Estimating the cognitive effects of prevalent diabetes, recent onset diabetes, and the duration of diabetes among older adults

Background: Little evidence is available on the effects of incident diabetes or diabetes duration on cognitive aging. Methods: We evaluated the effects of prevalent and incident diabetes on deteriorations in cognitive function, based on participants (n = 8,671) aged 65+ in the Health and Retirement Study in 2000. Inverse probability weighting was used to account for selective attrition and time-varying confounding of incident diabetes. Results: Prevalent diabetes predicted higher odds of dementia [odds ratio 1.27; 95% confidence interval (CI) 1.03-1.58] and worse memory (-0.06 in z-score units; 95% CI -0.10 to -0.02), but incident diabetes or diabetes duration up to 8 years of follow-up was not predictive. Conclusion: Prevalent diabetes predicted lower cognition but not recent onset diabetes.