The relevance of sleep abnormalities to chronic inflammatory conditions.

Sleep is vital to health and quality of life while sleep abnormalities are associated with adverse health consequences. Nevertheless, sleep problems are not generally considered by clinicians in the management of chronic inflammatory conditions (CIC) such as asthma, RA, SLE and IBD. To determine whether this practice is justified, we reviewed the literature on sleep and chronic inflammatory diseases, including effects of sleep on immune system and inflammation. We found that a change in the sleep-wake cycle is often one of the first responses to acute inflammation and infection and that the reciprocal effect of sleep on the immune system in acute states is often protective and restorative. For example, slow wave sleep can attenuate proinflammatory immune responses while sleep deprivation can aggravate those responses. The role of sleep in CIC is not well explored. We found a substantial body of published evidence that sleep disturbances can worsen the course of CIC, aggravate disease symptoms such as pain and fatigue, and increase disease activity and lower quality of life. The mechanism underlying these effects probably involves dysregulation of the immune system. All this suggests that managing sleep disturbances should be considered as an important factor in the overall management of CIC.

Effects of sleep deprivation on daytime sleepiness in primary insomnia.

STUDY OBJECTIVES: This study investigated changes in MSLT scores and recovery sleep following total sleep deprivation in subjects with insomnia as compared to normal sleepers. DESIGN: Matched-groups design. SETTING: A sleep disorders center in a large medical center. PARTICIPANTS: Ten individuals with psychophysiological insomnia and ten age- and sex-matched normal sleepers served as subjects. INTERVENTIONS: Subjects underwent total sleep deprivation after baseline polysomnography and MSLT. A post-deprivation MSLT was obtained, as well as polysomnography on the recovery night and an MSLT after the recovery night. MEASUREMENTS AND RESULTS: Both groups showed significant decreases in MSLT scores following total sleep deprivation, as compared to baseline. Both groups had significantly shorter scores on a nighttime MSLT compared to a daytime MSLT. The insomnia group also showed a significant increase in total sleep time on the recovery night compared to baseline. CONCLUSIONS: The MSLT is sensitive to changes in sleepiness associated with total sleep deprivation in individuals with primary insomnia.

Behavioral sleep medicine. An emerging subspecialty in health psychology and sleep medicine.

As the knowledge base in sleep disorders medicine has broadened, a subspecialty that we will refer to as "behavioral sleep medicine" area is emerging. This article will define this subspecialty area, provide some historical context for its emergence, review issues related to specialty training and clinical practice, and suggest needs for future research.The term "behavioral sleep medicine" was selected because it clearly denoted the two fields from which our subspecialty emerged (health psychology/behavioral medicine and sleep disorders medicine). It suggests much about our approach to training, clinical practice, and research, and it appropriately implies that the field is open to PhD sleep specialists, MD sleep specialists, and other health care providers with the relevant training. Formally, behavioral sleep medicine refers to the branch of clinical sleep medicine and health psychology that: (1) focuses on the identification of the psychological (e.g. cognitive and/or behavioral) factors that contribute to the development and/or maintenance of sleep disorders and (2) specializes in developing and providing empirically validated cognitive, behavioral, and/or other nonpharmacologic interventions for the entire spectrum of sleep disorders.

Sleep-disordered breathing in a predominantly African-American pediatric population.

The goal of this study was to characterize sleep and respiratory parameters in children with sleep-disordered breathing (SDB) as compared to children without SDB. Data are from 198 children and adolescents referred for sleep center evaluation, 128 of whom were diagnosed with SDB. In children with SDB, obesity (> 95% wgt for age) was more common than being severely underweight (< 5% wgt for age), but only the older children with SDB were heavier than age-matched normal sleepers. Children with SDB had increased EEG arousals; sleep architecture was not otherwise significantly different from the non-SDB group. African-American children with SDB had significantly greater oxygen desaturation with obstructive events compared to Caucasian and Latino children. It appears that the role of obesity as a risk factor for obstructive sleep apnea (OSA) increases in children above the age of 8-years. Additionally, African-American children with SDB may be at increased risk for hypoxemia and cardiovascular consequences of SDB.

Chemo- and baroresponses differ in African-Americans and Caucasians in sleep.

To determine sleep effects on baro- and ventilatory responses to transient chemo- and barostimulation in African-Americans and Caucasians, 26 nonobese normotensive young subjects (13 African-Americans and 13 Caucasians) were studied awake and in non-rapid-eye movement (NREM) and rapid-eye-movement sleep during induced transient hypoxemia (N2), hypertension (phenylephrine, PE), and concomitant hypoxemia and hypertension (N2 + PE). Arterial blood pressure was recorded by plethysmographic volume clamp, minute ventilation by pneumotachograph, and arterial O2 saturation by pulse oximeter. For all subjects, chronotropic baroresponse (Deltapulse interval/Deltasystolic blood pressure, where Delta is change) increased with NREM sleep (P = 0.007). Baroresponse slope was greater in Caucasians than in African-Americans (ANOVA, P = 0.02). Hypoxemic ventilatory response (Deltaminute ventilation/Deltaarterial O2 saturation) was greater in African-Americans than in Caucasians in NREM sleep (P = 0.01), as was hypoxemic attenuation of baroresponse (N2 + PE, P = 0.03). These data suggest sleep-related differences in arterial chemo- and baroreceptor responses in normal young African-Americans and Caucasians, which may have implications concerning development of systemic hypertension.

Clinical factors contributing to the differential diagnosis of primary insomnia and insomnia related to mental disorders.

OBJECTIVE: Primary insomnia and insomnia related to mental disorders are the two most common DSM-IV insomnia diagnoses, but distinguishing between them is difficult in clinical practice. This analysis was performed to identify clinical factors used by sleep specialists to distinguish primary insomnia from insomnia related to mental disorders. METHOD: Clinicians evaluated 216 patients referred for insomnia at five clinical sites, rated a list of clinical factors judged to contribute to each patient's presentation, and assigned diagnoses. Analysis of variance was performed, with contributing factors as the dependent variable and diagnostic group and clinic location as independent variables. RESULTS: Sleep specialists rated a psychiatric disorder as a stronger factor for insomnia related to mental disorders and rated negative conditioning and sleep hygiene as stronger factors for primary insomnia. However, a psychiatric disorder was rated as a contributing factor for 77% of patients who received a first diagnosis of primary insomnia. CONCLUSIONS: While neither sleep hygiene nor negative conditioning is a diagnostic criterion in DSM-IV, these results support the face validity of these clinical factors distinguishing between primary insomnia and insomnia related to mental disorders. The use of a psychiatric disorder as an inclusion criterion for insomnia related to mental disorders and an exclusion criterion for primary insomnia reinforces a categorical distinction between the two diagnoses, but the contribution of psychiatric symptoms in primary insomnia appears to be a clinically relevant one. These findings suggest the need for studies on the validity of negative conditioning and sleep hygiene in the etiology of primary insomnia, as well as on the significance of psychiatric disorders, especially depression, in primary insomnia.

Effects of diagnosis on treatment recommendations in chronic insomnia--a report from the APA/NIMH DSM-IV field trial.

The objective of this study was to determine whether sleep specialists and nonspecialists recommend different treatments for different insomnia diagnoses according to two different diagnostic classifications. Two hundred sixteen patients with chronic insomnia at five sites were each interviewed by two clinicians: one sleep specialist and one nonsleep specialist. All interviewers indicated diagnoses using the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV); sleep specialists also indicated diagnoses according to the International Classification for Sleep Disorders (ICSD). Interviewers then indicated how strongly they would recommend each item in a standard list of treatment and diagnostic interventions for each patient. We examined differences in treatment recommendations among the six most common DSM-IV diagnoses assigned by sleep specialists at different sites (n = 192), among the six most common ICSD diagnoses assigned by sleep specialists at different sites (n = 153), and among the six most common DSM-IV diagnoses assigned by nonspecialists at different sites (n = 186). In each analysis, specific treatment and polysomnography recommendations differed significantly for different diagnoses, using either DSM-IV or ICSD criteria. Conversely, different diagnoses were associated with different rank orderings of specific treatment and diagnostic recommendations. Sleep specialist and nonspecialist interviewers each distinguished treatment recommendations among different diagnoses, but in general, nonspecialists more strongly recommended medications and relaxation treatments. Significant site-related differences in treatment recommendations also emerged. Differences in treatment recommendations support the distinction between different DSM-IV and ICSD diagnoses, although they do not provide formal validation. Site-related differences suggest a lack of consensus in how these disorders are conceptualized and treated.

Sleep disorders in patients on continuous ambulatory peritoneal dialysis.

Sleep complaints, habits, and medical history were surveyed in 81 patients chronically receiving continuous ambulatory peritoneal dialysis. Seventy-three percent of the sample reported insomnia, and 52% reported unintentional napping during the day. Behavioral factors (such as caffeine or alcohol use) or the severity of concurrent medical disease did not account for the sleep problems. Eighteen of these patients subsequently underwent polysomnography and objective measurement of daytime sleepiness. Clinically significant sleep apnea syndrome was present in 11. The presence of sleep apnea was associated with increased levels of psychological distress and daytime sleepiness. Periodic leg movements during sleep were also frequently observed but had minimal effect on sleep quality. Implications of these findings for clinical practice are discussed.

Neuropsychological function in obstructive sleep apnea syndrome (OSAS) compared to chronic obstructive pulmonary disease (COPD).

Forty-nine men, 25 with obstructive sleep apnea syndrome (OSAS) and 24 with chronic obstructive pulmonary disease (COPD), were evaluated with a standard 8-hour nocturnal polysomnogram, multiple sleep latency test the following day and a neuropsychological test battery. The OSAS patients had more respiratory disturbances per hour of sleep, more stage 1 sleep and greater daytime sleepiness than COPD patients. The OSAS patients were as impaired as the COPD patients in neuropsychological test functioning, with the pattern of impairment nonspecific as to hypoxemic-sensitive versus sleepiness-sensitive tasks, with two exceptions. The OSAS patients performed more poorly on a test requiring sustained attention and considered sensitive to sleepiness, whereas the COPD patients performed more poorly on a test requiring motor skills and sensitive to hypoxemia. These deficits in psychomotor and attention appear to be specifically related to patients group (OSAS vs. COPD), but the other deficits found in complex reasoning and memory are nonspecific.

Effect of induced transient arousal on obstructive apnea duration.

Six untreated male patients (age 19-55 yr) with obstructive sleep apnea underwent nocturnal polysomnography with acoustic stimulation to determine the effect of transient arousal on obstructive apneas during sleep. Binaural tone bursts (25-95 dB) were delivered in late expiration during the second obstructive apnea of a cycle consisting of four consecutive apneas. For the group, stimulated apneas were significantly shorter (P < 0.05, Fisher's protected least significant difference test) than were the unstimulated apneas when transient electrocortical arousal was elicited in both non-rapid-eye-movement (non-REM) sleep [mean 17 +/- 7 (SD) vs. 26 +/- 9, 23 +/- 10, and 26 +/- 12 s for 2nd vs. 1st, 3rd, and 4th apnea, respectively, of each cycle] and REM sleep (mean 19 +/- 10 vs. 35 +/- 15, 45 +/- 18, and 39 +/- 20 s). Without electrocortical arousal, the stimulated apnea was significantly shortened in non-REM (23 +/- 9 vs. 25 +/- 7, 24 +/- 8, and 26 +/- 8 s) but not in REM (32 +/- 16 vs. 37 +/- 12, 32 +/- 15, and 30 +/- 16 s). Tones delivered relatively early and late in the apnea were equally likely to be associated with resolution of the apnea. The nadir of arterial oxygen saturation of hemoglobin was inversely proportional to apnea length, with higher saturation nadirs associated with the stimulated apneas. These data indicate that transient arousal, induced by nonrespiratory stimulation, influences the resolution of obstructive apneas during sleep.

Clinical diagnoses in 216 insomnia patients using the International Classification of Sleep Disorders (ICSD), DSM-IV and ICD-10 categories: a report from the APA/NIMH DSM-IV Field Trial.

Three diagnostic classifications for sleep disorders have been developed recently: the International Classification of Sleep Disorders (ICSD), the Diagnostic and Statistical Manual, 4th edition (DSM-IV), and the International Classification of Diseases, 10th edition (ICD-10). No data have yet been published regarding the frequency of specific diagnoses within these systems or how the diagnostic systems relate to each other. To address these issues, we examined clinical sleep disorder diagnoses (without polysomnography) in 257 patients (216 insomnia patients and 41 medical/psychiatric patients) evaluated at five sleep centers. A sleep specialist interviewed each patient and assigned clinical diagnoses using ICSD, DSM-IV and ICD-10 classifications. "Sleep disorder associated with mood disorder" was the most frequent ICSD primary diagnosis (32.3% of cases), followed by "Psychophysiological insomnia" (12.5% of cases). The most frequent DSM-IV primary diagnoses were "Insomnia related to another mental disorder" (44% of cases) and "Primary insomnia" (20.2% of cases), and the most frequent ICD-10 diagnoses were "Insomnia due to emotional causes" (61.9% of cases) and "Insomnia of organic origin" (8.9% of cases). When primary and secondary diagnoses were considered, insomnia related to psychiatric disorders was diagnosed in over 75% of patients. The more narrowly defined ICSD diagnoses nested logically within the broader DSM-IV and ICD-10 categories. We found substantial site-related differences in diagnostic patterns. These results confirm the importance of psychiatric and behavioral factors in clinicians' assessments of insomnia patients across all three diagnostic systems. ICSD and DSM-IV sleep disorder diagnoses have similar patterns of use by experienced clinicians.

Diagnostic concordance for DSM-IV sleep disorders: a report from the APA/NIMH DSM-IV field trial.

OBJECTIVE: The frequency and ranking of DSM-IV sleep disorder diagnoses of clinical patients with complaints of insomnia, as well as rates of diagnostic agreement and disagreement between two types of interviewers, were investigated. METHOD: Interviewers at five clinical sites assessed 216 patients referred for insomnia complaints. One sleep specialist and one general clinician interviewed each patient in an unstructured clinical interview, assigned DSM-IV diagnoses, and indicated their reactions to the diagnostic system. RESULTS: Insomnia due to another mental disorder was the most frequent DSM-IV diagnosis across sites, followed by primary insomnia. Interviewers at the five sites differed significantly in the rankings they assigned to different diagnoses. In addition, sleep specialists at most sites diagnosed psychiatric forms of insomnia more frequently than nonspecialists. Kappa values for agreement between the two types of clinicians on multiple DSM-IV sleep diagnoses ranged from 0.26 to 0.80 across sites, indicating moderate agreement overall. Kappa values for individual diagnoses varied across sites and specific diagnoses and ranged from poor to excellent. Interviewers' ratings of their confidence in diagnoses and the fit and ease of use of the DSM-IV categories also showed significant variability related to site and type of interviewer. CONCLUSIONS: The distribution of diagnoses highlights the importance of psychiatric and behavioral factors in the assessment of insomnia. Site-related variability indicates a need for greater standardization in the application of sleep disorder diagnostic criteria. Diagnostic concordance for these diagnoses, while only moderately good, likely reflects actual clinical practice and would be improved through the use of standardized (or structured) interviews and increased training.

Experimental sleep fragmentation.

Thirty-six healthy young men and women (age range 21-35 years) were studied in an experimental model of sleep fragmentation. On 2 nights sleep was disrupted by presenting tones to produce brief electroencephalogram (EEG) arousals (without shortening sleep time) and daytime function was assessed the following day with the Multiple Sleep Latency Test and a divided attention performance test. The fragmentation of sleep produced significant disruption of nocturnal sleep and reduced daytime alertness. Adaptation in EEG-defined arousals occurred from the 1st to the 2nd night of fragmentation. Threshold (measured indirectly) characteristics of EEG-defined arousals were somewhat different than those of previous studies requiring behavioral awakening. The percent of tone series producing arousal, number of tones necessary for arousal and duration of the arousal all reflected heightened thresholds in stage 3/4 and rapid eye movement (REM) sleep compared to stage 1 and stage 2 sleep. In the last 3 hours of sleep versus the first 3 hours, arousals occurred less frequently, required more tones to produce, resulted in shorter durations and in fewer sleep stage changes, except for REM sleep where the converse was the case.

Hypnotics and behavior.

Evaluation of the effects of hypnotics on waking behavior has primarily focused on two issues: (1) how these drugs affect performance the day after a nightly dose; and (2) how they affect memory processes, with special emphasis on anterograde amnesia. In terms of the relations between pharmacologic properties and residual effects, three conclusions can be drawn. First, dose is a major determinant of the presence or absence of morning effects. Every drug studied to date, if given in high enough dose, has produced morning performance decrements. Second, the longer-acting a compound, the more likely it is that a performance decrement will be observed. Finally, some data suggest that behavioral tolerance to the residual effects of hypnotics develops. The observation that benzodiazepines produce amnesia emerged from reports of their clinical use as presurgery medications. Although the initial reports involved intravenous diazepam and were anecdotal in nature, subsequent studies have demonstrated that amnesia is a characteristic of all the benzodiazepines, with the magnitude of the effect being a function of route of administration, dose, and the pharmacokinetics of the particular drug.

Psychometric profiles of patient populations with excessive daytime sleepiness.

Patients with narcolepsy have more psychiatric symptoms than normal controls as measured by psychometric tests. However, it is unclear whether these findings are specific to narcolepsy, as some studies have suggested, or related to excessive daytime sleepiness (EDS) or to chronic illness. We compared a group of 56 narcoleptics to age- and sex-matched controls with EDS. A group of 48 individuals with normal sleep architecture was also used as an additional control group. Both the narcoleptic group and the EDS-control group had significantly greater scores on Minnesota Multiphasic Personality Inventory scales but were not different from each other. Our data suggest that the psychopathology associated with narcolepsy is not specific and may be generalized among patients with disorders of excessive sleepiness.

Characteristics of individuals who do or do not seek treatment for chronic insomnia.

Survey data have shown that a minority of people who complain of insomnia receive medical treatment for this problem. Patients who seek treatment for insomnia at medical clinics and sleep disorders centers are a self-selected group who may not be representative of all individuals with insomnia. Fifty patients presenting to a sleep disorders center with an insomnia complaint were compared to 50 subjects with insomnia recruited through the newspaper for psychopharmacological studies. No differences in sleep parameters were found, but significant differences on psychometric measures and in daytime alertness were present. The implications of these differences are discussed.

Daytime alertness in patients with chronic insomnia compared with asymptomatic control subjects.

Despite the subjective reports of patients with difficulty initiating and maintaining sleep (DIMS) that they are impaired during the day, consistent differences in daytime functions have not been found between normal sleepers and patients with insomnia. The present study compares polysomnography and Multiple Sleep Latency Test (MSLT) data from 70 clinic patients seeking evaluation for chronic insomnia with data from a group of 45 asymptomatic sleepers. The DIMS group was found to sleep significantly less than the control group; yet they were also significantly more alert than the control group the following day, as measured by MSLT. Within the insomnia diagnostic subgroups, a correlation of -0.67 (p less than 0.05) was found between nocturnal total sleep time and mean MSLT. The results are interpreted as supporting the existence of a tendency towards physiological hyperarousal in patients with chronic insomnia. This tendency may be exacerbated by other factors (e.g., personality disorder, periodic leg movements) also associated with insomnia.

Sleep and memory.

Generally sleep is considered a time of amnesia. It is not uncommon for an individual to experience 8 h of sleep and have no memory for events during that time. Similarly, a substantial proportion of the population has no memory for dreams that occurred during the night, despite the fact that the literature on awakening during rapid eye movement (REM) sleep clearly shows that individuals normally have four to six "dream experiences" a night. Research on this issue seems to indicate that the lack of memory cannot be explained by the organisms' inability to perceive stimuli. The data indicate that although perceptual thresholds are elevated, organisms can clearly perceive stimuli, and, in fact, can discriminate between them during sleep. The amnesia also cannot be explained by a defect in long-term memory, as studies have indicated that stimuli put into the memory during wakefulness are more efficiently retrieved after a sleep period than after a comparable period of wakefulness. The most likely explanation for the amnestic property of sleep seems to be the inability of organisms to transfer information from short-term memory to long-term memory during sleep. There are several sources of evidence to support this hypothesis. First, the probability of remembering a stimulus given during wakefulness is related to the proximity of sleep onset to the stimulus. Generally, information put into the system within 5 min of sleep onset is lost from memory. Secondly, disorders of excessive daytime somnolence which cause individuals to have frequent microsleeps are often associated with complains of memory problems.(ABSTRACT TRUNCATED AT 250 WORDS)