# Energy Reserves, Physical Activity, and Alzheimer's Disease in the Baltimore Longitudinal Study of Aging

> **NIH NIH U01** · JOHNS HOPKINS UNIVERSITY · 2021 · $600,964

## Abstract

PROJECT SUMMARY
Alzheimer’s disease (AD) is the most common cause of dementia. Underlying pathological and physiological
changes related to the onset and progression of AD are believed to emerge several years prior to clinical
manifestations. Gait abnormalities and motor slowing typically precede the diagnosis of AD by a decade or
more, presenting the exciting possibility that changes in gait may act as early noninvasive biomarkers for AD.
Previous work by our group has identified key markers of impending and/or accelerated gait speed decline
based on physiological measures of the energy cost of slow walking, peak energy capacity, and quantities and
patterns of objectively measured free-living physical activity (PA), making them potential preclinical markers of
early AD pathology. We propose to use 8 years of existing longitudinal data, and ongoing/new data collection
in nearly 1,000 older adults in the Baltimore Longitudinal Study of Aging (BLSA), to examine the roles of
altered energy reserves, and reduced and fragmented daily PA as precursors to clinical markers of Alzheimer’s
disease and neuronal injury, which include Aβ deposition using [11C]-Pittsburgh compound B positron emission
tomography, brain atrophy using structural magnetic resonance imaging (MRI), and cognitive performance. We
will also explore potential vascular mechanisms linking energy reserves and PA to these outcomes, including
cerebral blood flow, ankle brachial index, and pulse wave velocity, as well as the role of mediating or modifying
factors such as inflammation and the apolipoprotein E genotype. The BLSA is a continuously enrolled cohort
study of aging that already contains repeated measures of cognition and adjudication of cognitive status, in
which a subset completes repeated MRI and PiB PET scans. Importantly, our preliminary cross-sectional data
from the BLSA indicate strong associations among energy reserves, cognitive performance, b-amyloid burden,
and diurnal patterns of daily PA. We propose to investigate the longitudinal associations among these
variables to identify physiological thresholds of poor energy reserve and reduced and fragmented patterns of
diurnal PA as early precursors to the onset and progression of AD pathology. A better understanding of the
association between energy reserves/PA, subclinical AD pathology, and cognitive performance may elucidate
a physiological threshold of diminished energy reserve that is associated with increased risk of poor cognitive
outcomes over time, and increase our understanding of the complex association between declines in physical
and cognitive functioning with age. Moreover, uncovering patterns of daily free-living PA most commonly
associated with this threshold will help define a phenotype of reduced and/or fragmented PA that signifies
impending emergence and progression of AD. Given the proliferation of wearable devices to monitor PA in the
consumer and research markets, identifying changes in PA consistent with ...

## Key facts

- **NIH application ID:** 10149893
- **Project number:** 5U01AG057545-05
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** JENNIFER ANN SCHRACK
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $600,964
- **Award type:** 5
- **Project period:** 2017-09-30 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10149893

## Citation

> US National Institutes of Health, RePORTER application 10149893, Energy Reserves, Physical Activity, and Alzheimer's Disease in the Baltimore Longitudinal Study of Aging (5U01AG057545-05). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10149893. Licensed CC0.

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