Diabetes and cognitive function in a population-based study of elderly women and men.

Objectives: The aim of this study was to examine the association between diabetes and cognitive function in the elderly.

Research Design And Methods: From January to December 2003, all 740 participants, aged 70 years or more, of an ongoing population-based cohort study were eligible for a telephone interview on cognitive function. Cognitive function was assessed using validated instruments, including the Telephone Interview of Cognitive Status (TICS) and the East Boston Memory Test (EBMT). Information on diabetes was available from prior questionnaires and was validated in 2002. We used multivariable logistic regression to estimate odds ratios (OR) of an impaired cognitive function (below 25th percentile) and their 95% confidence intervals (CI) adjusting for age, gender, smoking, alcohol consumption, body mass index (BMI), physical exercise, educational level, and depressive symptoms.

Results: Out of 473 participants interviewed (64.9%), 66 had diabetes (14.1%). The adjusted OR for diabetes and impaired cognitive function assessed by TICS was 2.3 (95% CI: 1.2-4.3). Diabetes was also associated with performance on delayed recall EBMT (adjusted OR=2.0; 95% CI: 1.0-4.1), but not immediate EBMT recall (adjusted OR=1.0; 95% CI: 0.5-2.1). The association between diabetes and cognitive function was a bit more pronounced in participants in whom diabetes was diagnosed 12 (median) or more years prior (adjusted OR with TICS=2.4; 95% CI: 1.0-5.8) and in those without antidiabetic treatment (age- and sex-adjusted OR=3.4; 95% CI: 1.7-6.5).

Conclusion: Diabetes should be considered to be a risk factor for cognitive impairment in the elderly, which might be attenuated by antidiabetic treatment.