Association between diabetes and cognitive function at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Diabetes has been associated with cognitive changes and an increased risk of vascular dementia and Alzheimer's disease, but it is unclear whether there are associations between diabetes and early alterations in cognitive performance. The present study consisted of a cross-section analysis of 14,444 participants aged 35-74 years and from a developing country at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil); these participants were recruited between 2008 and 2010. We investigated whether there was an association between diabetes and early changes in the cognitive performance of this Brazilian population. To assess cognitive domains, we used the word-list learning, word-list delayed recall and word recognition tests along. Phonemic verbal fluency tests included semantic phonemic test (animals) and a phonemic test (words beginning with the letter F). Executive functions associated with attention, concentration and psychomotor speed were evaluated using the Trail Making Test B. The exposure variable in the study was defined as diabetes. Multiple linear regression was used to estimate the association between diabetes and cognitive performance. The results were adjusted for age, sex, education, hypertension, coronary disease, depression, physical activity, smoking, alcohol consumption, and the cholesterol/HDL-C ratio. We found a significant association between diabetes and decreased memory, language and executive function (attention, concentration and psychomotor speed) performance in this population from a country with a distinct epidemiological profile, even after adjusting for the main intervening variables.