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Objective: Cerebral microvascular disease associated with type 2 diabetes may exacerbate the effects of aging on cognitive function. A considerable homology exists between the retinal and cerebral microcirculations; a hypothesized association between diabetic retinopathy (DR) and cognitive decline was examined in older people with type 2 diabetes.Research Design and Methods: In the population-based Edinburgh Type 2 Diabetes Study, 1,046 men and women aged 60-75 years with type 2 diabetes underwent standard seven-field binocular digital retinal photography and a battery of seven cognitive function tests. A general cognitive ability score (g) was generated by principal components analysis. The Mill-Hill Vocabulary Scale was used to estimate premorbid cognitive ability. DR was graded using a modification of the Early Treatment of Diabetic Retinopathy Scale.Results: After age and sex adjustment, a significant relationship was observed with increasing severity of DR (none, mild, and moderate to severe) for most cognitive measures. Participants with moderate-to-severe retinopathy had the worst g and the worst performances on the individual tests. There was a significant interaction between sex and retinopathy for g. In male subjects, the associations of retinopathy with g (and with tests of verbal fluency, mental flexibility, and processing speed but not memory and nonverbal reasoning) persisted (P < 0.05) when further adjusted for vocabulary (to estimate lifetime cognitive decline), depression, sociodemographic characteristics, cardiovascular risk factors, and macrovascular disease.Conclusions: DR was independently associated with estimated lifetime cognitive decline in older men with type 2 diabetes, supporting the hypothesis that cerebral microvascular disease may contribute to their observed accelerated age-related cognitive decline. A sex interaction with stronger findings in men requires further confirmation. [ABSTRACT FROM AUTHOR]

Objective: People with type 2 diabetes are at increased risk of cognitive impairment but the mechanism is uncertain. Elevated glucocorticoid levels in rodents and humans are associated with cognitive impairment. We aimed to determine whether fasting cortisol levels are associated with cognitive ability and estimated lifetime cognitive change in an elderly population with type 2 diabetes.Research Design and Methods: This was a cross-sectional study of 1,066 men and women aged 60-75 years with type 2 diabetes, living in Lothian, Scotland (the Edinburgh Type 2 Diabetes Study). Cognitive abilities in memory, nonverbal reasoning, information processing speed, executive function, and mental flexibility were tested, and a general cognitive ability factor, g, was derived. Prior intelligence was estimated from vocabulary testing, and adjustment for scores on this test was used to estimate lifetime cognitive change. Relationships between fasting morning plasma cortisol levels and cognitive ability and estimated cognitive change were tested. Models were adjusted for potential confounding and/or mediating variables including metabolic and cardiovascular variables.Results: In age-adjusted analyses, higher fasting cortisol levels were not associated with current g or with performance in individual cognitive domains. However, higher fasting cortisol levels were associated with greater estimated cognitive decline in g and in tests of working memory and processing speed, independent of mood, education, metabolic variables, and cardiovascular disease (P < 0.05).Conclusions: High morning cortisol levels in elderly people with type 2 diabetes are associated with estimated age-related cognitive change. Strategies targeted at lowering cortisol action may be useful in ameliorating cognitive decline in individuals with type 2 diabetes. [ABSTRACT FROM AUTHOR]