Blood, Iron, and Gray Hair: Anemia in Old Age Is a Rising Concern
Harder, Ben, Science News
The life of a red blood cell is brief but fast paced. Each heartbeat pumps millions of the tiny cells into the body's vascular system at speeds of more than a meter per second. In about a minute, they can carry oxygen from the lungs to tissues in the rest of the body and return to the lungs. And they die before they're 4 months old. The body replaces old red blood cells by generating fresh ones, typically producing about 2 million cells per second.
For a variety of reasons, however, the production of new red cells can fall behind the loss of old ones.
The resulting deficiency, called anemia, turns up among people of all ages, but recent research shows that it disproportionately affects seniors. One study estimates that after age 85, 26 percent of men and 20 percent of women are anemic. And while symptoms in young and old people alike include fatigue, headache, and pale skin, the new findings link anemia in elderly people to additional effects, including accelerated physical and mental decline and a shorter life span.
Far from being an innocuous part of old age, anemia may reflect a serious health problem, recent studies show.
"If you're anemic [and elderly], you won't live as long as a person who's not anemic," says hematologist Jerry L. Spivak of Johns Hopkins University in Baltimore.
"[Anemia] is associated with higher mortality, disability, higher risk of falls in the elderly, poorer quality of life, increased hospitalization risk, and increased health care utilization," says geriatrician and epidemiologist Luigi Ferrucci of the National Institute on Aging (NIA) in Baltimore.
Furthermore, in about one-third of anemia cases among elderly people, no obvious cause can be found. That makes treating anemia difficult, if not impossible.
Researchers have begun to investigate the causes of anemia in the elderly population and to explore possible treatments. So far, they have more questions than answers. But one early result suggests that injections of the hormone erythropoietin may relieve anemia's consequences in relatively healthy elderly people. If further trials bear out that finding, a vast number of senior citizens could have reason to seek the treatment.
PREVALENT PROBLEM Premenopausal women are much more likely to be anemic than are their male peers. About 12 percent of U.S. women between the ages 17 and 49 have anemia, while barely 1 percent of similarly aged men do, according to national data.
The study that yielded those figures, the National Health and Nutrition Examination Survey (NHANES), employed a widely used definition of anemia that the World Health Organization (WHO) developed decades ago. Anemia is typically measured in terms of blood concentration of hemoglobin, the red blood cell molecule that binds to oxygen in the lungs and releases it where it's needed. According to WHO, a man is anemic if he has a hemoglobin concentration lower than 13.0 grams per deciliter (dl), whereas a cutoff of 12.0 g/dl applies to women.
By comparison, average hemoglobin concentrations exceed 15.0 g/dl and 13.5 g/dl in non-elderly white men and white women, respectively. Average concentrations for black men and women are slightly lower than those for whites.
In contrast to the pattern seen in younger adults, "older men tend to have lower hemoglobin than older women," says geriatrician Claudia Beghe of the James A. Haley VA Medical Center in Tampa, Fla.
Two years ago, an analysis of the NHANES data found that 10 percent of women between 75 and 84 years old--and 16 percent of men in that age range--are anemic. In people 85 or older, each gender faced a 10 percent greater risk, Ferrucci and his colleagues reported in the Oct. 15, 2004 Blood. That research excluded people who were hospitalized or living in nursing homes.
In segments of the elderly population, anemia is even more prevalent than that. Beghe and two colleagues reviewed 71 studies in 2004, including the Blood study and some studies that examined only hospital patients or nursing home residents. …