Authors: Alice Weatherston
A new study has identified a link between disrupted sleep and the risk of cerebral blood vessel damage in the form of arteriosclerosis and macroscopic and microscopic infarcts in the elderly population. The research carried out at Sunnybrook Health Sciences Centre (ON, Canada) is the first to examine autopsied brains of individuals who had undergone sleep monitoring prior to death. The findings were published in Stroke recently.
Within the study population, which included autopsied brains of 315 individuals (70% women) with an average age at death of 90 from the Rush Memory and Aging Project, sleep was disrupted on average seven times an hour. All individuals had undergone at least one week of 24 hour monitoring of rest or activity prior to death, in which circadian rhythms and sleep quality were measured.
Results indicated that more pronounced sleep fragmentation was associated with 27% increased likelihood of arteriolosclerosis and for each two additional arousals from sleep during a one hour period, a 30% increase in the likelihood of visible signs of oxygen deprivation in the brain was exhibited. In total, 29% of the patients had suffered a stroke and 61% exhibited moderate to severe damage to blood vessels in their brain.
“There are several ways to view these findings: Sleep fragmentation may impair the circulation of blood to the brain, poor circulation of blood to the brain may cause sleep fragmentation, or both may be caused by another underlying risk factor,” explained lead investigator, Andrew Lim (Sunnybrook Health Sciences Centre).
The team believe that sleep monitoring could be a potentially effective technique for identifying elderly individuals at increased risk of stroke, however further studies are needed to fully unravel the link between brain blood vessel damage and sleep fragmentation, including the influence of additional sleep factors such as sleep apnea.
Sources: Sunnbrook Health Sciences Centre press release: http://sunnybrook.ca/media/item.asp?c=1&i=1371&page=33939&f=poor-sleep-stroke-seniors; Lim AS, Yu L, Schneider JA, Bennett DA, Buchman AS. Sleep Fragmentation, Cerebral Arteriolosclerosis, and Brain Infarct Pathology in Community-Dwelling Older People. Stroke [Epub ahead of print].