Exercise to Improve Brain Health in Older African Americans

Official title

Determinants of Individual Differences in the Efficacy of Aerobic Exercise to Improve Brain Health and Reduce Alzheimer's Disease Risk in Older African Americans

Overview

The goal of this clinical trial is to test the effects of different types of exercise on brain health and Alzheimer's risk in older African Americans. Specifically, the main question\[s\] it aims to answer are: * What is the effect of a Cardio-Dance Fitness (CDF) vs. a Strength, Flexibility, and Balance (SFB) intervention on a cognitive marker of Alzheimer's risk, generalization? * What is the effect of the CDF vs. SFB intervention on a fMRI biomarker of Alzheimer's, neural flexibility, and do improvements in neural flexibility mediate improvements in generalization? * Do ABCA7 genotypic variations moderate the efficacy of the CDF vs. SFB intervention for reducing Alzheimer's risk? Participants will undergo-- at baseline and post-test-- health assessments, cognitive tests, and structural and functional magnetic resonance imaging (fMRI), and a blood-draw to assess Alzheimer's risk biomarker levels.

Detailed description

Older African Americans-especially those with lower income and those living in urban neighborhoods- have a greater risk of Alzheimer's disease (AD) compared to the general population. This health disparity is attributable, in part, to modifiable factors including insufficient levels of aerobic exercise. However, not everyone gains the same degree of neuroprotection from exercise. For the proposed project, the investigators plan to investigate genetic risk as a novel source of response heterogeneity to exercise interventions in African Americans. Previously, the investigators demonstrated that five months of twice-weekly cardio-dance exercise can increase the dynamic rearrangement (or "neural flexibility") of resting-state networks within the medial temporal lobe (MTL), one of the earliest brain regions impacted by AD. Moreover, this improved neural flexibility mediates intervention-related improvements in generalization, the ability to apply past learning to novel task demands. Given our earlier findings that generalization is impaired in preclinical AD, these results suggest a novel circuit-level mechanism, MTL neural flexibility, through which exercise may reduce risk for dementia. Moreover, the investigators discovered that the cognitive benefits of exercise in older African Americans are diminished in those with a risk variant of the ABCA7 (rs3764650) gene. Two key limitations to our previous exercise studies were: (1) interventions limited to two 60-minute classes/week, below the recommended 150 minutes/week, and (2) too few participants to evaluate the effect of ABCA7 on exercise-induced changes on neural flexibility. The investigators propose to recruit 280 sedentary older African Americans, ages 60 and above, to be randomized to one of two equally engaging six-month interventions, a Cardio Dance Fitness (CDF) intervention, and a Strength, Flexibility, \& Balance active control. All participants will undergo-at enrollment and post-intervention-health assessments, cognitive tests, and structural and functional magnetic resonance imaging (fMRI), and a blood-draw to assess amyloid (Aβ 42/40) and tau (p-tau231, p-tau181). This will enable us to test: 1) the effect of the CDF intervention on a cognitive marker of AD risk, generalization; 2) the effect of the CDF intervention on a fMRI biomarker of AD, neural flexibility, and determine whether improvements in neural flexibility mediate improvements in generalization; and 3) whether ABCA7 genotypic variations moderate the efficacy of the CDF intervention for reducing AD risk. Impact: This work lays the foundation for future larger clinical trials to develop personalized exercise prescriptions for older African Americans with varying genetic, health, and social-determinant risk profiles, so as to optimize the impact of this low-cost non-pharmaceutical intervention for improving their brain health.

Interventions

• Behavioral Cardio-Dance Fitness
  This is an aerobic cardio-dance fitness exercise class in a social context with aerobic intensity assessed by heart rate monitoring throughout the class. Participants will meet three times a week for approximately 60 minutes per session, over 24 weeks (approximately 6 months).
• Behavioral Strength, Flexibility & Balance
  This intervention will serve as a stringent, structurally equivalent, active comparator to the CDF intervention, identical in duration, frequency, and social contact except for the content of this non-aerobic intervention. SFB will involve non-aerobic activity with strength, flexibility, and balance training.

Primary outcome measures

• Generalization Performance on the Concurrent Discrimination and Transfer Task [Time frame: Changes from baseline to six months]
• Generalization Performance on the Acquired Equivalence Task [Time frame: Changes from baseline to six months]
• Medial Temporal Lobe Neural Flexibility [Time frame: Changes from baseline to six months]

Eligibility criteria

Inclusion criteria

• self-identify as either African American or Black;
• be age 60 or older;
• able to speak, read, and understand English;
• available over the study period; independently ambulatory (i.e., not needing a wheelchair, walker, or cane);
• meet criteria for low levels of physical activity (less than 60 minutes per week) based on the International Physical Activity Questionnaire (IPAQ-short version);
• scoring 28-35 (inclusive) on the Telephone Interview for Cognitive Status Modified (sensitivity \[43%\], specificity \[94%\] for lower threshold; sensitivity \[93%\], specificity \[42%\] for upper threshold)55.
• scoring 20-26 (inclusive) on the Montreal Cognitive Assessment (MoCA) during the in-person screening
• have clearance to participate from their primary care physician, with oversight of all our patient health under the guidance of our physician-scientist Co-I, William Hu, Chief of Cognitive Neurology at Rutgers.

Exclusion criteria

• color-blindness (because some of our tasks utilize color as a cue);
• any diagnosed neurological disorder (including headaches and peripheral neuropathy); diagnosed or self-reported non-neurological conditions that likely affect MTL outcomes, such as, major depressive disorder (or a Geriatric Depression Scale-Short Form score ≥ 5), schizophrenia, delusional disorder, schizoaffective disorder or significant psychiatric symptoms that could impair the completion of the study (e.g., psychosis), substance-related and addictive disorders (or treatment in past five years), chemotherapy or radiation treatment for cancers, planning to undergo general anesthesia during the study period;
• exercise contraindications, such as, orthopedic complications, myocardial infarction, coronary artery bypass grafting, angioplasty or other cardiac condition in the past year, current treatment for congestive heart failure, angina, uncontrolled arrhythmia, deep vein thrombosis (DVT) or another cardiovascular event, and uncontrolled hypertension with resting systolic or diastolic blood pressures > 180/110 mmHg.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Prevention

Study locations

United States · 1 center

• Rutgers, The State University of New Jersey - Newark campus — Newark

Publications

• Gluck MA, Gills JL, Fausto BA, Malin SK, Duberstein PR, Erickson KI, Hu L. Examining the efficacy of a cardio-dance intervention on brain health and the moderating role of ABCA7 in older African Americans: a protocol for a randomized controlled trial. Front Aging Neurosci. 2023 Nov 21;15:1266423. doi: 10.3389/fnagi.2023.1266423. eCollection 2023. PMID 38076534

Identifiers

NCT: NCT05597124 · Pro2022001256

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗