A new five-year, $13 million Kaiser Permanente study will revisit physical exams undertaken from the 1960s through the 1980s to evaluate how risk factors in early and mid-life have affected brain health and dementia risk among a large, ethnically diverse cohort of seniors.
The Kaiser Permanente Northern California Division of Research will partner with the University of California Davis Alzheimer's Disease Center to undertake state-of-the-art brain imaging and cognitive testing of study participants, with funding from the National Institute on Aging.
"This study is like time travel, allowing us to look at risk and protective factors for cognitive decline throughout one's life," said Rachel Whitmer, PhD, principal investigator of the new study and research scientist with the Kaiser Permanente Northern California Division of Research. "We'll be able to analyze how factors such as midlife vascular health, psychosocial conditions, and early-life growth indicators have influenced brain health and dementia risk among current members of Kaiser Permanente."
In particular, researchers aim to explore how early-life conditions may play a role in racial and ethnic differences in dementia rates and risk factors for cognitive decline, an area that has not been well studied.
The older data will be pulled from the world-renowned multiphasic exam, which Kaiser Permanente Northern California began using in the early 1950s. The exam involved screening individuals for certain chronic illnesses early and identifying them early in their course. In the 1960s, medical professionals began administering the battery of tests to members in an automated, efficient routine. The results were analyzed in bulk by computer, which allowed doctors to spot trends in community health and work to address public health risks.
Later this year, the KHANDLE study (Kaiser Healthy Aging and Diverse Life Experience) will begin enrolling a total of 1,800 white, black, Asian and Latino Kaiser Permanente members, equally divided among the four ethnicities, who participated in the multiphasic exam. All study participants must be over age 65 and not have a current diagnosis of dementia.
To evaluate brain health and Alzheimer's and dementia risk, Kaiser Permanente researchers will conduct comprehensive medical and cognitive evaluations of study participants, and the UC Davis Alzheimer's Disease Center researchers will provide magnetic resonance imaging (MRI) and positron emission tomography (PET) scans.
"The bulk of what is known about early-life risk factors for dementia and brain pathology is from studies of highly educated whites," said Dan Mungas, PhD, professor of neurology at UC Davis. "This study will fill a much needed gap in understanding dementia and brain aging in a group that is representative of the aging U.S. population."
This new study is part of Whitmer's ongoing body of research at Kaiser Permanente to better understand the risk and protective factors for dementia. Whitmer has used the multiphasic data, paired with comprehensive data from Kaiser Permanente's electronic health record, to identify midlife dementia risk factors such as smoking, hypertension, depression, cholesterol, obesity and others.
Whitmer noted that the funding will allow Kaiser Permanente to establish a long-term study that is similar in scope to the now nearly 60-year-old Framingham Heart Study in Massachusetts, which has redefined what is known about early-life risk factors for dementia and heart disease.