Race May Affect Alzheimer's Survival
Study Shows Latinos and African-Americans With Alzheimer's Disease Live Longer Than Whites
Nov. 14, 2007 -- Race may be an independent predictor of survival among people diagnosed with Alzheimer's disease, with Latinos and blacks living longer than whites.
The findings from a study involving nearly 31,000 patients treated at more than 30 Alzheimer's centers across the country revealed that, compared with whites, Latinos were 40% and African-Americans were 15% less likely to die during the study period.
The ethnic differences were seen even after researchers accounted for other factors known to influence survival, including education level and age at symptom onset.
Researcher Kala Mehta, DSc, who is an epidemiologist at the University of California, San Francisco, says she went into the study expecting to find that whites live longer than the other ethnic groups studied following an Alzheimer's diagnosis.
"That was our original hypothesis, but it wasn't what we found," she tells WebMD.
Alzheimer's, Race, and Survival
The study is one of the largest ever to examine the impact of ethnicity on Alzheimer's disease outcomes.
But because it included only patients treated at Alzheimer's disease centers, the findings may not be an accurate indicator of what is happening with the Alzheimer's population at large, Mehta says.
"It is possible that these ethnic differences persist, but we can't say that from this study," she says.
Four out of five (81%) of the study participants were white, 12% were African-American, 4% were Latino, 1.5% were Asian, and 0.5% were American Indian.
The patients were followed for an average of 2.4 years, and they had a median survival of 4.8 years since their first visit to an Alzheimer's disease center.
Autopsy results from 3,000 patients revealed no significant differences in Alzheimer's disease progression at death by racial group.
But while Asians and American Indians lived about as long as whites with Alzheimer's disease, Latinos and African-Americans lived significantly longer.
Mehta says the reasons for this remain a mystery.
"Our goal is to try to understand the racial differences with a view toward improving the health of all people with Alzheimer's disease," she says.