Moderate Changes in the Circadian System of Alzheimer's Disease Patients Detected in Their Home Environment

• Published in: PloS one Vol. 11; no. 1; p. e0146200
• Main Authors: Weissová, Kamila, Bartoš, Aleš, Sládek, Martin, Nováková, Marta, Sumová, Alena
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04.01.2016; Public Library of Science (PLoS)
• Subjects: Actigraphy; Aged; Aged, 80 and over; Alzheimer Disease - complications; Alzheimer Disease - physiopathology; Alzheimer's disease; ARNTL Transcription Factors - biosynthesis; ARNTL Transcription Factors - genetics; Biological clocks; BMAL1 protein; Buccal mucosa; Care and treatment; Case-Control Studies; Circadian rhythm; Circadian Rhythm - physiology; Circadian rhythms; Clock gene; Complications and side effects; Diaries; Elderly; Environment; Female; Gene Expression Regulation; Geriatrics; Health aspects; Home environment; Housing; Humans; Male; Medical Records; Melatonin; Melatonin - analysis; Mouth Mucosa - chemistry; mRNA; Neurodegenerative diseases; Older people; Pathology; Patients; Period 1 protein; Period Circadian Proteins - biosynthesis; Period Circadian Proteins - genetics; Risk factors; RNA, Messenger - analysis; RNA, Messenger - biosynthesis; Saliva; Saliva - chemistry; Sleep; Sleep and wakefulness; Sleep Disorders, Intrinsic - complications; Sleep Disorders, Intrinsic - physiopathology; Suprachiasmatic nucleus; Waveforms; Czech Republic
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0146200

Alzheimer's disease (AD) is a neurodegenerative disease often accompanied with disruption of sleep-wake cycle. The sleep-wake cycle is controlled by mechanisms involving internal timekeeping (circadian) regulation. The aim of our present pilot study was to assess the circadian system in patients with mild form of AD in their home environment. In the study, 13 elderly AD patients and 13 age-matched healthy control subjects (the patient's spouses) were enrolled. Sleep was recorded for 21 days by sleep diaries in all participants and checked by actigraphy in 4 of the AD patient/control couples. The samples of saliva and buccal mucosa were collected every 4 hours during the same 24 h-interval to detect melatonin and clock gene (PER1 and BMAL1) mRNA levels, respectively. The AD patients exhibited significantly longer inactivity interval during the 24 h and significantly higher number of daytime naps than controls. Daily profiles of melatonin levels exhibited circadian rhythms in both groups. Compared with controls, decline in amplitude of the melatonin rhythm in AD patients was not significant, however, in AD patients more melatonin profiles were dampened or had atypical waveforms. The clock genes PER1 and BMAL1 were expressed rhythmically with high amplitudes in both groups and no significant differences in phases between both groups were detected. Our results suggest moderate differences in functional state of the circadian system in patients with mild form of AD compared with healthy controls which are present in conditions of their home dwelling.