I am Professor and Chief of Epidemiology at UC Davis ( rawhitmer@ucdavis.edu) and lead a Laboratory of Population Based Science in Brain Aging which is a collaboration of UC Davis ADC, UCSF EpiBiostat and Kaiser Division of Research . Our lab https://rachelwhitmer.ucdavis.edu focuses on 1).Ethnoracial disparities and diversity in cognitive aging and dementia outcomes, 2.) Early life contributions to brain health and dementia risk, 3.) Metabolic and vascular influences on brain aging, 4) Oldest-old and longevity and 5)Behavioral interventions to prevent cognitive decline. We have conducted significant studies on the role of midlife, modifiable risk factors for Alzheimer’s disease and dementia using the data resources of Kaiser Permanente Northern California (KPNC) as a natural laboratory for pursuing novel questions in dementia epidemiology with high clinical impact. Our work on obesity, central adiposity, smoking, total cholesterol, depression, cumulative vascular risk and diabetes were the first studies to establish that these risk factors in midlife are strongly associated with increased risk of dementia and Alzheimer’s disease. These findings, subsequently confirmed in several other data sources, contributed to a fundamental reconceptualization of dementia as a lifecourse disease with major, modifiable risk factors accumulating decades prior to diagnosis. Due to the long subclinical nature of neurodegenerative diseases, there is potential for reverse causality, and risk and protective factors operate differently, at different time points in the lifecourse, and in different populations. This overarching challenge in dementia epidemiology is a continuing, evolving, theme in our work which propels our scientific approaches.
Large racial/ethnic disparities in dementia have been established, but there are very few data sources with substantial non-white participation rates. The diversity of the KPNC membership supports important work evaluating whether findings initially established in whites also hold true for racial/ethnic minorities. Last year, our group published the largest and longest study of racial/ethnic differences in dementia incidence. We looked at six different racial/ethnic groups and were the first to determine the incidence of dementia for Asian-Americans and Native-Americans, and the magnitude of racial/ethnic differences comprehensively. Our recently launched NIH funded field studies, KHANDLE (Kaiser Healthy Aging and Diverse Life Experiences), STAR ( Study of Healthy Aging in African-Americans) and LifeAfter90 will hone in on the role of early life and lifecourse mechanisms in inequities in aging.
Another major focus of our group has been on trying to understand how and why those with diabetes have accelerated brain aging and what can be done to change this. While it’s known that those with type 2 diabetes have double the risk of dementia, the driving mechanisms, underpinning pathology, and etiology behind this is not well understood. Our work is examining the timing of glycemic control and vascular complications on brain health. Individuals with type 1 diabetes are living longer than ever before and ways to help this population age successfully are not well understood. Two years ago we commenced the NIH funded SOLID (Study of Longevity in Diabetes), a cohort study of 800 elderly individuals with type 1 diabetes with a primary goal of delineating successful mental and physical aging in this population. The primary objective of our research program is to identify and understand risk and protective factors for cognitive and brain aging in populations at high risk for dementia, including ethnic minority groups and those with chronic disease such as diabetes mellitus.
In February we will launch the US POINTER trial, https://alz.org/us-pointer/overview.asp, the first multi-domain behavioral intervention trial to prevent cognitive decline, funded by the Alzheimer's Association.