Obstructive Sleep Apnea (OSA) and Alzheimer's Disease (AD) are both complex conditions that until recently, have not been considered related. Both diseases are highly prevalent in the Veteran population and independently, both can have a profound impact on the lives of Veterans and their families. The scientific community has taken note of a relationship between OSA and AD. Specifically, studies now show that OSA causes an increased risk for acquiring Alzheimer's Disease.
Alzheimer’s Disease is a progressive neurodegenerative disorder that debilitates memory, thinking skills, and behavior. It is the most common cause of Dementia, accounting for 60-80% of all cases.
Relevant to this relationship are meta-analysis, studies that combine and analyze data from multiple research projects. One such meta-analysis of nine observational studies reported that OSA can increase the risk of cognitive decline or Alzheimer’s disease by more than two-fold. Another meta-analysis of five studies concluded that OSA is highly prevalent in Alzheimer’s patients, furthering the concept of correlation. In addition, research also suggests that cognitively healthy elderly individuals with OSA may have altered levels of Alzheimer’s disease biological markers (i.e., biomarkers) and that a diagnosis of OSA may further impair Alzheimer’s biomarkers over time.
OSA is characterized by pauses in breathing during sleep, leading to fragmented sleep and decreased oxygen levels in the blood. Studies show that over time, this chronic sleep disruption and oxygen deprivation can have detrimental effects on brain health and cognitive function. OSA disrupts sleep patterns and reduces the amount of deep sleep, it increases inflammation in the body, and it also damages blood vessels increasing the risk of stroke. In addition, OSA is associated with several other diseases, such as hypertension, cardiovascular disease, and depression, all of which increase the risk for Alzheimer’s disease.
More serious cases of OSA may need to be treated with the use of a CPAP device, a mouthpiece to prevent the tongue from blocking the upper airway. A good night of sleep is important for several brain processes including the consolidation of memories, the loss of which is a hallmark and debilitating symptom of Alzheimer’s Disease. Early detection and treatment of OSA are crucial not only for improving sleep quality and overall health but also for potentially reducing the risk of cognitive decline and Alzheimer's Disease.