Cognitive Effects of Multi-Domain Interventions Among Pre-Frail and Frail Community-Living Older Persons: Randomized Controlled Trial

Background: Cognitive, physical, and nutritional interventions may produce different cognitive effects for different groups of older persons. We investigated simultaneously the cognitive outcomes of cognitive, physical, and nutritional interventions singly and in combinations in older persons with the physical frailty phenotype at particular risk of cognitive decline. Method: Pre-frail and frail participants were randomly allocated to 24 weeks nutritional supplementation (N = 49), physical training (N = 48), cognitive training (N = 50), combination intervention (N = 49), or usual care control (N = 50). Cognitive domain and global functions were assessed at baseline (0M), 6 month (6M), and 12 month (12M). Results: The control group showed declines in z-scores (from -0.100 to -0.244) of all domains. The cognitive training compared to control group showed the greatest increase in global cognition at 6M (0.094 vs -0.174, p = .006) and 12M (0.099 vs -0.142, p = .002), immediate memory at 6M (0.164 vs -0.211, p = .010) and 12M (0.182 vs -0.142, p = .040), delayed memory at 6M (p = .010), and attention at 6M (p = .025). Nutritional intervention showed benefits at 6M for immediate memory (p = .028) and delayed memory (p = .024), but physical training showed no positive effects. The combination group showed the greatest increase for visuospatial construction at 6M (0.215 vs -0.141, p = .010) and 12M (0.166 vs -0.180, p = .016), and for global cognition at 12M (p = .016) and language at 12M (p = .023). Conclusion: Among frail older persons, cognitive training conferred the greatest cognitive benefits. Nutritional and physical interventions singly were associated with modest short-term or no cognitive benefits, but their combined effects on visuospatial construction should be further investigated.