Alzheimer's May Progress Differently in Women, Men
MONDAY Nov. 26, 2012 -- Alzheimer's disease may look and act differently in men and women, new research suggests.
An emerging field known as gender-specific medicine has shown pronounced differences among the sexes in terms of heart disease and other conditions. These latest findings -- if confirmed by further research -- may have significant implications for diagnosing and treating Alzheimer's among the sexes.
When people develop Alzheimer's disease, their brains atrophy or shrink. In the study of 109 people with newly diagnosed Alzheimer's, brain scans showed that this atrophy happens earlier in women than men. Women also lost more gray matter in their brains in the year before their diagnosis. However, men seemed to have more problems with their thinking ability when diagnosed with Alzheimer's than their female counterparts did. What's more, men and women lost gray matter in different areas of their brain.
"It is commonly known that loss of volume in hippocampus coincides with cognitive decline, but this is more true in males than females," said study author Dr. Maria Vittoria Spampinato, an associate professor of radiology at the Medical University of South Carolina.
The hippocampus is the part of the brain tasked with memory formation, organization and storage.
"The next step is to integrate this information on brain volume loss with other markers of Alzheimer's disease to understand if gender differences exist with other modalities or just brain volume alone," Spampinato said.
The study was presented Sunday at the Radiological Society of North America annual meeting, in Chicago.
Dr. Clinton Wright, scientific director of Evelyn F. McKnight Brain Institute at the University of Miami Miller School of Medicine, said it's too soon to draw any conclusions about gender differences in Alzheimer's disease.
"Additional information would need to be provided to know if the findings are attributable to sex differences or other factors," Wright said. "In particular, it is not clear if the authors adjusted for age. If women were older they might have had greater volume losses over the study period."
The finding that women had greater brain volume losses while men had worse mental function at the time of Alzheimer's diagnosis is also hard to explain, Wright said: "One would expect greater atrophy in those with worse cognition unless additional factors such as vascular damage explained these differences."
In a related presentation Monday, researchers from University of California, Los Angeles, reported that leading an active lifestyle may help halt brain aging and preserve gray matter volume even among people who already have evidence of dementia.
The study included 876 adults with an average age of 78. Individuals' mental function ranged from normal to Alzheimer's dementia. Researchers used MRI brain scans and a technique called voxel-based morphometry to see how physical activity affects gray matter volume. This technique allows a computer to analyze a brain scan and build a mathematical model that helps researchers understand the relationship between active lifestyle and gray matter volume.
Study participants who burned more calories via recreational sports, gardening and yard work, bicycling, dancing and riding an exercise cycle lost less gray matter in key areas of their brains. This was true even among those with evidence of mental decline. The finding held even after the team controlled for other factors known to influence brain volume including head size, mental impairment, gender, body weight, education and white matter disease.
Exercise likely improves blood flow to the brain, and strengthens the connections between brain cells, the study authors concluded.
Because these studies were presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
Learn more about Alzheimer's disease risk factors at the Alzheimer's Association.
Posted: November 2012
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