Cortisol levels in saliva could help identify older people at risk of cognitive decline.
The study revealed that senior citizens with high levels of cortisol in their saliva had smaller brain volumes, which was associated with poorer performance on tests of memory and thinking. The researchers believe that these findings could lead to a saliva test that helps determine which individuals may be at risk of Alzheimer’s disease and other dementias.
The researchers analyzed the saliva samples of 4,244 men and women with an average age of 76 who did not have dementia. These samples were taken on a single day, half an hour after awakening in the morning and again in the evening. The subjects were divided into three different groups depending on their hormone levels: high, medium or low.
The participants had tests designed to assess their higher brain functions such as thinking, memory. Moreover, magnetic resonance imaging (MRI) brain scans were taken, allowing the experts to assess brain volume. The researchers analyzed the cortisol levels, brain volumes and cognitive skills of the participants.
The research discovered that high cortisol group had about 16 milimeters smaller brain volume as compared to those with the low hormone levels. The difference in the brain volume was particularly noticeable in gray matter rather than white matter.
“It’s possible that the loss of brain volume that can occur with aging leads to a lesser ability of the brain to stop the effects of cortisol, which in turn leads to further loss of brain cells,” said Dr. Lenore Launer, lead researcher. “Understanding these relationships may help us develop strategies to reduce the effects of cortisol on the brain and thinking skills,” he added.
Cortisol is a steroid hormone, which is produced by the adrenal cortex and it is released in response to stress and hypoglycemia. The aforementioned hormone also affects immune function and metabolism. High levels of the stress hormone can lead to weight gain, hypertension, muscle weakness and mood swings. The levels are usually high in the morning but fall during the day reaching at their lowest in the evening. IMAGE/counselheal.com