Contribution of Diabetes and Its Causes to Signs of Brain Aging in a Young-to-Middle Age Cohort

The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a prospective, epidemiologic investigation of the determinants and evolution of cardiovascular risk factors among 5,115 African American and white young to middle age adults 18-30 years of age at baseline in 1985-86. Participants were recruited from the populations of four geographic locations (Birmingham, AL; Chicago, IL; Minneapolis, MN; and Oakland, CA). The study population was approximately balanced according to sex (54% women), ethnicity (52% African American), and education (40% with less than equal to 12 years of education) at each center (Friedman). After the 1984 baseline, additional examinations were undertaken at years 2 (1987-88), 5 (1990-91), 7 (1992-93), 10 (1995-96), 15 (2000-01) and 20 (2005-06). To date, 72% of the total baseline cohort is still active in the study.

Based on 20 years of follow-up, the longitudinal data on this cohort provide clear evidence of an increase in the prevalence of many cardiovascular risk factors, including obesity and diabetes. Therefore, the study presents an ideal and unique opportunity to study change in cardiovascular risk factors beginning at an age we hypothesize may be critical in determining future trajectories of brain disease. Furthermore, the trends in CV-RF reflect general trends in the US population. Thus, CARDIA participants are ideal to study now because the cohort reflects the characteristics of the next generation of older persons.

This is an ancillary study of MRI-evident neurodegenerative and vascular brain changes in a subset of 719 CARDIA participants who participate in the Year 25 Exam. Specifically, we will study the relations of timing length of exposure and levels of cardiovascular risk factors to presence of sub-clinical brain lesions and cognitive impairments. Participants were recruited from the CARDIA field sites at Birmingham, AL (PI: Cora E. Lewis, MD, MSPH- University of Lalbama, Nirmingham), Minneapolis, MN (PI: Pamela Schreiner, PhD, MS- University of Minnesota) and Oakland, CA (PI: Steve Sidney, MD, mPH- Kaiser Permanente).