Topline Results of EXERT: Can Exercise Slow Cognitive Decline in MCI?

Abstract

AbstractBackgroundThe EXERT trial (NCT02814526) was a Phase 3, multicenter, randomized single‐blind study that examined the effects of regular exercise on cognition and other measures of brain function in a planned sample of 300 older adults with amnestic mild cognitive impairment (MCI).MethodThe Alzheimer’s Disease Cooperative Study (ADCS) coordinated the trial, in partnership with Wake Forest and the YMCA of the USA. Participants were randomized to moderate intensity aerobic training (AX), or to stretching, balance and range of motion (SBR) for 18 months. In the first 12 months, exercise was supervised 2x/week and completed independently 2x/week. All exercise was unsupervised in Months 13‐18. Outcomes assessments were completed at baseline and every 6 months. The primary endpoint was 12‐month change from baseline on the ADAS‐Cog‐Exec, a validated measure of global cognitive function. In addition, 12‐month changes in the ADAS‐Cog‐Exec and CDR‐SB were compared for EXERT intervention groups relative to other cohorts to estimate effects of intervention versus no intervention (i.e., “Usual Care”).Result296 participants were enrolled, and over 31,000 exercise sessions were completed during the first 12 months. Attendance remained high (AX: 81%; SBR: 87%), and >60% of participants reported continued exercise through the pandemic. Neither the AX group nor the SBR group showed 12‐month declines on the ADAS‐Cog‐Exec and CDR‐SB. There were no significant treatment differences between AX and SBR on these outcomes. In the Usual Care analysis comparing ADNI‐1 and EXERT participants matched on key variables (demographics, baseline cognitive function, APOE4), ADNI‐1 MCI participants showed the expected 12‐month decline on the ADAS‐Cog‐Exec, but the EXERT AX and SBR groups did not (ADNI‐1 vs. AX: p = 0.012; vs. SBR: p = 0.00049).ConclusionGlobal cognitive function did not change over 12 months of follow‐up for MCI participants in EXERT, suggesting that both the AX and SBR interventions may have stalled cognitive decline. EXERT is the longest exercise trial conducted in MCI to date, and greater ‘volume’ of exercise may have provided more protection, regardless of exercise intensity. Both groups received equal amounts of weekly socialization, which may have contributed to this protection. Our results are noteworthy given that trial was conducted during the COVID‐19 pandemic.