Gradual weight loss can precede dementia and begin
as early as 10 years prior to memory loss, concludes
a Mayo Clinic study involving women with and without
dementia.
The findings may provide clues to the origins of
dementia, say the researchers, who were expected to
present the findings Sunday at the International Conference
on Alzheimer's Disease and Related Disorders, in Madrid,
Spain.
The Mayo team compared the long-term medical records
of 560 people diagnosed with the onset of dementia
between 1990 and 1994. These patients were compared
to a group of patients who did not have dementia.
Both groups averaged about the same weight -- 140
pounds -- at the beginning of the study. Women who
did not develop dementia maintained that weight over
the next 30 years.
In contrast, "The women who later developed
dementia started off at the same weight as those who
didn't develop dementia, but their weight drifted
downward to 136 pounds 10 years before symptom onset
and 128 pounds at symptom onset," Dr. David Knopman,
lead researcher and neurologist, said in a prepared
statement.
He and his colleagues said it's unclear what caused
the weight loss in the women who later developed dementia,
but they have some theories.
"The weight loss findings raise scientific questions
about the cause or causes of the weight loss. This
points to changes in the brain that develop years
before the actual memory loss. We think that there
are several possible explanations," Knopman said.
"The women might have less initiative and lose
interest in eating, they might develop a duller sense
of taste and smell, or they might experience an earlier
sense of satiety (feeling full). Also, because, we
didn't observe the anticipatory weight loss in men,
the weight loss could have something specific to do
with postmenopausal hormonal changes," he said.
Pinpointing the brain mechanisms that influence weight
loss in women who develop dementia may help researchers
better understand how it develops, Knopman said.
