Objective: Chronic lung disease has been associated with greater impairment in self-reported physical function in HIV-infected patients. We sought to study this association using objective measures of physical function and pulmonary function.
Design: Baseline data from the Examinations of HIV Associated Lung Emphysema study, a multicenter observational cohort of HIV-infected and uninfected veterans.
Methods: We assessed the association between clinical, laboratory, and pulmonary function measures with 6-minute walk test (6-MWT). Multivariable linear regression models were generated to identify factors associated with 6-MWT performance.
Results: Three hundred forty participants completed 6-MWT (mean age 55 years), with 68% blacks, 94% men, and 62% current smokers. Overall, 180 (53%) were HIV-infected and 63 (19%) had spirometry-defined chronic obstructive pulmonary disease. In a multivariable model, age, current smoking, and obesity (body mass index > 30) were independently associated with lower 6-MWT performance, but HIV infection was not; there was a significant interaction between HIV and chronic cough, such that distance walked among HIV-infected participants with chronic cough was 51.76 m less (P = 0.04) compared with those without cough or HIV. Among HIV-infected participants, the forced expiratory volume in 1 second (FEV1, percent predicted), to a greater extent than total lung capacity or diffusing capacity, attenuated the association with chronic cough; decreased FEV1 was independently associated with lower 6-MWT performance in those with HIV.
Conclusions: Older age, current smoking, and airflow limitation were important determinants of 6-MWT performance in the HIV-infected participants. These findings suggest that potential interventions to improve physical function may include early management of respiratory symptoms and airflow limitation.
*Department of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA;
†The Baltimore Veterans Affairs Medical Center, Geriatric Research, Education, and Clinical Center, Baltimore, MD;
‡University of Maryland School of Medicine, Baltimore, MD;
§Division of Pulmonary and Critical Care Medicine and HIV/AIDS Division, Department of Medicine, University of California, San Francisco, CA;
‖Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA;
¶Department of Medicine, Infectious Diseases Section, University of California—Los Angeles, David Geffen School of Medicine, Los Angeles, CA;
#Division of Infectious Diseases, Atlanta Veterans Affairs Medical Center;
**Department of Medicine, Emory University School of Medicine, Atlanta, GA;
††Pulmonary and Critical Care Section, West Los Angeles Healthcare Center, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA;
‡‡James J. Peters Veterans Affairs Medical Center;
§§Department of Medicine and Infectious Diseases, Icahn School of Medicine at Mount Sinai, Bronx, NY;
‖‖Infectious Diseases Section, Michael E. DeBakey VAMC, Houston, Texas;
¶¶Department of Medicine, Baylor College of Medicine, Houston, Texas; and
##Department of Internal Medicine, Veterans Affairs Connecticut Healthcare System, West Haven, CT;
***Yale School of Medicine, New Haven, CT.
Correspondence to: Monica Campo, MD, MPH, Department of Pulmonary and Critical Care Medicine, University of Washington, Harborview Medical Center 325 9th Avenue Box # 359762, Seattle, WA 98104 (e-mail: firstname.lastname@example.org).
Supported in part by a grant from the National Institutes of Health (NIH) HL090342 (to K.C.); M.C. was supported by the Firland Foundation. K.A.O. was supported by grant NIH R01 HL095136 and K23 AG02489. L.H. was supported by grant NIH HL 087713. Dr D.A. was supported through the Department of Veterans Affairs (VA), Health Services Research and Development. KMA was supported by the Department of Veterans Affairs, Veterans Health Administration, VISN 1 Career Development Award and the Association of Subspecialty Physicians and the CHEST Foundation of the American College of Chest Physicians.
The views expressed in the manuscript represent those of the authors and do not necessarily represent those of the Department of Veterans Affairs.
Received September 30, 2013
Accepted December 01, 2013