Daytime Sleepiness May Be A Risk Factor For Alzheimer’s

Beta amyloid proteins are characteristically seen in Alzheimer’s disease, making these finding relevant as it would suggest that getting a good night sleep may help to prevent the development of the brain wasting disease.

Risk for Alzheimer’s disease have already been shown to be reduced by modifying diet, exercise, and cognitive activity. There has been little study on sleep as a risk factor even though disturbed sleep is a hallmark of the disease, with the disturbed sleep patterns in those with Alzheimer’s disease thought to be due to growth of amyloid plaques and resulting neuronal changes.

This long term study was based on data from the BLSA initiated by the National Institute of Aging; and was designed to mirror long term health of thousands of volunteers to investigate and discover risk factors for age related conditions.

One of the components was a periodic questionnaire containing question such as “ Do you often become tired or fall asleep during the day when you wish to be awake?” and “ Do you take naps?”. The first question could only be answer yes or no; the second question could be answered by choosing either daily, 1-2 times per week, 3-5 times per weeks, rarely, or never.

A small group of volunteers began to undergo neuroimaging examinations with some receiving positron emission tomography using radioactive Pittsburgh compound B to pick up beta amyloid deposits in the brain. 123 volunteer participants provided answers to the questionnaires and had PET scans after 16 years on average, subgroup analysis showed those who answered yes had unadjusted risk of beta amyloid deposits that were 3 times higher than those who answered no to daytime drowsiness. After adjusting data for factors such as BMI, education, age, and sen risks still remained 2.75 times higher, suggesting that Alzheimer’s may in part be caused by nighttime sleep disturbances. Those reporting daytime napping also had unadjusted risks twice as high but was not statistically significant.

Correlation is not known but may be due to plaque forming activity of daytime sleepiness itself. It was noted that amyloid proteins may conceivably be cause for daytime drowsiness. Sleep disturbances or lack there of promotes formation of amyloid plaques via unknown mechanisms causing daytime drowsiness may be a more plausible reason.

Human and animal studies have shown links between restricted and/or poor nighttime sleep patterns and increased beta amyloid protein deposits in the nervous system. Results of this study suggest risks for developing Alzheimer’s may be reduced with appropriate interventions for disturbed or insufficient sleep, or modifying factors that act more broadly such as work related sleep loss or poor sleep habits.

Since there currently isn’t a cure for Alzheimer’s disease finding ways to best help prevent the brain wasting disease are important, prioritizing sleep may be one way to perhaps slow, or help prevent this devastating disease.