The Journals of Gerontology Series A: Biological Sciences and Medical Sciences Advance Access published online on January 27, 2009
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, doi:10.1093/gerona/gln017
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Published by Oxford University Press on behalf of The Gerontological Society of America 2009.
Fatigue in a Representative Population of Older Persons and Its Association With Functional Impairment, Functional Limitation, and Disability
1 Laboratory of Epidemiology, Demography, and Biometry
2 Geriatrics Branch, Geriatrics and Clinical Gerontology, National Institute on Aging, National Institutes of Health, Bethesda, Maryland
3 Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville
4 Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
5 Department of Internal Medicine and Biomedical Sciences, University of Parma, Italy
Address correspondence to Sonja Vestergaard, PhD, Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, 7201 Wisconsin Avenue, Gateway Building, Suite 3C309, Bethesda, MD 20892. Email: vestergaards{at}mail.nih.gov
| Abstract |
|---|
Background.: Older persons often complain of fatigue, but the functional consequences of this symptom are unclear. The aim of the present study was to evaluate fatigue and its association with measures of physical function and disability in a representative sample of the older population.
Methods.: Cross-sectional data from a population-based sample of 1,055 Italian men and women aged 65 and older were analyzed. Fatigue was defined according to two questions evaluating whether participants felt that "everything was an effort" and/or they "could not get going" on three or more days in the past week. Objective measures of physical function were handgrip strength, the Short Physical Performance Battery (SPPB), and 400-m walking speed. Disability was defined as the inability to complete the 400-m walk test and self-reported difficulty in activities of daily living (ADL) and instrumental activities of daily living (IADL).
Results.: The prevalence of fatigue was higher in women (29%) than in men (15%). In age-adjusted analyses, fatigued men and women had weaker handgrip strength, lower SPPB score, slower walking speed, and higher mobility, ADL, and IADL disability than nonfatigued persons. Further adjustment for health behaviors, diseases, inflammatory markers, and thyroid function generally reduced the relationship between fatigue and functional outcomes, but fatigue remained significantly associated with SPPB score, walking speed, and mobility and IADL disability.
Conclusions.: Older persons who report fatigue had significantly poorer functional status than those who did not report this symptom. The causal link between fatigue and these outcomes should be further investigated.
Keywords Fatigue; Aging; DisabilityPhysical function
Received: December 24, 2007; Accepted: March 28, 2008