12 Sep Sleep Apnea Predisposes To Impaired Brain Blood Flow With Physical Activity

MedicalResearch.com Interview with:
Paul M. Macey, Ph.D.
Assistant Professor in Residence
Associate Dean for Information Technology and Innovations,
Chief Innovation Officer UCLA School of Nursing and Brain Research Institute

Medical Research: What are the main findings of the study?

Dr. Macey: People with sleep apnea are less able to control the blood flowing to their brain, in particular when they grip tightly, or have their foot put in cold water. We measured changes in blood flowing through the brain using an MRI scanner while people gripped hard, had their foot placed in cold water, and breathed out hard into a tube with a very small hole in it. These activities all lead to more blood flowing to the brain in healthy people, which probably helps protect the cells from being starved of blood and oxygen. However, people with sleep apnea send less blood that the healthy participants during the gripped and cold foot activities.

A further important finding is that women with sleep apnea are worse off than men. The female patients showed much weaker blood flow than the males, even accounting for normal differences between men and women.

Medical Research: Were any of the findings unexpected?
Dr. Macey: We did not expect that breathing very hard into a small tube would lead to similar changes in brain blood flow in the sleep apnea and healthy people; we had expected the sleep apnea patients to show problems, as they did during the gripping and cold foot activities. We now believe the hand and foot activities need to use more higher brain areas, but that these areas are injured in people with sleep apnea, and so the brain processing is weaker. The breathing into the tube on the other hand works mostly of higher pressure in the chest squeezing the heart and blood vessels, and only uses lower brain areas, which appear to mostly be working in people with sleep apnea.

Medical Research: What should clinicians and patients take away from your report?

Dr. Macey: The brain in people with sleep apnea is at risk of being starved of blood and oxygen, especially as people go about their daily activities using their body for lifting or holding. Women seem to be even more at risk than men with sleep apnea. This weaker blood flow may tie in to the changes in brain function we see in people with sleep apnea, including memory problems, depression and anxiety, and “stress- like” symptoms

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Macey: The question is what treatments can improve the brain blood flow. Perhaps the usual treatment, CPAP, will help, but until we do more research we won’t know. Other possible treatments may be needed to complement CPAP.
Citation:

Global Brain Blood-Oxygen Level Responses to Autonomic Challenges in Obstructive Sleep Apnea

Paul M. Macey , Rajesh Kumar, Jennifer A. Ogren, Mary A. Woo,
Ronald M. Harper Published: August 28, 2014

PLoS DOI: 10.1371/journal.pone.0105261

Last Updated on September 12, 2014 by Marie Benz MD FAAD