Background/Aim: Impairments in specific cognitive domains in T2DM may be partly attributable to stiffness in cerebral arteries, resulting in poor cerebral perfusion. This cross-sectional study investigated whether impairments in the ability of the cerebrovasculature to supply blood in response to a battery of cognitive tests could predict poorer cognition in T2DM.
Methods: Forty nine T2DM and 28 non-T2DM adults underwent transcranial Doppler ultrasound measurements of basal mean cerebral blood flow velocity (MBFV) and pulsatility index, a measure of arterial stiffness, in the left and right middle cerebral arteries (MCA). A battery of cognitive tasks assessing domains of working memory, executive function and information processing speed was then administered whilst MBFV was recorded. Cerebrovascular responsiveness (CVR) to cognitive tasks was calculated as a percentage increase in MBFV from the basal level.
Results: Using t-tests, we found no differences in basal MBFV; however, cerebral vessels were 14 percent stiffer in T2DM (P < 0.05). As expected, T2DM performed poorer in tasks relating to working memory (i.e. N-back, Digit-Symbol Coding, Symbol-Digit Coding), executive function (Concept Shifting Task) and information processing speed. Importantly, CVR to the N-back task was reduced by 53 percent in T2DM (P <0.05) but was independent of task performance.
Conclusion: We have shown for the first time that impaired cerebral perfusion during a working memory task is accompanied by poor task performance. We plan to evaluate the ability of selected vasoactive nutrients to enhance cerebrovascular function and see whether this improves cognition in at-risk populations.
Funding source: None