Abstract 18239: Diabetes Status Does Not Modify the Association Between Prolonged Exposure to Elevated Fasting Blood Glucose and Midlife Cognitive Function

Abstract

Introduction: The association between type 2 diabetes mellitus (T2DM) and cognitive function(CF) has been well established. However, whether the impact of elevated fasting blood glucose(FBG) levels on CF according to T2DM status remains unclear. Hypothesis: We hypothesized that the impact of elevated FBG on midlife CF would be greater in people with T2DM than in those without T2DM. Methods: We studied 673 midlife participants of the Bogalusa Heart Study (age at baseline 36.7 ± 4.4 years, follow-up period 12.6 ± 1.0 years, age at midlife 49.2 ± 4.5 years, 63% women, 30.2% Black) with ≥3 measurements of FBG across the follow up period. Midlife T2DM status was defined as having FBG≥ 126 mg/dL or taking anti-diabetic medications at the time of midlife neuropsychological (NP) examination. Elevated FBG was defined as FBG≥ 100 mg/dL. Exposure duration of elevated FBG (ED_FBG) was defined as the time interval from initial detection of elevated FBG to midlife NP examination. Participants were classified into 3 distinct NP profiles (optimal, average, and mixed-low) using cluster analysis based on their NP performance, with mixed-low signifying worse CF. Associations between ED_FBG and NP profiles were analyzed using multinomial logistic regression models, adjusting for education status. Stratified analysis of the multinomial regression models according to midlife T2DM status, race and sex were performed. Results: Prevalence of midlife prediabetes and T2DM were 34.0% (n=229) and 11.1 % (n=75), respectively. A total of 120 participants (17.8%) were exposed to ED_FBG during the follow-up period. Mean ED_FBG was 9.1 ± 3.2 years. Mean ED_FBG was significantly longer in Black participants and men. The OR for having a mixed-low CF compared to optimal CF was 1.09 for a 1-year increase in ED_FBG (95% CI 1.02, 1.16), adjusted for education status. Stratified analysis according to midlife T2DM status, race, and sex did not yield significant results. Conclusions: Prolonged exposure to elevated FBG from early adulthood was associated with worse midlife cognitive function regardless of midlife T2DM status. Therefore, even among those without T2DM, prolonged exposure to elevated FBG may affect cognition.