Michael A. Gregory

Brain health and exercise in older adults.

Identifying feasible and effective interventions aimed at mitigating the effects of cognitive decline in older adults is currently a high priority for researchers, clinicians, and policy makers. Evidence suggests that exercise and cognitive training benefit cognitive health in older adults; however, a preferred modality has to be endorsed yet by the scientific community. The purpose of this review is to discuss and critically examine the current state of knowledge concerning the effects of aerobic, resistance, cognitive, and novel dual-task exercise training interventions for the preservation or improvement of cognitive health in older adults. A review of the literature suggests that the potential exists for multiple exercise modalities to improve cognitive functioning in older adults. Nonetheless current limitations within the field need to be addressed prior to providing definitive recommendations concerning which exercise modality is most effective at improving or maintaining cognitive health in aging.

The Healthy Mind, Healthy Mobility Trial: A Novel Exercise Program For Older Adults

BACKGROUND More evidence is needed to conclude that a specific program of exercise and/or cognitive training warrants prescription for the prevention of cognitive decline. We examined the effect of a group-based standard exercise program for older adults, with and without dual-task training, on cognitive function in older adults without dementia. METHODS We conducted a proof-of-concept, single-blinded, 26-wk randomized controlled trial whereby participants recruited from preexisting exercise classes at the Canadian Centre for Activity and Aging in London, Ontario, were randomized to the intervention group (exercise + dual-task [EDT]) or the control group (exercise only [EO]). Each week (2 or 3 d · wk(-1)), both groups accumulated a minimum of 50 min of aerobic exercise (target 75 min) from standard group classes and completed 45 min of beginner-level square-stepping exercise. The EDT group was also required to answer cognitively challenging questions while doing beginner-level square-stepping exercise (i.e., dual-task training). The effect of interventions on standardized global cognitive function (GCF) scores at 26 wk was compared between the groups using the linear mixed effects model approach. RESULTS Participants (n = 44; 68% female; mean [SD] age: 73.5 [7.2] yr) had on average, objective evidence of cognitive impairment (Montreal Cognitive Assessment scores, mean [SD]: 24.9 [1.9]) but not dementia (Mini-Mental State Examination scores, mean [SD]: 28.8 [1.2]). After 26 wk, the EDT group showed greater improvement in GCF scores compared with the EO group (difference between groups in mean change [95% CI]: 0.20 SD [0.01-0.39], P = 0.04). CONCLUSIONS A 26-wk group-based exercise program combined with dual-task training improved GCF in community-dwelling older adults without dementia.

A Six-Month Cognitive-Motor and Aerobic Exercise Program Improves Executive Function in Persons with an Objective Cognitive Impairment: A Pilot Investigation Using the Antisaccade Task

Persons with an objective cognitive impairment (OCI) are at increased risk for progression to Alzheimers disease and related dementias. The present pilot project sought to examine whether participation in a long-term exercise program involving cognitive-motor (CM) dual-task gait training and aerobic exercise training improves executive function in persons with an OCI. To accomplish our objective, individuals with an OCI (n = 12) as determined by a Montreal Cognitive Assessment (MoCA) score of less than 26 and older adults (n = 11) deemed to be cognitively healthy (i.e., control group: MoCA score ≥26) completed a six-month moderate-to-high intensity (65-85% maximum heart rate) treadmill-based CM and aerobic exercise training program wherein pre- and post-intervention executive control was examined via the antisaccade task. Notably, antisaccades require a goal-directed eye-movement mirror-symmetrical to a target and represent an ideal tool for the study of executive deficits because of its hands- and language-free nature. As well, the cortical networks mediating antisaccades represent regions associated with neuropathology in cognitive decline and dementia (e.g., dorsolateral prefrontal cortex). Results showed that antisaccade reaction times for the OCI group reliably decreased by 30 ms from pre- to post-intervention, whereas the control group did not produce a reliable pre- to post-intervention change in reaction time (i.e., 6 ms). Thus, we propose that in persons with OCI long-term CM and aerobic training improves the efficiency and effectiveness of the executive mechanisms mediating high-level oculomotor control.

Group-based exercise combined with dual-task training improves gait but not vascular health in active older adults without dementia

BACKGROUND Gait abnormalities and vascular disease risk factors are associated with cognitive impairment in aging. OBJECTIVE To determine the impact of group-based exercise and dual-task training on gait and vascular health, in active community-dwelling older adults without dementia. METHODS Participants [n=44, mean (SD) age: 73.5 (7.2) years, 68% female] were randomized to either intervention (exercise+dual-task; EDT) or control (exercise only; EO). Each week, for 26 weeks, both groups accumulated 50 or 75 min of aerobic exercise from group-based classes and 45 min of beginner-level square stepping exercise (SSE). Participants accumulating only 50 min of aerobic exercise were instructed to participate in an additional 25 min each week outside of class. The EDT group also answered cognitively challenging questions while performing SSE (i.e., dual-task training). The effect of the interventions on gait and vascular health was compared between groups using linear mixed effects models. RESULTS At 26 weeks, the EDT group demonstrated increased dual-task (DT) gait velocity [difference between groups in mean change from baseline (95% CI): 0.29 m/s (0.16-0.43), p<0.001], DT step length [5.72 cm (2.19-9.24), p =0.002], and carotid intima-media thickness [0.10mm (0.003-0.20), p=0.04], as well as reduced DT stride time variability [8.31 coefficient of variation percentage points (-12.92 to -3.70), p<0.001], when compared to the EO group. CONCLUSIONS Group-based exercise combined with dual-task training can improve DT gait characteristics in active older adults without dementia.

Combined Dual-Task Gait Training and Aerobic Exercise to Improve Cognition, Mobility, and Vascular Health in Community-Dwelling Older Adults at Risk for Future Cognitive Decline1

This 6-month experimental case series study investigated the effects of a dual-task gait training and aerobic exercise intervention on cognition, mobility, and cardiovascular health in community-dwelling older adults without dementia. Participants exercised 40 min/day, 3 days/week for 26 weeks on a Biodex GaitTrainer2 treadmill. Participants were assessed at baseline (V0), interim (V1: 12-weeks), intervention endpoint (V2: 26-weeks), and study endpoint (V3: 52-weeks). The study outcomes included: cognition [executive function (EF), processing speed, verbal fluency, and memory]; mobility: usual & dual-task gait (speed, step length, and stride time variability); and vascular health: ambulatory blood pressure, carotid arterial compliance, and intima-media thickness (cIMT). Fifty-six participants [age: 70(6) years; 61% female] were included in this study. Significant improvements following the exercise program (V2) were observed in cognition: EF (p = 0.002), processing speed (p < 0.001), verbal fluency [digit symbol coding (p < 0.001), phonemic verbal fluency (p < 0.001)], and memory [immediate recall (p < 0.001) and delayed recall (p < 0.001)]; mobility: usual & dual-task gait speed (p = 0.002 and p < 0.001, respectively) and step length (p = 0.001 and p = 0.003, respectively); and vascular health: cIMT (p = 0.002). No changes were seen in the remaining outcomes. In conclusion, 26 weeks of dual-task gait training and aerobic exercise improved performance on a number of cognitive outcomes, while increasing usual & dual-task gait speed and step length in a sample of older adults without dementia.

Multiple-modality exercise and mind-motor training to improve mobility in older adults: A randomized controlled trial

Objective: To investigate the effects of multiple‐modality exercise with or without additional mind‐motor training on mobility outcomes in older adults with subjective cognitive complaints. Methods: This was a 24‐week randomized controlled trial with a 28‐week no‐contact follow‐up. Community‐dwelling older adults underwent a thrice ‐weekly, Multiple‐Modality exercise and Mind‐Motor (M4) training or Multiple‐Modality (M2) exercise with an active control intervention (balance, range of motion and breathing exercises). Study outcomes included differences between groups at 24 weeks and after the no‐contact follow‐up (i.e., 52 weeks) in usual and dual‐task (DT, i.e., serial sevens [S7] and phonemic verbal fluency [VF] tasks) gait velocity, step length and cycle time variability, as well as DT cognitive accuracy. Results: 127 participants (mean age 67.5 [7.3] years, 71% women) were randomized to either M2 (n = 64) or M4 (n = 63) groups. Participants were assessed at baseline, intervention endpoint (24 weeks), and study endpoint (52 weeks). At 24 weeks, the M2 group demonstrated greater improvements in usual gait velocity, usual step length, and DT gait velocity (VF) compared to the M4 group, and no between‐ or within‐group changes in DT accuracy were observed. At 52 weeks, the M2 group retained the gains in gait velocity and step length, whereas the M4 group demonstrated trends for improvement (p = 0.052) in DT cognitive accuracy (VF). Conclusions: Our results suggest that additional mind‐motor training was not effective to improve mobility outcomes. In fact, participants in the active control group experienced greater benefits as a result of the intervention. HighlightsDeficits in cognitive function are associated with mobility impairment.We applied multiple‐modality exercise plus mind‐motor training to improve mobility in high‐functioning older adults.We targeted community‐dwelling older adults with subjective cognitive complaints.Multiple‐modality exercise with mind‐motor training did not affect mobility outcomes.More research is warranted in individuals at risk for cognitive and mobility impairment.

DUAL-TASK GAIT TRAINING AND AEROBIC EXERCISE TRAINING IMPROVES COGNITION IN OLDER ADULTS WITH EARLY INDICATIONS OF COGNITIVE IMPAIRMENT

reasoning Mean /SD 13.63 (1.50) 12.38 (1.94) <0.001 0.754 Memory Learning capacity Mean /SD 31.04 (5.36) 28.79 (5.29) <0.001 0.416 Recognition memory Mean /SD 23.14 (1.04) 22.58 (1.47) <0.001 0.474 Working memory Mean /SD 4.35 (0.90) 4.10 (0.86) 0.022 0.272 Verbal long term memory Mean/SD 7.76 (1.86) 7.41 (2.09) 0.135 0.178 Visuospatial function Mean /SD 3.84 (0.36) 3.66 (0.51) <0.001 0.439 Attention Mean /SD 8.57 (2.04) 8.19 (1.77) 0.028 0.261 Visual recognition Mean /SD 9.97 (0.20) 9.92 (0.27) 0.097 0.197 Poster Presentations: Sunday, July 24, 2016 P438

The Impact of Blood Pressure Dipping Status on Cognition, Mobility, and Cardiovascular Health in Older Adults Following an Exercise Program:

Objectives: To determine whether a dual-task gait and aerobic exercise intervention differentially impacted older adults with normal blood pressure (BP) dipping status (dippers) compared to those with nondipping status (nondippers). Methods: This study was a secondary analysis involving participants (mean age = 70.3 years, 61% women) who attended a laboratory-based exercise intervention over a 6-month period (40 min/day and 3 days/week). Participants were assessed in measures of cognition, mobility, and cardiovascular health at baseline, 3, 6, and 12 months (after a 6-month no-contact follow-up). Results: We observed improvements in cognition in both groups at 6 and 12 months, although no between-group differences were seen. Nondippers demonstrated superior improvements in usual gait velocity and step length after the exercise intervention compared to dippers. Dippers reduced daytime systolic BP at 6 and 12 months to a greater extent than nondippers. Discussion: BP dipping status at baseline did not influence exercise benefits to cognition but did mediate changes in mobility and cardiovascular health.

THE EFFICACY OF A MULTI-MODALITY EXERCISE PROGRAM COMBINED WITH MIND-MOTOR TASK TRAINING FOR OLDER ADULTS AT RISK OF COGNITIVE IMPAIRMENT ON USUAL AND DUAL-TASK GAIT: A RANDOMIZED CONTROLLED TRIAL

were found between the 3 risk groups. When obesity and hypertension were excluded from the index in late life, the risk for dementia increased as the index became higher (HR1⁄41.08, 1.021.15, p1⁄40.013) and individuals in the high-risk group had an increased risk for dementia compared to those in the low-risk group (HR1⁄41.26, 1.04-1.52, p1⁄40.018; Table 1). Conclusions: Our findings indicate that the LIBRA index might be a useful tool in midlife and, when adjusted, also in late life to identify individuals for primary prevention interventions of dementia and monitor individuals’ risk-change over time.

Preliminary findings from a 6-month randomized controlled trial of combined dual-task gait training and aerobic exercise in older adults with cognitive impairment but no dementia

changes in caregiving behaviors The participant’s abilities to respond to disruptive behaviors combined with increases in selfefficacy and role mastery upon completion of the skills training programs is demonstrated in this single site project with a small sample size of seven participants. This pilot program, with its baseline evidence, supports current evidence-based nursing research, can be expanded to meet the needs of interdisciplinary team members, is reusable in various formats and settings and can be revised to meet all levels of literacy.