Dementia-associated weight loss develops before onset of clinical symptoms and may be a useful early sign of disease
Dementia-associated weight loss begins before
the onset of definite dementia symptoms and accelerates by the time
of diagnosis, according to an article in the January issue of Archives
of Neurology.
Weight loss is common in the elderly and
may be related to various diseases, according to background information
in the article. “It has long been observed that weight loss is common
in Alzheimer disease, but this has been documented in people who
already have dementia.”
In the current study, Robert Stewart, MD, and his British colleagues
analyzed data from 1,890 men (aged 77-98 years) who were participants
in The Honolulu-Asia Aging Study. This population-based study of
Japanese American men included 112 men with incident dementia and
1,778 without dementia. Study participants were examined on six
occasions over a period of up to 34 years. Weight was measured at
each examination and dementia was ascertained at the three most
recent examinations.
“Incident dementia was associated with significant previous weight
loss, which was independent of a large number of potential confounding
factors,” the researchers found. “A high proportion of men with
dementia at examination 6 had lost at least 5 kg, which approaches
10 percent of average body weight for this cohort. This weight loss
occurred in many cases over the two to four years prior to reaching
the clinical threshold of dementia. The association was similar
in Alzheimer’s disease and vascular dementia.”
In conclusion the authors wrote: “An important consideration arising
from research in this area is the extent to which weight loss may
be prevented or minimized in dementia. Poor nutrition and frailty
frequently complicate later stages of dementia, causing falls, poor
wound healing, and increased physical dependence. … The results
presented here suggest that weight change and nutritional state
in people with dementia should be taken seriously at least from
the time of diagnosis if not at earlier stages of more mild cognitive
impairment.”
In an accompanying editorial, Michael Grundman, MD, MPH, wrote
“The article by Stewart et al in this issue of Archives of Neurology
provides evidence that men who develop dementia (both Alzheimer’s
disease and vascular dementia) tend to start losing weight at least
several years prior to their clinical diagnoses.”
“Since it is already known that specific risk factors and genes
are implicated in some patients who develop Alzheimer’s disease
and other susceptibility genes are likely to be discovered, it may
be too optimistic to suppose that nutritional approaches will necessarily
have a huge impact on preventing Alzheimer’s disease or slowing
cognitive decline. Nevertheless, even modest effects could have
large public health implications. The degree to which treatment
interventions directed toward maintaining optimal nutrition and
preventing excess weight loss could slow the disease course requires
more rigorous study.”
|