sleep Cohort Study. In-laboratory polysomnography was used to determine sleep-disordered breathing status, quantified as the number of apneas and hypopneas per hour of sleep (apnea-hypopnea index). Blood pressure was measured on the night polysomnography was performed. Results: Blood pressure increased linearly with increasing apnea-hypopnea index (P=.003 for systolic,P=.01 for diastolic, adjusted for confounding factors). The magnitude of the linear association increased with decreasing obesity. At a body mass index (weight in kilograms divided by the square of the height in meters) of 30 kg/m2, an apnea-hypopnea index of 15 (vs 0) was associated with blood pressure increases of 3.6 mm Hg for systolic (95% confidence interval, 1.3-6.0) and 1.8 mm Hg for diastolic (95% confidence interval, 0.3-3.3). The odds ratio for hypertension associated with an apneahypopnea index of 15 (vs 0) was 1.8 (95% confidence interval, 1.3-2.4). Conclusions: There is a dose-response relationship between sleep-disordered breathing and blood pressure, independent of known confounding factors. If causal, the high prevalence of sleep-disordered breathing could account for hypertension in a substantial number of adults in the United States. Arch Intern Med. 1997;157:1746-1752

An Instrument to Measure Functional Status Outcomes for Disorders of Excessive Sleepiness

Abstract: This article reports the development of the functional outcomes of sleep questionnaire (FOSQ). This is the first self-report measure designed to assess the impact of disorders of excessive sleepiness (DOES) on multiple activities of everyday living. Three samples were used in the development and psychometric analyses of the FOSQ: Sample 1 (n = 153) consisted of individuals seeking medical attention for a sleep problem and persons of similar age and gender having no sleep disorder; samples 2 (n = 24) and 3 (n = 51) were composed of patients from two medical centers diagnosed with obstructive sleep apnea (OSA). Factor analysis of the FOSQ yielded five factors: activity level, vigilance, intimacy and sexual relationships, general productivity, and social outcome. Internal reliability was excellent for both the subscales (alpha = 0.86 to alpha = 0.91) and the total scale (alpha = 0.95). Test-retest reliability of the FOSQ yielded coefficients ranging from r = 0.81 to r = 0.90 for the five subscales and r = 0.90 for the total measure. The FOSQ successfully discriminated between normal subjects and those seeking medical attention for a sleep problem (T157 = -5.88, p = 0.0001). This psychometric evaluation of the FOSQ demonstrated parameters acceptable for its application in research and in clinical practice to measure functional status outcomes for persons with DOES. Thus, the FOSQ can be used to determine how disorders of excessive sleepiness affect patients' abilities to conduct normal activities and the extent to which these abilities are improved by effective treatment of DOES.

Insomnia in Young Men and Subsequent Depression The Johns Hopkins Precursors Study

Abstract: The Johns Hopkins Precursors Study, a long-term prospective study, was used to study the relation between self-reported sleep disturbances and subsequent clinical depression and psychiatric distress. A total of 1,053 men provided information on sleep habits during medical school at The Johns Hopkins University (classes of 1948-1964) and have been followed since graduation. During a median follow-up period of 34 years (range 1-45), 101 men developed clinical depression (cumulative incidence at 40 years, 12.2%), including 13 suicides. In Cox proportional hazards analysis adjusted for age at graduation, class year, parental history of clinical depression, coffee drinking, and measures of temperament, the relative risk of clinical depression was greater in those who reported insomnia in medical school (relative risk (RR) 2.0, 95% confidence interval (CI) 1.2-3.3) compared with those who did not and greater in those with difficulty sleeping under stress in medical school (RR 1.8, 95% CI 1.2-2.7) compared with those who did not report difficulty. There were weaker associations for those who reported poor quality of sleep (RR 1.6, 95% CI 0.9-2.9) and sleep duration of 7 hours or less (RR 1.5, 95% CI 0.9-2.3) with development of clinical depression. Similar associations were observed between reports of sleep disturbances in medical school and psychiatric distress assessed in 1988 by the General Health Questionnaire. These findings suggest that insomnia in young men is indicative of a greater risk for subsequent clinical depression and psychiatric distress that persists for at least 30 years.

Sleep-disordered breathing and motor vehicle accidents in a population-based sample of employed adults.

Abstract: Studies have consistently shown that sleep apnea patients have high accident rates, but the generalizability of the association beyond clinic populations has been questioned. The goal of this investigation was to determine if unrecognized sleep-disordered breathing in the general population, ranging from mild to severe, is associated with motor vehicle accidents. The sample comprised 913 employed adults enrolled in an ongoing study of the natural history of sleep-disordered breathing. Sleep-disordered breathing status was determined by overnight in-laboratory polysomnography and motor vehicle accident (MVA) history was obtained from a statewide data base of all traffic violations and accidents from 1988 to 1993. Men with five or more apneas and hypopneas per hour of sleep [apnea-plus-hypopnea index (AHI) > 5], compared to those without sleep-disordered breathing, were significantly more likely to have at least one accident in 5 years (adjusted odds ratio = 3.4 for habitual snorers, 4.2 for AHI 5-15, and 3.4 for AHI > 15). Men and women combined with AHI > 15 (vs. no sleep-disordered breathing) were significantly more likely to have multiple accidents in 5 years (odds ratio = 7.3). These results, free of clinic selection bias, indicate that unrecognized sleep-disordered breathing in the general population is linked to motor vehicle accident occurrence. If the association is causal, unrecognized sleep-disordered breathing may account for a significant proportion of motor vehicle accidents.

Moderate-Intensity Exercise and Self-rated Quality of Sleep in Older Adults: A Randomized Controlled Trial

Abstract: Objective. —To determine the effects of moderate-intensity exercise training on self-rated (subjective) sleep quality among healthy, sedentary older adults reporting moderate sleep complaints. Design. —Randomized controlled trial of 16 weeks' duration. Setting. —General community. Participants. —Volunteer sample of 29 women and 14 men (of 67 eligible subjects) aged 50 to 76 years who were sedentary, free of cardiovascular disease, and reported moderate sleep complaints. No participant was withdrawn for adverse effects. Intervention. —Randomized to 16 weeks of community-based, moderate-intensity exercise training or to a wait-listed control condition. Exercise consisted primarily of four 30- to 40-minute endurance training sessions (low-impact aerobics; brisk walking) prescribed per week at 60% to 75% of heart rate reserve based on peak treadmill exercise heart rate. Main Outcome Measure. —Pittsburgh Sleep Quality Index (PSQI). Results. —Compared with controls (C), subjects in the exercise training condition (E) showed significant improvement in the PSQI global sleep score at 16 weeks (baseline and posttest values in mean [SD] for C=8.93 [3.1] and 8.8 [2.6]; baseline and posttest values for E=8.7 [3.0] and 5.4 [2.8]; mean posttest difference between conditions=3.4; P Conclusions. —Older adults with moderate sleep complaints can improve selfrated sleep quality by initiating a regular moderate-intensity exercise program.

Symptoms of sleep disorders, inattention, and hyperactivity in children

Abstract: Children with sleep disorders are often inattentive or hyperactive, and some carry a diagnosis of attention deficit/hyperactivity disorder (ADHD) until their sleep disorder is detected. However, the potential behavioral impact of undiagnosed sleep disorders is not known. We sought to determine whether children with higher levels of inattention and hyperactivity more frequently have symptoms of sleep-related breathing disorders (SRBDs) or periodic limb movement disorder (PLMD). We surveyed parents of 2-18-year-old patients at a child psychiatry clinic (n = 70) and a general pediatrics clinic (n = 73) to assess the children's behavior, snoring, complaints of restless legs at night, and daytime sleepiness. A validated pediatric sleep questionnaire provided the explanatory variables, and a scale for inattention and hyperactivity, derived from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), provided the dependent variable. Habitual snoring was more frequent (33%) among children who carried a diagnosis of ADHD than among the other children at the psychiatry or general pediatric clinics (11 and 9%, respectively, chi-square test, p = 0.01). Snoring scores, derived from six snoring- and SRBD-related question items, were associated with higher levels of inattention and hyperactivity. The complaint of restless legs and a composite score for daytime sleepiness showed some evidence, though less consistent, of an association with inattention and hyperactivity. The association of snoring with inattention and hyperactivity suggests that SRBDs and perhaps other sleep disorders could be a cause of inattention and hyperactivity in some children. If a causal effect is present, our data suggest that 81% of habitually snoring children who have ADHD--25% of all children with ADHD--could have their ADHD eliminated if their habitual snoring and any associated SRBD were effectively treated.

Daytime Sleepiness and Sleep Habits of Australian Workers

Abstract: Excessive daytime sleepiness in the general community is a newly recognized problem about which there is little standardized information. Our aim was to measure the levels of daytime sleepiness and the prevalence of excessive daytime sleepiness in a sample of Australian workers and to relate that to their self-reported sleep habits at night and to their age, sex, and obesity. Sixty-five percent of all 507 employees working during the day for a branch of an Australian corporation answered a sleep questionnaire and the Epworth sleepiness scale (ESS) anonymously. Normal sleepers, without any evidence of a sleep disorder, had ESS scores between 0 and 10, with a mean of 4.6 +/- 2.8 (standard deviation). They were clearly separated from the "sleepy" patients suffering from narcolepsy or idiopathic hypersomnia whose ESS scores were in the range 12-24, as described previously. ESS scores > 10 were taken to represent excessive daytime sleepiness, the prevalence of which was 10.9%. This was not related significantly to age (22-59 years), sex, obesity, or the use of hypnotic drugs but was related significantly but weakly to sleep-disordered breathing (frequency of snoring and apneas), the presence of insomnia, and reduced time spent in bed (insufficient sleep).

Benzodiazepines and Zolpidem for Chronic Insomnia: A Meta-analysis of Treatment Efficacy

Abstract: Objective. —To evaluate the efficacy of benzodiazepines and zolpidem tartrate in chronic insomnia based on a quantitative review of literature. Data Sources. —Articles from 1966 to 1996 were identified using MEDLINE, by a manual review of relevant journals, and from bibliographies of identified articles. Study Selection. —Studies using randomized, double-blind, placebo-controlled, parallel or crossover designs with benzodiazepines or zolpidem in adults younger than 65 years with chronic insomnia (modified Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for primary insomnia) were selected for review. Self-report and polysomnographic measures of sleep-onset latency, total sleep time, number of awakenings, and sleep quality were selected as outcomes. Data Extraction. —Twenty-two studies met the selection criteria. A combined test of P values was performed, pooling broadly from the 22 studies to determine whether medication was superior to placebo. A combined test of effect sizes was performed on the subset of studies that reported effect size information to determine the magnitude of medication effect. Data Synthesis. —A homogeneous sample of studies summarized 1894 patients treated for a median duration of 7 days. The combined test of P values demonstrated that medication was superior to placebo in all 4 outcome measures. Treatment response was moderate in magnitude by the combined test of effect sizes. Conclusions. —Benzodiazepines and zolpidem produced reliable improvements in commonly measured parameters of sleep in patients with chronic insomnia. Relative to the chronic and recurring course of insomnia, both the limited duration of treatments studied and the lack of follow-up data from controlled trials represent challenges for developing evidence-based guidelines for the use of hypnotics in the management of chronic insomnia.

HLA DQB1*0602 is Associated With Cataplexy in 509 Narcoleptic Patients

Abstract: Narcolepsy is a sleep disorder associated with HLA DR15 (DR2) and DQB1*0602. We HLA typed 509 patients enrolled in a clinical trial for the drug modafinil and analyzed the results in relation to cataplexy, a symptom of narcolepsy characterized by muscle weakness triggered by emotions. The patients were either subjects with cataplexy who had a mean sleep latency (SL) of less than 8 minutes and two or more sleep onset rapid eye movement (REM) periods (SOREMPs) during a multiple sleep latency test, or narcoleptic patients without cataplexy but with a mean SL shorter than 5 minutes and two or more SOREMPs. The respective values of DRB1*15 (DR2) and DQB1*0602 as markers for narcolepsy were first compared in different ethnic groups and in patients with and without cataplexy. DQB1*0602 was found to be a more sensitive marker for narcolepsy than DRB1*15 across all ethnic groups. DQB1*0602 frequency was strikingly higher in patients with cataplexy versus patients without cataplexy (76.1% in 421 patients versus 40.9% in 88 patients). Positivity was highest in patients with severe cataplexy (94.8%) and progressively decreased to 54.2% in patients with the mildest cataplexy. A voluntary 50-item questionnaire focusing on cataplexy was also analyzed in 212 of the 509 HLA-typed patients. Subjects with definite cataplexy as observed by an experienced clinician were more frequently HLA DQB1*0602-positive than those with doubtful cataplexy, and the manifestations of cataplexy were clinically more typical in DQB1*0602-positive patients. These results show that the HLA association is as tight as previously reported (85-95%) when cataplexy is clinically typical or severe. We also found that patients with mild, atypical, or no cataplexy have a significantly increased DQB1*0602 frequency (40-60%) in comparison with ethnically matched controls (24%). These results could be explained by increased disease heterogeneity in the noncataplexy group or by a direct effect of the HLA DQB1*0602 genotype on the clinical expression of narcolepsy.

Prevalence of sleep-disordered breathing in ages 40-64 years: a population-based survey.

Abstract: Previous research has offered widely varying prevalence estimates for sleep apnea in the population, leaving uncertain which breathing patterns are abnormal. To explore the distribution of sleep apnea in the population and its co-morbidities, random telephone dialing was used between 1990 and 1994 to recruit subjects for a prevalence survey of sleep-disordered breathing in San Diego adults. Events from which blood oxygen desaturations ≥4% resulted were monitored with home recording instruments, usually for three consecutive nights. Among 190 women ages 40–64 years, a median of 4.3 desaturation events per hour of sleep were observed. A higher median of 6.7 events per hour was observed among 165 men. Frequencies were much higher among members of minority groups, leading to a standard estimate that 16.3% of U.S. Hispanics and racial minorities have ≥20 events/hour as compared to 4.9% of non-Hispanic Whites ages 40–64. Obesity indicated by body-mass index was the most important demographic predictor of sleep-disordered breathing, followed by age, male gender, and ethnicity. Quality of well-being was not significantly impaired in subjects with more respiratory events; however, there was some increase in blood pressure and wake-within-sleep associated with sleep-disordered breathing. This survey indicates that sleep-disordered breathing is more common, especially among minorities, than had been previously believed, but less co-morbidity may be associated.

Sleep disturbance, psychosocial correlates, and cardiovascular disease in 5201 older adults: the Cardiovascular Health Study.

Abstract: OBJECTIVES: To describe the prevalence of self reported sleep disturbances in older men and women and to describe their relationships with health status and cardiovascular diseases (CVD). DESIGN: Cross-sectional study of sleep disturbance, CVD, general health, psychosocial factors, physical function, and use of psychotropic medications. SETTING: Participants of the Cardiovascular Health Study, 5201 adults aged 65 and older recruited from a random sample of noninstitutionalized Medicare enrollees in four US communities. MEASURES: Self-reported sleep disturbances and standardized questionnaires for cardiopulmonary symptoms and diseases, depression, social support, activities of daily living, physical activity, cognitive function, and current medications, spirometry, ECG, echocardiography, and carotid ultrasound. RESULTS: Women were twice as likely as men to report difficulty falling asleep (30% vs 14%). Daytime sleepiness, difficulty falling asleep, and frequent awakenings increased in prevalence with age. All symptoms were related strongly to depression. Symptoms of daytime sleepiness were also related strongly to poor health and limitations in activities of daily living in men and women. In multivariate analysis, men taking benzodiazepines were likely to report difficulty falling asleep and daytime sleepiness, whereas women taking benzodiazepines reported difficulty falling asleep and waking up too early. After accounting for these factors, the only cardiovascular disease independently associated with sleep disturbances was angina. Men and women with confirmed angina were 1.6 times more likely to report trouble falling asleep. Independent relationships between sleep disturbances and cardiovascular risk factors such as obesity, hypertension, smoking, and diabetes were relatively weak and inconsistent, though smokers were less likely to report frequent awakenings. CONCLUSIONS: Sleep disturbances are relatively common in older men and women and are associated with poor health, depression, angina, limitations in activities of daily living, and the use of benzodiazepines.

The indications for polysomnography and related procedures.

Abstract: This paper is a review of the literature on the use of polysomnography in the diagnosis of sleep disorders in the adult. It is based on a search of MEDLINE from January 1966 through April 1996. It has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association and provides the background for the accompanying ASDA Standards of Practice Committee's Parameters for the Practice of Sleep Medicine in North America. The diagnostic categories reviewed are: sleep-related breathing disorders; other respiratory disorders; narcolepsy; parasomnias and sleep-related epilepsy; restless legs syndrome and periodic limb movement disorders: insomnia; and circadian rhythm sleep disorders. Where appropriate, previously published practice parameters papers are cited and discussed. The relevant published peer-reviewed literature used as the basis for critical decisions was compiled into accompanying evidence tables and is analyzed in the text. In the section on the assessment of sleep apnea syndrome, options for estimating pretest probability to select high risk patients are also reviewed. Sleep-testing procedures other than standard polysomnography are also addressed (daytime polysomnography, split-night studies, oximetry, limited full respiratory recordings, and less-than-full respiratory recording) and treatment-related follow-up studies are discussed.

Habitual sleep patterns and risk for stroke and coronary heart disease: a 10-year follow-up from NHANES I.

Abstract: Background Habitual sleep patterns may independently affect morbidity and mortality. However, the effect of habitual sleep patterns on the risk for stroke and coronary heart disease is unclear. Methods We evaluated the association between sleep duration and daytime somnolence (often or almost always taking daytime naps) with the incidence of stroke and coronary heart disease in a national cohort of 7,844 adults who participated in the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study. Cox proportional hazards analyses were used to examine these relationships during the 10-year follow-up. Results After adjusting for differences in age, race, gender, education, cigarette smoking, body mass index, serum cholesterol, systolic blood pressure, and diabetes mellitus, the risk for stroke was increased in persons who reported sleeping greater than 8 hours at night compared with persons who slept between 6 and 8 hours (relative risk [RR] = 1.5, 95% confidence interval [CI] = 1.1 to 2.0). Daytime somnolence was also associated with stroke incidence (RR = 1.4, 95% CI = 1.1 to 1.8). Persons who reported both greater than 8 hours of sleep and daytime somnolence were at the greatest risk for stroke (RR = 1.9, 95% CI = 1.2 to 3.1). Similar results were also found for coronary heart disease, although the results did not reach statistical significance in the multivariate adjusted model. Conclusions Habitual sleep patterns have significant effects on the risk for stroke.

Sleep disturbances in a young adult population: can gender differences be explained by differences in psychological status?

Abstract: To study the prevalence of reported sleep disturbances and the association between these complaints and psychological status, 529 randomly selected subjects aged 20-45 years were questioned about their sleep symptoms and psychological status by means of questionnaires. In this young population, feeling refreshed in the morning almost every day was reported by only 15.3%. Females reported a significantly longer mean total sleep time (TST) than males (F: 425 +/- 58 minutes, M: 403 +/- 50 minutes; p or = 3/week) (F: 20.1%, M: 10.4%; p < 0.01), the absence of feeling refreshed in the morning (F: 36.2%, M: 26.8%; p < 0.05), and excessive daytime sleepiness (EDS) (F: 23.3%, M: 15.9%; p < 0.05) were significantly more common among females. According to the Hospital Anxiety and Depression scale, females suffered from anxiety more frequently than males (F: 32.8%, M: 18.9%; p < 0.001). An association was found between anxiety and many sleep disturbances. After making adjustments for age, smoking, snoring, gender and psychological status by means of multiple regression, the gender differences mentioned above remained significant. We conclude that despite a longer TST, females report insufficient sleep, EDS, DMS, and the absence of feeling refreshed in the morning more frequently than males. The higher prevalence of anxiety among females alone cannot explain the gender differences in sleep disturbances seen in this population.

Health status and disease severity in fibromyalgia: results of a six-center longitudinal study.

Abstract: Objective. To determine the intermediate and long-term outcomes of fibromyalgia in patients seen in rheumatology centers in which there is special interest in the syndrome. Methods. We conducted a longitudinal outcome study by mailed comprehensive Health Assessment Questionnaire administered every 6 months to 538 patients, from 6 rheumatology centers, whose median duration of disease at first assessment was 7.8 years. The final assessment took place after 7 years. In addition, there was study followup on 85 patients who had attended the Wichita center for > 10 years. Results. Although functional disability worsened slightly and health satisfaction improved slightly, measures of pain, global severity, fatigue, sleep disturbance, anxiety, depression, and health status were markedly abnormal at study initiation and were essentially unchanged over the study period. Correlations between first and last assessment values were as high as r = 0.82. For some variables, abnormalities were 3 times greater at one center compared with another. Conclusion. Patients with established fibromyalgia, seen in rheumatology centers in which there a special interest in the disease and followed up for as long as 7 years, have markedly abnormal scores for pain, functional disability, fatigue, sleep disturbance, and psychological status, and these values do not change substantially over time. Half the patients are dissatisfied with their health, and 59% rate their health as fair or poor. There are marked differences in disease severity among the various centers, but <14% of the variance in outcomes can be explained by demographic or center factors. Values at the first assessment are predictive of final values.

Sleep Problems of Elementary School Children A Community Survey

Abstract: Objective: To examine the prevalence, co-occurrence, and correlates of sleep problems among elementary school children. Design: Survey. Setting: General community. Participants: The parents of 987 children aged 5 to 12 years completed an anonymous survey distributed in their children's schools. Main Outcome Measures: The survey form asked about background characteristics, children's sleep environment, sleep habits, adult interventions, sleep history, and specific sleep problems. Results: Bedtime resistance was the most prevalent sleep problem (27%). Sleep-onset delays (11.3%), night waking (6.5%), morning wake-up problems (17%), and fatigue complaints (17%) were also common. Among children with sleep-onset problems, 80% displayed bedtime resistance, while 34% of bedtime resisters had onset problems. Onset problems correlated with more fears, night waking, psychiatric and medical conditions, the need for reassurance and caregiver proximity, and history of sleep problems. Bedtime resistance was associated with an inconsistent bedtime and falling asleep away from bed. Those who display delayed sleep onset and bedtime resistance also wake later, suggesting that sleep-phase delays may maintain these problems. Conclusions: The results confirm bedtime resistance as parents' principal sleep-related complaint for this age group but reveal a subgroup more prone to insomnia, night waking, and anxiety-related features. Phase delay findings suggest the importance of limits around wake-up time as well as bedtime. The results highlight the importance of distinctly evaluating bedtime resistance, sleep onset, sleep maintenance, waking, and emotional adjustment. Arch Pediatr Adolesc Med. 1997;151:473-480

How Sleep and Mental Disorders Are Related to Complaints of Daytime Sleepiness

Abstract: Background: Daytime sleepiness is widespread and has negative impacts on the public sector. Objective: To ascertain the incidence and prevalence of daytime sleepiness and associated risk factors in the general population. Method: In 1994, a representative sample of the noninstitutionalized British population aged 15 years or older was interviewed via telephone using an expert computer-assisted program designed to facilitate surveys of this type (Sleep-Eval, M. M. Ohayon, Montreal, Quebec). Subjects were classified into 3 groups based on the severity of their daytime sleepiness. We completed 4972 interviews (acceptance rate, 79.6%). Results: Severe daytime sleepiness was reported in 5.5% (95% confidence interval, 4.9%-6.1%) of the sample, and moderate daytime sleepiness in another 15.2% (95% confidence interval, 14.2%-16.2%). Associated factors with severe daytime sleepiness included female sex, middle age, napping, insomnia symptoms, high daily caffeine consumption, breathing pauses or leg pain in sleep, depres sive disorder (based on theDiagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria), falling asleep while reading or watching television, and motor vehicle crashes or accidents involving use of machinery. Moderate daytime sleepiness was associated with female sex, napping, insomnia symptoms, arthritis or heart disease, and gross motor movements during sleep. Conclusions: It is likely that daytime sleepiness deleteriously affects work activities, social and/or marital life, and exhibits a negative socioeconomic impact. In addition, the risk of a motor vehicle crash appears to be higher in this specific population: twice as many subjects operating a motor vehicle or using machine tools reported having a crash or accident, respectively, in the previous year in the groups with severe daytime sleepiness or moderate daytime sleepiness than did the general population with no daytime sleepiness. The high prevalence rates of daytime sleepiness and multiplicity of related factors mandate further scrutiny by public health officials. Arch Intern Med. 1997;157:2645-2652

The effect of nonvisible sleep fragmentation on daytime function.

Abstract: Patients with sleep apnea/hypopnea syndrome (SAHS) suffer from impaired daytime function that correlates with hypoxemia and visible electroencephalographic (EEG) arousals. However, not all breathing irregularities during sleep terminate with visible EEG arousal. We hypothesized that sleep disturbance without visible EEG change may impair daytime function. Twelve normal subjects spent two pairs of 2 nights each in the laboratory. The first night of each pair was for acclimatization. On the second night, subjects either slept undisturbed or had sleep fragmented every minute to cause a transient increase in arterial blood pressure or increase in heart rate without visible EEG arousal. We tested daytime function after each study night. We presented 253 +/- 23 tones (mean +/- SD), 79 +/- 7% of which did not cause visible EEG arousals. Fragmentation did not alter total sleep time (undisturbed: 419 +/- 27 min; fragmented: 414 +/- 32 min; p = 0.5) or arousal frequency (undisturbed: 22 +/- 4/h; fragmented: 25 +/- 6/h; p = 0.4). Fragmentation reduced slow-wave sleep (undisturbed: 24 +/- 5%; fragmented: 20 +/- 4%; p < 0.01), mean sleep onset latency on the multiple sleep latency test (MSLT) (undisturbed: 8.0 +/- 3.1; fragmented: 6.2 +/- 2.1 min; p = 0.01) and the maintenance of wakefulness test (MWT) (undisturbed: 29.0 +/- 10.0 min; fragmented 25.7 +/- 9.7 min; p = 0.04). Fragmentation decreased hedonic tone at 7 A.M. (27 +/- 4, 25 +/- 6; p = 0.03). Nonvisible (autonomic) sleep fragmentation makes normal subjects sleepier and impairs their mood.

Randomized, double-blind, placebo-controlled crossover trial of modafinil in the treatment of excessive daytime sleepiness in narcolepsy

Abstract: Seventy-five patients meeting international diagnostic criteria for narcolepsy enrolled in a 6-week, three-period, randomized, crossover, placebo-controlled trial. Patients received placebo, modafinil 200 mg, or modafinil 400 mg in divided doses (morning and noon). Evaluations occurred at baseline and at the end of each 2-week period. Compared with placebo, modafinil 200 and 400 mg significantly increased the mean sleep latency on the Maintenance of Wakefulness Test by 40% and 54%, with no significant difference between the two doses. Modafinil, 200 and 400 mg, also reduced the combined number of daytime sleep episodes and periods of severe sleepiness noted in sleep logs. The likelihood of falling asleep as measured by the Epworth Sleepiness Scale was equally reduced by both modafinil dose levels. There were no effects on nocturnal sleep initiation, maintenance, or architecture, nor were there any effects on sleep apnea or periodic leg movements. Neither dose interfered with the patients' ability to nap voluntarily during the day nor with their quantity or quality of nocturnal sleep. Modafinil produced no changes in blood pressure or heart rate in either normotensive or hypertensive patients. The only significant adverse effects were seen at the 400-mg dose, which was associated with more nausea and more nervousness than either placebo or the 200-mg dose. As little as a 200-mg daily dose of modafinil is therefore an effective and well-tolerated treatment of excessive daytime somnolence in narcoleptic persons.

Idiopathic hypersomnia : A series of 42 patients

Abstract: The features of idiopathic hypersomnia are not well defined. We reviewed clinical and laboratory information on 42 subjects with idiopathic hypersomnia and obtained detailed follow-up evaluations on 28 of them. Only 29% of subjects had 'classic' idiopathic hypersomnia with non-imperative sleepiness, long unrefreshing naps, prolonged night-time sleep, difficult awakening with sleep drunkenness and prominent mood disturbances. Thirty-two percent had clinical features similar to narcolepsy, i.e. irresistible sleepiness, short and refreshing naps, few problems with awakening and good response to stimulants, without cataplexy or any indication of abnormal REM (rapid eye movement) sleep. The other 39% had intermediate clinical characteristics. We found no increase in the frequency of the human leucocyte antigens associated with narcolepsy. Overall, response to stimulants was good in three-quarters of the patients and spontaneous improvement of sleepiness occurred in one-quarter. Possible aetiologies identified in 10 patients included viral illness, head trauma and primary mood disorder. Idiopathic hypersomnia is a rare syndrome in which clinical heterogeneity suggests a variable or multifactoral pathogenesis. Only a minority of cases correspond to classical descriptions. Stimulants are often beneficial and spontaneous improvement appears to be more common than in narcolepsy.

Value of the multiple sleep latency test (MSLT) for the diagnosis of narcolepsy.

Abstract: Since its introduction, the multiple sleep latency test (MSLT) has played a major role in the diagnosis of narcolepsy. We assessed its diagnostic value in a series of 2,083 subjects of whom 170 (8.2%) were diagnosed with narcolepsy. The sensitivity of the combination of two or more sleep onset rapid eye movement (REM) periods (SOREMPs) with a mean sleep latency of < 5 minutes on an initial MSLT was 70% with a specificity of 97%, but 30% of all subjects with this combination of findings did not have narcolepsy. In some narcoleptics who had more than one MSLT, the proportion of naps with SOREMPs varied substantially from the initial MSLT to the follow-up test. The highest specificity (99.2%) and positive predictive value (PPV) (87%) for MSLT findings was obtained with the criteria of three or more SOREMPs combined with a mean sleep latency of < 5 minutes, but the sensitivity of this combination was only 46%. The combination of a SOREMP with a sleep latency < 10 minutes on polysomnography yielded a specificity (98.9%) and PPV (73%) almost equal to those obtained from combinations of MSLT findings, but the sensitivity was much lower. Our results suggest that the MSLT cannot be used in isolation to confirm or exclude narcolepsy, is indicated only in selected patients with excessive daytime sleepiness, and is most valuable when interpreted in conjunction with clinical findings.

DSM-IV and ICSD-90 insomnia symptoms and sleep dissatisfaction.

Abstract: BACKGROUND The complex nature of insomnia and its relationship with organic and mental disorders render diagnosis problematic for epidemiologists and physicians. METHOD A representative UK sample (non-institutionalised, > 14 years old) was interviewed by telephone (n = 4972; 79.6% participation rate) with the Sleep-EVAL system. Subjects fell into three groups according to presence of insomnia symptom(s) and/or sleep dissatisfaction. RESULTS Insomnia symptoms occurred in 36.2% of subjects. Most of these (75.9%), however, reported no sleep dissatisfaction. In comparison, those also with sleep dissatisfaction had higher prevalence of sleep and mental disorders and longer duration of insomnia symptoms, and were more likely to take sleep-promoting medication, dread bedtime, and complain of light sleep, poor night-time sleep and daytime sleepiness. CONCLUSIONS Insomnia sufferers differ as to whether they are satisfied or dissatisfied with sleep. Although insomnia symptoms are common in the general population, sleep disturbances among sleep-dissatisfied individuals are more severe. Sleep dissatisfaction seems a better indicator of sleep pathology than insomnia symptoms.