ISSN: 2574-7770
Authors: Ronald A Cohen*, Rachel Gonzalez-Louis, Heshan J Fernando, Jeffrey Friedman, Alexander Ayzengart, Eric Porges, Adam J Woods, Joseph Gullett, Michael Marsiske, John Gunstad, Christa M Ochoa, William T Donahoo and Kenneth Cusi
Background/Objectives: Severe obesity is associated with cognitive deficits in adults without current or past neurological brain disturbances. This study examined the relationship between specific metabolic and vascular risk factors and cognitive performance on a computerized neurocognitive assessment battery in adults with BMI > 35. Subjects/Methods: 123 adults with Class II or III obesity, ages 20-75, were enrolled in a study of the cognitive and brain effects of reduced BMI and improved diabetes mellitus (DM) following bariatric surgery. Baseline clinical/cognitive assessments were conducted with the NIH Toolbox (NIH-TB) cognitive module prior to surgery, and in severely obese controls recruited from the community. Global, Fluid and Crystallized indices were derived from performance across nine tasks. Hierarchical regression analyses examined six obesity-associated clinical factors (BMI, HbA1c, and DM, hypertension, sleep apnea, and osteoarthritis diagnoses) relative to NIH-TB performance. Results: Fluid Cognition deficits were observed, greatest on attention-executive and cognitive processing speed tasks (Flanker and Pattern Comparison). DM diagnosis was most strongly associated with weaker cognitive performance (Global and Fluid Cognition), and with poorer performance on the Flanker, Pattern Comparison, Picture Sequencing, Verbal Learning, and Symbol Coding tasks. Elevated HbA1c was associated with weaker Card Sorting and Symbol Coding performance, hypertension with poorer Fluid Cognition, and osteoarthritis with lower List Sorting performance. Elevated BMI was only associated with Flanker performance, though DM was more strongly associated with this measure. Conclusion: Deficits of fluid cognitive functions (attention-executive, processing speed) exist among adults with Class II and III obesity. DM was most consistently associated with weaker NIH-TB performance. BMI was not as strongly associated with NIH-TB performance, perhaps reflecting the elevated BMI of the entire sample. That cognitive deficits were linked to specific obesity-associated comorbidities support the validity and potential clinical utility of the NIH-TB for the assessment and management of adults with severe obesity.
Keywords: NIH Toolbox; Obesity; Diabetes Mellitus; Cognitive Deficits
