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2011 Grants - Osorio
Is Sleep Disordered Breathing in Normal Aging a Risk Factor for Alzheimer's Disease?
Ricardo S. Osorio, M.D.
New York University School of Medicine
New York, New York
2011 New Investigator Research Grant
Sleep-disordered breathing (SDB) refers to several types of breathing problems that occur during sleep, including apnea and hypopnea. Because of age-related changes to respiratory functions, the risk of acquiring such disorders increases as people grow older. For example, people over the age of 60 are at least three times as likely to have sleep-disordered breathing as people at age 40. Recent evidence suggests that SDB may cause damage to the brain by temporarily depriving it of oxygen, promoting brain inflammation or using other toxic mechanisms. However, the links between sleep disorders and brain health have not been sufficiently explored.
Ricardo S. Osorio, M.D., and colleagues, in preliminary research, have found that elderly people with insomnia tend to show cognitive decline. They also found an association between sleep loss and abnormally low levels of the protein fragment beta-amyloid in cerebrospinal fluid surrounding the brain. Low cerebrospinal beta-amyloid levels are an indication of high amyloid levels in the brain, a key hallmark of early Alzheimer's disease. Because of these findings, the researchers hypothesize that SDB may be associated with other hallmarks of Alzheimer's, including brain shrinkage and cognitive decline.
For this study, Dr. Osorio and colleagues will use a home-based sleep monitoring system called the Apnea Risk Evaluation System to identify two groups of cognitively healthy older participants — those with SDB and those with normal sleep. All selected participants will undergo brain scans, neuropsychological exams and other tests of brain health. In addition, two groups of participants with varying degrees of SDB will undergo a procedure called polysomnography, which monitors biological changes that occur during sleep. Results of this procedure will help determine associations between sleep disorders and levels of beta-amyloid in the brain. Collectively, Dr. Osorio's research efforts could identify SDB as a risk factor for Alzheimer's disease. They could also identify CPAP and other sleep disorder treatments as novel Alzheimer's therapies.