title: Pulmonary function and the risk of functional limitation in chronic obstructive pulmonary disease.
abstract: The authors' objective was to analyze the impact of respiratory impairment on the risk of physical functional limitations among adults with chronic obstructive pulmonary disease (COPD). They hypothesized that greater pulmonary function decrement would result in a broad array of physical functional limitations involving organ systems remote from the lung, a key step in the pathway leading to overall disability. The authors used baseline data from the Function, Living, Outcomes, and Work (FLOW) study, a prospective cohort study of adults with COPD recruited from northern California in 2005-2007. They studied the impact of pulmonary function impairment on the risk of functional limitations using validated measures: lower extremity function (Short Physical Performance Battery), submaximal exercise performance (6-Minute Walk Test), standing balance (Functional Reach Test), skeletal muscle strength (manual muscle testing with dynamometry), and self-reported functional limitation (standardized item battery). Multiple variable analysis was used to control for confounding by age, sex, race, height, educational attainment, and cigarette smoking. Greater pulmonary function impairment, as evidenced by lower forced expiratory volume in 1 second (FEV(1)), was associated with poorer Short Physical Performance Battery scores and less distance walked during the 6-Minute Walk Test. Lower forced expiratory volume in 1 second was also associated with weaker muscle strength and with a greater risk of self-reported functional limitation (p < 0.05). In conclusion, pulmonary function impairment is associated with multiple manifestations of physical functional limitation among COPD patients. Longitudinal follow-up can delineate the impact of these functional limitations on the prospective risk of disability, guiding preventive strategies that could attenuate the disablement process.
authors.affiliation: Division of Occupational and Environmental Medicine and Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California, San Francisco, CA 94117, USA. mark.eisner@ucsf.edu
authors.forename: Mark D
authors.initials: MD
authors.lastname: Eisner
authors.forename: Carlos
authors.initials: C
authors.lastname: Iribarren
authors.forename: Edward H
authors.initials: EH
authors.lastname: Yelin
authors.forename: Stephen
authors.initials: S
authors.lastname: Sidney
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Katz
authors.forename: Lynn
authors.initials: L
authors.lastname: Ackerson
authors.forename: Phenius
authors.initials: P
authors.lastname: Lathon
authors.forename: Irina
authors.initials: I
authors.lastname: Tolstykh
authors.forename: Theodore
authors.initials: T
authors.lastname: Omachi
authors.forename: Nancy
authors.initials: N
authors.lastname: Byl
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
mesh_terms: D000328:Adult; D000368:Aged; D002140:California; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D004522:Educational Status; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016014:Linear Models; D008176:Lung Volume Measurements; D008297:Male; D008329:Managed Care Programs; D008875:Middle Aged; D053580:Muscle Strength; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000503:physiopathology*; D013147:Spirometry