Knowledge Structure and Emerging Trends of Mild Cognitive Impairment with Dyssomnias in Recent 20 Years: A Bibliometric Analysis via CiteSpace and VOSviewer

Background

Mild cognitive impairment (MCI), an intermediate stage between normal aging and dementia, has emerged as a prominent research area in geriatric care due to its heightened propensity for progressing toward dementia. Sleep plays a pivotal role in cognitive function, with dyssomnias not only exacerbating cognitive and affective symptoms associated with neurodegenerative diseases but also contributing to disease progression.

Aim

This bibliometric analysis investigates the global research on MCI with dyssomnias over the past two decades, aiming to discern key findings, research domains, and emerging trends in this field.

Methods

In this study, a bibliometric analysis was conducted using the search terms "MCI" and "sleep". Data were extracted from the Web of Science Core Collection database, and visualization and collaborative analysis were performed using CiteSpace and VOSviewer.

Results

This study encompassed 546 publications from 2003 to 2023. The publication volume and citation rate consistently increased over time. Neurosciences, Clinical Neurology, and Geriatrics Gerontology emerged as the top three research fields. The Journal of Alzheimer's Disease had the highest publication count, while Sleep Medicine received the most citations. USA, China, and Italy led in publication output. Collaborative clusters among authors and institutions were identified, but cooperation between clusters was limited. Active cocited reference clusters included "obstructive sleep apnea", "possible mediating pathways", and "isolated rapid eye movement sleep behaviour disorder". The top frequently mentioned keywords, besides "MCI", were "Alzheimer's disease", "dementia", "risk factor", and "Parkinson's Disease". Notable keyword clusters spanned circadian rhythm, Parkinson's disease, MCI, dementia with Lewy body, subjective cognitive impairment, Lewy body disease, Alzheimer's disease, and dietary patterns.

Conclusion

The field of MCI with dyssomnias is rapidly expanding, encompassing a wide range of neurodegenerative disorders and sleep disturbances. Current research endeavors are primarily focused on elucidating the underlying pathogenesis, predicting disease progression, and developing innovative treatment strategies for individuals affected by MCI with dyssomnias.

Dietary amino acid intake and sleep duration are additively involved in future cognitive decline in Japanese adults aged 60 years or over: a community-based longitudinal study

BACKGROUND

Sleep duration and amino acid intake are independently associated with cognitive decline. This study aimed to determine the longitudinal association between sleep duration and cognitive impairment incidence and to examine the involvement of diet, particularly amino acid intake, in these associations in community dwellers.

METHODS

In this longitudinal study in a community-based setting, we analyzed data from 623 adults aged 60-83 years without cognitive impairment at baseline. Sleep duration was assessed using a self-report questionnaire. Amino acid intake was assessed using 3-day dietary records. Cognitive impairment was defined as a Mini-Mental State Examination score ≤ 27. Participants were classified into short-, moderate-, and long-sleep groups according to baseline sleep duration (≤ 6, 7-8, and > 8 h, respectively). Using moderate sleep as a reference, odds ratios (ORs) and 95% confidence intervals (CIs) of short- and long-sleep for cognitive-impairment incidence were estimated using the generalized estimating equation. Participants were classified according to sex-stratified quartiles (Q) of 19 amino acid intake: Q1 and Q2-Q4 were low- and middle to high-intake groups, respectively. Using middle- to high-intake as a reference, ORs and 95% CIs of low intake for cognitive impairment incidence were estimated using the generalized estimating equation in each sleep-duration group. Follow-up period, sex, age, body mass index, depressive symptoms, education, smoking status, employment status, sleep aids use, physical activity, medical history, and Mini-Mental State Examination score at baseline were covariates.

RESULTS

Mean follow-up period was 6.9 ± 2.1 years. Adjusted ORs (95% CIs) for cognitive impairment in short- and long-sleep groups were 0.81 (0.49-1.35, P = 0.423) and 1.41 (1.05-1.87, P = 0.020), respectively. Particularly in long sleepers (i.e., > 8 h), cognitive impairment was significantly associated with low cystine, proline, and serine intake [adjusted ORs (95% CIs) for cognitive impairment were 2.17 (1.15-4.11, P = 0.017), 1.86 (1.07-3.23, P = 0.027), and 2.21 (1.14-4.29, P = 0.019), respectively].

CONCLUSIONS

Community-dwelling adults aged ≥ 60 years who sleep longer are more likely to have cognitive decline, and attention should be paid to the low cystine, proline, and serine intake.

The effect of exercise on sleep in adults with type 1 diabetes

The aim of this pilot study was to investigate the effect of exercise on sleep and nocturnal hypoglycaemia in adults with type 1 diabetes (T1D). In a 3-week crossover trial, 10 adults with T1D were randomized to perform aerobic, resistance or no exercise. During each exercise week, participants completed 2 separate 45-minutes exercise sessions at an academic medical center. Participants returned home and wore a continuous glucose monitor and a wrist-based activity monitor to estimate sleep duration. Participants on average lost 70 (±49) minutes of sleep (P = .0015) on nights following aerobic exercise and 27 (±78) minutes (P = .3) following resistance exercise relative to control nights. The odds ratio with confidence intervals of nocturnal hypoglycaemia occurring on nights following aerobic and resistance exercise was 5.4 (1.3, 27.2) and 7.0 (1.7, 37.3), respectively. Aerobic exercise can cause sleep loss in T1D possibly from increased hypoglycaemia.

Relationship between circadian blood pressure variability and function of islet α and β cell in type 2 diabetes with dyssomnia

AIMS

To investigate the relationship between circadian blood pressure (BP) variability and function of islet α and β cell in type 2 diabetes (T2D) with dyssomnia.

METHODS

Patients with T2D were divided into dyssomnia group and non-dyssomnia group by PSQI. OGTT, insulin and glucagon-releasing test were tested, and ambulatory BP was monitored for 24 hours to compare two groups with α and β cell, circadian BP variability and fasting and post-meal BP variability. The correlation and regression analysis were made between PSQI and other indicators.

RESULTS

In dyssomnia group, ① Glucagon, glucagon/insulin ratio and AUCG were significantly higher (P < 0.05). ② Fasting insulin (13.32 ± 4.54 mIU/L), AUCI (8.51 ± 0.54) and HOMA-IR (4.62 ± 1.11) were high (P < 0.05). But ISI (-4.27 ± 0.77) was low (P < 0.05). ③ Mean 24-hour and nighttime SBP and DBP, as well as their standard deviations and coefficients of variation, were all higher in the dyssomnia group (P < 0.05). Multiple stepwise regression analysis showed that PSQI score was positively related to AUCG, HOMA-IR, nighttime SBP, and negatively related to ISI and nocturnal BP fall (P < 0.05).

CONCLUSION

Dyssomnia may cause abnormal circadian BP variability through various mechanisms. Improving dyssomnia can help to better function the islet α and β cell and restore normal circadian BP variability.

Lucid dreaming in narcolepsy

OBJECTIVE

To evaluate the frequency, determinants and sleep characteristics of lucid dreaming in narcolepsy.

SETTINGS

University hospital sleep disorder unit.

DESIGN

Case-control study.

PARTICIPANTS

Consecutive patients with narcolepsy and healthy controls.

METHODS

Participants were interviewed regarding the frequency and determinants of lucid dreaming. Twelve narcolepsy patients and 5 controls who self-identified as frequent lucid dreamers underwent nighttime and daytime sleep monitoring after being given instructions regarding how to give an eye signal when lucid.

RESULTS

Compared to 53 healthy controls, the 53 narcolepsy patients reported more frequent dream recall, nightmares and recurrent dreams. Lucid dreaming was achieved by 77.4% of narcoleptic patients and 49.1% of controls (P < 0.05), with an average of 7.6±11 vs. 0.3±0.8 lucid dreams/ month (P < 0.0001). The frequency of cataplexy, hallucinations, sleep paralysis, dyssomnia, HLA positivity, and the severity of sleepiness were similar in narcolepsy with and without lucid dreaming. Seven of 12 narcoleptic (and 0 non-narcoleptic) lucid dreamers achieved lucid REM sleep across a total of 33 naps, including 14 episodes with eye signal. The delta power in the electrode average, in delta, theta, and alpha powers in C4, and coherences between frontal electrodes were lower in lucid than non-lucid REM sleep in spectral EEG analysis. The duration of REM sleep was longer, the REM sleep onset latency tended to be shorter, and the percentage of atonia tended to be higher in lucid vs. non-lucid REM sleep; the arousal index and REM density and amplitude were unchanged.

CONCLUSION

Narcolepsy is a novel, easy model for studying lucid dreaming.

Sleep and type 2 diabetes mellitus- clinical implications

Sleep is essential for life. Body systems require sleep of good quantity and quality for their proper functioning. Glucose metabolism can be affected adversely by several sleep disorders. Obstructive sleep apnea (OSA) is one of the most important disorder identified in the last 50 years which has systemic effects including glucose metabolism. Aging process also has its effects on glucose metabolism. There is a close relation between sleep, aging and metabolic syndrome. OSA and Type 2 Diabetes Mellitus (Type 2 DM) share several features in common. There is mounting evidence to show a close association between sleep deprivation, sleep disordered breathing-OSA, excessive sleepiness, insomnia, restless legs syndrome and Type 2 DM. The role of sleep deprivation, particularly REM sleep deprivation, in the genesis of obesity needs to be recognized. The close association of OSA with insulin resistance demands the recognition of OSA in fatty liver and polycystic ovary syndrome. Treatment of OSA by continuous positive airway pressure has been shown to increase insulin sensitivity. It is important for primary care physicians to have a high degree of suspicion of an underlying sleep disorder in patients with diabetes. Management of sleep disorder is highly rewarding.

Short sleep duration in prevalent and persistent psychological distress in young adults: the DRIVE study

OBJECTIVES

Young people are sleeping less. Short sleep duration has a range of negative consequences including a hypothesized link with psychological distress, which has yet to be studied

DESIGN

Prospective cohort study

SETTING

Community-based sample from Australia

PARTICIPANTS

Twenty thousand (20,822) young adults (aged 17-24) identified through the state vehicle licensing authority. A random sample (n = 5000) was approached for follow-up 12-18 months later, with 2837 providing full data.

MAIN OUTCOME MEASURE

Psychological distress, determined by a Kessler 10 score > 21, at baseline; and as both onset and persistence of distress at follow-up.

RESULTS

Shorter sleep duration was linearly associated with prevalent psychological distress: relative risk (RR) 1.14 (95% CI 1.12 to 1.15). Only the very short (< 5 h) sleepers among those not distressed at baseline had an increased risk for onset of psychological distress (RR 3.25 [95% CI 1.84, 5.75]). Of 945 cohort participants reporting psychological distress at baseline, 419 (44%) were distressed at follow-up. Each hour less of sleep increased the risk of psychological distress persisting after adjustment for potential confounding variables: RR 1.05 (95% CI 1.01 to 1.10). Long sleep duration showed no association with distress at any time point.

CONCLUSIONS

Self-reported shorter sleep duration is linearly associated with prevalent and persistent psychological distress in young adults. In contrast, only the very short sleepers had a raised risk of new onset of distress. Different approaches to sleep duration measurement yield different results and should guide any interventions to improve subjective sleep duration in young adults.

Effect of brief sleep hygiene education for workers of an information technology company

To investigate the effects of sleep hygiene education for workers of an information technology (IT) company, we conducted a controlled clinical trial providing 581 workers one-hour sleep hygiene education. The contents of the sleep hygiene education program were a review of sleep habits, provide sleep hygiene education, and the establishment of sleep habit goals. A self-report questionnaire was used to measure outcomes including the Pittsburgh Sleep Quality Index (PSQI), Karolinska Sleepiness Scale (KSS), Checklist Individual Strength (CIS), Center for Epidemiologic Studies for Depression (CES-D), and mean sleep duration on weekdays before and 4 wk after the intervention. A total of 391 participants were included in the analysis, with 214 participants in the sleep hygiene education group and 177 in the waiting list group. KSS score at 2 P.M. decreased by 0.42 points in the sleep hygiene education group, but increased by 0.08 points in the waiting list group, showing a significant effect size of 0.50 (95%CI, -0.97 to -0.04, p<0.05). PSQI score also improved, but the inter-group difference was not statically significant. The present study provides preliminary evidence that brief sleep hygiene education may improve afternoon sleepiness at work, but not sleep at night for IT workers.

Sleep quality after initial chemotherapy for breast cancer

GOALS OF WORK

The goal of this study is to characterize sleep quality and quantity prior to and in the first three nights after initial chemotherapy for breast cancer.

MATERIALS AND METHODS

This study makes use of secondary analysis of data from two separate randomized clinical trials (RCT) of behavioral interventions to improve fatigue and sleep. Patients came from two comprehensive cancer centers, three clinical cancer centers, and 10 community clinics in five states. Participants were women with stage I-IIIA breast cancer treated with anthracycline and/or cyclophosphamide-based regimens.

MAIN RESULTS

Baseline data from each RCT were used in the analysis. Sixty-five percent of women self-reported poor sleep in the month preceding chemotherapy using the Pittsburgh Sleep Quality Index (PSQI) score >5. Three nights of actigraphy data indicated a wide range of sleep experience with an average of 10 awakenings and time (minutes) awake after sleep onset (WASO-M) averaging 61 min per night. The first night's sleep was the worst. There was no statistically significant relationship between self-reported poor sleep and sleep measures obtained by actigraphy. Women with poor sleep at baseline (global PSQI >5) had significantly lower (p < 0.001) physical (PCS) and mental (MCS) health status. However, neither the PCS nor MCS was associated with any of the average actigraphy sleep parameters or night 1 parameters in the aggregated sample. Increasing age was also associated with poorer sleep.

CONCLUSIONS

A high percent of women with breast cancer begin chemotherapy with disturbed sleep and the initial nights after chemotherapy are characterized by sleep fragmentation that disrupts sleep maintenance. Interventions should focus on strategies to decrease the number and duration of night awakenings. Further research is needed to identify predictors of poor sleep during this time.

Sleep-related disturbances and physical inactivity are independently associated with obesity in adults

OBJECTIVE

To study relationships between obesity, physical inactivity and sleep-related disturbances (obstructive sleep apnea (OSA), sleep duration, sleep disturbances concomitant with daytime tiredness) in adults (> or =30 years).

DESIGN

Cross-sectional study with a random population sample.

PARTICIPANTS

A total of 3377 men (mean age 52.3, s.d. 14.8, years) and 4264 women (56.4, s.d. 17.2, years).

MAIN OUTCOME MEASURES

Dependent variables, measured: Waist circumference (WC) and body mass index (BMI). Independent variables, from a detailed interview/questionnaire: probable OSA, other sleep-related disturbances, sleep duration, type and frequency of leisure physical activity. Age, mental health, smoking and education were included in analyses as potential confounders.

RESULTS

In men, OSA and physical inactivity increased likelihood for abdominal obesity (WC > or =102 cm). Physical inactivity also increased, but long (> or =9 h/day) sleep decreased likelihood for abdominal overweight (WC: 94-101 cm) in men. In women, abdominal obesity (WC > or =88 cm) was associated positively with OSA, moderate sleep-related disturbances, and physical inactivity. Education modulated the influence of age on abdominal obesity in both genders. Using BMI as the dependent variable did not change the general information obtained by the model. In addition, abdominal obesity was found to be an independent risk factor also in multivariable models predicting categories of a combined sleep duration and sleep disturbances.

CONCLUSIONS

Sleep duration and sleep-related disturbances are associated with obesity, even after controlling for OSA and physical inactivity. The results support the hypothesis of vicious circle between sleep and obesity.

Relationship Between Serum Substance P Levels and Daytime Sleepiness in Obstructive Sleep Apnea Syndrome

OBJECTIVE

We hypothesized that intermittent hypoxia might influence serum substance P levels, and that this effect might in turn contribute in excessive daytime sleepiness (EDS) in patients with obstructive sleep apnea syndrome (OSAS).

PATIENTS AND METHODS

Fifty-five patients with newly diagnosed OSAS and 15 age-matched nonapneic control subjects were enrolled in this study. Full polysomnography was performed in all patients. Single blood samples were drawn between 8:00 am and 9:00 am after the sleep study. Substance P levels were analyzed with a competitive enzyme immunoassay (substance P EIA kit; Cayman Chemical; Ann Arbor, MI).

RESULTS

There were no significant differences in age, gender, body mass index, smoking habit, and snoring between the two groups. Serum substance P levels in the OSAS group were significantly lower than that in the control group (p < 0.0001). Serum substance P levels were positively correlated with rapid eye movement sleep (r = 0.330, p = 0.049) and slow-wave sleep (r = 0.324, p = 0.049) phases. Serum substance P levels were negatively correlated with Epworth sleepiness scale score (r = - 0.253, p = 0.048), number of total apneas during the night (r = - 0.247, p = 0.036), number of respiratory events during the night (r = - 0.266, p = 0.024), apnea-hypopnea index (r = - 0.287, p = 0.015), respiratory arousal index (r = - 0.267, p = 0.026), time spent in apnea and hypopnea (r = - 0.307, p = 0.01), average oxygen desaturation (r = - 0.265, p = 0.026), and oxygen desaturation index (r = - 0.254, p = 0.031).

CONCLUSION

We concluded that EDS seen in some of the OSAS patients might be associated with various pathophysiologic mechanisms including substance P levels.

Sleep and the metabolic syndrome

The metabolic syndrome represents a clustering of several interrelated risk factors of metabolic origin that are thought to increase cardiovascular risk. It is still uncertain whether this clustering results from multiple underlying risk factors or whether it has a single cause. One metabolic abnormality that may underlie several clinical characteristics of the metabolic syndrome is insulin resistance. This review discusses the evidence that sleep disturbances (obstructive sleep apnoea, sleep deprivation and shift work) may independently lead to the development of both insulin resistance and individual clinical components of the metabolic syndrome. The converse may also be true, in that metabolic abnormalities associated with the metabolic syndrome and insulin resistance may potentially exacerbate sleep disorders. The notion that sleep disturbances exert detrimental metabolic effects may help explain the increasing prevalence of the metabolic syndrome and insulin resistance in the general population and may have important implications for population-based approaches to combat the increasing epidemic of metabolic and cardiovascular disease.

Efficacy and tolerability of open-label topiramate in the treatment of sleep-related eating disorder: a retrospective case series

OBJECTIVE

Determine the efficacy and tolerability of topiramate in the treatment of sleep-related eating disorder (SRED).

METHOD

This is a retrospective chart review of consecutive patients treated in an open-label trial of topiramate for SRED in a sleep disorders clinic. Patients were diagnosed according to the second edition of the International Classification of Sleep Disorders. Patients with a Clinical Global Impressions of Improvement (CGI-I) rating of "very much" or "much" improved were considered treatment responders.

RESULTS

30 subjects were prescribed topiramate, of whom 25 had at least 1 postbaseline follow-up appointment. The mean age of these 25 patients was 44 +/- 12 years, 76% were female, and the mean age at onset of SRED was 25.2 +/- 12.8 years. The mean dose of topiramate was 135 +/- 61.6 mg (range, 25-300 mg) over a mean period of 11.6 +/- 11.4 months (range, 1-42 months). Over two thirds of the patients (17/25 or 68%) were considered topiramate responders. Twenty-eight percent (7/25) of the patients lost more than 10% of body weight. Adverse events were reported by 84% (21/25) of patients. Nearly half (7/17 or 41%) of the responders discontinued topiramate after a mean of 12.4 months.

CONCLUSION

In this open-label retrospective trial, topiramate was found to be very effective in reducing nocturnal eating in patients with chronic SRED. The tolerability of topiramate was an issue in some patients. Given the promise of this approach, but the limitations of this study, prospective, double-blind study of topiramate in a larger sample of patients with SRED is warranted.

Sleep disturbance at simulated altitude indicated by stratified respiratory disturbance index but not hypoxic ventilatory response

At high altitudes, the clinically defined respiratory disturbance index (RDI) and high hypoxic ventilatory response (HVR) have been associated with diminished sleep quality. Increased RDI has also been observed in some athletes sleeping at simulated moderate altitude. In this study, we investigated relationships between the HVR of 14 trained male endurance cyclists with variable RDI and sleep quality responses to simulated moderate altitude. Blood oxygen saturation (SpO2%), heart rate, RDI, arousal rate, awakenings, sleep efficiency, rapid eye movement (REM) sleep, non-REM sleep stages 1, 2 and slow wave sleep as percentages of total sleep time (%TST) were measured for two nights at normoxia of 600 m and one night at a simulated altitude of 2,650 m. HVR and RDI were not significantly correlated with sleep stage, arousal rate or awakening response to nocturnal simulated altitude. SpO2 was inversely correlated with total RDI (r = -0.69, P = 0.004) at simulated altitude and with the change in arousal rate from normoxia (r = -0.65, P = 0.02). REM sleep response to simulated altitude correlated with the change, relative to normoxia, in arousal (r = -0.63, P = 0.04) and heart rate (r = -0.61, P = 0.04). When stratified, those athletes at altitude with RDI >20 h(-1) (n = 4) and those with <10 h(-1) (n = 10) exhibited no difference in HVR but the former had larger falls in SpO2 (P = 0.05) and more arousals (P = 0.03). Neither RDI (without stratification) nor HVR were sufficiently sensitive to explain any deterioration in REM sleep or arousal increase. However, the stratified RDI provides a basis for determining potential sleep disturbance in athletes at simulated moderate altitude.

Sleep mechanisms in health and disease

Excess sleepiness, abnormal sleep patterns, non-restorative sleep, and fatigue are becoming increasingly pervasive in modern society. Identifying substances and mechanisms that modulate sleep and vigilance during health and disease is a critical prelude to eventual development of interventions to prevent or alleviate these disabling problems. A unified interdisciplinary approach that includes neurophysiology, neuroanatomy, neurochemistry, and molecular biology will promote elucidation of the complex biology of sleep. Integration of basic sleep physiology with modern genetic techniques will eventually lead to identification of specific genes and substances involved in regulation of various facets of sleep. The review presented here highlights recent progress in defining the anatomy and physiology of sleep-wake regulatory systems, delineating the role of homeostatic and circadian process in regulating sleep and wakefulness, and establishing the relationship of sleep and sleep disorders to other medical conditions. Particular emphasis is placed on reviewing the interactions between sleep, infectious challenge, and host defense response, and on identifying mechanisms that contribute to variation in sleep patterns among various strains of inbred mice.

Cognitive behavior therapy for chronic insomnia

Approximately 20% of patients presenting in general medical settings have severe and persistent insomnia. Studies consistently find that trouble initiating and maintaining sleep are independent risk factors for medical and psychiatric morbidity, but insomnia is often underdetected and undertreated in primary care settings. Cognitive-behavioral treatment approaches for chronic insomnia and related sleep disorders have been shown to be effective in various patient populations. This article reviews the most common cognitive-behavioral interventions for insomnia, and discusses their efficacy and durability. Possible adaptations for the integration of these approaches into primary care settings and a description of the emerging field of behavioral sleep medicine as a resource for health care providers treating patients with chronic insomnia are also presented.

[Clinical study of calcium-containing bioactive food additive in postmenopausal osteoporosis]

The purpose of the investigation: to study the biological active supplement (BAS) Calcimax influence on the pain syndrome (PS) dynamics and the psycho-emotional breaches, on the ionized calcium level in the blood plasma of the osteoporosis patients. The Calcimax has been produced by the "Artlife" company (Tomsk, Russia). The calcium hydroxiapatit (200 mg per 1 capsule) It is balanced with the microelements and vitamins. 31 women, who suffer from the osteoporosis disease, at the age of 47 to 64, took place in the prospective randomized investigation. All the patients were subdivided in two groups (16 and 15 patients). The basic group patients, exempt prophylaxis and following the recommendations took two capsules after light supper within 6 months. The comparative analysis of the monthly monitoring of the average number of the PS intensity has shown the trustworthy (p < 0.05) lowering of them. The Calcimax rises the (IC) level in the blood plasma also. Thus the Calcimax may be used as the common preventive remedy.

Daytime sleepiness and cognitive impairment in the elderly population

BACKGROUND

Recent findings suggest that there may be a relationship between excessive daytime sleepiness (EDS) and cognitive deficits. This study aims to determine to what extent EDS is predictive of cognitive impairment in an elderly population.

METHODS

A total of 1026 individuals 60 years or older representative of the general population living in the metropolitan area of Paris, France, were interviewed by telephone using the Sleep-EVAL expert system. To find these individuals, 7010 randomly selected households were called: 1269 had at least 1 household member in this age range (participation rate, 80.9%). In addition to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and International Classification of Sleep Disorders diagnoses, the system administered to participants the Psychological General Well-being Schedule, the Cognitive Difficulties Scale (MacNair-R), and an independent living scale.

RESULTS

Excessive daytime sleepiness was reported by 13.6% of the sample, with no significant difference among age groups. Compared with nonsleepy participants, those with EDS were at increased risk of cognitive impairment on all the dimensions of the MacNair-R scale after controlling for age, sex, physical activity, occupation, organic diseases, use of sleep or anxiety medication, sleep duration, and psychological well-being. The odd ratios were 2.1 for attention-concentration deficits, 1.7 for praxis, 2.0 for delayed recall, 2.5 for difficulties in orientation for persons, 2.2 for difficulties in temporal orientation, and 1.8 for prospective memory.

CONCLUSIONS

Among elderly individuals in the general population, EDS is an important risk factor for cognitive impairment. A complaint of EDS by an elderly patient should signal the possibility of an underlying cognitive impairment in need of evaluation.

Quality of sleep and its daily relationship to pain intensity in hospitalized adult burn patients

Sleep disturbances are frequently reported in victims following burn injuries. This prospective study was designed to assess sleep quality and to examine its daily relationship to pain intensity within the first week of hospitalization. Twenty-eight non-ventilated patients were interviewed during 5 consecutive mornings (number of observations=140) to collect information about perceived quality of sleep (visual analogue scale, number of hours, number of awakenings, presence of nightmares). Pain intensity was assessed at rest (nighttime, morning, during the day) and following therapeutic procedures using a 0-10 numeric scale. Seventy-five percent of patients reported sleep disturbances at some point during the study although, in most patients, sleep quality was not consistently poor. Pooled cross-section regression analyses showed significant temporal relationships between quality of sleep and pain intensity such that a night of poor sleep was followed by a significantly more painful day. Pain during the day was not found to be a significant predictor of poor sleep on the following night. These results support previous findings that perceived quality of sleep following burn injury is poor. Moreover, they show a daily relationship between quality of sleep and acute burn pain in which poor sleep is linked to higher pain intensity during the day.

Quality of sleep and its daily relationship to pain intensity in hospitalized adult burn patients

Sleep disturbances are frequently reported in victims following burn injuries. This prospective study was designed to assess sleep quality and to examine its daily relationship to pain intensity within the first week of hospitalization. Twenty-eight non-ventilated patients were interviewed during 5 consecutive mornings (number of observations=140) to collect information about perceived quality of sleep (visual analogue scale, number of hours, number of awakenings, presence of nightmares). Pain intensity was assessed at rest (nighttime, morning, during the day) and following therapeutic procedures using a 0-10 numeric scale. Seventy-five percent of patients reported sleep disturbances at some point during the study although, in most patients, sleep quality was not consistently poor. Pooled cross-section regression analyses showed significant temporal relationships between quality of sleep and pain intensity such that a night of poor sleep was followed by a significantly more painful day. Pain during the day was not found to be a significant predictor of poor sleep on the following night. These results support previous findings that perceived quality of sleep following burn injury is poor. Moreover, they show a daily relationship between quality of sleep and acute burn pain in which poor sleep is linked to higher pain intensity during the day.

Dangers of sleepiness and inattention while driving

Sleepiness occurs in almost everyone at some time during each day. If sleepiness becomes moderate to severe, it can have an impact on an individual's ability to perform tasks that are prolonged or require a high degree of concentration. Driving is a daily activity that usually involves repetitive behaviors over a prolonged period, and it may be adversely affected by an individual who is sleepy. Data from the Department of Transportation show that sleepiness and fatigue contribute to numerous accidents on the road. This article reviews information related to the effects of sleepiness on driving, the types of sleepiness, and some tools for assessing sleepiness.