Being ‘Housebound’ Linked to Alzheimer’s in Elderly

By Randy Dotinga
HealthDay Reporter

TUESDAY, April 26 (HealthDay News) — Seniors who are “housebound” seem to have nearly double the risk of developing Alzheimer’s disease, a new study suggests.

The research doesn’t prove that being confined to the house causes dementia, and other factors
could explain the association. Still, the findings raise questions about the possible cost of isolation, said lead investigator Bryan D. James, a postdoctoral fellow at Rush Alzheimer’s Disease Center in Chicago.

“People who don’t leave their home as much aren’t engaging with their environment and meeting new people,” James said. “They may not be using their minds as much.”

But James and his colleagues noted that underlying brain disease may also explain the results — that is, people may not be getting out as much because the insidious workings of Alzheimer’s or another form of dementia may affect the way one moves through the world long before they affect memory or speech.

Alzheimer’s disease afflicts an estimated 5.2 million people in the United States. That number is expected to grow to as many as 7.7 million Americans by 2030 as the Baby Boom generation ages.

The new study, published online April 15 in the American Journal of Geriatric Psychiatry, looks at something known as “life space.”

“[Life space] is actually a measure that has come into vogue with gerontologists lately,” James said. “Mostly it’s been a measurement of mobility, figuring out whether people are getting around their environment, how much they’re seeing that’s different from their couch or bedroom or living room.”

Researchers followed 1,294 seniors from two separate studies of older adults whose health was being tracked over time. At the beginning of this study, none of the elders showed signs of dementia. Over an average of 4.4 years, 180 developed Alzheimer’s disease.

The researchers found that people who reported that they never left their home environment during a given week were about twice as likely to develop Alzheimer’s disease in the five years of follow-up as those who traveled out of town. The research, James said, offers “a new way to see who’s going to be more likely to develop dementia in the future.”

The study also found that those who did not go beyond their driveway or front yard were also more likely to develop mild cognitive disorder, which can be an early manifestation of Alzheimer’s.

There are some caveats to the research. Some of the participants lived in retirement homes and may have led full lives without needing to leave the buildings where they live; however, they were still counted as being housebound.

Still, the researchers found that the connection between isolation and Alzheimer’s disease remained even when they adjusted their statistics so they wouldn’t be thrown off by factors such as depression, social networks, disease and disability, as well as age, sex, education, race or preclinical dementia.

Why does all this matter? “People are interested in figuring out who’s going to develop Alzheimer’s and new ways to target more people likely to develop it,” James said. “Maybe with the limited interventions we do have available, we can target them toward people who aren’t leaving their homes.”

Dr. James R. Burke, director of the Memory Disorders Clinic at Duke University Medical Center, said isolation could offer a clue to possible dementia problems before they become obvious. “This will be particularly important when disease-modifying therapies are available, so that evaluations can be started and interventions considered before there are significant cognitive problems,” Burke said.

“This paper is consistent with, but extends, previous findings that physical activity, intellectual engagement and social stimulation are important to delaying cognitive decline,” Burke added.

More information

For more about Alzheimer’s disease, visit the U.S. National Institute of Neurological Disorders and Stroke.

SOURCES: Bryan D. James, Ph.D., postdoctoral fellow, Rush Alzheimer’s Disease Center, Chicago; James R. Burke, M.D., Ph.D., director, Memory Disorders Clinic, Duke University Medical Center, Durham, N.C.; April 15, 2011, American Journal of Geriatric Psychiatry, online

Last Updated: April 26, 2011

Copyright © 2011 HealthDay. All rights reserved.

Alzheimer’s Cases Could Double With New Guidelines: Expert

By Amanda Gardner
HealthDay Reporter

TUESDAY, April 19 (HealthDay News) — The first new guidelines in 27 years for the diagnosis of Alzheimer’s disease could double the number of Americans defined as having the brain-robbing illness.


The guidelines, issued Tuesday by the Alzheimer’s Association and the U.S. National Institute of Aging, differ in two important ways from the last recommendations, which have been in use since 1984.

First, Alzheimer’s is now being recognized as a continuum of stages: Alzheimer’s itself with clear symptoms; mild cognitive impairment (MCI) with mild symptoms; and also the “preclinical” stage, when there are no symptoms but when recognizable brain changes may already be occurring.

Second, the new guidelines incorporate the use of so-called “biomarkers” — such as the levels of certain proteins in blood or spinal fluid — to diagnose the disease and assess its progress, but almost exclusively for research purposes only.

Still, the authors of the guidelines emphasized that these revisions are unlikely to change what happens in doctors’ offices when diagnosing Alzheimer’s or its precursors.

“It will not change practice,” said Dr. Guy M. McKhann, one of the guideline authors, at a Monday press conference.

MCI will, however, become a new diagnosis. And that could mean that the number of people considered to be on the new Alzheimer’s continuum could double, said Marilyn Albert, another author, director of the division of cognitive neuroscience at Johns Hopkins. But how MCI is determined won’t change.

The new U.S. National Institute on Aging/Alzheimer’s Association Diagnostic Guidelines for Alzheimer’s Disease now recognize three clear stages of Alzheimer’s disease.

The first and most severe is Alzheimer’s dementia, when patients are clearly cognitively and functionally impaired. This is to be characterized now not just by memory loss but also visual, spatial and judgment problems.

The new guidelines also make a clearer distinction between Alzheimer’s dementia and vascular dementia (such as that caused by stroke), McKhann said. The diagnosis will still be made by a doctor, with help from someone who knows the patient and perhaps the patient him- or herself, but biomarkers may be called in “to augment our certainty about the diagnosis,” said McKhann, a professor of neurology and neuroscience at Johns Hopkins University School of Medicine in Baltimore.

Another stage, MCI, can represent an earlier phase of dementia and consists of modest impairments, primarily in memory, which can be a harbinger of full-blown Alzheimer’s years down the road. In the research arena, investigators will be working towards standardizing biomarkers which indicate, for example, the presence of amyloid protein or nerve damage in the brain.

But for now, how diagnoses are made “will be extremely similar to what’s been used in the last 10 years,” said Albert, who added that “a very large number” of individuals with MCI do go on to develop Alzheimer’s.

“Older adults with MCI progress to dementia at a higher rate than those with no impairment, but progression is not inevitable,” according to the Alzheimer’s Association’s online overview of mild cognitive impairment.

“Not everyone diagnosed with MCI goes on to develop Alzheimer’s,” the association noted.

The preclinical category was formulated for research purposes only, namely to study biomarkers that may be present in the blood or cerebrospinal fluid or evident on different imaging tests that would indicate the build-up of amyloid plaque or damage to nerve cells.

“The main conceptual point was to define Alzheimer’s on the basis of the underlying brain changes rather than just requiring clinical symptoms,” said Dr. Reisa A. Sperling, a neurologist at Brigham and Women’s Hospital and associate professor of neurology at Harvard Medical School in Boston. “We thought our best chance for disease-modifying therapy was to detect evidence of the disease and intervene much earlier.”

As in cancer and diabetes, McKhann pointed out, if you’re trying therapies “only in people who have advanced dementia, the chances of them working is not very great.”

“We’re worried that there could be drugs around now that could be beneficial but that we could be using them too late in the disease course,” added Albert.

The new guidelines, summarized William Thies, chief medical and scientific officer of the Alzheimer’s Association, “will result in little change in current clinical practice of medicine as applied to Alzheimer’s disease. . . . [However] the new criteria are really extending the range of our ability to investigate this disease and eventually to find treatments that will be so necessary to avoid the epidemic of Alzheimer’s that we see facing us.”

The new guidelines appear in four papers in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

More information

The Alzheimer’s Association has more about mild cognitive impairment (MCI).

SOURCES: April 18, 2011 teleconference with William Thies, Ph.D., chief medical and scientific officer, Alzheimer’s Association; Guy M. McKhann, M.D., professor of neurology and neuroscience, Johns Hopkins University School of Medicine; Marilyn Albert, Ph.D., director, division of cognitive neuroscience, department of neurology, Johns Hopkins University School of Medicine and Reisa A. Sperling, M.D., neurologist, Brigham and Women’s Hospital and associate professor of neurology, Harvard Medical School

Last Updated: April 19, 2011

Copyright © 2011 HealthDay. All rights reserved.