Diabetes and dementia: The concept of attributable risk in the Honolulu heart program/Honolulu-asia aging study

Background: Diabetes and dementia are two of the most prevalent and health-impairing conditions of the elderly. Pathophysiologically, diabetes is a likely risk factor for dementia; however, studies on the association of diabetes and dementia show conflicting results. Objectives and methods: The objectives of this presentation are: 1) to review the literature on the association of diabetes and dementia; 2) to compare previously published data (from 2002) with updated data from the Honolulu Heart Program/Honolulu-Asia Aging Study (a cohort study of 2697 Japanese-American men) on the relative risk of total dementia, Alzheimer's disease, and vascular dementia related to diabetes; 3) to calculate the population attributable risk of dementia attributable to diabetes based on this data; and, 4) to discuss potential implications of this attributable risk. Results: The relative risks for total dementia, Alzheimer's disease, and vascular dementia in this new study were 1.16, 1.00, and 1.68, respectively; compared with 1.5, 1.8, and 2.3 from the previous study. Population attributable risks from this new study were 4.5%, 0%, and 16.5% (again, compared with 14.9%, 21.9%, and 31.3% calculated from the previous study). Discussion: It is noteworthy that, relative to previously published data, the prevalence of all types of dementia are elevated in this new study (as would be expected with increasing age) and it is possible that the differences in risk related to diabetes tend to equalize with advancing age.