Table 4.
Overview of observational studies evaluating physical activity via fitness assessment or questionnaires in cognitive impairment.
| Study | Description of sample |
Content |
Results |
|||
|---|---|---|---|---|---|---|
| Included sample size; gender (F/M) | Mean age in years (SD) | Description | Outcome measures MRI and cognition | Main MRI results | Cognitive results | |
| Burns et al., 2008 | 121 (64 HC, 57 early AD) | 73.5 | pVO2 via treadmill test | Whole brain volume, WM, GM Neuropsychology PASE |
Association of fitness with whole brain, gray and white matter volume in AD; Association between increased fitness and increased brain volume in AD |
In AD association between pVO2 and performance on Logical Memory II, Trail Making B and Digit symbol test |
| Honea et al., 2009 | 117 (56 HC, 61 early AD) | 73.8 (6.3) | pVO2 via treadmill test | VBM analysis, whole brain volume WM, GM volume PASE ApoE4 status |
Association between fitness and WM in bilateral inferior parietal cortex, and after SVC in hippocampus/parahippocampus in AD In HC no association |
– |
| Smith et al., 2011a | 18 aMCI (9 high PA, 9 low PA) | Low PA: 73.6 (8.3); High PA 75.0 (5.5) | High PA and Low PA group according to SBAS | 3 T fMRI with semantic memory task Neuropsychology |
Increased activation in left caudate in High-PA aMCI No difference in volume of caudate nucleus |
No difference in neuropsychological or discrimination performance |
| Vidoni et al., 2012a | 90 (37 early AD, 53 HC) | HC 73.2 (6.7), AD 73.8 (5.8) | pVO2 over 2 years via treadmill test | VBM Neuropsychology (Burns et al., 2008) |
Association between fitness and atrophy mainly in left parahippocampus in AD | Association between fitness and increased progression of dementia severity |
| Vidoni et al., 2013 | 34 (18 HC, 16 early AD) | HC 72.2 (7.2), AD 74.9 (7.4) | pVO2 via treadmill test | fMRI Stroop task PPT |
Association between fitness and increased activation in ACC only in HC | – |
| Braskie et al., 2014 | 82 (43 HC; 39 ADCE) | Controls 79.3 (4.8) AD 81.9 (5.1) | MLTPA Walking questionnaire |
Whole brain volume at year 9 Neuropsychology TNFα |
Association between PA and total brain volume after 9 years | Association between lower PA and risk of AD |
| Perea et al., 2016 | 37 ADCE | 72.35 (7.9) | pVO2 in cardio-pulm. Exercise test | DTI Neuropsychology |
Association between fitness and increased white matter integrity in right IFOF | No sign. Results on UDS |
| Raji et al., 2016 | 876 (213 MCI or AD) | 78.3 (3.9) | MLTPA | VBM Neuropsychology |
Association between caloric expenditure and precuneus, posterior cingulate, vermis in MCI/AD Interaction between increasing caloric expenditure and cognitive impairment in left hippocampus and cerebellar vermis |
Not reported |
| Teixeira et al., 2016 | 22 aMCI | 68.5 (5.3) | pVO2 via treadmill test | VBM, DTI Neuropsychology CSF |
Correlation of aerobic fitness with gray matter in frontal and parietal areas Positive correlation with FA + negative correlation with MD, RD, and AxD in multiple tracts |
Not reported |
| Ding et al., 2017 | 81 (26 HC, 55 aMCI) | 65 (7) | VO2max | DTI Neuropsychology |
Positive correlation of fitness with FA + negative correlation with MD, RD in multiple tracts | Association between DTI results and executive performance in MCI |
| Makizako et al., 2015 | 310 MCI | 71.3 (4.4) | Triaxial accelerometer for 2 weeks | MRI Neuropsychology |
Association between moderate PA and hippocampal volume | No association between PA and memory performance |
Abbreviations: ACC = Anterior Cingulate Cortex, AD = Alzheimer’s Disease, aMCI = amnestic mild cognitive impairment, AxD = axial diffusivity, CSF = Cerebrospinal Fluid, DTI = Diffusion-Tensor Imaging, FA = Fractional Anisotropy, DTI = Diffusion-tensor-imaging, GM = Gray Matter, HC = Healthy Controls, IFOF = inferior fronto-occipital fasciculus, MCI = Mild Cognitive Impairment, MD = Mean diffusivity, MLTPA = Minnesota Leisure Time Physical Activity questionnaire, PA = Physical Activity, PASE = Physical Activity Scale for the Elderly, PPT = Physical performance test, RD = Radial diffusivity, SBAS = Stanford Brief Activity Survey, SVC = Small Volume Correction, TNFα = Tumor Necrosis Factor, UDS = uniform data set, VBM = voxel-based-morphometry, WM = White Matter.