Sleep discrepancy has clinical significance in older adults
medwireNews: Discrepancy between self-report and actigraphy-measured sleep in older adults with insomnia who perceive their poor sleep to be a problem may be indicative of a meaningful sleep disturbance rather than a measurement error, researchers suggest.
"We posit that sleep discrepancy reflects a localized sleep disturbance, which affects brain networks involved in perception of self, neurocognitive processing, and time awareness," they comment in Journal of Gerontology: Psychological Sciences and Social Sciences.
The researchers, led by Christina McCrae (University of Florida, Gainesville, USA), examined sleep discrepancy in 152 adults aged an average of 72 years. Of these, 48 had insomnia and complained of sleep problems, and 19 had insomnia but did not complain of sleep problems. The remaining 75 participants did not have insomnia, although 20 complained of sleep problems.
Discrepancy in self-reported sleep, measured using 14 nights of sleep diaries, and actigraphy-measured sleep was greatest for patients with insomnia and sleep complaint.
Discrepancies in this group were most commonly seen for middle of the night events, with duration and frequency of wake after sleep onset (WASO) most commonly overestimated.
"These results suggest that sleep discrepancy is a defining feature of older adults who have insomnia symptoms and who perceive this poor sleep as problematic," say McCrae et al.
They note, however, that "complaint does not necessarily indicate a general propensity to misperceive sleep," as discrepancy among individuals who complained about their sleep but did not have insomnia was relatively low and infrequent.
Depressive symptoms, measured on the Beck Depression Inventory-second edition (BDI-II), were also highest among the insomnia and sleep complaint group and significantly predicted sleep discrepancy.
But in a multiple regression model including age, gender, number of medical conditions, BDI-II score, having insomnia and sleep complaints, and the interaction between BDI-II score and insomnia and sleep complaints, the latter was the only variable to significantly predict sleep discrepancy.
This also suggests that the "combined effects of depression symptoms and complaint/insomnia group do not share a unique relationship with sleep discrepancy," the researchers point out.
They conclude that "sleep discrepancy can be conceptualized as a proxy measure for localized sleep deprivation that may lead to specific sleep-related impairments, such as depressed mood."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lucy Piper, Senior medwireNews Reporter