Cardiorespiratory fitness and cognition in healthy elderly and MCI patients

Abstract

AbstractBackgroundCurrent research indicates a positive impact of physical activity on healthy ageing, on brain plasticity and on the risk for dementia. Furthermore, several epidemiological, cross‐sectional and interventional studies have shown that cardiorespiratory fitness is associated with cognitive performance, especially regarding executive functions.MethodHere, we investigated the relationship between cardiorespiratory fitness and cognition in both healthy elderly (n=33; age: 68.8 ± 6.9) and in patients with mild cognitive impairment (MCI; n=27, age: 70.8 ± 6.1). Cardiorespiratory fitness was assessed using bicycle spiroergometry (cosmos torqualizer 600ef med; Germany) with an incremental step test. To determine the metabolic status, capillary blood samples were taken from the ear at rest (baseline), after each step and one, three and five minutes after the incremental step test was finished. The lactate concentration was measured with lactate scout sensors (SensLab GmbH Leipzig, Germany). Cognitive abilities were measured with the extended CERAD plus neuropsychological test battery (including Trial making test & verbal fluency S words).ResultStatistical analysis revealed significant between group differences in cognitive functions (e.g. MMSE, p<.001 TMT‐A, p<.001), but no significant differences in cardiorespiratory fitness (e.g. VO2peak, Wpeak, lactate). Furthermore, correlation analysis showed a significant correlation between VO2peak and MMSE in healthy elderly (p=.029, r=‐0.333)), but not in MCI patients (p=.317, r=‐0.096).ConclusionOur results indicate no differences in cardiorespiratory fitness between healthy elderly and MCI patients. However, cardiorespiratory fitness is associated with general cognition in healthy elderly. Why this correlation was not seen in MCI patients needs to be assessed in more detail in future research.