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.

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.

Characteristics of obstructive and central sleep apnea in the elderly: an interim report.

Home sleep recordings were done on 358 randomly selected elderly volunteers (mean age 72.4). When men and women were combined, 62 (17%) had predominantly obstructive sleep apnea, 21 (6%) had predominantly central sleep apnea, and 3 (1%) had mixed sleep apnea. Although the prevalence of sleep apnea in women does increase after menopause, sleep apnea was still significantly more common in older men (31%) than in older women (19%). There were no significant differences in age among groups with different types of apnea. There was a significant correlation of age with increasing apnea index within the obstructive sleep apnea group. Elderly volunteers with central sleep apnea had more midsleep awakenings. Elderly volunteers with obstructive sleep apnea had longer apneas. Unlike previous studies, we found many similarities and only modest differences in the presentations of central and obstructive sleep apnea.

Does obstructive sleep apnea confound sleep architecture findings in subjects with depressive symptoms?

BACKGROUND: Compared with normal subjects, depressed patients have shorter rapid eye movement sleep latency (REML), increased REM and decreased slow wave sleep as a percentage of total sleep time (REM%, SWS%), and longer sleep latency (SL). Obstructive sleep apnea (OSA) patients experience longer REML, decreased REM% and SWS%, and shorter SL. We examined the interplay of depressive symptoms, OSA, and sleep architecture. METHODS: Subjects (n = 106) were studied with polysomnography. OSA was defined as a Respiratory Disturbance Index > or = 15. Subjects were divided into Hi/Lo groups using a Center for Epidemiological Studies-Depression (CES-D) score of 16. RESULTS: OSA patients had shorter SL than non-OSA patients (14.5 vs. 26.8 min, p <.001); Hi CES-D subjects showed a trend toward longer SL than Lo CES-D subjects (23.7 vs. 17.5 min, p =.079). Significant OSA x CES-D interactions emerged, however, for REM% (p =.040) and SL (p =.002): OSA/Hi CES-D subjects had higher REM% than OSA/Lo CES-D subjects (19.3% vs. 14.3%, p =.021); non-OSA/Hi CES-D subjects had SL (35.3 min) 2-3 times as long as other subjects (p =.002-.012). CONCLUSIONS: Because of the high prevalence of OSA and depression, findings suggest that OSA must be considered in studies of mood and sleep architecture. Conversely, depressive symptoms must be considered in studies of OSA and sleep architecture.

Sleep duration, illumination, and activity patterns in a population sample: effects of gender and ethnicity.

BACKGROUND: Current knowledge of the population's sleep durations emanates primarily from questionnaires and laboratory studies. Using Actillumes, we investigated whether self-reported sleep durations were indicative of a population decline in sleep duration. We also explored illumination and activity patterns. METHODS: San Diego adults (n = 273, age range: 40-64) were recruited through random telephone calls and were monitored at home while engaging in usual daily routines. RESULTS: Volunteers slept an average of 6.22 hours and received an average of 554 lux (environmental illumination). The timing of sleep, illumination, and activity occurred at 2:44, 12:57, and 13:43, respectively. Irrespective of ethnicity, age, and time reference, men received greater illumination than did women, but this gender effect was not independent of work status. Women and men exhibited a similar circadian activity profile; however, women exhibited better sleep-wake patterns. Interactions between gender and ethnicity suggested worse sleep-wake patterns among minority men. An age-related decline in activity was found, but no age trend in sleep duration or illumination patterns was observed. CONCLUSIONS: This study showed an objective population decline in sleep duration. Sociodemographic effects should be considered in analyses of sleep-wake patterns and illumination exposures.

Low illumination experienced by San Diego adults: association with atypical depressive symptoms.

We explored the illumination exposure of middle-aged adults to determine normal values and to explore several correlates of daily light exposures. Subjects aged 40-64 years in San Diego, CA were recruited by random telephone dialing. Subjects completed a demographic interview and the Center for Epidemiologic Studies Depression self-rating scale (the CES-D) supplemented with eight questions related to seasonal affective disorders (SAD). Data were analyzed for 106 volunteers who wore a device that monitors illumination exposures and activity. The median subject was exposed to illumination > or = 1000 lux for only 4% of the time observed, that is, only about 58 min per day were spent in daylight. Subjects scoring higher on the atypical SAD mood symptoms spent less time in bright illumination rs = -0.266, p = 0.003. The CES-D depression score was similarly correlated with illumination but of borderline significance (rs = -0.150, p = 0.063). These results suggest the hypothesis that many Americans may be receiving insufficient light exposure to maintain optimal mood.

Sleep-disordered breathing and periodic limb movements in sleep in older patients with schizophrenia.

BACKGROUND: Since the prevalence of both sleep-disordered breathing (SDB) and periodic limb movements in sleep (PLMS) increase with age, we explored whether older schizophrenia patients would have a high incidence of SDB and PLMS. Correlations between sleep and clinical variables were also examined. METHODS: Fifty-two patients (mean age = 59.6 years, SD = 8.9) had their sleep/wake, respiration, and leg movements recorded using a modified Medilog/Respitrace portable recording system plus oximetry. A battery of clinical, psychosocial, and motor disturbance variables were collected by research center staff. RESULTS: Forty-eight percent of these patients had at least 10 respiratory events per hour of sleep. These patients reported more symptoms of daytime sleepiness than patients with fewer than 10 events per hour. The relatively high prevalence of SDB in this group may contribute to overall sleep disturbances, and does not appear to be a result of high body mass index. Only 14% of the patients had at least five limb movements per hour of sleep, suggesting the prevalence of PLMS is much lower than expected in this age group. The number of leg jerks was inversely related to symptoms of tardive dyskinesia. CONCLUSIONS: The disturbance of sleep in these patients may be due, in part, to SDB, but is unlikely due to PLMS.

Sleep apnea and nocturnal myoclonus in the elderly.

Insomnia, daytime sleepiness, and nocturnal wandering, so common in the elderly, are caused largely by two specific pathophysiologic processes. Sleep apnea is a condition where respiration pauses during sleep, leading to arousal. Sleep apnea is due either to obstruction in the throat or failure of the central respiratory center. Periodic movements in sleep are characterized by frequent ankle and leg flexions, leading to arousal. Sleep apnea and periodic movements in sleep require specific diagnoses and treatments. Each process occurs in 20%-30% of people over 65, and perhaps the majority of older people have one or the other condition or both. Because of possible interactions with these sleep disorders, the widespread prescribing of sleeping pills to elderly patients is irrational and often dangerous. In the future, large-scale clinical trials will be needed to define effective long-term treatments for these conditions and to define when treatment is worthwhile.

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.

Insomnia in the elderly: a review for the primary care practitioner.

The elderly are known to have a high prevalence of insomnia. Causes of insomnia include: medical, psychiatric, and drug issues; circadian rhythm changes; sleep disorders; and psychosocial factors. The elderly frequently use sleeping aids. Risks associated with elderly patients' use of hypnotic drugs are attributable to concomitant comorbid conditions, use of multiple medications, altered pharmacokinetics, and increased central nervous system sensitivity to these drugs. Treatment options for insomnia include behavior modification and pharmacotherapy. The choice of hypnotics is based on matching the nature of the insomnia to the hypnotic agent. Benzodiazepine receptor agonists are common hypnotics prescribed for insomnia in the elderly. The ideal agent has rapid onset, duration of action that lasts through the night but no residual daytime effects, and no adverse effects. The longer-acting agents have been shown to result in a higher risk of falls and hip fractures in the elderly. This relationship is not apparent with short-acting agents. Zaleplon, the newest benzodiazepine receptor agonist, has the shortest half-life of available agents. Studies have demonstrated that zaleplon is effective in improving sleep latency, duration, and sleep quality in the elderly. Zaleplon does not appear to cause rebound insomnia, residual sedation, or adversely affect psychomotor function. The key for the healthcare professional is finding the appropriate treatment or treatment combination, including behavioral modification and pharmacotherapy. When hypnotics are indicated, the most appropriate short-acting agent should be considered.

Characteristics of insomnia in the United States: results of the 1991 National Sleep Foundation Survey. I.

The National Sleep Foundation in conjunction with the Gallup Organization conducted telephone interviews with a sample of Americans (N = 1000) to examine the prevalence and nature of difficulty with sleep. Consistent with other national studies, about one-third of Americans reported some type of sleep problem. Approximately one in four reported occasional insomnia while 9% reported that their sleep difficulty occurred on a regular nightly basis. The problem most frequently reported by insomniacs was waking up in the morning feeling drowsy or tired, followed by waking up in the middle of the night, difficulty going back to sleep after waking up and difficulty falling asleep initially. Importantly, insomniacs rarely visited a physician to discuss their sleep problem and four out of ten insomniacs self-medicated with either over-the-counter medications or with alcohol. Two-thirds of the insomniacs reported that they did not have an understanding of available treatments for insomnia.

Daytime consequences and correlates of insomnia in the United States: results of the 1991 National Sleep Foundation Survey. II.

The daytime consequences and correlates of insomnia were examined in the National Sleep Foundation and the Gallup Organization survey of 1,000 randomly selected Americans. Respondents were grouped as having occasional insomnia, chronic insomnia or no insomnia. There were dramatic differences in reported waking behaviors and psychosocial measures by insomniacs compared to those who do not report sleep difficulty. These problems include impaired concentration, impaired memory, decreased ability to accomplish daily tasks and decreased enjoyment of interpersonal relationships. Importantly, most of these variables showed an increasing degree of impairment with greater frequency of sleep disturbance. These findings suggest that insomnia negatively impacts aspects of waking function related to quality of life.

Sleep and quality of well-being.

BACKGROUND: It is commonly believed that sleep duration in the population has been declining gradually. Whereas sleep restriction in the laboratory induces sleepiness and mood disturbances, it is not certain whether a short sleep duration impairs the quality of everyday life. METHODS: Using population-based data, we explored whether greater habitual sleep duration is a predictor of better health-related quality of life, measured by the Quality of Well-Being (QWB) scale. The relationships between QWB and several potential correlates were examined in a stepwise linear regression analysis. RESULTS: Neither subjective nor actigraphic sleep duration were associated with QWB. Greater quality of well-being was associated with greater sleep satisfaction, younger age, less obesity, non-Hispanic White ethnicity, and greater experienced illumination. CONCLUSION: These data suggest that increasing sleep duration may not directly improve quality of life, despite evidence that curtailment of nocturnal sleep is associated with fatigue.

Body position changes and periodic movements in sleep.

What triggers episodes of periodic movements in sleep (PMS) remains unknown. Despite the uncertainties, there is no doubt of the widespread prevalence of PMS, particularly in elderly populations. This study explored possible consistent temporal relationships between body position and PMS episodes. Eleven subjects, monitored by polygraph and videotape, averaged 299 leg jerks in nine episodes, and 13 body position changes of greater than or equal to 90 degrees. Leg jerk episodes had a significant tendency to terminate soon before body position changes, and likewise there was a trend for leg jerk episodes to begin soon after position changes. It is hypothesized that adverse body positioning, via an influence upon the spinal cord or peripheral tissue perfusion, triggers PMS episodes, which persist until the adverse positions are changed. In this small sample, "adverse" positions could not be elucidated.

Insomnia in primary care patients.

STUDY OBJECTIVES: To determine the prevalence and characteristics of insomnia in primary care patients, to examine patients' help-seeking behavior, and to compare the frequency of insomnia in primary care patients to the general population. METHODS: 286 patients from primary care clinics in San Diego, California (n = 96), and in Haleiwa and Honolulu, Hawaii (n = 190) participated. Sleep study questionnaires were distributed by front desk receptionists to all patients over 18 years of age upon arrival at the clinic for an appointment with the physician. Completed questionnaires were collected at the clinic or returned by mail. Comparisons were made by using nonparametric statistics. A logistic regression analysis using backward elimination was done to develop a model showing predictors of who would consult with the physician about a sleep problem. RESULTS: The prevalence of insomnia in primary care patients was 69%, with 50% reporting occasional insomnia and 19% reporting chronic insomnia. As expected, patients with chronic insomnia had the most severe sleep complaints as well as the poorest daytime functioning, and exhibited the most help-seeking behaviors. The four predictors of discussing insomnia with a physician were how patients felt physically, number of years of insomnia, age, and income. CONCLUSIONS: The primary care population has a higher prevalence of insomnia than the general population, probably because of concomitant psychiatric and medical illnesses. Although many of the characteristics of the sleep complaints are easily detected, most patients with insomnia are not treated effectively.

Sleep apnea and nocturnal myoclonus in a senior population.

Studies have suggested that sleep apnea is especially prevalent among seniors. We recruited and recorded senior volunteers who reported symptoms raising suspicion of sleep apnea or nocturnal myoclonus. Of 24 subjects, 62.5% had one of these disorders-six had sleep apnea alone, three had sleep apnea and nocturnal myoclonus, ans six had nocturnal myoclonus alone. Sleep stages were also analyzed. Subjects with sleep apnea and/or nocturnal myoclonus had significantly less rapid eye movement sleep, significantly more stage 1 sleep, and significantly more awakenings than other subjects. This sample suggests that the prevalence of sleep apnea and nocturnal myoclonus may be very substantial among seniors. Because of this high prevalence, extreme caution is needed in prescribing hypnotics for older patients with sleep complaints, since most hypnotics are respiratory depressants. We must rethink our approach to treating sleep disorders in the older population.

Comparisons of home sleep recordings and polysomnograms in older adults with sleep disorders.

A major problem with studying the prevalence of sleep disorders is the high cost. We tested a portable home recording system which can decrease the cost of screening sleep recordings. Twenty-four senior volunteers and 12 patients referred to our sleep disorders clinic were studied for two nights. On one night, recordings were done in the laboratory with a traditional polysomnogram and the portable home recorder. On another night, portable home recorders were used in the subjects' homes. Of 36 subjects, 42% had sleep apnea and 39% had nocturnal myoclonus. Intermethod correlations were highly significant for sleep apnea index, nocturnal myoclonus index, total sleep period (TSP), total sleep time (TST), and wake time after sleep onset (WASO). The portable home recorder detected sleep apnea on 100% of nights during which sleep apnea was diagnosed by polysomnogram. The labor-saving and cost-saving benefits of home recordings as well as the increased comfort, privacy, and convenience will make the portable home recording the preferred method for many research and clinical applications.

Apnea revisited: a longitudinal follow-up.

Volunteers aged 65 years and over who were previously studied underwent follow-up interviews and sleep recordings several years later (mean follow-up, 4.6 years). Modest correlations between the initial and subsequent recordings were found for apnea index, hypopnea index, and respiratory disturbance index. Sleep apnea indices did not increase over time; however, individual subjects showed great variability in amount of apnea. Periodic leg movement indices, on the other hand, significantly increased. Subjective reports indicated a significant increase in the amount of time spent awake and a significant decrease in the amount of loud snoring.

Types of coping strategies are associated with increased depressive symptoms in patients with obstructive sleep apnea.

STUDY OBJECTIVES: Some, but not all, researchers report that obstructive sleep apnea (OSA) patients experience increased depressive symptoms. Many psychological symptoms of OSA are explained in part by other OSA comorbidities (age, hypertension, body mass). People who use more passive and less active coping report more depressive symptoms. We examined relationships between coping and depressive symptoms in OSA. SETTING: N/A. DESIGN/PARTICIPANTS: 64 OSA (respiratory disturbance index (RDI) > or = 15) patients were studied with polysomnography and completed Ways of Coping (WC), Profile of Mood States (POMS), Center for Epidemiological Studies-Depression (CESD) scales. WC was consolidated into Approach (active) and Avoidance (passive) factors. Data were analyzed using SPSS 9.0 regression with CESD as the dependent variable and WC Approach and Avoidance as the independent variables. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: WC Approach factor (B=-1.105, beta=-.317, p=.009) was negatively correlated and WC Avoidance factor (B=1.353, beta=.376, p=.007) was positively correlated with CESD scores. These factors explained an additional 8% of CESD variance (p<.001) beyond that explained by the covariates: demographic variables, RDI, and fatigue (as measured by the POMS). CONCLUSIONS: More passive and less active coping was associated with more depressive symptoms in OSA patients. The extent of depression experienced by OSA patients may not be due solely to effects of OSA itself. Choice of coping strategies may help determine who will experience more depressive symptoms.

Periodic limb movements in sleep in community-dwelling elderly.

The prevalence of periodic limb movements in sleep (PLMS) in a randomly selected elderly sample is reported. In San Diego, 427 elderly volunteers aged 65 yr and over were recorded in their homes. Forty-five percent had a myoclonus index, MI greater than or equal to 5. Correlates of PLMS included dissatisfaction with sleep, sleeping alone and reported kicking at night. Although statistically significant, the strengths of the associations between interview variables and myoclonus indices were all small. No combination of demographic variables and symptoms allowed highly reliable prediction of PLMS.