Glucose tolerance status associates with improvements in cognitive function following high-intensity exercise in adults with obesity

Abstract

PurposeObesity, insulin resistance (IR), and proinflammatory cytokines associate with cognitive decline. Numerous studies document cognitive benefits of acute exercise bouts in lean individuals. However, how co-morbidities such as obesity and IR influence cognitive changes induced by acute exercise is unclear. We examined the effects of acute high-intensity aerobic exercise on cognitive function in age-matched and BMI-matched obese adults with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) and in lean, NGT adults. Methods49 adults (15 Lean, 18 Obese-NGT, 16 Obese-IGT) performed one session of high-intensity interval exercise (four cycles of 4-min at 75% Wmax with 3-min rest). Cognitive function testing and blood sampling were performed pre- and post-exercise. ResultsFollowing exercise, measurements of executive function and working memory were improved in Lean and Obese-NGT (p < 0.05), but not Obese-IGT. Changes in cognitive function following exercise negatively correlated with 2-hr glucose during an OGTT after controlling for body weight and body composition (rp = -0.40, p = 0.007). Serum levels of inflammatory cytokines IL-6 and CRP remained increased 60-minutes post-exercise in Obese-IGT, but not in Lean or Obese-NGT, which positively associated with 2-hr glucose during an OGTT (p < 0.01) and negatively with changes in cognitive function following exercise (p < 0.01). Greater insulin levels in Obese-IGT post-exercise also negatively correlated with changes in cognitive function following exercise (p < 0.01). ConclusionImprovements in cognition following acute high-intensity exercise positively associate with glucose tolerance, independent of body weight and body composition. Further, poorer changes in cognitive performance following exercise associate with persistent peripheral inflammation.