Impaired glucose regulation is associated with poorer performance on the Stroop Task

Abstract

Background Type 2 diabetes is a risk factor for development of cognitive dysfunction. Impairments in glucose regulation have been associated with poorer performance on tests of executive function and information processing speed. Methods We administered the Stroop Color Word Task, where higher interference scores are indicative of decreased selective attention, to 98 non-diabetic volunteers (64m; %fat=37±12; age=36±9 y, race=41 NA/30 C/13 H/14 AA) on our inpatient unit. After 3d on a weight maintaining diet, % body fat was measured by DXA and a 75g oral glucose tolerance test (OGTT) was administered. Impaired glucose regulation (IGR) was defined as: fasting plasma glucose ≥100 and ≤125 mg/dL and/or 2h plasma glucose between ≥140 and ≤199 mg/dL (IGR; n = 48; NGR; n = 50). Total and incremental area under the curve (AUC) for insulin and glucose were calculated. Results Stroop interference scores were not significantly associated with any measure of adiposity or insulin concentrations. Individuals with IGR had significantly higher interference scores than those with normal glucose regulation (NGR; p=0.003). Higher interference scores were significantly correlated with fasting plasma glucose concentrations (r=0.26, p = 0.007) and total glucose AUC (r=0.30, p = 0.02) and only trending so for iAUC and 2h plasma glucose (r=0.18, p=0.08; r=0.17, p=0.09 respectively). In separate multivariate linear models, fasting plasma glucose (p = 0.002) and total glucose AUC (p = 0.0005) remained significant predictors of Stroop interference scores, even after adjustment for age, sex, race, education and %fat. Conclusions Individuals with IGR had decreased performance on a test of selective attention. Fasting plasma glucose was more strongly associated with lower performance scores than 2h plasma glucose. Our results indicate that even mild hyperglycemia in the non-diabetic range is associated with attentional processing difficulties in a sample of younger adults. Whether these impairments precede or are induced by impaired glucose regulation is not clear.

Associations between Markers of Glucose and Insulin Function and Cognitive Function in Healthy African American Elders

“…Our results extend prior empirical findings from predominately White samples by demonstrating that cognitive abilities most vulnerable to T2DM and AD may also be sensitive to variations in FPG even before the threshold of T2DM is crossed [6,27]. This relationship was independent of age, education, BMI, and antihypertensive medication use.…”

Cognitive Dysfunctions in Middle-Aged Type 2 Diabetic Patients and Neuroimaging Correlations: A Cross-Sectional Study

“…Gluck et al demonstrated that even mild hyperglycemia in the non-diabetic range is associated with attentional processing difficulties in a sample of younger adults [40]. Therefore, in an attempt to clarify the role of T2DM in cognition, we controlled for the influence of other conditions (hypertension, depression) which could also impact on cognitive function [37].…”

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“…Habits are understood as behaviors that are frequently repeated over time and have been reinforced over time by rewarding experiences. Following specific habitual behaviors appears more dependent on environment and, to a lesser extent, on intentional control (29). Frequent consumption of plain wheat rolls can be interpreted as habitual behavior, and thus, the declared willingness to purchase rolls enriched with fiber by those who consume plain rolls more frequently than once a day may be a weak predictor of future consumption of fiber-enriched products.…”

“…This suggests positive overall acceptance and declared willingness to purchase rolls enriched with fiber will not always be associated with a change in the type of consumed rolls. Furthermore, people who are following habitual patterns require little information to make decisions and pay less attention to information about alternatives (29). Although in the scenario of foods sold without packaging is of less importance, it should be taken into account when a product enriched with fiber will replace a conventional product.…”

“…High fasting glucose, impaired glucose regulation, and hypoglycemia result in lower scores on executive function tests, information processing speed, and selective attention (28,29). Findings from various cohorts show that those with diabetes, prediabetes, and impaired glucose tolerance are at significant risk for MCI and have a substantially accelerated progression from MCI to dementia (16,20,(30)(31)(32).…”