Alzheimer's Is Poised for Exponential Increase
Sullivan, Michele G., Clinical Psychiatry News
The prevalence of Alzheimer's disease is expected to quadruple over the next 40 years, affecting almost 107 million people--1 in 85--worldwide by 2050.
This projected exponential increase points up even more sharply the need for advances in both prevention and treatment, according to Ron Brookmeyer, Ph.D., who presented the data at a meeting sponsored by the Alzheimer's Association.
"Everyone would like us to hit the home run--a cure for Alzheimer's," said Dr. Brookmeyer, a professor of biostatistics at Johns Hopkins University, Baltimore. "But we found that even modest successes in prevention and treatment interventions could have a big impact in reducing the number of cases. A 1-year delay in onset and progression together would decrease the worldwide prevalence by more than 9 million people by 2050, with an accompanying reduction in the numbers with costly late-stage disease."
The increase in disease is inevitable, he said in an interview, because it is driven by the aging of the world's population. "It's clear that the biggest predictor of developing Alzheimer's is age, and more and more people are living longer."
Interestingly, he said, the risk of developing Alzheimer's appears constant throughout the world, despite the wide variety of environmental and economic factors that occur in different regions. He and his colleague, Kathryn Ziegler-Graham, Ph.D., of St. Olaf College, North-field, Minn., previously concluded that the risk of Alzheimer's doubles every 5 years
once a person reaches a critical age, regardless of location (Alzheimers Dement. 2007;3:S168-9).
"At age 80, the average risk of developing Alzheimer's within the next 12 months is 1.5%," Dr. Brookmeyer said. "At age 85, the risk is 3%, and it continues to double every 5 years. We did find some variation across countries in when the risk begins to build, but wherever you start, the doubling occurs every 5 years. It's remarkably consistent."
Using this finding and the worldwide literature on current prevalence, Dr. Brookmeyer concluded that Alzheimer's is poised for an explosive increase (Alzheimers Dement. 2007;3:186-91).
However, his projection for 2050 is based on current estimates that don't include data for every country in the world. …