Commonly associated with iron deficiency or nutritional factors, anemia occurs frequently among elderly people, with increased prevalence after age 65 and approximately 25 percent prevalence by age 85, as reported by the National Anemia Action Council. Scientists at the University of Vermont now have new evidence of a link between anemia and increased risk of illness and death in the elderly population, according to a study in the October 24 Archives of Internal Medicine, one of the JAMA/Archives journals.

Anemia is defined by the World Health Organization (WHO) as a hemoglobin concentration of less than 12 grams per one tenth liter for women and less than 13 grams per one tenth liter for men. Hemoglobin is the component of red blood cells that carries oxygen and ensures the normal function of every cell in the body; iron is an essential component of hemoglobin. This study showed that elderly people with the lowest and highest hemoglobin concentrations are at increased risk of death over 11 years.

Neil A. Zakai, M.D., a former chief resident in internal medicine at Fletcher Allen Health Care, and Mary Cushman, M.D., associate professor of medicine at the University of Vermont College of Medicine, compared the association of hemoglobin concentration and anemia status with subsequent death over the course of eleven years in elderly adults living in four U.S. communities. Hemoglobin concentrations were determined for participants recruited between 1989 and 1993. Participants were contacted biannually and deaths were reviewed and classified as cardiovascular or noncardiovascular.

Hemoglobin concentration was analyzed in two ways: by dividing the participants’ baseline hemoglobin into five equal levels and by the WHO criteria for anemia. Based on the WHO criteria for anemia, 498 individuals were anemic on enrollment (8.5 percent of the 5,797 included in the analysis; 17.6 percent among African Americans), the researchers report. The hemoglobin concentration for the 1,205 individuals in the lowest fifth was higher than the WHO criteria for anemia, and fully 41.3 percent of these 1,205 people did qualify as anemic by WHO standards.

“In this elderly cohort, the prevalence of anemia was seven percent among white and 17.6 percent among black individuals,” the authors write. “After 11.2 years of follow-up, lower hemoglobin concentrations were associated with a 33 percent higher risk of mortality, even after accounting for presence of other health conditions and risk factors for death. The magnitude of this association was similar whether the lowest fifth of hemoglobin or the WHO criteria for anemia was used; however, the number of participants was much larger when considering the lowest fifth of hemoglobin concentration.”

Another finding of the study was that there was elevated mortality among those in the highest hemoglobin fifth, even after extensive adjustment for other factors.

“In this study, we were unable to assess the cause of low hemoglobin in relation to mortality, but we hope to study this in the future by analyzing other blood tests in this study,” said Cushman. “It’s very clear that people age 65 and older should have their blood counts checked by their physician, so that if they have anemia, they can be treated,” said Cushman.

This research, which is affiliated with the Cardiovascular Health Study, was supported by the National Heart, Lung, and Blood Institute.