Metabolic Risk in Older Adults is Associated with Impaired Sustained Attention

Objective: Metabolic syndrome (MetS), the presence of three or more cardiovascular risk factors, has been associated with subtle and diffuse neural compromise but has not been consistently associated with cognitive dysfunction. Sustained attention is a fundamental cognitive operation that relies on multiple brain networks and is impaired in a broad array of neurologic conditions. We examined whether a well-validated measure of sustained attention would be sensitive to vascular risk, as compared with more standard neuropsychological measures of attention and executive functioning. Method: We assessed vascular risk factors (VRFs; blood pressure, waist circumference, cholesterol, glucose, and triglycerides) in 93 middle-to-older aged adults (45-75 years). MetS was defined based on current guidelines from the National Cholesterol Education Program Adult Training Program (NCEP ATP III). Participants were grouped according to number of VRFs: high risk (MetS; 3+ VRFs; N = 32), medium risk (1 or 2 VRFs; N = 35), and low risk (0 VRFs; N = 26). All participants underwent a neuropsychological battery of tests measuring executive functioning. Participants also performed the gradual-onset continuous performance task (gradCPT), a measure of sustained attention. Results: There was a significant main effect of VRF group on sustained attention performance; participants with lower vascular risk were better able to sustain attention. No significant effects were detected on standard neuropsychological tests of executive function. Conclusion: Our results suggest that the gradCPT is sensitive to the potentially negative effects of MetS on subtle aspects of neurocognitive functioning. General Scientific Summary In this study, we examined the relationship between vascular risk factors and attention/executive functioning. We found that greater vascular risk was associated with significantly worse sustained attention. Our results suggest the gradCPT may be sensitive to the subtle effects of vascular risk and metabolic syndrome on cognition.