Milwaukee Journal Sentinel - August 04, 2004
Philadelphia -- As America becomes a more racially diverse nation in the coming decades, it could face an exploding number of Alzheimer’s disease cases among minorities, according to research presented here recently.
A new study of Spanish-speaking Latinos living in the U.S. found that the first symptoms of Alzheimer’s appeared nearly seven years earlier in them than in non-Latinos. A separate study found that Alzheimer’s was two to three times more common in blacks than in whites.
Cases may triple
About 4.5 million Americans now have the brain disorder, a number that is projected to increase to between 11 million and 16 million by 2050. But those projections are based on population samples in which Latinos and blacks are underrepresented, researchers said at the 9th International Conference on Alzheimer’s Disease and Related Disorders of the Alzheimer’s Association.
"If anything, the projections probably are going upward," said James Jackson, a researcher with the University of Michigan and an adviser to the Alzheimer’s Association.
A University of Pennsylvania study presented here found that symptoms of Alzheimer’s first appeared at an average age of 67.6 in Latinos, compared with 73.1 for non-Latinos, even after taking into account differing rates of education and illnesses such as diabetes and depression.
The study involved patients in clinics serving Latinos in New York, Philadelphia and two communities in California.
"We were continually surprised at the young age," said Chris Clark, associate director of the Alzheimer’s Disease Center at the University of Pennsylvania. "It was not uncommon for them to be in their 50s or early 60s."
Clark said he has yet to come up with an explanation for why the symptoms are appearing sooner.
"I don’t believe it’s a biological effect," he said.
A more likely cause may be higher rates of stress among Latinos living in the U.S., he said.
The researchers now are looking at Alzheimer’s cases in Puerto Rico and Mexico to see if there is any difference in the age that symptoms first appear.
In a separate study, researchers with the University of South Carolina-Columbia found dramatically higher rates of Alzheimer’s among blacks than whites.
South Carolina is one of only two states that keeps an extensive registry of Alzheimer’s cases dating to 1988.
Among people aged 55 to 64, the Alzheimer’s rate was more than three times higher in blacks than in whites. Among those aged 65 to 84, the rate was more than double.
Some diagnosis errors
Some of the difference could be explained by errors in diagnosis of the disease, said James Laditka, an epidemiologist with the University of South Carolina. In the past, there was a stigma attached to Alzheimer’s that may have resulted in whites being less likely to be diagnosed with the disease, he said.
However, he said blacks have lower levels of education and higher rates of obesity and high blood pressure, all of which may increase their risk of having Alzheimer’s.
In related research presented at the conference, a Duke University analysis of the Medicare program showed that the overall number of Alzheimer’s cases during the 1990s increased 250%. Among blacks, the increase was 460%.