Brain-Imaging Study Supports the Relevance of a Common Genetic Risk Factor for Alzheimer's Disease in Latinos

Research shows how brain imaging techniques can be used in healthy people to evaluate Alzheimer's disease risk factors

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Apr 14, 2010, 02:21 ET

PHOENIX, April 14 /PRNewswire/ -- A brain-imaging study published today in the Archives of Neurology suggests that a major genetic risk factor for Alzheimer's disease in the Anglo population is also a risk factor for the disease in Latinos.

While a gene called APOE4 has been firmly established to increase an Anglo person's risk of Alzheimer's disease, its relationship to the disease in different Latino populations has been less clear. In previous studies, researchers from the Banner Alzheimer's Institute and their collaborators in the Arizona Alzheimer's Consortium used a brain-imaging technique called PET to show that cognitively healthy late-middle-aged carriers of the APOE4 gene have lower activity than non-carriers of the gene in brain regions known to be affected by Alzheimer's disease.

In the present study, they extended their findings to 27 Latinos with and without the APOE4 gene, mostly from Arizona's Mexican-American community. As predicted, cognitively healthy Latinos in their 50s and 60s with the APOE4 gene had lower activity than non-carriers of the gene in brain regions known to be affected by Alzheimer's disease.

"This study provides support for the relationship between the APOE4 gene and the risk of Alzheimer's disease in Latinos," said Dr. Jessica Langbaum, staff scientist at the Banner Alzheimer's Institute and the study's lead author. "It also shows how brain imaging techniques can be used in healthy people to evaluate genetic and non-genetic risk factors for this disorder."

Latinos are about 1.5 times more likely than Anglos to develop Alzheimer's disease, according to the Alzheimer's Association. Alzheimer disease is the most common form of dementia. Between the years 2000 and 2050, the number of affected Latinos is projected to increase by 600 percent. Latinos may be at higher risk due to higher amounts of diabetes mellitus, obesity, cardiovascular disease and hypertension, each of which is also a risk factor for Alzheimer's disease.

The researchers have proposed using the same brain imaging techniques in healthy APOE4 carriers to evaluate promising treatments to prevent Alzheimer's disease without having to wait many years to determine whether they go on to develop symptoms. Among other things, the present study supports the inclusion of APOE4 carriers from Latino community in these studies.

About the study

The study was conducted by a team of researchers at Banner Alzheimer's Institute, Translational Genomics Research Institute (TGen), Arizona State University, Mayo Clinic Arizona, University of Arizona, University of California San Diego and the Arizona Alzheimer's Consortium.

The authors include Jessica B.S. Langbaum, PhD; Kewei Chen, PhD; Richard J. Caselli, MD; Wendy Lee, MS; Cole Reschke, BS; Daniel Bandy, MS; Gene E. Alexander, PhD; Christine M. Burns, BA; Alfred W. Kaszniak, PhD; Stephanie A. Reeder, BA; Jason J. Corneveaux, BS; April N. Allen, BS; Jeremy Pruzin, BS, BA; Matthew J. Huentelman, PhD; Adam S. Fleisher, MD; and Eric M. Reiman, MD.

The authors gratefully acknowledge support from National Institute of Mental Health grant R01MH57899 (Dr. Reiman), National Institute on Aging grants R01AG031581 and P30AG19610 (Dr. Reiman), the Evelyn G. McKnight Brain Institute (Dr. Alexander), the state of Arizona (Drs. Reiman, Caselli, Alexander, and Chen), and contributions from the Banner Alzheimer's Foundation and Mayo Clinic Foundation.

About Banner Alzheimer's Institute

Banner Alzheimer's Institute (BAI) is a treatment and research facility dedicated to helping patients with memory and thinking problems. It offers clinical care for patients; provides education, referral and support services for families and caregivers; and conducts leading-edge brain-imaging, clinical trials, brain imaging and genetics studies. The Institute is devoted to finding effective Alzheimer's disease-slowing and prevention treatments in the shortest time possible. BAI is owned and operated by Phoenix-based Banner Health, a nonprofit organization. For more information, visit www.banneralz.org.

About Mayo Clinic

Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. As a leading academic medical center in the Southwest, Mayo Clinic focuses on providing specialty and surgical care in more than 65 disciplines at its outpatient facility in north Scottsdale and at Mayo Clinic Hospital. The 244-licensed bed hospital is located at 56th Street and Mayo Boulevard (north of Bell Road) in northeast Phoenix, and provides inpatient care to support the medical and surgical specialties of the clinic, which is located at 134th Street and Shea Boulevard in Scottsdale.

About TGen

The Translational Genomics Research Institute (TGen), a nonprofit 501(c)(3) organization, is focused on developing earlier diagnostics and smarter treatments. Translational genomics research is a relatively new field employing innovative advances arising from the Human Genome Project and applying them to the development of diagnostics, prognostics and therapies for cancer, neurological disorders, diabetes and other complex diseases. TGen's research is based on personalized medicine and the institute plans to accomplish its goals through robust and disease-focused research.

About University of Arizona

The University of Arizona is one of the nation's leading public universities, with a long history of academic excellence, research innovation and a student-centered approach. A member of the prestigious Association of American Universities, the UA is ranked 13th among public universities by the National Science Foundation with total research expenditures last year of $530 million. With more than 38,000 students across three campuses representing 50 states and 124 nations, the UA is on the forefront of discoveries – from the depths of space to the medical and genetic mysteries of life, from emerging trends in climate change to the broad complexities of the human condition. For more information, visit www.arizona.edu

About Arizona State University

The Biodesign Institute at Arizona State University integrates diverse fields of science to cure and prevent disease, overcome the limitations of injury, renew the environment and improve national security. By fusing research in biology, engineering, medicine, physics, information technology and cognitive science, the institute accelerates discoveries into uses that can be adopted rapidly by the private sector. For more information, visit http://www.biodesign.asu.edu.

About Arizona Alzheimer's Consortium

The Arizona Alzheimer's Consortium (AAC) capitalizes on the complementary resources of its seven member institutions to promote the scientific understanding and early detection of Alzheimer's disease and find effective disease-stopping and prevention therapies. Established in 1998, the Consortium also seeks to educate Arizona's residents about Alzheimer's disease, research progress in the state and the resources needed to help patients, families, and professionals manage the disease. The AAC is comprised of both the NIA-funded Arizona Disease Core Center (ADCC) and the state-funded Arizona Alzheimer's Research Center (AARC). The AAC's member research institutions include Arizona State University, the Banner Alzheimer's Institute, the Barrow Neurological Institute, Mayo Clinic Arizona, Sun Health Research Institute, the Translational Genomics Research Institute (TGen) and the University of Arizona.

About National Institute on Aging

The NIA leads the federal government effort conducting and supporting research on the biomedical, social and behavioral issues of older people. For more information on aging-related research and the NIA, go to www.nia.nih.gov. The NIA provides information on age-related cognitive change and neurodegenerative disease specifically at its Alzheimer's Disease Education and Referral (ADEAR) Center site at www.nia.nih.gov/Alzheimers.