Neurobiology of Aging 26S (2005) S11–S16 Obesity, diabetes and cognitive deficit: The Framingham Heart Study Merrill F. Elias a,b,∗ , Penelope K. Elias a,b , Lisa M. Sullivan a,c , Philip A. Wolf d , Ralph B. D’Agostino a a Boston University, Department of Mathematics and Statistics, Statistics and Consulting Unit, 111 Cummington Street, Boston, MA 02215, USA b The University of Maine, Department of Psychology, 5742 Little Hall, Orono, ME 04469-5742, USA c The Boston University School of Public Health, Department of Biostatistics, Boston, MA 02118, USA d The Boston University School of Medicine, Department of Neurology, 715 Albany Street, Room B608, Boston, MA 02118, USA Received 24 August 2005; accepted 29 August 2005 Abstract Objective:: To determine the independent effects of obesity on cognitive performance and to examine interactions between obesity and non-insulin dependent diabetes mellitus (NIDDM). Methods:: Using a prospective design, male (n = 551) and female (n = 872) participants of the Framingham Heart Study were classified as obese (yes/no), diabetic (yes/no), and the number of diabetes-years was determined by data collected over an 18-year surveillance period. All subjects were free from dementia, stroke, and clinically diagnosed cardiovascular disease up to the time of cognitive testing. Statistical models were adjusted for age, education, occupation, native language, and cardiovascular disease risk factors. Body mass index status (non-obese or obese) and NIDDM status (diabetic/non-diabetic) were related to cognitive performance on multiple cognitive measures. Results:: Adverse effects of obesity on cognitive performance were observed for men only. Diabetes-years related to poorer cognitive performance, but only when men and women were combined for analyses. Neither diabetes nor diabetes-years by obesity interactions were observed. Conclusions:: The gender-specific results for obesity, but not for diabetes, suggests that the underlying mechanisms linking them to cognition may be different. © 2005 Elsevier Inc. All rights reserved. Keywords: Obesity; Diabetes mellitus; Men; Women; Cognitive functioning 1. Background The Framingham Heart Study (FHS) has made it possi- ble for us to characterized relations among obesity, diabetes and cognitive functioning for a large-community based sam- ple. We summarize these studies [2,3] and present several new analyses designed to better understand these relations. The prevalence of type II diabetes mellitus and obesity increase with age and both are risk factors for cognitive deficit [2,3,14]. The average age in the present study was 67 years (range = 55–88). Thus, we present data for persons at a vul- nerable age with respect to diabetes, obesity, and cognitive deficit. ∗ Corresponding author. Tel.: +1 207 244 9674. E-mail address: mfelias@aol.com (M.F. Elias). 1.1. Few studies relate obesity to cognition Reviews of the literature [14] generally support the hypothesis that there is an association between non-insulin dependent diabetes and lowered cognitive performance, although negative findings have been reported. Indeed, we have reported inverse associations between the number of years our participants were diagnosed as non-insulin depen- dent diabetics (NIDDM) (diabetes-years) and level of cog- nitive performance [3]. The presence of hypertension and diabetes together was associated with lower levels of perfor- mance than either diabetes or hypertension alone. Consequently, it is surprising to find that there are so few studies relating obesity, an important cofactor in diabetes, to cognitive performance. Obesity and even overweight have been found to be independent risk factors for CVD in a 0197-4580/$ – see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.neurobiolaging.2005.08.019