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 happened 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.