SUNDAY, June 10, 2007 (HealthDay News) -- There's more evidence that cardiovascular problems help drive Alzheimer's disease, scientists say, and that treating the heart might help protect the brain.
The findings "represent hope that interventions with well-known drugs can interfere with the disease's progression," said lead investigator Yan Deschaintre, a neurologist and research fellow at the University Regional Hospital Center in Lille, France.
In fact, cognitive impairment, as measured by a standard test, stayed in the low end of the mild range over 36 months for Alzheimer's patients who got treatments for both the neurological disease and their cardiovascular problems, the researchers reported.
In contrast, Alzheimer's patients with vascular trouble who did not receive these medications experienced declines in cognition that approached the severe level, Deschaintre's team found.
They were slated to present the findings Sunday at the Alzheimer Association's International Conference on Prevention of Dementia, in Washington, D.C.
According to the National Institute on Aging, about 4.5 million Americans have Alzheimer's disease. Rates rise steadily with age, and experts estimate that "nearly half of those 85 and older may have the disease." One recent study from the World Health Organization, released this week, warned that Alzheimer's -- which currently has no cure -- could affect 100 million people worldwide by 2050.
The new study was based on chart reviews of 891 French patients diagnosed with either Alzheimer's disease, cardiovascular disease plus Alzheimer's disease, or vascular dementia. The cognitive risk factors included in the study were high blood pressure, diabetes, high cholesterol, atherosclerotic disease and tobacco smoking.
Treatment was defined as receiving an antihypertensive drug, insulin or drugs to lower blood sugar, a cholesterol-lowering statin, or anti-clotting medications. The patients with Alzheimer's disease typically received medications aimed at temporarily curbing their symptomsthat included Aricept, Exelon or Reminyl.
Deschaintre's findings represent "pretty exciting work," because cardiovascular risk factors are "something we can do something about," said Dr. Sam Gandy, director of Emory University's Center for Neurodegenerative Diseases. Gandy also is chairman of the Alzheimer's Association's National Medical and Scientific Advisory Council.
The work done by Deschaintre's team is consistent "with what we've been hearing over the past three to five years" about vascular risk factors increasing the risk for Alzheimer's, Gandy said. The new study, "really nails that down by looking at the other side of the coin by establishing that treating vascular risk factors slows the progression of cognitive decline," he added.
He suggested that physicians begin to take vascular risk factors seriously as they treat patients with Alzheimer's. The vascular risk factors for early Alzheimer's patients "certainly should be treated" because it "seems to slow progression," Gandy said.
Another expert agreed.
The Lille results "reinforce the treatment guidelines for these vascular conditions, such as hypertension and diabetes, and emphasize that Alzheimer's and demented patients should be treated, too," said Hugh C. Hendrie, a professor of psychiatry at the Indiana University Medical School and a scientist at its Center for Aging Research.
However, Deschaintre and Hendrie both noted that physicians at times may not treat vascular risk factors in Alzheimer's patients, for a variety of reasons. For example, Alzheimer's disease often leaves patients apathetic, so they may neglect to tell their physicians about vascular symptoms, Hendrie said.
And Deschaintre noted that, in the clinic where the research was done, patients with Alzheimer's were less likely than other patients to be treated for vascular risk factors. The reverse was true, as well -- patients with vascular dementia were more likely to be treated for heart risk factors, but not for Alzheimer's.
But, "since the majority of patients have both Alzheimer's disease and cerebrovascular disease, and since patients with pure Alzheimer's do seem to benefit from treatment of vascular risk factors, the message is to treat both conditions rather than to focus only on one," he said.
Hendrie remained cautious about the scientific impact of Deschaintre's study, however. He said results from a clinical epidemiological study, such as the Lille research, aren't as conclusive or compelling as those from randomized, controlled clinical trials.
Two other studies scheduled for release at the Alzheimer's conference on Sunday also emphasized the role of the brain-body connection in cognitive impairment and dementia.
Weight loss may signal the onset of Alzheimer's, and the rate of weight loss could be early warning of dementia severity, according to a new review of data from what's known as the Nun's Study. That effort followed health outcomes for a group of 537 non-demented Catholic sisters, aged 75 to 102, for 10 years.
In the study, a team led by Dr. James Mortimer, a professor of epidemiology and biostatistics at the University of South Florida, Tampa, found that unexplained weight loss late in life was often linked to Alzheimer's neuropathology in the brain and not to any change in eating habits linked to Alzheimer's.
Mortimer explained that, "early weight loss appears to result from the Alzheimer's disease process itself before that process leads to dementia. That's why it is a marker of impending dementia."
In a third study, a team from the Mayo Clinic in Rochester, Minn., found an increased risk of mild cognitive impairment (MCI) or dementia among 70- to 89-year-olds who have had a carotid endarterectomy (surgical clearance of the carotid artery, which brings blood to the brain) or a stroke or "mini-stroke," also known as a transient ischemic attack (TIA).
In the study, the team compared the medical histories of 295 people with MCI and 590 age and sex-matched controls. "Elderly subjects who have had a carotid endarterectomy or stroke or TIA are about two times more likely to have MCI," lead researcher Dr. Rosebud O. Roberts, a Mayo epidemiologist, said in a prepared statement.
For more on Alzheimer's disease, visit the Alzheimer's Association.