New research suggests that living in a disadvantaged neighbourhood is associated with higher blood pressure and lower cognitive scores, even among people who do not have an existing diagnosis of mild cognitive impairment.
Cognition refers to the mental process of thinking, learning, remembering, being aware of surroundings and using judgment. Mild cognitive impairment is a decline in memory and thinking skills that is greater than expected with normal aging and is a risk factor for dementia.
“We know that inequitable access to education, employment, income and housing increases the risk for Alzheimer’s disease and related dementias,” said James Bateman, assistant professor of neurology at Wake Forest University School of Medicine and principal investigator of the study.
“However, more research is needed to better understand the impact of social determinants of health, including what this study analysed with neighbourhood disadvantage.”
Bateman said neighbourhood disadvantage refers to the lack of social and economic resources in one’s environment. To assess neighbourhood disadvantage, the research team used the highly recognised national Area Deprivation Index, which measures housing quality, education and income.
“Our goal of the study was to analyse the relationship of neighbourhood disadvantage with measures of cardiometabolic health and cognition in individuals with and without diagnosed mild cognitive impairment,” said Bateman.
Bateman said it was important for the team to compare individuals with a diagnosis to those without one to better understand how a person’s current cognitive state impacts the relationship between their environment and their health.
Bateman noted that many cardiometabolic diseases may increase the risk for cognitive impairment and dementia. Cardiometabolic health is the cardiovascular and metabolic health of an individual and involves the management of risk factors such as blood glucose, high blood pressure, high cholesterol and obesity.
For the study, Bateman and team analysed data from 537 adults over the age of 55 from the Alzheimer’s Disease Research Center Healthy Brain Study at Wake Forest University School of Medicine from 2016 to 2021.
Individuals received clinical exams, neurocognitive testing and neuroimaging, in addition to cardiometabolic tests to screen for diabetes, high cholesterol and high blood pressure.
The neurocognitive testing included in the study evaluated constructs such as memory, executive function, language, visuospatial skills, concentration and attention.
“We found an association between neighbourhood disadvantage and higher blood pressure and cardiometabolic index, as well as lower cognitive scores in individuals who did not have a diagnosed mild cognitive impairment,” said Sudarshan Krishnamurthy, student at Wake Forest University School of Medicine and first author of the paper.
Krishnamurthy said that neighbourhood disadvantage was only associated with higher haemoglobin A1C, which measures blood sugar, in people with diagnosed mild cognitive impairment.
“These findings show that living in a disadvantaged neighbourhood has a bigger impact on heart health and brain function in people without pre-existing cognitive issues,” Bateman said.
“Our study highlights the importance of implementing structural changes to address social determinants of health to mitigate cardiometabolic and cognitive risks.”
Krishnamurthy added that the study underscores the impact of a person’s living environment.
“This study confirms what we had hypothesised: Where you live and the resources and opportunities that are available to you as a result, have a tangible impact on your risk for dementia,” Krishnamurthy said.
