Jan. 23, 2008 -- A review of epidemiological data has found evidence that people who spend fewer years in school may experience a slight but statistically significant delay in the realization that they're having cognitive problems that could be Alzheimer's disease.
Scientists at the Alzheimer's Disease Research Center (ADRC) at Washington University School of Medicine in St. Louis reviewed data on 1,449 Alzheimer's patients from their center and 21,880 patients from the National Alzheimer's Coordinating Center (NACC), a collaboration of approximately 30 Alzheimer's disease research centers nationwide.
"We may have a group of people who are at risk for slightly delayed detection of Alzheimer's disease," says lead author Catherine Roe, Ph.D., a neurology research instructor at the ADRC. "Early detection of Alzheimer's disease is important as we progress toward treatments and cures because those treatments will need to be applied as early as possible to have the maximum possible benefit."
The paper appears in this month's issue of Archives of Neurology.
In an earlier study of patients with a form of Alzheimer's disease linked to a genetic mutation, Roe and other Washington University researchers found patients with more years of education were likely to be diagnosed with Alzheimer's disease earlier. This surprised them because higher levels of education have typically been associated with decreased risk of Alzheimer's disease.
The new study confirmed those surprising results, revealing that patients with 12 years or more of schooling were on average slightly younger when diagnosed with Alzheimer's disease than patients with less than eight years of schooling. Age of diagnosis for a group with eight to 11 years of schooling fell in-between the other two groups.
Next, researchers analyzed the severity of patients' dementia when they went to the Alzheimer's disease center for the first time. They found that patients with fewer years of education were likely to be more severely impaired on their first visit.
Alzheimer's disease is cumulatively disabling: The longer one has it, the worse the symptoms become. This suggested to the researchers that those with lower education levels may be slower to notice the early signs of disease, only going to see a specialist after their symptoms become impossible to ignore. Those with more education may be becoming aware of their symptoms while they are still relatively subtle, and seek a specialists' help early on in the disease process.
"People with higher education levels may be more likely to have a job or a hobby that highlights early cognitive impairment as well as better access to medical care," Roe says. "These could be factors that we need to incorporate into our procedures for screening patients for early signs of cognitive impairment."
Roe CM, Xiong C, Grant E, Miller JP, Morris JC. Education and reported onset of symptoms among individuals with Alzheimer's disease. Archives of Neurology, January 2008.
Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.