Diabetes as a risk factor for cognitive decline in older patients.

To assess the role of type 2 diabetes as a risk factor for cognitive decline among elderly people. Analyses were carried out on data from the Italian Longitudinal Study on Aging, a study on 5,632 subjects aged 65-84 years, with baseline in 1992 and follow-ups in 1996 and 2000. At baseline, diabetic women had significantly worse scores on all cognitive tests compared to nondiabetic women, but did not show worsening over time, whereas men with diabetes did not show worse scores on cognitive tests at baseline compared to nondiabetic males; however, diabetes in men was associated with a risk of cognitive decline over time, particularly in attention. Higher levels of HbA(1c) were associated with poorer performance on memory tests at follow-up in both sexes. The impact of diabetes on cognitive status might differ in older men and women, probably because of a survival effect, with a higher mortality at a younger age among diabetic men. The metabolic and cardiovascular abnormalities associated with diabetes might be responsible for the cognitive decline, at different rates and ages, in men and women. The routine assessment of diabetes complications in the elderly should include cognitive evaluation in both sexes.