 As
people with HIV live longer
thanks to effective antiretroviral
therapy, aging has become a key focus of HIV medicine. A
growing body of evidence indicates that HIV positive people
have a higher risk of progressive age-related conditions such
as cardiovascular disease, osteoporosis, and neurocognitive
impairment -- and tend to develop them at younger ages -- but
the relation between HIV and physical functioning has not been
extensively studied.
To investigate this issue, Krisann Oursler from the University
of Maryland School of Medicine and colleagues performed a cross-sectional
analysis of physical function in 3227 HIV positive and 3240
HIV negative participants enrolled in the Veterans Aging Cohort
Study (VACS-8) during 2002-2006. Most were men and the average
age was about 50 years. Poor health predictors (such as smoking
and heavy alcohol use) and comorbid conditions were common in
both groups.
The researchers asked about areas of physical function ranging
from basic activities of daily living (feeding, bathing, dressing)
to instrumental activities of daily living (light, moderate,
and heavy work), mobility (walking a few steps, walking inside,
walking 1 block), and vigorous activity (walking uphill, running,
sports). Participants report their current ability to perform
each activity. Self-reported physical function correlated with
results on a standardized test, the Short Form-12 physical subscale.
Results
 |
Overall,
better physical function predicted longer survival. |
|
Across
all age groups, decline in physical function per year
was greater for HIV positive compared with HIV negative
participants -- a small but statistically significant
difference. |
|
The
physical function of the average 50-year old HIV positive
patient was equivalent to that of the average 51.5-year-old
HIV negative participant. |
|
When
stratifying by age, however, HIV positive people in the
youngest group (< 44 years) had better function
than HIV negatives, while in the oldest group (> 55
years) they had worse function. |
|
HIV
positive people were more likely than HIV negative participants
to have certain cofactors for decreased physical function,
including injection drug use (34% vs 16%, respectively)
and hepatitis C (31% vs 15%, respectively). |
|
After
controlling for confounding factors, HIV itself was no
longer significantly associated with poorer physical function. |
|
History
of cardiovascular disease was a significant predictor
of poorer function, with a similar effect in the HIV positive
and negative groups. |
|
Among
people with chronic pulmonary disease, HIV positive patients
fared worse, however, with a 50-year old having physical
function equivalent to that of a 68.1-year-old HIV negative
person. |
Based on these findings, the study authors wrote, "We conclude
that age-associated comorbidity affects physical function in
HIV-infected patients, and may modify the effect of aging."
"Longitudinal [following over time] research with markers
of disease severity is needed to investigate loss of physical
function with aging, and to develop age-specific HIV care guidelines,"
they added.
"Within the limits of a cross-sectional study, the difference
in function between younger and older patients was greater in
HIV-infected patients compared to the uninfected patients, adjusted
for comorbidity," they elaborated in their discussion.
"It should be noted in the younger (age < 44
years) age group that HIV-infected patients reported higher
function than uninfected patients," they continued. "Only
this age group of HIV-infected patients had similar frequency
of exercise compared to the uninfected patients. This finding
raises the question of the role of physical inactivity in worse
physical function among older HIV-infected patients.
Investigator affiliations: University of Maryland School
of Medicine, Veterans Affairs Maryland Healthcare System, Baltimore,
MD; Yale University School of Medicine and Public Health, Veterans
Affairs Connecticut Healthcare System, West Haven, CT; Center
for Health Services Research on Pharmacotherapy, Chronic Disease
Management, and Outcomes, Institute for Health, Rutgers University,
New Brunswick, NJ; University of Washington, Seattle, WA; University
of Pittsburgh School of Medicine, Veterans Affairs Pittsburgh
Healthcare System, Pittsburgh, PA; Michael E. DeBakey VA Medical
Center, Department of Medicine, Baylor College of Medicine,
Houston, TX; UCLA School of Medicine, Greater Los Angeles Veterans
Affairs Healthcare System Los Angeles, CA; Baltimore Veterans
Affairs Medical Center Geriatric Research, Education, and
Clinical Center, Baltimore, MD.
1/14/11
Reference
KK Oursler, JL Goulet, S Crystal, and others. Association
of Age and Comorbidity with Physical Function in HIV-Infected
and Uninfected Patients: Results from the Veterans Aging Cohort
Study 25(10): 13-20 (Abstract).
January 2011.
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