Physical activity and healthy blood sugar levels during midlife may be linked to significantly slower cognitive decline later in life, according to a new study from UT Health San Antonio. The findings suggest that regular exercise may be especially important for protecting brain health among Hispanic adults.
Researchers have long known that cardiovascular problems in midlife can increase the risk of cognitive decline and dementia. The new study is among the first to examine how individual cardiovascular health factors are associated with cognitive aging across different ethnic groups.
The research team analyzed data from 402 adults in San Antonio. Hispanic participants made up 52% of the study population, while the remaining participants were non-Hispanic white adults. The average age was 57.9 years, and 58.5% of participants were women.
The associations differed by ethnicity. Among Hispanic participants, higher levels of physical activity were linked to slower cognitive decline. Among non-Hispanic white participants, lower fasting blood glucose levels were associated with a slower rate of cognitive decline.
“Improving cardiovascular health through modifiable lifestyle changes has the potential to meaningfully reduce the public health burden of Alzheimer’s disease and other dementias, especially in high-risk populations,” said Claudia Satizábal, Ph.D., an associate professor and director of the Population Neuroscience Core in UT Health San Antonio’s Department of Population Health Sciences and its Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases.
Satizábal is co-senior author of the study with Dr. Chen Ping Wang, an associate professor and researcher in the Department of Population Health Sciences. The study, titled “Longitudinal Associations of Midlife Cardiovascular Health and Cognitive Change in a Bi-Ethnic Cohort,” was published July 23 in Alzheimer’s Disease and Dementia: The Behavior and Socio-Economics of Aging.
All of the study authors are affiliated with either the Glenn Biggs Institute or the University of Texas Rio Grande Valley.
Cardiovascular health may affect dementia risk
As people live longer and the global population ages, conditions such as Alzheimer’s disease and dementia are becoming increasingly common. The study notes that approximately 6.7 million people in the United States currently live with Alzheimer’s disease.
Research also indicates that many risk factors for cognitive decline and dementia can be modified. Recent estimates suggest that nearly 40% of Alzheimer’s disease cases may be associated with potentially modifiable factors. Cardiovascular health, in particular, plays an important role in brain aging.
One commonly used measure of cardiovascular health is the American Heart Association’s Life’s Simple 7 (LS7) framework. It includes three lifestyle factors—healthy diet, smoking cessation, and physical activity—and four health measures: blood pressure, body mass index (BMI), total cholesterol, and fasting blood glucose.
LS7 provides a broad assessment of cardiovascular health and has also been proposed as a tool for promoting better brain health. Previous studies have found that stronger adherence to LS7 recommendations is associated with better cognitive performance, healthier brain structure, and a lower risk of dementia. However, these relationships may vary among different populations.
Hispanic older adults experience a disproportionate burden of Alzheimer’s disease and related dementias. About 14% of Hispanic adults over age 65 have Alzheimer’s disease, compared with approximately 10% of non-Hispanic white adults in the same age group. Mexican Americans, the largest Hispanic population in the United States, also have high rates of diabetes, obesity, and abnormal cholesterol levels, all of which may increase dementia risk.
Why South Texas provides important research insights
Despite these health disparities, Hispanic adults remain underrepresented in Alzheimer’s disease research. This lack of representation makes it more difficult to understand how dementia risk develops over time and which prevention strategies may be most effective for different communities.
To help address this research gap, investigators at UT Health San Antonio examined the relationship between midlife cardiovascular health, measured using LS7 scores, and later cognitive decline among Mexican American and non-Hispanic white adults. Study participants had previously taken part in the San Antonio Heart Study (SAHS) and the San Antonio Longitudinal Study of Aging (SALSA).
SAHS was a long-term research project led by UT Health San Antonio to investigate the causes of type 2 diabetes and heart disease. Conducted from 1979 through the 2000s, the study followed more than 5,000 people to better understand why certain ethnic groups faced higher risks of chronic disease.
SALSA later expanded on that work. Also conducted by UT Health San Antonio, the large observational study focused on chronic disease, healthy aging, disability, and the factors that influence health in later life. Participants in SALSA had previously been enrolled in SAHS.
“Importantly, the inclusion of both ethnic groups from the same population of origin and geographic environment allows for direct comparisons within the framework of a shared context, strengthening our ability to identify differences in cognitive aging and its cardiovascular correlates,” the researchers wrote.
Researchers tracked cognitive changes over time
For the new analysis, researchers used LS7 scores to evaluate cardiovascular health among SAHS participants who later enrolled in SALSA.
Cognitive function was assessed four times using the Mini-Mental State Examination, an established 11-question screening tool that evaluates memory, attention, and thinking skills.
The research team also used generalized estimating equation models to examine how individual cardiovascular health factors were associated with changes in cognitive function. The analysis accounted for age, sex, income, and education.
Researchers conducted an additional sensitivity analysis to evaluate potential attrition bias. These statistical tests examined whether participants who left the study may have influenced the results.
Physical activity and blood sugar showed different associations
The analysis found that engaging in physical activity, rather than maintaining a sedentary lifestyle, was particularly associated with slower cognitive decline among Mexican American participants.
Fasting blood glucose also emerged as an important factor. This measurement indicates the amount of sugar in the blood after an 8- to 12-hour fast. Among non-Hispanic white participants, fasting blood glucose levels below 126 milligrams per deciliter were associated with slower cognitive decline.
“Our findings suggest that engaging in all levels of physical activity during midlife and potentially maintaining optimal fasting blood sugar levels is associated with significantly slower rates of cognitive decline in later life,” said Janet Vasquez, Ph.D., the study’s lead author and a senior postdoctoral fellow at the Glenn Biggs Institute. She noted that the results differed by ethnicity and that larger studies are needed to confirm the findings.
The results indicate that cardiovascular health during midlife may influence cognitive aging years later. They also suggest that the cardiovascular factors most strongly associated with cognitive health may differ among populations.
“Investigating cardiovascular health longitudinally throughout the lifespan, rather than assessing it at a single point in time, may provide further insight into the phenotype of trajectories that contribute to cognitive decline by ethnicity,” Vasquez said.
Participants in the study have now been invited to take part in the San Antonio Heart and Mind Study (SAHMS) at the Glenn Biggs Institute. Researchers hope the ongoing project will provide additional information by collecting advanced brain imaging and other neurological data.
Source: www.sciencedaily.com