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Grant Details

Grant Number: 5R21AG053198-02 Interpret this number
Primary Investigator: Schrack, Jennifer
Organization: Johns Hopkins University
Project Title: Defining and Quantifying Fatigability in Functionally Independent Older Adults
Fiscal Year: 2017
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PROJECT SUMMARY Background: Fatigue is a common symptom in older adults, but accurate assessment and measurement of fatigue is confounded by perception and self-pacing of daily tasks. The concept of fatigability anchors perceived or performance-based fatigue to a specific activity, and thus may be a more reliable and discriminating indicator of health and risk of functional decline with aging. Reliable, valid measures of fatigability are needed to support new insights into mechanisms of aging and disease pathophysiology, and may serve as important outcome measures related to benefit or harm in future clinical trials. Accordingly, this proposal will define measures of perceived and performance fatigability using existing data collected longitudinally in the Baltimore Longitudinal Study of Aging (BLSA), combined with new measures to enhance validity and reliability testing. Given the breadth and depth of data already collected in the BLSA, these fatigability measures will be evaluated, independently and together, with a broad range of factors that will provide a greater understanding of the underlying mechanisms of fatigability by identifying a link with longitudinal changes in energy regulation and daily physical activity. Methods: To evaluate cross sectional and longitudinal characteristics of fatigability in older adults, we propose to assess reliability, construct, convergent/divergent, discriminant, and predictive validity and criteria for meaningful change in three candidate measures of fatigability in older adults participating in the BLSA: slowing during the 400m walk, perceived exertion during a standardized treadmill walk, and the Pittsburgh Fatigability Scale (PFS). We will also investigate potential whole-organism contributors to, and consequences of, fatigability including daily physical activity, aerobic capacity, walking efficiency, multimorbidity, and resting metabolic rate. We hypothesize that: (i) all three measures will have high test-retest reliability, and discriminate and predict longitudinal change in self-reported and performance physical function better than traditional measures of self-reported fatigue, and (ii) the magnitude of change in physical activity, multimorbidity, and energy regulation will be associated with corresponding changes in all three fatigability measures. Output: The information obtained from this research will provide critical evidence in the development of valid measures of fatigability using multiple candidate measures of fatigability, extensive indicators of potential population strata and cofactors, and novel measures of community based physical activity and metabolic efficiency. Validating measures of fatigability will improve use in the clinical setting and provide important outcome measures for future clinical trials. Understanding the physiological mechanisms of fatigability will shed light on the temporal associations among fatigability, physical activity, and functional decline in the pathway from robust health to functional limitations and define the critical threshold at which fatigability seriously limits the ability to maintain independence later in life.

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Pittsburgh Fatigability Scale: One-Page Predictor of Mobility Decline in Mobility-Intact Older Adults.
Authors: Simonsick E.M. , Schrack J.A. , Santanasto A.J. , Studenski S.A. , Ferrucci L. , Glynn N.W. .
Source: Journal Of The American Geriatrics Society, 2018-10-13 00:00:00.0; , .
EPub date: 2018-10-13 00:00:00.0.
PMID: 30315707
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Contrasting characteristics of daily physical activity in older adults by cancer history.
Authors: Wanigatunga A.A. , Gresham G.K. , Kuo P.L. , Martinez-Amezcua P. , Zipunnikov V. , Dy S.M. , Simonsick E.M. , Ferrucci L. , Schrack J.A. .
Source: Cancer, 2018-10-01 00:00:00.0; , .
EPub date: 2018-10-01 00:00:00.0.
PMID: 30276791
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The Health of America's Aging Prison Population.
Authors: Skarupski K.A. , Gross A. , Schrack J.A. , Deal J.A. , Eber G.B. .
Source: Epidemiologic Reviews, 2018-06-01 00:00:00.0; 40(1), p. 157-165.
PMID: 29584869
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Longitudinal Relationship between Interleukin-6 and Perceived Fatigability among well-functioning Adults in mid-to-late Life.
Authors: Wanigatunga A.A. , Varadhan R. , Simonsick E.M. , Carlson O.D. , Studenski S. , Ferrucci L. , Schrack J.A. .
Source: The Journals Of Gerontology. Series A, Biological Sciences And Medical Sciences, 2018-05-26 00:00:00.0; , .
EPub date: 2018-05-26 00:00:00.0.
PMID: 29846512
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Accelerating Accelerometer Research in Aging.
Authors: Shiroma E.J. , Schrack J.A. , Harris T.B. .
Source: The Journals Of Gerontology. Series A, Biological Sciences And Medical Sciences, 2018-03-27 00:00:00.0; , .
EPub date: 2018-03-27 00:00:00.0.
PMID: 29596566
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Fatigability and functional performance among older adults with low-normal ankle-brachial index: Cross-sectional findings from the Baltimore Longitudinal Study of Aging.
Authors: Martinez-Amezcua P. , Matsushita K. , Simonsick E.M. , Ferrucci L. , Schrack J.A. .
Source: Atherosclerosis, 2018-03-22 00:00:00.0; 272, p. 200-206.
EPub date: 2018-03-22 00:00:00.0.
PMID: 29627740
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Fatigability and endurance performance in cancer survivors: Analyses from the Baltimore Longitudinal Study of Aging.
Authors: Gresham G. , Dy S.M. , Zipunnikov V. , Browner I.S. , Studenski S.A. , Simonsick E.M. , Ferrucci L. , Schrack J.A. .
Source: Cancer, 2018-03-15 00:00:00.0; 124(6), p. 1279-1287.
EPub date: 2018-02-08 00:00:00.0.
PMID: 29419879
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Using Heart Rate and Accelerometry to Define Quantity and Intensity of Daily Physical Activity in Older Adults.
Authors: Schrack J.A. , Leroux A. , Fleg J.L. , Zipunnikov V. , Simonsick E.M. , Studenski S.A. , Crainiceanu C. , Ferrucci L. .
Source: The Journals Of Gerontology. Series A, Biological Sciences And Medical Sciences, 2018-03-02 00:00:00.0; , .
EPub date: 2018-03-02 00:00:00.0.
PMID: 29509832
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Lumbopelvic Pain and Threats to Walking Ability in Well-Functioning Older Adults: Findings from the Baltimore Longitudinal Study of Aging.
Authors: Simonsick E.M. , Aronson B. , Schrack J.A. , Hicks G.E. , Jerome G.J. , Patel K.V. , Studenski S.A. , Ferrucci L. .
Source: Journal Of The American Geriatrics Society, 2018-02-07 00:00:00.0; , .
EPub date: 2018-02-07 00:00:00.0.
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Wearable activity monitors in oncology trials: Current use of an emerging technology.
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Source: Contemporary Clinical Trials, 2018 Jan; 64, p. 13-21.
EPub date: 2017-11-09 00:00:00.0.
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Perceived fatigability and objective physical activity in mid- to late-life.
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Source: The Journals Of Gerontology. Series A, Biological Sciences And Medical Sciences, 2017-09-19 00:00:00.0; , .
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Objectively Measured Physical Activity and Falls in Well-Functioning Older Adults: Findings From the Baltimore Longitudinal Study of Aging.
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Source: American Journal Of Physical Medicine & Rehabilitation, 2017-09-14 00:00:00.0; , .
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Understanding physical activity in cancer patients and survivors: new methodology, new challenges, and new opportunities.
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Source: Cold Spring Harbor Molecular Case Studies, 2017 Jul; 3(4), .
EPub date: 2017-07-05 00:00:00.0.
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Fatigued, But Not Frail: Perceived Fatigability As A Marker Of Impending Decline In Mobility-intact Older Adults
Authors: Simonsick E.M. , Glynn N.W. , Jerome G.J. , Shardell M. , Schrack J.A. , Ferrucci L. .
Source: Journal Of The American Geriatrics Society, 2016 Jun; 64(6), p. 1287-92.
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