Day-to-day variability in nap duration predicts medical morbidity in older adults.
ABSTRACT Objective: The objectives for the present study were to (a) examine within-person variability of nap duration and (b) assess how variability in nap duration is related to the number of health conditions in a sample of older adults. For highly variable behaviors such as sleep, it is important to consider fluctuations within the person instead of solely comparing averages of behaviors across persons. Method: Data were drawn from a previous study examining sleep in 103 community-dwelling older adults. Subjective estimates of napping behavior were obtained from sleep diaries and objective estimates of napping behavior were obtained using actigraphy. Both measures were collected for 14 consecutive days. The sampled data were aggregated in terms of (a) average daily time spent napping and (b) average within-person fluctuations in daily nap duration. The health measure consisted of the number of self-reported health conditions. Results: Both the objective and subjective measures revealed that there was considerable day-to-day fluctuation in nap duration and that variability in nap duration, not mean duration, uniquely predicted the number of health conditions, b = .03, b* = .26, t(100) = 2.71, p = .01. Conclusions: Duration of napping in older adults is a highly variable behavior, fluctuating as much within- as between-persons. Furthermore, variability in nap duration from day to day is predictive of greater medical morbidity, suggesting that clinicians should assess for inconsistencies in nap behavior in addition to duration, frequency, and timing. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
- SourceAvailable from: ncbi.nlm.nih.govSleep 01/2012; 35(9):1189-90. · 5.06 Impact Factor
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ABSTRACT: Sleep-wake disturbances and concomitant cognitive dysfunction in Parkinson's disease (PD) contribute significantly to morbidity in patients and their carers. Subjectively reported daytime sleep disturbance is observed in over half of all patients with PD and has been linked to executive cognitive dysfunction. The current study used daytime actigraphy, a novel objective measure of napping and related this to neuropsychological performance in a sample of PD patients and healthy, age and gender-matched controls. Furthermore this study aimed to identify patients with PD who may benefit from pharmacologic and behavioural intervention to improve these symptoms. Eighty-five PD patients and 21 healthy, age-matched controls completed 14 days of wrist actigraphy within two weeks of neuropsychological testing. Objective napping measures were derived from actigraphy using a standardised protocol and subjective daytime sleepiness was recorded by the previously validated Epworth Sleepiness Scale. Patients with PD had a 225% increase in the mean nap time per day (minutes) as recorded by actigraphy compared to age matched controls (39.2 ± 35.2 vs. 11.5 ± 11.0 minutes respectively, p < 0.001). Significantly, differences in napping duration between patients, as recorded by actigraphy were not distinguished by their ratings on the subjective measurement of excessive daytime sleepiness. Finally, those patients with excessive daytime napping showed greater cognitive deficits in the domains of attention, semantic verbal fluency and processing speed. This study confirms increased levels of napping in PD, a finding that is concordant with subjective reports. However, subjective self-report measures of excessive daytime sleepiness do not robustly identify excessive napping in PD. Fronto-subcortical cognitive dysfunction was observed in those patients who napped excessively. Furthermore, this study suggests that daytime actigraphy, a non-invasive and inexpensive objective measure of daytime sleep, can identify patients with PD who may benefit from pharmacologic and behavioural interventions to improve these symptoms.PLoS ONE 11/2013; 8(11):e81233. · 3.53 Impact Factor
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ABSTRACT: The purpose of this study is twofold: (a) to determine whether daily or overall cognitive and somatic arousal better predict sleep and (b) to investigate age differences in the arousal-sleep relation. Fifty younger and 50 older adults completed the Pre-Sleep Arousal Scale and sleep diaries for 14 consecutive days. Analyses revealed mean arousal may better predict sleep regardless of age. However, daily arousal represents an important avenue of research as it may uncover lagged or coupling effects in the arousal-sleep relation. Significant age differences in the arousal-sleep relation suggest age-dependent associations between the type of arousal and sleep. Implications for assessment of sleep in older and younger adults are discussed.Behavioral Sleep Medicine 06/2013; · 1.74 Impact Factor