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Biomedical subjects

D L Bliwise

Publications and source records attributed to D L Bliwise.

At least 19 recordsLinked to original sources
PubMed2001

Survival by time of day of hemodialysis in an elderly cohort.

CONTEXT: Patients with end-stage renal disease (ESRD) typically undergo hemodialysis (HD) during the morning or afternoon, with time of treatment generally based on space availability or patient preference. No studies have investigated variation in patient survival as a function of the time of day when they receive dialysis. OBJECTIVE: To investigate the association of elderly patients' HD treatment shift with their continued survival, controlling for well-established HD-related mortality risk factors. DESIGN, SETTING, AND PARTICIPANTS: An 11-year follow-up cohort study conducted among 242 ESRD patients aged 60 years or older who underwent HD at 58 dialysis facilities in Georgia either during a morning shift (n = 167) or an afternoon shift (n = 75) and who completed baseline (1988) [corrected] and follow-up (1991) interviews. MAIN OUTCOME MEASURE: Mortality from all causes occurring through July 7, 1999, as verified by death-certificate reviews, and compared by morning vs afternoon-shift HD. RESULTS: Morning-shift HD patients survived significantly longer than afternoon-shift patients (median survival, 941 days vs 470 days; P<.001). A Cox proportional hazards model indicated that the morning shift was protective (relative risk, 0.71; 95% confidence interval, 0.53-0.95) independent of age, race, sex, body mass index, functional status, diabetic ESRD, cardiovascular comorbidity, weekly hours of dialysis, and months of dialysis. CONCLUSIONS: Possible explanations for differential survival in association with morning vs afternoon dialysis include salutary effects of sleep in the morning or less efficient biochemical exchange during afternoon dialysis. Results from this cohort study may warrant prospective observational studies and randomized clinical trials that systematically alter the time of day at which HD is administered.

Aged↗
PubMed2001

Genetic factors in self-reported snoring and excessive daytime sleepiness: a twin study.

Subjects in this study included 1,560 intact male-male twin pairs (818 monozygotic [MZ], 742 dizygotic [DZ]) of mean age (+/- SD) 74.2 +/- 2.8 yr. The Epworth Sleepiness Scale (ESS) was used to assess daytime sleepiness and standardized questionnaires assessed snoring. Multivariate genetic model fitting was used to estimate the contribution of genetic and nongenetic (environmental) influences to the variation and covariation of obesity with snoring and daytime sleepiness. In this sample, 26% were habitual snorers, 18% reported excessive daytime sleepiness (ESS > or = 11), and 29% were obese (body mass index [BMI] > or = 28). By using structural equation modeling, we estimated that genetic factors accounted for 64% of the variance in obesity, 40% of the variance in daytime sleepiness, and 23% of the variability in self-reports of snoring. We found a significant genetic correlation between obesity and snoring and between obesity and excessive daytime sleepiness (EDS), although for the most part the genetic variance in snoring and sleepiness was nonoverlapping with the genetic variance for obesity. We conclude from these data that self-reported symptoms of snoring and daytime sleepiness in older men have a genetic basis that is largely independent of genes associated with obesity.

Aged↗
PubMed2001

A genetic analysis of the Epworth Sleepiness Scale in 1560 World War II male veteran twins in the NAS-NRC Twin Registry.

Responses to the eight-item Epworth Sleepiness Scale (ESS) obtained from 1560 World War II male veteran twin pairs [818 monozygotic (MZ), 742 dizygotic (DZ)] were analysed to determine the extent to which genetic influences are involved in self-reported daytime sleepiness in the elderly. Average ESS score (+/- SD) in this sample was 7.1 +/- 3.9, range 0--24. More than half of the twins (65%--67%) reported a moderate to high chance of falling asleep while lying down to rest; fewer than 3% admitted that this would occur while sitting and talking to someone or while stopped in traffic. Daytime sleepiness was not associated with age but was significantly and positively associated with obesity. The intraclass twin correlation on ESS scores was 0.39 in MZ pairs and 0.21 in DZ pairs (both P < 0.001). Structural equation modeling of the observed variance-covariance matrices for MZ and DZ twins estimated the heritability of ESS to be 38% (95% confidence interval 33%--44%). Environmental influences not shared by twin brothers accounted for the remaining variance in daytime sleepiness. A reasonable interpretation of the heritability of ESS in this healthy cohort of elderly male twins is a genetic susceptibility for disordered breathing during sleep.

Aged↗
PubMed2001

Race and restless sleep complaint in older chronic dialysis patients and nondialysis community controls.

There is mixed evidence about the relation of race to risk of sleep disturbance. We explored the relation of race to restless sleep complaint in survey data from a cohort of 311 older patients undergoing chronic renal dialysis and a similarly aged cohort of 354 nondialysis controls. Older dialysis patients were significantly more likely to report restless sleep. Restless sleep complaint was related to comorbidity, depressed mood, use of sleep medications, and perceived health status in both groups. Black patients in the dialysis cohort had decreased odds of restless sleep, but Black and White controls did not differ significantly in reporting restless sleep. Compared with their more socially advantaged White counterparts, older Black dialysis patients may perceive the chronic dialysis care environment more favorably. The findings are consistent with the view that sleep quality in late life is likely to reflect a delicate balance between psychological as well as physical well-being.

Black or African American↗
PubMed2000

Laboratory sleep correlates of nightmare complaint in PTSD inpatients.

BACKGROUND: Nightmares are rare in the sleep laboratory, even in patients with posttraumatic stress disorder for whom nightmare complaints are diagnostic. Nevertheless, it is possible that laboratory conditions do not preclude the observation of telltales-nightmare-related modifications of tonic sleep-given sufficiently large samples. METHODS: Sixty-three unmedicated, nonapneic Vietnam combat veterans undergoing inpatient treatment for posttraumatic stress disorder underwent polysomnographic testing and assessment of nightmare complaint. RESULTS: Trauma-related nightmare complaint, but not non-trauma-related complaint, was associated with increased wake-after-sleep-onset in the sleep laboratory. No relationships between nightmare complaint and rapid eye movement sleep architecture were observed. CONCLUSIONS: Increased wake-after-sleep-onset was specifically associated with trauma-related nightmare complaint, confirming data from other quarters suggesting they are both phenomenologically and functionally distinct from normal dreaming.

Adult↗
PubMed2000

Intradialytic subjective sleepiness and oral body temperature.

STUDY OBJECTIVES: Hemodialysis (HD) patients are often observed to sleep during treatment. Because of the well-described, inverse association between body temperature and sleep propensity, the purpose of this study was to describe the course of intradialytic (during HD) subjective sleepiness and examine its relationship to oral body temperature. In addition, we sought to determine if that relationship varied with dialysis treatment time of day. DESIGN: Subjective sleepiness and oral body temperature were recorded every 15 minutes through the entire course of HD. SETTING: The study was conducted at two large, inner-city dialysis units. PATIENTS OR PARTICIPANTS: The sample included 60 chronic HD patients, 20 on each of three shifts based on treatment time of day (shift 1-6:00A.M. to 10:00A.M.; shift 2-10:00A.M. to 2:00P.M.; and shift 3-2:00P.M. to 6:00P.M.. MEASUREMENTS AND RESULTS: Subjects on shift 1 were found to have a mean intradialytic sleepiness level greater than those on shift 2 (p<.04) and shift 3 (p<.003). Irrespective of shift, sleepiness increased during the first half of dialysis and decreased slightly as treatment progressed, a significant quadratic trend (p<.001). During the same period, temperature initially increased, subsequently dropped in temporal proximity to maximal sleepiness and increased again, a significant quadratic trend (p<.02). The relationship between sleepiness and temperature revealed a significant negative correlation (r=-.59, p<.03) and did not vary with treatment time of day. CONCLUSIONS: The results argue that sleep propensity increases during HD, an effect that may be related to treatment induced alterations in arousal and/or thermoregulatory processes. The effect is unrelated to treatment time of day.

Body Temperature↗
PubMed2000

Inter-rater reliability for identification of REM sleep in Parkinson's disease.

Recently described functional connections between basal ganglia and brainstem circuits provide a neurobiologic basis for the absence of REM sleep atonia in Parkinson's disease (PD). However, identifying atypical REM sleep in PD may be problematic. Reliable sleep staging has never been demonstrated in such patients. In this study, 3 experienced scorers independently evaluated overnight polysomnograms from 10 (PD) patients. Results indicated good agreement for distinguishing REM from NREM sleep and waking. Reliable differentiation among NREM stages was more difficult to achieve. The results suggest that, despite suspension of REM sleep atonia accompanying PD, trained scorers can distinguish REM from wakefulness and NREM sleep.

Aged↗
PubMed2000

Prevalence of sleep apnea and electrocardiographic disturbances in morbidly obese patients.

OBJECTIVE: To determine the prevalence of sleep apnea in morbidly obese patients and its relationship with cardiac arrhythmias. RESEARCH METHODS AND PROCEDURES: Fifty-two consecutive morbidly obese (body mass index > or = 40 kg/m2) outpatients from the Obesity Clinic of the National Institute of Nutrition Salvador Zubirán underwent two nights of polysomnography with standard laboratory techniques. Electrocardiographic polysomnography signals (Lead II) were evaluated by two experienced cardiologists, and sleep complaints were measured with a standard sleep questionnaire (Sleep Disorders Questionnaire). In order to make comparisons between groups with different severities of sleep-disordered breathing, we classified the patients in four groups using the apnea-hypopnea index (AHI): Group 1, AHI 5 < 15 (n = 10); Group 2, AHI 15 < 30 (n = 10); Group 3, AHI 30 < 65 (n = 14); Group 4, AHI > or = 65 (n = 17). RESULTS: A wide range of sleep-disordered breathing, ranging from AHI of 2.5 to 128.9 was found. Ninety-eight percent of the sample (n = 51) had an AHI > or = 5 (mean = 51 +/- 37), and 33% had severe sleep apnea with AHI > or = 65 with a mean nocturnal desaturation time of <65% over 135 minutes. Electrocardiographic abnormalities were present in 31% of the patients. Cardiac rhythm alterations showed an association with the level of sleep-disordered breathing and oxygen desaturation. DISCUSSION: We conclude that there is a high prevalence of sleep apnea in morbidly obese patients and that the risk for cardiac arrhythmias increases in this population in the presence of a severe sleep apnea (AHI > or = 65) with severe oxygen desaturation (SaO2 < or = 65%).

Adult↗
PubMed2000

Relationship of 30-year changes in obesity to sleep-disordered breathing in the Western Collaborative Group Study.

OBJECTIVE: Obesity is an important etiologic factor in sleep-disordered breathing (SDB), but the extent to which changes in obesity across adult life contribute independently to SDB in old age has not been studied. In this study, we examined the association between changes in obesity from midlife to late adulthood and overnight recording of respiration during sleep. RESEARCH METHODS AND PROCEDURES: Subjects in this study are from the Western Collaborative Group Study, a longitudinal cardiovascular epidemiological study that began in 1960 through 1961. Overnight sleep recordings were obtained from 281 male participants in the 1995 through 1996 follow-up of the Western Collaborative Group Study. Subjects were 75 to 91 years old when assessed for SDB as indexed by the respiratory disturbance index and an oxygen desaturation index (O2DI). Long-term changes in anthropometrics were evaluated and examined in relation to SDB severity. RESULTS: Over the 30 years of follow-up, body mass index and waist circumference increased significantly for this sample and were associated with SDB severity as indexed by respiratory disturbance index and O2DI. Waist circumference at baseline and gain in waist circumference over the 30 years of follow-up (both p = 0.01) were significantly and independently associated with SDB severity as assessed by O2DI. However, percentage of variance as accounted for by waist circumference was modest. DISCUSSION: This study supports the hypothesis that gain in waist circumference over adult life is significantly associated with SDB severity in older men.

Adipose Tissue↗
PubMed2000

FAST TRACK: daytime sleepiness in Parkinson's disease.

We describe multiple sleep latency test (MSLT) results in 27 adult patients with idiopathic Parkinson's disease (PD). Pathological sleepiness (i.e. mean sleep latency </=5 min) was common (40 of 134 nap opportunities), and sleep-onset REM periods were also observed (13 of 134 nap opportunities). These findings bore little relationship to disease specific variables (e.g. level of disability, medication use), or sleep architecture measures (e.g. total sleep time, sleep stage percentage's). Our findings speak against a simple association of excessive sleepiness and the quality and quantity of prior night's sleep, but rather, argue for primary impairments of waking arousal and REM-sleep expression in a sizeable subpopulation of PD patients.

Aged↗
PubMed2000

Sleep problems as a risk factor for falls in a sample of community-dwelling adults aged 64-99 years.

OBJECTIVES: The purpose of this study was to determine if reported nighttime sleep problems and daytime sleepiness were associated with reported falling during the previous 12 months in a representatively sampled older adult population. DESIGN: Random-digit dial telephone survey. SETTING: Representatively sampled older adult population living in northern California. PARTICIPANTS: Participants were 971 women and 555 men, aged 64 to 99 years. MEASUREMENTS: Twenty-minute telephone interview adapted from the National Health Interview Survey. RESULTS: Two hundred and eighty-four participants reported falling during the previous 12 months (19% of the sample). Significantly more women fell than men (20% and 14%, respectively, P < .001). The following variables were significant risk factors for falling in univariate analyses: female gender, being unmarried, living alone, income less than $15,000 per year, difficulty walking, having more than one chronic medical condition, history of cardiovascular disease, hypertension, arthritis, sensory impairment, psychological difficulties, and nighttime sleep problems. All of the nighttime sleep problem variables remained significant risk factors for falling after controlling for other risk factors for falling. CONCLUSIONS: The results provide support for an independent association between reported sleep problems and falls in an older population. One of the implications of these data is that behavioral research focusing on the effectiveness of insomnia treatment in old age should not only examine typical sleep-related outcomes (e.g., total time asleep, number of awakenings) but also the occurrence of falls as well.

Accidental Falls↗
PubMed2000

An actigraphic comparison of sleep restriction and sleep hygiene treatments for insomnia in older adults.

We compared the efficacy of sleep restriction therapy combined with sleep hygiene, nap modification of sleep restriction therapy combined with sleep hygiene, and sleep hygiene alone as treatments for insomnia in 39 community-dwelling men and women 55 years and older. We used the wrist actigraph as an objective outcome measure for all subjects at baseline, end of treatment, and 3-month follow-up; polysomnography (PSG) was conducted in a subgroup of subjects. Although subjects appeared to follow restriction instructions through follow-up, we found few between-group differences in treatment efficacy. Lack of treatment effect might be explained by the efficacy of HYG as a treatment in itself and the relatively low symptom level in these healthy older poor sleepers. At baseline, actigraphic results were found to correlate more highly than sleep log data with PSG in our sample. Actigraphic total sleep time, in particular, was highly correlated with PSG.

Adult↗
PubMed1999

Juvenile Parkinson's disease with REM sleep behavior disorder, sleepiness, and daytime REM onset.

We describe an unmedicated patient with juvenile PD with difficulties maintaining wakefulness and the atonia of REM sleep. Laboratory testing showed enhanced muscle activity in REM sleep consistent with a history of dream enactment behavior (i.e., REM sleep behavior disorder) and daytime sleepiness, and REM-sleep onsets on multiple sleep latency testing. The results emphasize the potential role of dopamine and basal ganglia circuits in the modulation of activated behavioral states (e.g., wakefulness and REM sleep).

Adolescent↗
PubMed1999

Objective and subjective sleep disturbances in patients with systemic lupus erythematosus.

OBJECTIVE: To assess objective and subjective evidence of sleep disorders in patients with systemic lupus erythematosus (SLE) and to examine correlations between parameters of lupus activity, depression, and sleep disturbances. METHODS: Fourteen SLE patients and 11 normal control subjects of similar age underwent all-night polysomnography on 3 consecutive nights. The patients and controls were also evaluated for daytime sleepiness by the Multiple Sleep Latency Test and completed a sleep disorders questionnaire and the Beck Depression Inventory. RESULTS: The polysomnographic data showed that sleep in SLE patients was characterized by respiratory and movement disorders. These intrinsic primary sleep disorders are related to the symptom of restless, poor sleep at night. Lupus patients were more sleepy during the day, and their sleepiness was related to sleep fragmentation, with more arousals and stage transitions than the control group. Disease activity was associated with decreases in sleep efficiency and delta sleep and with increases in sleep fragmentation. Depression was not correlated with the activity of the disease. CONCLUSION: There is an enhanced presence of sleep disorders in patients with SLE. The most frequent primary sleep disorders are respiratory and movement disorders.

Adult↗
PubMed1999

Rate of 24-hour blood pressure decline and mortality after spontaneous intracerebral hemorrhage: a retrospective analysis with a random effects regression model.

OBJECTIVE: To study the effect of decline in blood pressure on mortality in patients with spontaneous intracerebral hemorrhage (ICH). DESIGN: Retrospective chart review. SETTING: University-affiliated teaching hospital. PATIENTS: Consecutive patients admitted with spontaneous ICH over a 3-year period. MEASURES: Blood pressure recordings were obtained from the first 24 hrs. Patients (n = 105) with more than five blood pressure recordings and on average greater than one measurement per 2 hrs were included (mean measurements per patient = 20.3). Mean arterial pressure (MAP) recordings over the first 24 hrs after presentation were regressed on time for each patient. Each patient's MAP was calculated as a slope (change mm Hg/hr). We performed logistic regression analyses to determine the effect of MAP slope on mortality and functional outcome, adjusting for other predictive factors including Glasgow Coma Scale (GCS) score and hematoma volume. The effect of MAP slope on mortality was also evaluated in subsets of patients based on age, gender, initial GCS score, initial MAP, treatment status, hematoma volume, and presence of ventricular blood. MAIN RESULTS: Mean slope of change in MAP was -2.0 mm Hg/hr (+/- 1.9, range -8.5 to +0.6). The slope of MAP (faster rate of decline) within the first 24 hrs was significantly associated with higher mortality (p =.04), independent of initial GCS score and hematoma volume. In subgroup analyses, MAP slope was significantly associated with mortality in men (p = .08), patients with hematoma volume <50 mm3 (p =.08), initial MAP < or = 146 mm Hg (p = .006), and those with initial GCS score > or = 10 (p= .07). MAP slope did not predict functional outcome among survivors. CONCLUSIONS: A rapid decline in MAP within 24 hrs after presentation is independently associated with increased mortality in patients with ICH. A large, prospective, randomized trial is required to confirm these findings.

Antihypertensive Agents↗