The association between sleep patterns and obesity in older adults.

BACKGROUND: Reduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals. METHODS: Wrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping. RESULTS: Greater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1 h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1 h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent. CONCLUSIONS: In both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism.

Sleep disturbances in nursing homes.

OBJECTIVES: To review the literature on sleep disturbances in nursing home settings. Although 50% of older adults complain of sleep difficulties, increased reports of sleep disturbances are generally associated with poor health. After controlling for comorbidities that often contribute to poor sleep, studies have shown that primary sleep disturbances in healthy older adults are, in fact, rare. Although common in older adults, sleep complaints are even more prevalent in elders living in nursing homes and the sleep disturbances experienced by institutionalized older adults are more severe. Factors contributing to sleep impairment in nursing home residents include age-related changes in sleep architecture and circadian rhythms, sleep disorders, dementia, depression, other medical illness, polypharmacy, and institutional and environmental factors. It is important that nursing home residents suffering from sleep problems be evaluated and treated. CONCLUSION: Implementing some environmental and culture changes could result in significant improvement in the sleep of nursing home residents.

The association between sleep duration and obesity in older adults.

BACKGROUND: Reduced sleep has been reported to predict obesity in children and young adults. However, studies based on self-report have been unable to identify an association in older populations. In this study, the cross-sectional associations between sleep duration measured objectively and measures of weight and body composition were assessed in two cohorts of older adults. METHODS: Wrist actigraphy was performed for a mean (s.d.) of 5.2 (0.9) nights in 3055 men (age: 67-96 years) participating in the Osteoporotic Fractures in Men Study (MrOS) and 4.1 (0.8) nights in 3052 women (age: 70-99 years) participating in the Study of Osteoporotic Fractures (SOF). A subgroup of 2862 men and 455 women also underwent polysomnography to measure sleep apnea severity. RESULTS: Compared to those sleeping an average of 7-8 h per night, and after adjusting for multiple risk factors and medical conditions, a sleep duration of less than 5 h was associated with a body mass index (BMI) that was on average 2.5 kg/m(2) (95% confidence interval (CI): 2.0-2.9) greater in men and 1.8 kg/m(2) (95% CI: 1.1-2.4) greater in women. The odds of obesity (BMI >or= 30 kg/m(2)) was 3.7-fold greater (95% CI: 2.7-5.0) in men and 2.3-fold greater in women (95% CI: 1.6-3.1) who slept less than 5 h. Short sleep was also associated with central body fat distribution and increased percent body fat. These associations persisted after adjusting for sleep apnea, insomnia and daytime sleepiness. CONCLUSIONS: In older men and women, actigraphy-ascertained reduced sleep durations are strongly associated with greater adiposity.

The attenuating effect of personal mastery on the relations between stress and Alzheimer caregiver health: a five-year longitudinal analysis.

The objectives of this study were to evaluate the impact of personal mastery and caregiving stress on caregiver depressive symptoms and health over time and to examine the moderating effect of mastery on the relations between stress and these outcomes. A total of 130 spousal Alzheimer caregivers completed yearly assessments of personal mastery, role overload, health symptoms and depressive symptoms. Random regression was used to evaluate the relations between time-varying values for stress and mastery in predicting depressive and health symptoms. It was found that variation in depressive symptoms over time was significantly related to role overload (p<0.05) and personal mastery (p<0.001). A significant overload-by-mastery interaction was found for predicting depressive symptoms (p=0.002) and caregiver health (p=0.008), whereby mastery attenuated the effect of stress on these outcomes. We conclude that personal mastery appears to reduce the effects of stress on depression and health outcomes over time.

Preclinical cognitive decline and subsequent sleep disturbance in older women.

OBJECTIVE: To determine whether longitudinal cognitive decline is associated with increased risk of sleep disturbance in older, nondemented, community-dwelling women. METHODS: We studied 2,474 women (mean age 68.9 years) who were part of a prospective study started in 1986; women with baseline or follow-up evidence of possible dementia were excluded. Cognitive data were gathered over 15 years for modified Mini-Mental State Examination (mMMSE) and 13 years for Trails B; cognitive decline was defined as declining >1.5 SDs on the mMMSE (> or =3 points) or Trails B (>92 seconds). Sleep disturbance was measured objectively using actigraphy (Sleepwatch-O, Ambulatory Monitoring) at the 15-year follow-up visit; measures included total sleep hours, sleep efficiency, sleep latency, napping, and time awake after sleep onset (WASO). RESULTS: During follow-up, 11% of women declined on mMMSE and 15% on Trails B. Cognitive decliners were more likely than non-decliners to experience sleep disturbance at follow-up on most measures. For women who declined on mMMSE, adjusted ORs (aOR) (95% CI) were 1.71 (1.24, 2.37) for sleep efficiency <70%, 1.57 (1.12, 2.21) for sleep latency > or =1 hour, and 1.43 (1.07, 1.92) for WASO > or =90 minutes. Results were similar for women who declined on Trails B; in addition, these women were more likely to nap >2 hours per day (aOR: 1.73; 95% CI: 1.28, 2.33). Cognitive decline on either test was not associated with total sleep time. CONCLUSIONS: Cognitive decline is associated with sleep disturbance in nondemented community-dwelling elderly women.

Indiplon: the development of a novel therapy for the treatment of sleep onset and sleep maintenance insomnia.

Indiplon is a novel non-benzodiazepine sedative-hypnotic that modulates the GABAA receptor complex. It appears to be more selective for the alpha1-receptor subunit, associated with sedation, than other hypnotics. Two different formulations of indiplon have been developed: an immediate release (IR) version targeting sleep onset insomnia and a modified release (MR) version addressing sleep maintenance insomnia. Early results from clinical trials indicate that both formulations are well tolerated and effective at improving both objective and subjective measures of sleep. As of May 2006 indiplon-IR has been provisionally approved for use in the US market and discussions are continuing with the FDA regarding the MR formulation.

Taking fatigue seriously: I. Variations in fatigue sampled repeatedly in healthy controls.

OBJECTIVE: The four objectives of this study were to test the ability of a 1-item fatigue scale to correlate with the fatigue subscale of the Profile of Mood States (POMS), to test the acceptability of recording hourly fatigue ratings, to examine the chronobiological variation in self-reports of fatigue, and finally to examine the degree to which self-report of fatigue correlated with actigraphy findings. METHODS: Ten healthy normal controls completed the POMS fatigue subscale hourly for three days. The same 10 healthy subjects wore an actigraph for 72 consecutive hours. The actigraph was modified to incorporate two event buttons which subjects were asked to push hourly to report their level of fatigue. RESULTS: The 1-item fatigue rating correlated significantly (mean r = 0.61) with the rest of the POMS subscale for fatigue. Subjects had no difficulty using the event button on the actigraph in entering the 1-item fatigue ratings. Fatigue ratings revealed marked differences in how healthy subjects report fatigue. There was no consistent diurnal patterning of fatigue. The fatigue ratings in general were not correlated with actigraphic measures. DISCUSSION: The study documents that fatigue can be repeatedly assessed with an ambulatory device and that self-reported fatigue levels vary enormously from hour to hour in a healthy normal sample.

Sleep quality and blood pressure dipping in obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with poor sleep quality and a high incidence of nondipping. The aim of this study was to determine the association of sleep quality and nocturnal blood pressure (BP) dipping in an OSA population. METHODS: A total of 44 untreated subjects with mild to severe OSA underwent overnight-attended polysomnography and 24-h ambulatory BP monitoring. Subjects were off antihypertensive medication. The percentage of slow wave sleep, percentage of time awake after sleep onset during the sleep period, sleep efficiency, and arousal index were chosen as measurements of sleep quality. Dipping was evaluated using the change in systolic BP, diastolic BP, and mean arterial pressure. Patients were classified as dippers and nondippers based on a nocturnal drop in mean arterial pressure > 10%. Differences between groups were evaluated by independent sample t tests. Pearson correlation and linear regression were used to evaluate the association of sleep quality and dipping. RESULTS: There were no differences between dippers and nondippers with regard to body mass index, age, or respiratory disturbance index. A total of 84% were nondippers. No difference was found between dippers and nondippers in sleep quality. None of the sleep quality measures correlated with the measurements of dipping. In multiple regression analyses, the percentage of slow wave sleep and arousal index each independently predicted only a small percentage of the variance (approximately 10%) of nocturnal DBP dipping. CONCLUSIONS: The prevalence of nondipping was very high in a population of untreated patients with mild to severe OSA. Nonetheless, sleep quality did not appear to be related to BP dipping.

"Sleep is not tangible" or what the Hebrew tradition has to say about sleep.

Much of what is known about sleep disorders has been uncovered in the last forty years. As scientists, we consider these discoveries to be landmarks. Yet there is a tremendous amount of information written about sleep in the Bible and its commentaries. Sleep, and even sleep disorders, are referred to in many instances and can be directly interpreted by what we know today. Our forefathers and foremothers generally viewed sleep as both pleasant and necessary and were aware that sleep was not one continuous stage. They referred to the function of sleep as being restorative. They deplored sleep deprivation, believing that it impaired life. They felt that excessive sleepiness was harmful. They understood that insomnia could be caused by stress and anxiety and by excessive alcohol, and that physical activity (exercise) and drinking milk could improve sleep. They suggested cures for insomnia, including some of the ideas included in today's sleep hygiene rules. They understood that there was a rhythm or timing to sleep. They even understood that it is easier to delay the circadian rhythm that to advance it. Although naps are not recommended, they sometimes took naps in the afternoon, but suggested just how long that nap should last-about one-half hour. And they knew that with age, although sleep is advanced, healthy elderly do not have difficulty sleeping. Although we think we have discovered many new features about sleep disorders, much of what we know today was suggested thousands of years ago and documented in the Bible and the Talmud.

Effect of continuous positive airway pressure and placebo treatment on sympathetic nervous activity in patients with obstructive sleep apnea.

STUDY OBJECTIVES: We studied the effect of continuous positive airway pressure (CPAP) treatment on sympathetic nervous activity in 38 patients with obstructive sleep apnea. DESIGN: Randomized, placebo-controlled trial. SETTING: Patients underwent polysomnography on three occasions in a clinical research center, and had BP monitored over 24 h at home. All of the patients had sleep apnea with a respiratory disturbance index (RDI) > 15. INTERVENTIONS: The patients were randomized blindly to CPAP or placebo (CPAP at ineffective pressure) treatment. MEASUREMENTS AND RESULTS: Prior to therapy, the number of apneas and the severity of nocturnal hypoxia correlated significantly with daytime urinary norepinephrine (NE) levels, but not nighttime urinary NE levels. CPAP treatment lowered daytime BP from 99 +/- 2 mm Hg to 95 +/- 3 mm Hg (mean +/- SEM) and nighttime BP from 93 +/- 3 mm Hg to 88 +/- 3 mm Hg. Placebo CPAP treatment decreased both day and night mean BP only 2 mm Hg. CPAP, but not placebo, treatment lowered daytime plasma NE levels by 23%, daytime urine NE levels by 36%, daytime heart rate by 2.6 beats/min, and increased lymphocyte beta(2)-adrenergic receptor sensitivity (all p < 0.05). The effect of CPAP treatment on nighttime urine NE levels and heart rate did not differ from placebo treatment. There was a suggestion of an effect of placebo CPAP treatment on nighttime measures, but not on daytime measures. CONCLUSION: We conclude that daytime sympathetic nervous activation is greater with more severe sleep apnea. CPAP treatment diminished the daytime sympathetic activation; the potential nighttime effect of CPAP treatment was obscured by a small placebo effect.

Neuropsychological effects of one-week continuous positive airway pressure treatment in patients with obstructive sleep apnea: a placebo-controlled study.

OBJECTIVE: To determine whether 1-week continuous positive airway pressure (CPAP) treatment, compared with placebo CPAP, improves cognitive functioning in patients with obstructive sleep apnea (OSA). METHODS: 36 OSA patients (aged 32-60 years, respiratory disturbance index [RDI] > 15) were monitored 2 nights with polysomnography, then randomized for 1-week treatment to CPAP or placebo (CPAP at 2 cm H2O with holes in mask). Participants completed Wechsler Adult Intelligence Scale-Revised Digit Symbol and Digit Span, Trailmaking A/B, Digit Vigilance, Stroop Color-Word, Digit Ordering, and Word Fluency tests pre- and posttreatment. These produced 22 scores per participant, which were analyzed by use of repeated-measures analysis of variance (ANOVA) and a rank-sum test. RESULTS: In ANOVA, only 1 of the 22 scores showed significant changes specific to CPAP treatment, a number that could be expected by chance alone: Digit Vigilance-Time (p = .035). The CPAP group improved their time (from 7.5 to 6.9 minutes. p = .013). The rank-sum test revealed that the CPAP group had significantly better overall cognitive functioning posttreatment than the placebo group (mean ranks of 17.8 vs. 20.2, respectively; p = .022). CONCLUSIONS: Although results suggest overall cognitive improvement due to CPAP, no beneficial effects in any specific cognitive domain were found. Future studies of neuropsychological effects of CPAP treatment should include a placebo CPAP control group. Placebo studies that use longer-term treatment might demonstrate additional effects. It is also possible that, even at 2 cm H2O, CPAP conveys some beneficial neuropsychological effects.

The hypercoagulable state in sleep apnea is related to comorbid hypertension.

OBJECTIVE: Obstructive sleep apnea (OSA) is associated with increased prevalence of atherosclerotic disease. A hypercoagulable state thought to underly atherosclerosis has been described in both OSA and systemic hypertension. We wondered about the respective contribution of apnea and hypertension to a hypercoagulable state. DESIGN: Eighty-seven subjects with symptoms suggestive of OSA, mean age 47 years (range 32-64 years), underwent polysomnography and blood pressure (BP) screening. OSA was diagnosed when respiratory disturbance index (RDI) > or = 15. Subjects having systolic BP (SBP) > 140 mmHg and/or diastolic BP (DBP) > 90 mmHg were classified as having hypertension. Three hypercoagulability markers were measured: thrombin/antithrombin III complex (TAT), fibrin D-dimer (DD), and von Willebrand factor antigen (vWF:ag). RESULTS: Analysis of variance and multiple linear regression were performed on the following four subject groups: (1) normotensive non-apneics (n = 19), (2) normotensive apneics (n = 38), (3) hypertensive non-apneics (n = 11), and (4) hypertensive apneics (n = 19). OSA (groups 2 and 4) had no significant main effect on hemostasis. Hypertensives (groups 3 and 4) had higher plasma levels of TAT (median/inter-quartile range, 148/59-188 versus 77/53-108 pmol/l; P = 0.009) and of DD (376/265-721 versus 303/190-490 ng/ml; P = 0.040) than normotensives (groups 1 and 2). Across all subjects, SBP was the only significant predictor of TAT (P = 0.001) and of DD (P = 0.004), whereas DBP was the only significant predictor of vWF:ag (P = 0.029). These findings persisted even after controlling for gender, age, body mass index, RDI, mean SaO2, and hematocrit. CONCLUSION: Hypercoagulability in OSA is mediated by comorbid hypertension and might account for high cardiovascular morbidity in OSA in general.

Sleep disorders in the elderly.

Sleep disorders and sleeping difficulty are among the most pervasive and poorly-addressed problems of aging. As the population ages, a burgeoning cadre of seniors will seek attention for sleeping difficulties and sleep disorders. Sleep changes with age, and sleeping problems and disorders generally increase with aging. At present, health care professionals are not receiving adequate preparation and training to help the elderly cope with age-related sleeping problems, and several specific areas are ripe for investigation.

Actigraphic estimates of circadian rhythms and sleep/wake in older schizophrenia patients.

Twenty-four hour circadian activity rhythms and light-exposure levels of 28 older schizophrenia patients (mean age=58years) were examined using an Actillume recorder. Sleep and wake were scored using the algorithm of the ACTION3 software which revealed that the patients slept for 67% of the night and napped for 9% of the day. Patients with more disturbed sleep and less robust circadian rhythms performed more poorly on neuropsychological tests. Patients with higher cognitive functioning and fewer extrapyramidal symptoms were more alert during the day. Few patients were exposed to high levels of illumination during the day, and older age was associated with lower levels of light exposure. Duration of antipsychotic use and higher antipsychotic doses were associated with decreased daytime alertness and less robust circadian activity rhythms. Patients taking antipsychotics were more sleepy both during the day and night than patients not taking antipsychotics. The circadian rhythm disturbances found in these patients did not seem to be due solely to low levels of illumination exposure. Life-style factors, behavioral factors, psychiatric symptoms and medications were likely contributors to the disturbed rhythms. The effects of the sleep disturbances did not seem to be benign. There were strong relationships between sleep and circadian rhythms and functioning.

Obstructive sleep apnea and hypertension: are peripheral chemoreceptors involved?

The mechanism of pathogenesis of hypertension in patients with obstructive sleep apnea (OSA) is unknown. Many investigators point to the high sympathetic nervous system activity (SNS) observed in OSA patients. However, there is no clear explanation as to the mechanism for the development of SNS hyperactivity in these patients. A common feature of patients with OSA is repetitive bouts of transient hypoxemia during sleep. Repetitive transient hypoxemia in rats has resulted in hypertension. In OSA patients, resolution of nocturnal hypoxemia with CPAP has corrected nocturnal and diurnal hypertension. Also, exposure to hyperoxia reduces blood pressure and sympathetic activity in OSA patients, but not in normals. These data suggest a significant role of peripheral chemoreceptors in the regulation of vascular tone. We hypothesize that peripheral chemoreceptors significantly contribute to the pathogenesis of hypertension in patients with OSA and that this is associated with chemoreceptor hyperactivity. This implies that correcting the intermittent nocturnal hypoxemia alone may prevent the cardiovascular morbidity associated with obstructive sleep apnea.

Sleep Disorders in the Elderly.

Sleep disturbances in the elderly may not be a result of the aging process per se, but rather are likely caused by many factors that are amenable to treatment. These factors include medical and psychiatric problems, medications, and circadian rhythm changes, all of which can cause difficulties during sleep at night, and can lead to complaints of insomnia. Other factors that cause disturbances include a high prevalence of specific sleep disorders such as sleep disordered breathing (SDB), periodic limb movements during sleep (PLMS) and rapid eye movement (REM) sleep behavior disorder (RBD). Although these disorders are more prevalent in the older than younger population, they are not exclusive to this age group, and treatment options that are applicable to young adults are also applicable to older adults. On the other hand, dementia and Parkinson's disease are two neurologic disorders that are almost exclusive to the elderly and most often involve sleep disturbances. Because there are many causes of sleep complaints, when considering treatment options one must identify the underlying problem. If caused by illness, effective treatment of a specific medical or psychiatric problem should help alleviate the sleep problem as well. Changes in the timing of drug administration may improve sleep. For the treatment of chronic insomnia, behavior techniques should always be used in combination with pharmacologic therapy, and sedative-hypnotic medications should be considered when appropriate. The treatment of choice for obstructive sleep apnea is continuous positive airway pressure (CPAP). For PLMS, dopaminergic agents are most effective. For RBD, clonazepam effectively controls the aversive sleep behaviors. Sleep disturbances secondary to dementia and Parkinson's disease are usually problematic for the patient as well as the caregiver, whether in the home or in the nursing home. Proper management of these disturbances is beneficial in terms of delaying institutionalization and reducing nursing care costs, as well as improving the quality of life for both patient and caregiver.

Association between polysomnographic sleep measures and health-related quality of life in obstructive sleep apnea.

Many facets of health-related quality of life are diminished in obstructive sleep apnea (OSA) as they are in other chronic medical conditions. We speculated that impairment in health-related quality of life (HRQoL) might result from the fatigue and daytime somnolence associated with the sleep disorder, as an indirect result from the fragmentation of night-time sleep in OSA. Our hypothesis was that sleep fragmentation measures would correlate with poorer HRQoL measured by medical outcomes study (MOS) subscales. Thirty-nine patients with polysomnographically-confirmed OSA participated in this study. Pearson's correlations were performed with the following sleep architecture variables: wake after sleep onset, the total number of brief arousals, the number of respiratory-related arousals, the rate of respiratory events per hour, and total sleep time. To our surprise, although the total number of arousals was associated with health distress (r=-0.481, P < 0.005), it did not correlate with any other subscales indicating poorer physical and mental health. The relatively insensitive measure of total sleep time (TST) correlated in the expected direction with most subscales. However, after controlling for age and gender, respiratory disturbance indices (RDI) and/or number of arousals emerged as significantly associated with mobility, cognitive functioning, social functioning, energy and fatigue, and health distress. Our findings suggest that polysomnographic indicators of sleep quality and sleep continuity may be an important influence determining many aspects of HRQoL in OSA patients.

Long-term follow-up of sleep disordered breathing in older adults.

OBJECTIVE: The current study was designed to determine whether, with increasing age, sleep apnea improves, becomes worse, or stays the same. BACKGROUND: There is a high prevalence of sleep disordered breathing (SDB) in older adults, but little is known about longitudinal changes. This study followed older adults to examine the natural history of SDB. METHODS: Subjects were randomly selected community-dwelling elderly (n=427). A subset of subjects was studied approximately every 2 years over an 18-year period. Overnight sleep recordings and sleep questionnaires were completed at each time point. RESULTS: Multiple linear regression showed that three variables were associated with change in respiratory disturbance index (RDI):body mass index (BMI) at initial visit (P=0.001), change in BMI (P=0.02), and a consistent self-report of high blood pressure (P=0.005). RDI increase was associated with BMI increase and presence of self-reported high blood pressure. CONCLUSIONS: The changes in RDI that occurred were associated only with changes in BMI and were independent of age. This underscores the importance of managing weight for older adults, particularly those with hypertension.