Blacks, Hispanics Live Longer With Alzheimer's

Blacks, Hispanics Live Longer With Alzheimer's
WEDNESDAY, Nov. 14 (HealthDay News) -- Blacks and Hispanics appear tolive longer following an Alzheimer's diagnosis than white patients, a newstudy suggests.
While men and women of Asian and American Indian descent diagnosed withthe disease were found to have survival expectancies equivalent to that ofwhite Alzheimer's patients, patients of Hispanic or black ethnicity werefound to live 40 percent and 15 percent longer, respectively.
The observation held up even after accounting for a wide range offactors -- including age, gender, and living environment -- that couldinfluence post-diagnosis longevity.
"This study didn't address all of the reasons why, and there's a lotmore work that needs to done in this area, but we found thatAfrican-Americans and Latinos with Alzheimer's lived on average longerthan white patients with Alzheimer's," said study lead author Kala M.Mehta, an assistant adjunct professor at the University of California, SanFrancisco.
"We were surprised by the finding," she added. "In fact, we hadhypothesized that it would be in the other direction. So, now we're hopingto do more research in the area of racial and ethnic differences andcognitive decline in Alzheimer's to get at the reasons for why differencesoccur."
Mehta and her team reported their findings in the Nov. 14 online issueof the journal Neurology.
According to the Alzheimer's Association, more than five millionAmericans now have Alzheimer's. The study team pointed out that by 2050,estimates suggest that more than three million Alzheimer's patients willbe of non-white origin.
Currently, the disease ranks seventh among causes of death in theUnited States.
To assess potential differences in Alzheimer's outcome among races,Mehta and her team analyzed data collected between 1984 and 2005 at morethan 30 Alzheimer's Disease Centers (ADCs) across the United States.ADCs are standardized Alzheimer's care facilities funded by the U.S.National Institute on Aging, many of which are affiliated with localuniversities.
The study was large, including information on more than 31,000 men andwomen aged 65 and older, all of whom had received a possible or probableAlzheimer's diagnosis.
Patient ethnicity, race, age, gender, educational background, maritalstatus, living situation, and cognitive function scores were recorded atinitial diagnosis, as was the first subsequent evidence of dementiaonset.
The authors reported that 81 percent of the patients were white, 12percent were black, 4 percent were Hispanic, and 1.5 percent wereAsian.
The average patient age was about 78, and 65 percent were women.
During the observation period, patients lived an average of 4.8 yearsfollowing diagnosis, and almost 39 percent of the patients died. Autopsieswere conducted on 3,000 of the deceased.
Overall, deaths were more common among patients who were older, male,and had poorer initial cognitive skills scores.
With respect to race and ethnicity, the research team found that whitepatients were more likely to die than patients of other backgrounds. Thedeath rate was 41 percent among whites compared to 30 percent among blacksand 21 percent for Hispanics.
After accounting for all the demographic factors that might influenceoutcome, the researchers concluded that black and Hispanic Alzheimer'spatients had a lower risk for mortality than their white counterparts.
Mehta and her colleagues stressed, however, that the pool of ADCpatients examined was not necessarily representative of U.S. Alzheimer'spatients as a whole. Most patients received care outside the confines of agovernment-funded medical center, she said, and as such they wouldpresumably have received a much more varied, non-standardized level ofcare.
The researchers cautioned, therefore, that the findings might not beapplicable to all Alzheimer's patients.
Just why blacks and Hispanic patients live longer with Alzheimer'sremains unclear, Mehta said.
"For example, we might consider the differing amounts of social supportfrom family members in the differing ethnic groups," she observed. "Andalso the different amounts of other diseases found in these patients, andthe treatment of those other diseases, which could be different betweengroups."
"But what's really important here is that, if we do find the underlyingfactors that account for the differences, we might be able to improvesurvival for patients, regardless of their race," she added.
Greg M. Cole is a neuroscientist with the Greater Los Angeles VAHealthcare System and an associate director with the Alzheimer's DiseaseResearch Center in the David Geffen School of Medicine at the Universityof California, Los Angeles. He expressed surprise at the studyresults.
"In general, things run in the opposite direction for some prettywell-understood reasons," he noted. "That black and Latino populations asa group have less access to health care, more metabolic syndrome, morecardiovascular risk factors putting them at risk for earlier mortality,lower socio-economic backgrounds, a lot of hypertension, diabetes, andthese sorts of things. So, we're accustomed to seeing more rapid declineand more mortality and shorter life expectancy among thoseminorities."
Cole agreed with Mehta that most probably a complex combination ofgenetic, cultural, and routine health care differences would account forthe mortality spread.
"But there's all kind of heterogeneity among populations, and much moreinvestigation will be needed to get at the cause," he added.