Time for a new view of late-life dementia

SEATTLE—Two new studies published in the December 16, 2009 issue of the Journal of the American Medical Association point to the need for a broader scientific perspective on late-life dementia, according to an editorial in the same issue by Thomas J. Montine, MD, PhD, University of Washington (UW) professor of neuropathology, and Eric B. Larson, MD, MPH, executive director of Group Health Research Institute.

One study, led by Robert C. Green, MD, MPH, of Boston University School of Medicine, shows that the drug tarenflurbil—which aims to suppress the accumulation of amyloid protein (plaque) in brain tissue—did not slow cognitive decline or loss of usual daily activities.

"This is yet another example among several drug candidates" that was shown to work in mice "but failed to translate into demonstrated benefit for patients," Drs. Montine and Larson write.

Since dementia research began, scientists have narrowly focused on Alzheimer's disease and its specific characteristics, explains Dr. Larson. "But we're now starting to see that dementia is a confluence of three common disease processes—Alzheimer's disease, vascular brain injury, and Lewy body disease—any one of which can be a target for prevention or treatment in efforts to relieve the burden of late-life dementia."

The second study, led by Wolfgang Lieb, PhD, of the Framingham Heart Study, showed that higher levels of leptin—a hormone involved in fat metabolism—is linked to reduced risk of Alzheimer's disease.

"This is a surprising new association—the magnitude and strength of which is striking," says Dr. Larson. "If it's confirmed, it could lead to further research on how lifestyle and other factors like habitual exercise figure in the prevention and treatment of age-related decline and diseases such as Alzheimer's."

Dramatically increasing global life expectancy makes it "imperative for research to find solutions that prevent, delay, slow, and treat Alzheimer's disease and related dementias," write Drs. Montine and Larson. "It would be difficult to overstate the urgency of this need."

Dr. Larson also leads the Adult Changes in Thought (ACT) study—a joint project between Group Health Research Institute and the UW. ACT focuses on finding ways to delay or prevent dementia, including Alzheimer's disease, and declines in memory and thinking. The National Institute on Aging recently awarded the ACT study a grant of nearly $12 million to continue its work for five more years. Dr. Montine is a co-investigator for the ACT study and the Alvord Professor of Neuropathology at the UW. He also leads the Udall Center of Excellence in Parkinson's disease at the UW.

(A video of Dr. Larson describing their research on healthy aging and dementia is available at http://ghcnews.org.)

Founded in 1947, Group Health Cooperative is a Seattle-based, consumer-governed, nonprofit health care system. Since 1983, its Group Health Research Institute (www.grouphealthresearch.org) has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems. Government and private research grants provide the Institute's main funding.

UW Medicine includes the School of Medicine, Harborview Medical Center, UW Medical Center, Northwest Hospital, UW Medicine Neighborhood Clinics, UW Physicians, Airlift Northwest, and the UW's involvement in the Seattle Cancer Care Alliance. UW Medicine has major academic and service affiliations with Seattle Children's, Fred Hutchinson Cancer Research Center, and the Veteran's Affairs Puget Sound Health Care System in Seattle and VA Hospital in Boise. The UW School of Medicine is the top public institution in federal funding for biomedical research.

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