New Studies Reinforce Link Between Cholesterol-lowering Statins and Reduced Risk of Alzheimer's 7/23/2002
From: Elizabeth Wilson or Jim Prescott, 312-335-4078 (Chicago) or 46-872720-05 (Stockholm, July 20-25), both of the Alzheimer's Association (USA) E-mail: media@alz.org STOCKHOLM, Sweden, July 23 -- Three new studies being released this week strengthen evidence linking the use of statins -- drugs prescribed to lower low-density lipoprotein (LDL) cholesterol, the type most strongly linked with coronary artery disease and stroke -- with a reduced risk of Alzheimer's disease. Previous epidemiological studies have indicated a relationship between taking statins to reduce cholesterol levels and a decreased occurrence of Alzheimer's. The new research builds on that evidence and begins to explain why and how these drugs -- whose role in lowering risk of heart attacks is well established -- may affect cellular processes involved in Alzheimer's disease. An epidemiological study by Robert C. Green, MD, MPH, and colleagues at Boston University School of Medicine found that individuals taking statins to lower cholesterol reduced their risk of developing Alzheimer's disease by 29 percent. At 2,378 participants, the study was the largest to date exploring the statin-Alzheimer connection as well as the first to include a large number of African Americans. The researchers found the same level of risk reduction in whites and African Americans and no difference in the protective effects of natural statins compared to synthetic statins. In addition, the investigators found that non-statin cholesterol-lowering medications were not significantly associated with reduced risk of Alzheimer's. The work of Brian Austen and colleagues at St. George's Hospital Medical School in London begins to shed light on biochemical mechanisms that may account for statins' protective effects. Using laboratory cell cultures, Austen's team explored the relationship between statins, cholesterol levels, and production of beta-amyloid, the protein fragment that aggregates into amyloid plaques, a defining pathological hallmark of Alzheimer's. The group found that using statins to reduce cellular cholesterol levels dramatically lowered production of beta-amyloid. Previous work by the group showed that raising cellular cholesterol increased beta-amyloid production. "The small amounts of beta-amyloid normally found in the blood of healthy people are quickly cleared from the brain," Austen explains. "In people with Alzheimer's, the beta-amyloid protein is abnormally processed by nerve cells and deposited into the brain where it builds up over time resulting in the amyloid plaques that are the hallmark of Alzheimer pathology. Austen concludes, "In the general population, people taking statins to reduce their blood cholesterol, for whatever reason, have a 70 percent reduction rate for Alzheimer's. An elevated cholesterol level is a risk factor for the disease explaining this effect." Another study by Tsuneo Yamazaki from the department of Neuropathology at the University of Tokyo further explores the effects of statins on beta-amyloid. Yamazaki's team found that statins reduced production of beta-amyloid in a cell culture, with the reduction directly proportional to the statin dose. The study also implicated a particular cholesterol-processing pathway in the protective effect of statins, suggesting that cholesterol levels and differences in the body's cholesterol-processing capabilities may influence Alzheimer risk. An increasing number of studies which suggest that people with cardiovascular risk factors have an increased risk of Alzheimer's has heightened interest in this area of research. According to William Thies, vice president of medical and scientific affairs for the Alzheimer's Association, "The relationship between cholesterol levels and Alzheimer's disease continues to be one of the more active areas of Alzheimer research. The current generation of statin studies is very exciting in that they may give us a way to reduce the risk of developing AD. To confirm the theory that statins can reduce the risk of dementia, a randomized trial is starting in the U.S." The Alzheimer's Association is hosting the 8th International Conference on Alzheimer's Disease and Related Disorders, July 20-25, 2002, in Stockholm, Sweden. The Conference is the largest gathering of Alzheimer's researchers in history. As many as 4,000 researchers from around the world will present and discuss the findings of nearly 2,000 studies on the prevention, diagnosis and treatment of Alzheimer's disease. The Alzheimer's Association is the premier source of information and support for the 4 million Americans with Alzheimer's disease. The largest private funder of Alzheimer research in the United States, the Association has committed $138 million toward research into the causes, treatment and prevention of Alzheimer's. --- Abstract Nos. 1025, 530, 380 Sessions: Monday, July 22, 3-5 p.m. (1025) Sunday, July 21, 3-5 p.m. (530) Sunday, July 21, 12:30-2:45 p.m. (380) Researchers: Robert C. Green, Brian Austen, Tsuneo Yamazaki --- Editor's Note: News releases of selected research presented at the 8th International Conference on Alzheimer's Disease and Related Disorders are available on the Alzheimer's Association's Web site, at www.alz.org/internationalconference/newsroom.htm. Scientific abstracts are accessible on the Web at http://www.alz.org/internationalconference/programs.htm, then click on Program Navigator link. |