Prediction of cardiorespiratory fitness in older men infected with the human immunodeficiency virus: clinical factors and value of the six-minute walk distance.
OBJECTIVE
To investigate factors related to cardiorespiratory fitness in older human immunodeficiency virus (HIV)-infected patients and to explore the utility of 6-minute walk distance (6-MWD) in measuring fitness.


METHODS
Cross-sectional study in clinic-based cohort.


METHODS
Veterans Affairs Medical Center, Baltimore, Maryland.


METHODS
Forty-three HIV-infected men, median age 57 (range 50-82), without recent acquired immunodeficiency syndrome-related illness and receiving antiretroviral (ARV) therapy.


METHODS
Peak oxygen utilization (VO(2)peak) according to treadmill graded exercise testing, 6-MWD, grip strength, quadriceps maximum voluntary isometric contraction, cross-sectional area, muscle quality, and muscle adiposity.


RESULTS
There was a moderate correlation between VO(2)peak (mean +/- SD; 18.4 +/- 5.6 mL/kg per minute) and 6-MWD (514 +/- 91 m) (r=0.60, P<.001). VO(2)peak was lower in subjects with hypertension (16%, P<.01) and moderate anemia (hemoglobin 10-13 gm/dL; 15%, P=.09) than in subjects without these conditions. CD4 cell count (median 356 cells/mL, range 20-1,401) and HIV-1 viral load (84% nondetectable) were not related to VO(2)peak. Among muscle parameters, only grip strength was an independent predictor of VO(2)peak. Estimation of VO(2)peak using linear regression, including age, 6-MWD, grip strength, and hypertension as independent variables, explained 61% of the variance in VO(2)peak.


CONCLUSIONS
Non-AIDS-related comorbidity predicts cardiorespiratory fitness in older HIV-infected men receiving ARV therapy. The 6-MWD is a valuable measure of fitness in this patient population, but a larger study with diverse subjects is needed.
Department of Medicine, School of Medicine, University of Maryland, Baltimore, Maryland 21201, USA. koursler@grecc.umaryland.edu
Krisann K
KK
Oursler
Leslie I
LI
Katzel
Barbara A
BA
Smith
Wayne B
WB
Scott
David W
DW
Russ
John D
JD
Sorkin
D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000175:diagnosis / Q000503:physiopathology; D019380:Anti-HIV Agents / Q000627:therapeutic use; D015142:Baltimore; D018791:CD4 Lymphocyte Count; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005080:Exercise Test; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006787:Hospitals, Veterans; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010100:Oxygen / Q000097:blood*; D010809:Physical Fitness / Q000502:physiology*; D012307:Risk Factors; D013990:Tidal Volume / Q000502:physiology*; D014728:Veterans
D019380:Anti-HIV Agents; D010100:Oxygen