NEW YORK (Reuters Health) - Alzheimer's disease and milder forms of dementia are associated with an increased risk of death, but contrary to some earlier reports, the risks are similar for blacks and whites, according to findings in the Archives of Neurology.
Whereas two national surveys have suggested that life expectancy in patients with Alzheimer's disease may be greater for African Americans than for whites, other studies have not shown this difference, the researchers note.
To evaluate the risk of death associated with Alzheimer's disease and mild thinking impairment in both races, Dr. Robert S. Wilson and colleagues at Rush University Medical Center in Chicago studied 1715 older black and white adults from four adjacent neighborhoods in Chicago.
When the study began, 802 subjects had no thinking or "cognitive" impairment, 597 had mild impairment, 296 had Alzheimer's disease, and 20 had other forms of dementia.
During up to 10 years of observation, 634 subjects died. They observed that 40.4 percent of those with mild cognitive impairment died, 59.1 percent of those with Alzheimer's disease, 60.0 percent with other forms of dementia, and 25.8 percent of patients who were free of cognitive impairment died.
Compared with participants without cognitive impairment, the risk of death was approximately 50 percent higher in mildly impaired patients and nearly 200 percent higher in those with Alzheimer's disease.
These effects did not vary by race, the researchers report.
"Alzheimer's disease is a malignant condition," Wilson said in an interview with Reuters Health. "It is possible that interventions designed to enhance (cognitive) skills may reduce mortality risk in affected persons."
"We are trying to better understand the biologic basis of the link between Alzheimer's disease and death," he noted.
SOURCE: Archives of Neurology, June 2009.
