Research Review

Study Continues Assessment of Cognition and Decline in Aging Latinos

$25 million grant supports longitudinal research chronicling brain function and impairment in aging Latinos of diverse heritages; will also look at long-term impact of COVID-19

Researchers at University of California San Diego School of Medicine have received a $24.5 million grant from the National Institutes of Health/National Institute on Aging to continue the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA), a 12-year assessment of cognitive and brain aging and impairment among aging Latinos.

The new SOL-INCA-AD grant continues a nationwide longitudinal study looking for telltale biomarkers of risk and resilience related to cognitive aging among Latinos of diverse heritages.
In the initial study, earlier this year, researchers reported that higher midlife cardiovascular disease burden was significantly associated with increased rates of cognitive decline and prevalent mild cognitive impairment among Latinos. The cardiovascular burden varied by Latino heritage.

Latinos are exposed to early excess and chronic cardiovascular disease burden—particularly diabetes—which can contribute to cognitive decline and dementia onset.

SOL-INCA-AD extends the initial study to examine 10-year cognitive aging and dementia blood-based biomarker trajectories, including variations in cognitive decline, mild cognitive impairment, and Alzheimer ’s disease and related dementias (ADRD) among diverse Latinos.

Hector González, PhD, a professor of neurosciences at UC San Diego School of Medicine and codirector of the Latino Corps of the UC San Diego Shiley-Marcos Alzheimer's Disease Research Center, is coprincipal investigator for the study.

Charles DeCarli, MD, a professor of neurology at UC Davis Health and director of the UC Davis Alzheimer’s Disease Research Center, is coprincipal investigator.

Gonzalez says the funding is crucial to better understanding the aging brains of diverse Latinos who comprise nearly one-fifth of the US population.

In 2020, Latinos represented 18.7% of the US population and nearly 40% of the country’s two most populous states, California and Texas. By 2060, the US Census projects a 391% increase in Latinos aged 65 years and older. The CDC estimates that the largest increase in ADRD will affect aging Latinos, primarily due to excess cardiovascular disease burden. The new grant allows for upgrading data found in now-outdated studies.

“Studying diverse Latino populations is a neglected field in neuroscience and cognitive brain aging,” González says. “We really don’t know the neurobiology of diverse Latinos as we should. This new study enables us to examine genetic, cardio-metabolic, and sociocultural contributions to the aging brain.”

The researchers say that SOL-INCA-AD will gather data that could translate to real-world therapies, and potentially lessen the disease burden of dementia affecting Latinos.

“We can’t achieve health equity if we don’t have studies to develop the knowledge we need,” DeCarli says.

Notably, SOL-INCA-AD will also examine how COVID-19 impacts the aging brain and cognitive health of Latinos. DeCarli says COVID-19 could negatively impact otherwise normal cognitive aging and increase dementia risk.

“COVID-19 has disproportionately impacted Latinos in the US and especially here in California,” González says. “Since SOL-INCA-AD is a longitudinal study, we’re in a unique position to understand the impacts of COVID-19 on cognitive aging in a large and understudied population. One potential outcome is using disease-modifying therapies, like new drugs just now coming onto the market, for people experiencing long-haul symptoms of COVID-19. My hope is that we can alter the trajectory for stability and improvement.”

SOL-INCA AD is also in collaboration with Wayne State University in Detroit. Wayne State University houses the study’s analytics and biostatistics core study, with Wassim Tarraf, PhD, an associate professor of gerontology healthcare sciences, as study site principal investigator.

Tarraf says the research provides an unprecedented opportunity to understand the complex pathways underlying cognitive aging and ADRD in diverse Hispanics and Latinos, beginning
with middle age.

“This new funding allows us to delve into both the psychosocial and biological risk and protective factors for cognitive disease in a largely understudied population,” Tarraf says. “It is an exciting opportunity to expand the science and to train and involve the next generation of scientists focused on working on equitable healthy aging.”

Source: University of California San Diego Health