Thesis defense Marit Sanders (Donders series 448)

18 September 2020

NeuroExercise: The effects of exercise on cognition, central and cerebral hemodynamics in mild cognitive impairment

Worldwide there is a rapid increase in the number of people with dementia, and with the current lack of therapeutic options available, there is increasing research focus on early stage prevention, including lifestyle interventions. In the multi-center NeuroExercise study we investigated the effect of a 12 month exercise intervention on cognition in elderly people with mild cognitive impairment. Participants were randomised over three groups, an aerobic exercise group, a non-aerobic stretching and toning group and a control group. In the two exercise groups, the participants followed exercise sessions 3 times per week, whereas the control group did not follow any intervention. Before and after the intervention cognitive functioning of six cognitive domains were assessed and these results were combined in one composite cognition score. Analysis results showed no differences in composite cognitive performance between the intervention groups together and the control group, nor between the two intervention groups. Furthermore, no significant differences were identified in any of the separate cognitive domains. Respiratory fitness was significantly improved in the intervention groups, therefore we can confirm the physical effect of the intervention. In a local add-on study we investigated the effect of the exercise intervention on blood pressure and cerebral blood flow. Blood pressure significantly reduced in both intervention groups together and concomitant reduction of cerebral blood flow was absent. This indicates a normal cerebral blood flow regulative function, even after lowering of blood pressure caused by the exercise intervention. On the long term this blood pressure lowering might have long-term beneficial effects on the risk of dementia. Since cognitive decline is a process of years to decades, we recommend longer interventions. Prevention of further cognitive decline may be most successful when interventions are a combination of multiple domains and personalized to either disease pathology or the person’s personal goals or preferences.