Cognitive Aging and Brain Health

BACKGROUND AND OBJECTIVES: Super movers are individuals aged ≥80 years with gait speeds ≥1.5 SDs above age- and sex-adjusted means. Super movers tend to have lower prevalence of chronic medical conditions, healthier lifestyles, and younger biological age. The aim of this study was to examine their risk of incident cognitive impairment, trajectories of cognitive decline, and brain health. METHODS: This study used a retrospective study design using data from older adults aged ≥80 without Alzheimer disease or dementia enrolled in 5 Health and Retirement Study International Network of Studies (HRS-INS), the LonGenity Study, and the RUSH Memory Aging Project (RUSH MAP). HRS-INS data were used to assess incident cognitive impairment (>1.5 SD below the age-adjusted means on any cognitive test plus impaired Instrumental Activities of Daily Living) in super movers vs nonsuper movers. Age- and sex-adjusted hazard ratios (HRs) from Cox models were pooled in a meta-analysis to obtain risk of incident cognitive impairment. LonGenity data were used to examine (1) decline in cognitive domains using linear mixed-effects models adjusted for age, sex, education, and parental longevity; (2) trajectories of global cognition before and after age 80; and (3) brain structural differences (cortical thickness, hippocampal volume) between super vs nonsuper movers. RUSH MAP data were used to assess dementia-related pathology. RESULTS: HRS-INS study (n = 3,989, baseline age 83.6-84.4 years, 47%-65% females, 358 super movers), after excluding 274 adults with cognitive impairment at baseline, super movers had lower risk of incident cognitive impairment (HR 0.49, 95% CI 0.28-0.71) over follow-ups ranged between 3.4 and 5.4 years. In LonGenity (n = 197, baseline age 84.6 [SD 3.3], 57.8% women), super movers showed slower memory and non-memory-related cognitive decline and preserved hippocampal volume in specific subfields. In RUSH MAP (n = 692, baseline age 85.6 [SD 4.0], 68.9% women), super movers had better antemortem cognition and lower Alzheimer disease and dementia prevalence, but no differences in postmortem dementia-related pathologies. DISCUSSION: Super movers show slower cognitive aging-indicated as lower risk for cognitive impairment and slower cognitive decline-and preserved hippocampal volumes. Investigating their behavioral and biological traits may reveal novel protective mechanisms against cognitive decline and dementia.