Abstract
BACKGROUND: Identifying strategies to mitigate age-associated cognitive decline is crucial. High-velocity power training enhances physical function in older adults and cognitive training has mixed cognitive benefits, however the combined effects of these interventions remain uncertain. OBJECTIVE: This 18-month cluster randomized controlled trial investigated whether dual-task functional power training (DT-FPT) enhances cognition in older adults and assessed if responses differ by apolipoprotein-E and brain-derived neurotrophic factor (BDNF) polymorphisms. SUBJECTS AND METHODS: Twenty-two independent-living retirement communities (300 residents, ≥65y at increased falls risk) were randomized to 12-months of group-based DT-FPT (6-months supervised +6-months maintenance, 45-60 minutes, 2/week) performed simultaneously with cognitive and/or motor tasks, followed by 6-months follow-up, or usual care control (CON). Cognitive domains were assessed using CogState at baseline, 6, 12 and 18-months. Z-scores were created to form composites for psychomotor-attention, learning-working memory and global cognition. BDNF and APOE polymorphism data were obtained from blood samples. RESULTS: Overall, 223 (74%) participants completed the 18-month intervention; mean exercise adherence was 50% at 6-months and 40% at 12-months. Net benefits in choice reaction time and attention (0.17 SD, P = 0.016), psychomotor-attention (0.19 SD, P = 0.029), and a composite of psychomotor-attention, learning-working memory (0.11 SD, P = 0.046) were detected in DT-FPT vs CON after the 6-month supervised phase. At 12 and 18 months, benefits from DT-FPT relative to CON were extended to visual learning (0.29 SD, P = 0.013; 0.27 SD, P = 0.008) and learning-working memory (0.13 SD, P = 0.047; 0.18 SD, P = 0.013). CON exhibited a 0.19 SD net benefit for executive function (P = 0.003) after 18 months. BDNF Met carriers at 18 months showed improved working memory (0.35 SD, P = 0.042) and learning-working memory (0.37 SD, P = 0.011) in DT-FPT versus CON. CONCLUSIONS: In older retirement living residents, DT-FPT may improve cognitive domains critical for functional independence, with genotype potentially influencing these outcomes.Australian New Zealand Clinical Trials Registry (ACTRN12613001161718). This project was funded by the National Health and Medical Research Council (NHMRC) (APP1046267).