Tolerance of chronic 90-minute time-in-bed restriction in older long sleepers.
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STUDY OBJECTIVES: To examine the influence of chronic time-in-bed (TIB) restriction on selected health-related outcome variables in older long sleepers. DESIGN: Randomized, controlled trial. SETTING: Home-based. PARTICIPANTS: Forty-two older adults (aged 50-70 y) who reported sleeping at least 8.5 hours. Following extensive screening, participants were assessed for 10 weeks. INTERVENTION: During a two-week baseline, participants followed their usual sleep-wake habits. Participants were then randomized to one of two eight-week treatments: (1) TIB restriction, in which participants were asked to follow a fixed sleep schedule with a TIB of 90 minutes less than recorded during baseline or (2) a control treatment, which involved following a fixed sleep schedule (consistent with average baseline) but no TIB restriction. MEASUREMENTS AND RESULTS: Continuous wrist actigraphic sleep estimation indicated that TIB restriction elicited significant reductions in TIB and total sleep time compared with the control treatment and significant (albeit modest) improvements in sleep efficiency and sleep latency. However, compared with the control treatment, TIB restriction elicited no significant change in depression, sleepiness, health-related quality of life, or neurobehavioral performance. Moreover, follow-up assessments for one year indicated that, after completing the experiment, the participants assigned to TIB restriction continued to restrict their TIB (at their own initiative) by an average of approximately one hour. CONCLUSIONS: The results suggest good tolerance of chronic moderate TIB restriction, without detrimental effects, among older long sleepers. (+info)
Sleep disturbance and baroreceptor sensitivity in women with posttraumatic stress disorder.
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Working memory capacity is decreased in sleep-deprived internal medicine residents.
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BACKGROUND: Concerns about medical errors due to sleep deprivation during residency training led the Accreditation Council for Graduate Medical Education to mandate reductions in work schedules. Although call rotations with extended shifts continue, effects on resident sleep-wake times and working memory capacity (WMC) have not been investigated. OBJECTIVES: The objective of this study was to measure effects of call rotations on sleep-wake times and WMC in internal medicine residents. METHODS: During 2 months of an internal medicine training program adhering to ACGME work-hour restrictions (between April 2006 and June 2007), residents completed daily WMC tests, wore actigraphy watches, and logged their sleep hours. This observational study was conducted during a call month requiring 30-hour call rotations every fourth night, whereas the noncall month, which allowed sleep/wake cycle freedom, was used as the control. MAIN OUTCOME MEASURES: Sleep hours per night and WMC testing. RESULTS: Thirty-nine residents completing the study had less sleep per night during their call month (6.4 vs 7.3 h per night noncall, p < 0.001) and sleep per night varied from 3.7 to 10.1 hours. Call rotation caused greater self-assessed sleepiness and reduced WMC recall scores (-2.6/test, p < 0.05), and more math errors occurred when on call (+1.07/test, p < 0.04). Full recovery of WMC did not occur until the fourth day after call. On-call rotation on the first month had a confounding detrimental effect on WMC. CONCLUSION: A month of call rotations reduced overall sleep per night; sleep hours per night were variable, and WMC was adversely affected. Decreased WMC could explain impaired judgment during sleep deprivation, although clinical error rates were not evaluated. (+info)
Prevalence and prediction of primary sleep disorders in a clinical trial of depressed patients with insomnia.
(15/483)
Insomnia-pharmacology clinical trials routinely exclude primary sleep disorders, such as obstructive sleep apnea (OSA) and periodic limb movement disorder (PLMD), with a single night of polysomnography (PSG). Given the expense of PSG, we examined whether a thorough clinical screening, combined with actigraphy, would successfully identify OSA and PLMD as part of baseline screening for a clinical trial of insomnia treatment in depressed patients. Of the 73 patients with a complete baseline dataset, 12 screened positive for OSA/PLMD (AHI > 15, or PLMAI > 15), while 61 "passed" the PSG screen. The OSA/PLMD+ patients were older (51.4 +/- 10.2 y) and took more naps (2.6 per week) than the OSA/PLMD- patients (41.3 +/- 12.8 y; and 1.1 naps per week). The combination of age and nap frequency produced a "good" receiver operating characteristic (ROC) model for predicting OSA/PLMD+, with the area under the curve of 0.82. There were no other demographic, sleep diary, or actigraphic variables, which differed between OSA/PLM + or -, and no other variable improved the ROC model. Still, the best model misclassified 16 of 73 persons. We conclude that while age and the presence of napping were helpful in identifying OSA and PLM in a well-screened sample of depressed insomniacs, PSG is required to definitively identify and exclude primary sleep disorders in insomnia clinical trials. (+info)
Night-to-night sleep variability in older adults with and without chronic insomnia.
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