ANEMIA INCREASES HOSPITALIZATION AND MORTALITY RISK IN OLDER ADULTS

Reuters Health, NEW YORK, Jun 29

Blood 2006;107:3841-3846.

Anemia in community-dwelling older adults is associated with an increased risk of hospitalization and death, according to a report from Canada in the May 15th issue of Blood.

"The identification of anemia in older individuals is a flag for adverse health outcomes," Dr. Bruce F. Culleton from the University of Calgary, Alberta, told Reuters Health. "Physicians should use their clinical and decision-making skills to search for reversible factors responsible for the anemia."

Dr. Culleton and colleagues used information from the Calgary Laboratory Services database, the Calgary Health Region database, and the Alberta Health and Wellness Vitals Statistics registry to investigate whether there was a relationship between anemia and incident hospitalizations and all-cause mortality among more than 17,000 community-dwelling adults 66 years of age and older.

The cohort was followed from 2001 to the end of 2004, during which time there were 1983 deaths and 7278 first hospitalizations.

The overall mortality was 5-fold higher among individuals with anemia (hemoglobin < 110 g/L), the investigators report.

There was an interaction between anemia and renal function. Among individuals with a normal GFR, anemia was associated with a 4-fold increased risk of death. With decreasing GFR, the mortality risk imposed by anemia declined.

The findings were similar when only individuals over 80 years old were included in the analysis.

Anemia was also associated with nearly a 3-fold increased risk of all-cause hospitalization, the researchers note. As with mortality risk, the risk for hospitalization attributable to anemia was most notable in individuals with normal GFR.

There was a reverse J-shaped relationship between hemoglobin and all-cause mortality in both sexes, the report indicates, although the relationship was statistically significant only for women. Lowest mortality was associated with hemoglobin levels of 140-170 g/L for men and 130-150 g/L for women.

"These results should provide an impetus for future interventional trials of anemia correction in the elderly," the investigators conclude.

"There is no evidence from valid randomized trials establishing improved mortality and/or hospitalization rates with anemia treatment," Dr. Culleton said. "We are participating in two industry (Amgen)-sponsored placebo-controlled trials examining the impact of anemia treatment."

The other major point from the research "involves the definition of anemia," Dr. Culleton added. "Our study suggests that definitions of normality (normal levels of hemoglobin in the elderly) should be developed using outcome events (such as death) instead of the statistical distribution of a variable, which is the current means to define normal hemoglobin levels."