FATIGABILITY: A WINDOW ON ANEMIA OF CHRONIC DISEASE?

• Published in: Innovation in aging 2017-07, Vol.1 (suppl_1), p.1207-1207
• Main Authors: Simonsick, E.M., Schrack, J., Studenski, S.A., Ferrucci, L.
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 2399-5300; 2399-5300
• DOI: 10.1093/geroni/igx004.4391

Fatigue is a hallmark symptom of anemia which in older adults typically signifies underlying disease processes and not iron-deficiency. Subjectively measured fatigue, however, may be an unreliable symptom as individuals typically equilibrate their activity levels to remain below their fatigue threshold. Fatigability, in contrast, overcomes this limitation by providing context for fatigue and has been operationalized as the level of exertion experienced during a standardized task. Recent evidence shows that fatigability is superior to fatigue symptoms in predicting mobility decline; whether fatigability is a more sensitive indicator of prevalent and incident/persistent subclinical and clinical non-iron-deficient anemia is unknown. We evaluated the association between perceived fatigability (Borg rating of perceived exertion (RPE; range 6–20) following 5 minutes of treadmill walking at .67m/s) in 855 mobility-intact men (48%) and women aged 60–89 participating in the Baltimore Longitudinal Study of Aging. Adjusting for age, age-squared, sex, race and body mass index, each RPE increment was associated with 10% (p=.02) and 19% (p.4). Fatigability appears superior to fatigue symptoms for identifying emerging or chronic non-iron-deficient anemia which may facilitate identification of persons with worsening health earlier in the disease trajectory.