January 4, 2011
Researchers who studied seniors living in Minnesota found that elderly men were more likely than their female peers to have serious memory problems. Men were more likely to have a condition called mild cognitive impairment, or MCI, a form of memory loss that sometimes progresses to full-blown Alzheimer’s disease. The findings appeared in the journal Neurology, published by the American Academy of Neurology.
Scientists are looking for ways to identify Alzheimer’s at its earliest stages, when treatment may be most effective. Many researchers believe that subtle symptoms of the disease may begin to appear a decade or more before the severe memory loss and thinking problems become evident.
“This is the first study conducted among community-dwelling persons to find a higher prevalence of MCI in men,” said study author Ronald Petersen, M.D., Ph.D., with the Mayo Clinic in Rochester, Minn. “If these results are confirmed in other studies, it may suggest that factors related to gender play a role in the disease. For example, men may experience cognitive decline earlier in life but more gradually, whereas women may transition from normal memory directly to dementia at a later age but more quickly.”
The study looked at over 2,000 men and women in their 70s and 80s who were living in Olmstead County, Minn., in the southeast part of the state. All were interviewed about their memory and medical histories and given tests of memory and thinking skills.
The researchers found that about 10 percent of the study participants had Alzheimer’s or another form of dementia. Of the 1,969 participants without dementia, more than one in six had mild cognitive impairment. MCI was more common among the men: about 19 percent of men had the problem, compared to 14 percent of women.
“Our results, showing combined rates of MCI and dementia at 22 percent, highlight the public health impact these conditions have and the importance of finding treatments for them,” said Dr. Petersen.
People in the study who had fewer years of formal schooling and those who had never been married also had a higher rate of mild cognitive impairment. Less education has also been recognized as a risk factor for Alzheimer’s, and having strong social ties, including a good marriage, may also help protect against the disease.
Estimates of the prevalence of mild cognitive impairment vary around the world, in part because of variations in diagnostic criteria. One survey in Sweden found a prevalence of MCI of 11 percent in men and women ages 75 to 95, and a German study yielded rates over 19 percent in those older than 75. Many American studies have noted rates over 20 percent in those age groups.
A few European studies also noted a higher prevalence of MCI in women. This study used more detailed diagnostic testing and is the first to note a higher prevalence of MCI among men compared to women. If confirmed, it could provide new insights into the mechanisms of Alzheimer’s disease and the ways in which hormones and other sex-specific factors might affect its course.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University
Source: R.C. Petersen, R.O. Roberts, D.S. Knopman, et al: “Prevalence of Mild Cognitive Impairment is Higher in Men: The Mayo Clinic Study of Aging.” Neurology, Sept. 7, 2010, pages 889-897.