Chronotherapy Improves Sleep in Mild Cognitive Impairment

Megan Brooks

July 16, 2019

LOS ANGELES — A personalized behavioral medicine program helps reset the biological clock to improve sleep quality in older adults with mild cognitive impairment (MCI), results of a new proof-of-concept study show.

"Our hope is that, by improving sleep quality, we can contribute to preventing further cognitive decline in older adults with MCI, but more research is needed to test this possibility," said Ryan Falck, MSc, PhD candidate at the University of British Columbia in Vancouver, Canada.

The study was presented at a press briefing here at the Alzhiemer's Association International Conference (AAIC) 2019.

Significant Improvement

Research has shown that older adults with poor sleep have an increased risk of MCI and dementia, and those with MCI have an increased risk of sleep disturbances.

Falck and colleagues tested the effects of chronotherapy on improving sleep quality in a randomized controlled trial of 96 adults ages 65 to 85 years old (57% women) with probable MCI, poor subjective sleep quality, and no obstructive sleep apnea.

They randomly assigned half to the chronotherapy intervention, which comprised four general sleep hygiene education classes (one per week), followed by 20 weeks of individually timed "bright light" therapy, biweekly individually tailored physical activity counseling phone calls, and a consumer-available activity tracker. The other half were randomly assigned to the wait-list usual care (control) group and received general health education.

Primary outcomes were sleep quality, measured objectively using an activity monitor and subjectively with a sleep quality index (Pittsburgh Sleep Quality Index). Sleep quality was recorded at baseline, 12 weeks, and 24 weeks.

Participants in the intervention group experienced significant improvement in objectively measured sleep efficiency (P = .03), sleep fragmentation (P = .02), wake after sleep onset (P = .04) and subjective sleep quality (P = .03).

"The intervention group maintained their sleep quality at 12 weeks while the control group declined in sleep quality at 12 weeks. However, there were no significant differences between the groups at 24 weeks follow-up," said Falck.

Subjective sleep quality also significantly improved in the intervention group as compared with the control group at both 12 and 24 weeks, he noted.

"This study shows that potentially using bright light therapy in conjunction with physical activity promotion and sleep hygiene education can improve overall sleep quality. But we can't at this time say whether this intervention was successful in improving cognitive function," Falck told reporters attending the briefing.

"Doing behavioral interventions is very challenging, and as a preliminary study there were some promising results that hopefully will lead to a larger study that will provide more data," said briefing moderator David Knopman, MD, a clinical neurologist at the Mayo Clinic in Rochester, Minnesota, and member of the Alzheimer's Association Medical and Scientific Advisory Group.

Dementia Accelerant

Commenting on the results for Medscape Medical News, Raman Malhotra, MD, of the Washington University Sleep Center in St. Louis, Missouri, and spokesperson for the American Academy of Sleep Medicine (AASM), noted that poor sleep quality is a "common and significant issue in elderly patients, especially with those that complain of memory problems. Not only can poor sleep worsen memory, there is emerging evidence that it may play a role in accelerating the onset of dementia."

"We do not like to use medications to help with poor sleep in the elderly population mainly due to side effects and risk of falls," said Malhotra, who was not associated with the current study. "Behavioral strategies, education, and light therapy, which was used in this study, are a better option. Though involved, this is definitely preferable to having to use pharmacological agents for sleep. The main barrier, besides time commitment, are trained professionals available to help 'coach' or 'counsel' these patients."

Funding for the study was provided by the Jack Brown and Family Alzheimer Research Foundation, Vancouver Coastal Health Research Institute Innovation and Translational Research Awards, a Canadian Institutes of Health Research Operational Grant (F14-03974), and the Alzheimer's Society Research Program. The authors and Malhotra have disclosed no relevant financial relationships.

Alzheimer's Association International Conference (AAIC) 2019: Abstract P2-619. Presented July 15, 2019.

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