Author response: Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia

We thank Dr. Munakomi for the letter regarding our recent article on prolonged sleep duration as a potential marker of early-onset neurodegeneration and subsequent dementia.1 We agree it is important to unpack the associations between sleep and Alzheimer disease (AD). The fascinating study by Xie et al.2 demonstrated that the rate of β-amyloid clearance is increased during sleep. However, the role of REM sleep or sleep hygiene in the neurodegenerative process is unclear. In the experiments of Xie et al.,2 sleep was characterized by an increased prevalence of delta wave activity, typical of deep sleep as compared with REM sleep. In cross-sectional studies,3,4 REM sleep was reduced in patients with dementia and cognitive impairment. However, dementia is associated with comorbidities that can affect sleep, and associations between sleep and AD may be bidirectional.5 Prospective studies are needed to investigate the association between sleep architecture and the future risk of AD and dementia; this is a project that we are currently pursuing using home-based polysomnography and prospective follow-up for incident dementia in the Framingham Heart Study.

Source: Neurology - October 2, 2017 Category: Neurology Authors: Pase, M. P., Westwood, A. J., Beiser, A., Jain, N., DeCarli, C., Himali, J. J., Auerbach, S. H., Seshadri, S. Tags: WRITECLICK & amp;reg; EDITOR ' S CHOICE Source Type: research