0203 GMT December 13, 2019
"We already know that vascular risk factors damage the brain and can result in cognitive impairment," said Kevin S. King, an assistant professor of radiology at the Keck School of Medicine of the University of Southern California. "But our findings give us a more concrete idea about the relationship between specific vascular risk factors and brain health."
According to Medical Xpress, prior studies have linked cardiovascular risk factors and cognitive decline, but the new study focused on specific risk factors and examined three main brain regions, including the hippocampus, precuneus and posterior cingulate cortex. Because of each region's connection to memory retrieval, gray matter volume loss in these areas may be a predictor of Alzheimer's disease and dementia.
In the new study, Dr. King and colleagues analyzed results from 1,629 individuals in the Dallas Heart Study (DHS) and divided the participants into two age groups. There were 805 participants under age 50, and 824 age 50 and older.
By comparing the initial visit in which cardiovascular risk factors were identified to the MRI results and cognitive scores, the team was able to distinguish the specific risk factors of smoking, diabetes, and obesity and their relationship to smaller volumes in the three targeted regions of the brain. The results confirmed that lower cognitive test scores correlated with lower brain volumes in each area.
The study found that risk factors of diabetes was associated with smaller total brain volume, while smoking and obesity were linked with reduced volumes of the posterior cingulate cortex, the area of the brain connected with memory retrieval as well as emotional and social behavior. In addition, lower hippocampal mass was linked to smoking whereas obesity and high fasting blood glucose numbers correlated with reduced precuneus size.
The findings also suggest that in patients age 50 and older, diminished hippocampal and precuneus volumes may be early risk indicators for cognitive decline, while smaller posterior cingulate volumes are better predictors in patients under age 50.