Anemia elevates risk of physical decline in older people
Anemia doubles the risk that an older person will develop serious
physical declines that can erode the ability to live independently,
according to a new epidemiological study supported by the National
Institute on Aging (NIA) and others*. It is the first longitudinal
research to find an association between physical decline in later life
and anemia, a blood condition that affects about 13 percent of older
Americans.
The study,** published in the August 1, 2003 issue of the American
Journal of Medicine, also found that older people who do not yet have
anemia, but whose blood tests are just above the traditional cut off
point for diagnosing the condition, are 1.5 times more likely to develop
physical declines than those who have normal blood hemoglobin levels.
"This study suggests that even mild anemia is a risk factor linked to
reduced ability of older people to function at their fullest potential,"
said Jack Guralnik, M.D., Ph.D., an NIA epidemiologist who co-authored
the study. "Further research will tell us whether the treatment of
anemia can prevent the progressive decline in function that eventually
results in disability."
The investigators, led by Brenda Penninx, Ph.D., of Wake Forest
University School of Medicine in Winston-Salem, North Carolina, followed
a group of 1,146 people, ages 71 and older, for more than 4 years,
assessing their ability to perform three physical tasks: standing
balance, a timed 8-foot walk, and ability to rise from a chair. Each of
these activities was scored on a 5-point scale (0= an inability to do
the test; 4=top performance). These points were added together to create
a 0 to 12 overall score. These scores were correlated with blood samples
obtained from the participants. Anemia is defined by the World Health
Organization (WHO) as hemoglobin levels below 12g/dL in women and below
13g/dL in men. For this study, Dr. Penninx classified men and women
whose blood hemoglobin levels were within1g/dL of the WHO standard
(12-13g/dL for women, 13-14g/dL for men) as having borderline anemia.
At the end of the four-year study, two-thirds of the participants had at
least modest declines in physical performance scores, with 346 people
(30 percent) having substantial decreases. Overall, those who did not
have anemia averaged a 1.4 point decline on the 12-point scale during
the study. In contrast, those who had borderline anemia dipped an
average of 1.8 points and those with anemia dropped an average of 2.3
points on the 12-point scale.
Women with anemia showed the greatest physical decline followed by women
who had borderline anemia. Also, men with anemia had significantly
greater physical decline than men with normal blood hemoglobin levels.
Men with borderline anemia were more likely to show physical decline
than those whose hemoglobin levels were slightly higher than the WHO
standard. Excluding people who had ailments associated with anemia, such
as cancer, kidney disease, and infections, did not change the findings.
In a previous study, using the same data, Dr. Penninx found that a
decrease in physical performance is highly predictive of
hospitalization, nursing home admission and mortality. In his work, Dr.
Guralnik has found that a 1.5 point decrease is associated with a 50
percent increased risk of developing a disability that impairs a
person's ability to do activities of daily living, such as bathing,
eating and dressing.
"Although no study yet shows that treating anemia in older people
reduces the incidence of physical decline, our study certainly suggests
that this may be the case," Dr. Penninx said. "Anemia deserves clinical
attention. That's the take home message." Anemia affects at least 3.4
million Americans and is the most common blood disorder in the United
States. It occurs when the body doesn't produce enough red blood cells
or red blood cells are prematurely destroyed. More specifically, it is
defined as a low concentration of hemoglobin, the main component of red
blood cells that transports oxygen from the lungs to other tissues and
then returns carbon dioxide from the body to the lungs. A person who has
anemia can feel fatigued, dizzy, apathetic or irritable. Other common
symptoms include muscle weakness, shortness of breath, rapid heart beat,
and pale skin. However, the warning signs are often subtle and can be
difficult for doctors to detect.
###
Anemia can be caused by vitamin or mineral deficiencies, particularly of
iron, vitamin B12, and folic acid. Underlying diseases including cancer,
rheumatoid arthritis and chronic kidney disease also can trigger anemia.
But in up to 25 percent of cases, no cause can be identified. Treatment
varies, but dietary changes, nutritional supplements, and medications
can help. The National Institute on Aging is one of 27 Institutes and
Centers that constitute the National Institutes of Health. The NIA leads
Federal efforts to support and conduct basic, clinical, epidemiological,
and social research on aging and the special needs of older people.
Press releases, fact sheets, and other materials about aging and aging
research can be viewed at the NIA's general information Web site,
http://www.nia.nih.gov.
* This study was funded by the National Institute on Aging and through
support from Ortho Biotech Products, L.P.
** B.W.J.H. Penninx, J.M. Guralnik, G. Onder, L. Ferrucci, R.B. Wallace,
and M. Pahor, "Anemia and decline in physical performance among older
persons," American Journal of Medicine, Vol. 115, No. 2, pp. 104-110.
--
Kathrynne Holden, MS, RD
"Ask the Parkinson Dietitian" http://www.parkinson.org/
"Eat well, stay well with Parkinson's disease"
"Parkinson's disease: Guidelines for Medical Nutrition Therapy"
http://www.nutritionucanlivewith.com/
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