Amyloid imaging was not performed at baseline, but was done 12-18 months into the study. At that point, the combination intervention group had the lowest percentage of amyloid-positive subjects (22%). The rate of amyloid positivity was 34% in the training program alone; 46% in the DHA group alone; and 51% in the placebo group.
It’s not possible to determine whether the intervention altered the trajectory of amyloid deposition, Dr. Vellas said; that will be explored in a different study.
PET imaging showed striking between-group differences in glucose metabolism. Those in the training-alone group experienced a transient metabolic increase in the right and left temporal regions, which, compared with placebo, was significant at 6 months but not at 12 months.
In the DHA-only group, there was no difference at 6 months, compared with placebo. At 12 months, there was significantly more activity in the left supplementary motor area.
The combination group showed significant increases in metabolism in a number of regions, including the right hemisphere cluster (insula/putamen/amygdala/superior and middle temporal region); the left middle temporal pole fusiform gyrus and anterior temporal region; the right middle and inferior frontal region; and the right rolandic opercula.
The European Commission funded the study. Dr. Vellas had no financial disclosures.