WINSTON-SALEM, N.C. – Older adults with anemia are twice as likely to have a significant decline in physical performance that could threaten their independence, report researchers from Wake Forest University Baptist Medical Center in the current issue of the American Journal of Medicine.
"Our results suggest that anemia is an independent risk factor for physical decline, which puts older adults at higher risk for nursing home admission, disability and death," said Brenda Penninx, Ph.D., associate professor of gerontology. "Future research should explore whether the treatment of late-life anemia helps preserve physical function."
Researchers measured whether anemia was related to physical performance over a four-year period. Anemia, which is a reduced level of oxygen-carrying red blood cells, affects about 13 percent of people over age 70. It has a variety of causes, from iron or vitamin B-12 deficiencies to chronic diseases such as cancer or liver disease.
The study involved 1,146 adults age 71 and older. The researchers measured physical performance using tests of standing balance, walking speed and ability to rise from a chair. Previous studies illustrated that these tests can predict the likelihood of nursing home admission, mortality, hospitalization and later disability.
Penninx and colleagues found that in participants with anemia, the mean decline in physical performance was 2.3 points on a 12-point scale. For those without anemia, the mean decline was 1.4 points.
"Participants with anemia were 2.1 times more likely than non-anemic subjects to decline substantially in performance, which we defined as a three-point decline over four years," said Penninx. "Subjects with borderline anemia were 1.5 times more likely to have a substantial decline."
A three-point, or 25 percent, decline in physical performance has been shown to increase the risk of hospitalization by 150 percent, the risk of nursing home administration by 200 percent and the risk of disability by 400 percent.
"This finding demonstrates that anemia is often associated with high risk of decline of health and well-being in older individuals, and suggests that treating anemia may slow down this process" says Luigi Ferrucci, M.D., a co-author of the study and Director of the National Institute of Aging's Baltimore Longitudinal Study of Aging. "It also highlights the need for additional study of other factors that may be associated with physical decline among older people."
Penninx said the relationship between anemia and physical decline was also present in people without diseases associated with anemia, such as cancer and kidney failure – showing that anemia itself is a risk factor – not just the underlying disease. The researchers also adjusted for other factors that might affect the results, such as age, sex, cigarette smoking and blood pressure, and found that anemia is an independent risk factor.
The researchers hypothesize that anemia may affect physical function because it causes people to feel weak, increasing the chance of falling. Because it reduces oxygen levels in the blood, muscle weakness may result. In addition, anemia may cause blood vessels to dilate to compensate for lower oxygen levels. This can cause changes to the cardiovascular system, including congestive heart failure. Anemia is typically a result of cancer or kidney disease or other conditions. But, about 30 percent of cases in older adults are not related to underlying conditions and are not linked to nutrition, said Penninx.
She said anemia is a condition that is relatively unexplored by researchers.
"Our research suggests that anemia deserves more attention," said Penninx. "It seems to be an important risk factor for physical decline and is potentially treatable. We need to learn whether treatment can help restore physical function or prevent a physical decline." The data was collected as part of the Established Populations for Epidemiologic Studies of the Elderly, sponsored by the National Institute on Aging, Data analyses were supported through Ortho Biotech Products, L.P.
Materials provided by Wake Forest University Baptist Medical Center. Note: Content may be edited for style and length.
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