Effects of a 3-Year Multi-Domain Intervention with or without Omega-3 Supplementation on Cognitive Functions in Older Subjects with Increased CAIDE Dementia Scores

Findings from recent Alzheimer's disease prevention trials have shown subjects with increased dementia score based upon mid-life cardiovascular risk factors, to benefit from multi-domain intervention strategies to some extent. The effects of such interventions on cognitive functions remains yet to be well-established. This study is a secondary analysis of the MAPT study, 1,293 older subjects (mean age 75 years) with high CAIDE score (i.e., >= 6) were classified according to the four intervention groups: 1) multi-domain intervention plus placebo, 2) isolated supplementation with Omega-3 polyunsaturated fatty acid (n-3 PUFA), 3) combination of the two interventions, and 4) placebo alone. Linear mixed-model repeated-measures analyses were used to assess the cognitive changes according to various neuropsychological test scores between intervention groups compared to the placebo at 36 months from baseline. Compared to the placebo, group with multidomain intervention in combination withn-3PUFA was found to show significant improvement in the delayed total recall test of the free and cued selective reminding test (FCSRT) (mean +/- standard error(SE) +/- 0.20 +/- 0.10) and MMSE orientation test (mean +/- SE = 0.15 +/- 0.06) at 36 months. Isolated multi-domain intervention group showed significant less decline in the MMSE orientation test (mean +/- SE = 0.12 +/- 0.06) compared to the placebo. There was significant less improvement (mean +/- SE = -1.01 +/- 0.46) in the FCSRT free recall test in the n-3 PUFA intervention group compared to the placebo at 36 months. Our findings show high-risk subjects for dementia screened with CAIDE dementia score might benefit from multi-domain intervention strategies as in the MAPT study, particularly in the orientation and delayed recall domain.