Impaired autonomic nervous system activity during sleep in family caregivers of ambulatory dementia patients in Japan

The number of dementia patients requiring care is rapidly increasing in Japan. Consequently, a large percentage of family members, including spouses and children of those with dementia, are assuming the role of primary caregiver. Many caregivers develop health problems including sleep disorders. Some report poor quality of sleep even when sleep duration is normal. In the present study, we used actigraphy and heart rate variability spectral analysis to assess autonomic nervous system activity and quality of sleep in family caregivers of people with ambulatory dementia. The 20 caregivers who participated in our study exhibited significantly higher levels of sympathetic nervous system activity during sleep than noncaregivers. This abnormal activity was most prominent during the first half of the sleep period and was not related to overall sleep duration. We propose that relaxation is inhibited during the first half of the sleep period in this caregiver population. This may be due to increased stress, as caregivers of people with ambulatory dementia may worry about their patients waking and wandering at night, potentially injuring themselves. Our findings indicate a need for increased support for caregivers of people with dementia, including the assessment and treatment of sleep disorders.