Alzheimer's and Even Mild Dementia Hasten Death

12 june 2009-- Older adults with mild cognitive impairment or Alzheimer's disease have a shorter life span than other older adults, but the risk of death is no greater for whites or blacks, a new study says.

The study, conducted by researchers at Rush University Medical Center in Chicago, contradicts earlier information indicating blacks with Alzheimer's live longer than whites with the disease.

Researchers examined 1,715 older adults with an average age of 80 from four adjacent neighborhoods in Chicago. About 52 percent of participants were black.

Each participant had a clinical evaluation that included medical history, a neurological examination and a series of thinking, learning and memory tests to determine cognitive function.

About 17.3 percent were found to have Alzheimer's disease, 34.8 percent had mild cognitive impairment, 1.2 percent had other forms of dementia and 46.8 percent had no cognitive impairment.

During up to 10 years of follow-up, 37 percent of the participants died, including 25.8 percent of those without cognitive impairment, 40.4 percent of those with mild cognitive impairment, 59.1 percent of those with Alzheimer's disease and 60 percent of those with other forms of dementia.

Those with Alzheimer's disease had a three-fold greater risk of dying compared to those not experiencing cognitive function problems. Those with mild cognitive impairment were 50 percent more likely to die. The risk of death increased as cognitive impairment became more severe.

The study appears in the June issue of Archives of Neurology.

Alzheimer's disease reduces life expectancy and has emerged as a leading cause of death in the United States, according to the study.

Two previous national surveys found that life expectancy among black Alzheimer's patients might be longer than for whites.

But the current study, which was based on uniform clinical exams and not medical records of varying degrees of completeness, found race had no bearing on life expectancy.