Abstract
Background: Aerobic training (AT) is a promising intervention for mild
cognitive impairment (MCI).
Objective: To evaluate the effects of AT on cognition and regional brain
glucose metabolism (rBGM) in MCI patients.
Methods: Subjects performed a twice-a-week, moderate intensity, AT program
for 24 weeks. Assessment with ADAS-cog, a comprehensive neuropsychological battery, and
evaluation of rBGM with positron emission tomography with
18F-fluorodeoxyglucose ([18F]FDG-PET) were performed before and
after the intervention. Aerobic capacity was compared using the maximal oxygen consumption
VO2max (mL/Kg/min). [18F]FDG-PET data were analyzed on a
voxel-by-voxel basis with SPM8 software.
Results: Forty subjects were included, with a mean (M) age of 70.3 (5.4)
years and an initial Mini-Mental State Exam score of 27.4 (1.7). Comparisons using paired
t-tests revealed improvements in the ADAS-cog (M difference: −2.7
(3.7), p < 0.001) and VO2max scores (M difference: 1.8
(2.0) mL/kg/min, p < 0.001). Brain metabolic analysis revealed a
bilateral decrease in the rBGM of the dorsal anterior cingulate cortex, pFWE = 0.04. This
rBGM decrease was negatively correlated with improvement in a visuospatial
function/attentional test (rho =−0.31, p = 0.04). Several other brain
areas also showed increases or decreases in rBGM. Of note, there was an increase in the
retrosplenial cortex, an important node of the default mode network, that was negatively
correlated with the metabolic decrease in the dorsal anterior cingulate cortex
(r =−0.51, p = 0.001).
Conclusion: AT improved cognition and changed rBGM in areas related to
cognition in subjects with MCI.
