Higher Fasting Glucose Is Associated With Poorer Cognition Among Healthy Young Adults

• Published in: Health psychology 2016-02, Vol.35 (2), p.199-202
• Main Authors: Hawkins, Misty A. W, Gunstad, John, Calvo, Dayana, Spitznagel, Mary Beth
• Format: Article
• Language: English
• Subjects: Blood; Blood Glucose - metabolism; Body Mass Index; Chronic illnesses; Cognition Disorders - metabolism; Cognitive ability; Cognitive Impairment; Fasting; Fasting - blood; Female; Glucose; Human; Humans; Impulsivity; Insulin; Male; Neuropsychological assessment; Obesity; Obesity - metabolism; Obesity - psychology; Prediabetic State; Prospective studies; Resistance; Response inhibition; Short Term Memory; Sustained Attention; Type 2 diabetes mellitus; Young Adult; Young adults
• ISSN: 0278-6133; 1930-7810
• DOI: 10.1037/hea0000248

Objective: Obesity is associated with cognitive deficits; however, the mechanisms are unclear, especially among otherwise healthy adults. Our objectives were to examine (a) whether obesity is linked to elevations in fasting glucose and (b) whether these elevations are associated with cognitive impairment among otherwise healthy young adults. Method: Participants were 35 normal weight adults and 35 young adults with obesity who completed a task from the Automated Neuropsychological Assessment Metrics-4 (ANAM-4). Measured body mass index (BMI) and fasting blood glucose levels (mg/dL) were examined. Results: Persons with obesity had higher fasting glucose levels than normal weight persons (p = .03). After applying Bonferroni correction for multiple tests, higher fasting glucose predicted less accurate performance on tests of inhibitory control: Go/No-Go Commission Errors (β = .33, p = .004). No effects were observed for sustained attention or working memory (ps ≥. 049). Persons with glucose levels in the prediabetes range had nearly twice as many errors as those with normal glucose, a large effect that was independent of BMI. Conclusions: Young adults who were obese but otherwise healthy had higher fasting glucose levels compared with normal weight peers. Higher glucose levels were associated with poorer cognitive performance on tests of inhibitory control, especially among individuals with prediabetes levels. Thus, subclinical elevations in blood glucose may contribute to cognitive impairment and, ultimately, greater impulsivity-well in advance of the development of chronic disease states (e.g., insulin resistance or Type 2 diabetes) and independently of excess adiposity-though prospective studies are needed to determine directionality of this relationship.