Cognitive Impairment Spikes Death Risk for Seniors
Alzheimer disease raises death risk nearly three-fold over those with no cognitive impairment
MONDAY, June 8 (HealthDay News) -- Mild cognitive impairment (MCI) and Alzheimer disease (AD) increase the risk of death, and the risk increases as the severity of the impairment increases, according to a study in the June Archives of Neurology.
Robert S. Wilson, Ph.D., of Rush University Medical Center in Chicago, and colleagues studied a group of older blacks and whites from four neighborhoods in Chicago who were considered dementia-free in an earlier data collection initiative of 1,715 subjects. Upon clinical evaluation, the cohort was found to include 802 people with no cognitive impairment, 597 with MCI, 296 with AD, and 20 with other forms of dementia. The group was followed for up to 10 years (mean, 4.7 years) for all-cause death.
During follow-up, the researchers report that 634 people died. Compared to subjects without cognitive impairment, the risk of death was approximately 50 percent higher for those with MCI (hazard ratio, 1.48) and was nearly three times higher for those with AD (hazard ratio, 2.84). For subjects with MCI or AD, the risk of death increased as cognitive impairment increased, and was more pronounced for perceptual speed than for other cognitive factors. The relationship between cognitive impairment and risk of death was similar in blacks and whites, except for a slightly elevated risk of death for blacks with AD.
"The presence and severity of MCI and AD are associated with reduced survival among African Americans, and these effects are comparable to those seen among whites," the authors write.