TUESDAY, May 10 (HealthDay News) -- Mild problems with thinking and memory, as well as full-blown dementia, are common in the "oldest old" women, a new study finds.
The oldest old refers to people age 85 and older -- the fastest-growing segment of the U.S. population. Their numbers are expected to increase by 40 percent during the next decade, according to background information in the study.
"The 'oldest old,' defined as people 85 years or older, is the fastest growing segment of the United States' population. The nature and prevalence of cognitive impairment in this group has not been fully determined," noted Dr. Marc L. Gordon, a neurologist and Alzheimer's researcher at The Feinstein Institute for Medical Research in Manhasset, N.Y. He was not involved in the new research.
In the study, researchers at the University of California, San Francisco, analyzed data on nearly 1,300 women averaging just over 88 years of age who were enrolled in the Women Cognitive Impairment Study of Exceptional Aging. Of those women, 231 (17.8 percent) had been diagnosed with dementia and 301 (about 23 percent) had been diagnosed with "mild cognitive impairment."
Women aged 90 or older were more likely to have mild cognitive impairment than those aged 85 to 89 (24.5 percent vs. 22.7 percent), said Dr. Kristine Yaffe and colleagues at UCSF.
They also found that prevalence of dementia in women aged 90 or older was nearly double that of those aged 85 to 89 -- 28.2 percent vs. about 14 percent.
On average, women with dementia were older, less likely to have completed high school, more likely to live in a nursing home, and more likely to have a history of depression and stroke.
Gordon stressed that even this study might not have captured the true range of mental impairment in elderly women.
"Because women who develop cognitive impairment may be more likely to drop out of the study, the actual prevalence may be even higher than estimated on the basis of this study," he explained. "Nonetheless, the authors have established that the prevalence of dementia continues to increase with advancing age, while the subtypes of dementia and MCI are similar to 'younger old' populations. They underscore the importance of screening for cognitive disorders in the oldest old."
The study appears in the May issue of the Archives of Neurology.
The U.S. National Institute of Neurological Disorders and Stroke has more about dementia.
-- Robert Preidt
SOURCES: Marc L. Gordon, M.S., neurologist and Alzheimer's researcher, The Feinstein Institute for Medical Research, Manhasset, N.Y.; JAMA/Archives journals, news release, May 9, 2011
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