Cognitive impairment: an increasingly important complication of type 2 diabetes: the age, gene/environment susceptibility--Reykjavik study

UMMS Affiliation

Department of Medicine, Division of Geriatric Medicine; Department of Quantitative Health Sciences; Meyers Primary Care Institute

Publication Date


Document Type



Aged; Blood Glucose; Cognition Disorders; Cohort Studies; Diabetes Mellitus, Type 2; Environment; Fasting; Female; Genetic Predisposition to Disease; Glycemic Index; Hemoglobin A, Glycosylated; Humans; Iceland; Logistic Models; Male; Psychological Tests; Questionnaires


Biostatistics | Epidemiology | Health Services Research


Persons with type 2 diabetes are at increased risk of cognitive dysfunction. Less is known about which cognitive abilities are affected and how undiagnosed diabetes and impaired fasting glucose relate to cognitive performance. The authors explored this question using data from 1,917 nondemented men and women (average age = 76 years) in the population-based Age, Gene/Environment Susceptibility-Reykjavik Study (2002-2006). Glycemic status groups included diagnosed diabetes (self-reported diabetes or diabetic medication use; n = 163 (8.5%)), undiagnosed diabetes (fasting blood glucose >or=7.0 mmol/L without diagnosed diabetes; n = 55 (2.9%)), and impaired fasting glucose (fasting blood glucose 5.6-6.9 mmol/L; n = 744 (38.8%)). Composites of memory, processing speed (PS), and executive function were constructed from a neuropsychological battery. Linear regression was used to investigate cross-sectional differences in cognitive performance between glycemic groups, adjusted for demographic and health factors. Persons with diagnosed diabetes had slower PS than normoglycemics (beta = -0.12; P < 0.05); diabetes duration of >or=15 years was associated with significantly poorer PS and executive function. Undiagnosed diabetics had slower PS (beta = -0.22; P < 0.01) and poorer memory performance (beta = -0.22; P < 0.05). Persons with type 2 diabetes have poorer cognitive performance than normoglycemics, particularly in PS. Those with undiagnosed diabetes have the lowest cognitive performance.

DOI of Published Version



Am J Epidemiol. 2008 Nov 15;168(10):1132-9. Epub 2008 Oct 3. Link to article on publisher's site

Journal/Book/Conference Title

American journal of epidemiology

PubMed ID


Related Resources

Link to Article in PubMed