Claudio Liguori1, Nicola Biagio Mercuri1,2,3, Marzia Nuccetelli4, Francesca Izzi1, Sergio Bernardini4, Fabio Placidi1. 1. Department of Systems Medicine, Sleep Medicine Centre, University of Rome "Tor Vergata", Rome, Italy. 2. IRCCS Fondazione Santa Lucia, Rome, Italy. 3. Department of Systems Medicine, Neurology Unit, University of Rome "Tor Vergata", Rome, Italy. 4. Department of Clinical Biochemistry and Molecular Biology, University of Rome "Tor Vergata", Rome, Italy.
Abstract
BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia. It is characterized by a progressive deterioration of cognition, frequently associated with neuropsychiatric symptoms (NPS). Among NPS, sleep disturbances often affect AD patients. Orexinergic system dysregulation has been associated with sleep impairment in AD patients. OBJECTIVE: The present study investigated CSF orexin levels in AD patients and their relationship with both NPS, measured by the neuropsychiatric inventory (NPI), and sleep, measured via polysomnography. METHODS: This is a secondary analysis of a previous study investigating CSF biomarkers, sleep impairment and cognitive decline in AD patients. AD patients completing the NPI were included in this analysis and distributed in two groups based on the presence (NPI score ≥4, AD/NPS+) or absence (NPI score <4, AD/NPS-) of NPS. RESULTS: Twenty-two AD patients constituted the AD/NPS+ group and 20 patients constituted the AD/NPS-group. We observed higher CSF orexin levels in AD/NPS+ than AD/NPS-patients. Moreover, AD/NPS+ showed a more fragmented and the reduction of REM sleep compared to AD/NPS-patients. Notably, higher NPI scores correlated with a more altered sleep structure, higher CSF orexin levels and lower MMSE scores. CONCLUSION: This study documented that AD patients showing NPS present a more fragmented sleep coupled with higher CSF orexin levels compared to AD patients not affected by NPS. This finding showing the increased orexinergic tone in AD patients affected by NPS suggests the possible influence of the orexinergic system dysregulation not only on sleep impairment but also on neurobehavioral disturbances.
BACKGROUND:Alzheimer's disease (AD) is the most common form of dementia. It is characterized by a progressive deterioration of cognition, frequently associated with neuropsychiatric symptoms (NPS). Among NPS, sleep disturbances often affect ADpatients. Orexinergic system dysregulation has been associated with sleep impairment in ADpatients. OBJECTIVE: The present study investigated CSF orexin levels in ADpatients and their relationship with both NPS, measured by the neuropsychiatric inventory (NPI), and sleep, measured via polysomnography. METHODS: This is a secondary analysis of a previous study investigating CSF biomarkers, sleep impairment and cognitive decline in ADpatients. ADpatients completing the NPI were included in this analysis and distributed in two groups based on the presence (NPI score ≥4, AD/NPS+) or absence (NPI score <4, AD/NPS-) of NPS. RESULTS: Twenty-two ADpatients constituted the AD/NPS+ group and 20 patients constituted the AD/NPS-group. We observed higher CSF orexin levels in AD/NPS+ than AD/NPS-patients. Moreover, AD/NPS+ showed a more fragmented and the reduction of REM sleep compared to AD/NPS-patients. Notably, higher NPI scores correlated with a more altered sleep structure, higher CSF orexin levels and lower MMSE scores. CONCLUSION: This study documented that ADpatients showing NPS present a more fragmented sleep coupled with higher CSF orexin levels compared to ADpatients not affected by NPS. This finding showing the increased orexinergic tone in ADpatients affected by NPS suggests the possible influence of the orexinergic system dysregulation not only on sleep impairment but also on neurobehavioral disturbances.
Authors: Maria Casagrande; Giuseppe Forte; Francesca Favieri; Ilaria Corbo Journal: Int J Environ Res Public Health Date: 2022-07-11 Impact factor: 4.614