Resumen de Brain Function Is Linked to LDL Cholesterol in Older Adults with Cardiovascular Risk

Liesel Ann C. Meusel, Nicole D. Anderson, Matthew D. Parrott, William Yuen, Ekaterina Tchistiakova, Bradley J. MacIntosh, Sid- Feldman, Carol E. Greenwood

• Objectives To determine how cardiovascular risk is associated with working memory task performance and task-related suppression of default-mode network (DMN) activity in cognitively intact older adults.

  Design A cross-sectional functional magnetic resonance imaging study of older adults with cardiovascular risk factors.

  Setting Rotman Research Institute, Baycrest Health Sciences.

  Participants Thirty older adults with cardiovascular risk factors.

  Measurements Participants provided health information and a blood sample, and underwent functional magnetic resonance imaging during a working memory task and during a breath-hold task to assess cerebrovascular reactivity.

  Results Higher plasma low-density lipoprotein cholesterol (LDL-C) was associated with poorer working memory task performance (P = 0.008) and reduced task-related DMN suppression (P = 0.005). A composite index of cardiovascular risk, the Framingham General Cardiovascular Risk Profile, showed no associations with task performance or task-related DMN suppression. These findings were independent of white matter burden and cerebrovascular reactivity and thus cannot be accounted for by individual differences in neurovascular health.

  Conclusion These findings suggest a deleterious effect of elevated LDL-C on working memory task performance and task-related DMN suppression in older adults with cardiovascular risk. The relations between the Framingham General Cardiovascular Risk Profile, cognitive task performance, and DMN function require further study.