title: Association of chronic cough and pulmonary function with 6-minute walk test performance in HIV infection.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: *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.
authors.forename: Monica
authors.initials: M
authors.lastname: Campo
authors.forename: Krisann K
authors.initials: KK
authors.lastname: Oursler
authors.forename: Laurence
authors.initials: L
authors.lastname: Huang
authors.forename: Matthew Bidwell
authors.initials: MB
authors.lastname: Goetz
authors.forename: David
authors.initials: D
authors.lastname: Rimland
authors.forename: Guy Soo
authors.initials: GS
authors.lastname: Hoo
authors.forename: Sheldon T
authors.initials: ST
authors.lastname: Brown
authors.forename: Maria C
authors.initials: MC
authors.lastname: Rodriguez-Barradas
authors.forename: David
authors.initials: D
authors.lastname: Au
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Akgün
authors.forename: Shahida
authors.initials: S
authors.lastname: Shahrir
authors.forename: Kristina
authors.initials: K
authors.lastname: Crothers
mesh_terms: D002908:Chronic Disease; D015331:Cohort Studies; D003371:Cough / Q000453:epidemiology* / Q000209:etiology; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests / Q000379:methods*; D012140:Respiratory Tract Diseases / Q000175:diagnosis / Q000453:epidemiology*; D014728:Veterans; D016138:Walking