The number of U.S. adults 65 years of age and older — approximately 40 million as of the 2010 census — is expected to nearly double to 71 million by 2030 and to reach 98 million by 2060, according to a report from the University of California at Los Angeles.
Dr. Ron Brookmeyer, a professor of biostatistics at the university’s Fielding School of Public Health, has employed sophisticated computer models to visualize the looming Alzheimer’s epidemic, as well as the potential positive effect of future therapies and other strategies to prevent or delay the onset and progression of symptoms.
Brookmeyer’s work in this arena began nearly 20 years ago with a paper he wrote in the American Journal of Public Health projecting that the prevalence of Alzheimer’s disease in the U.S. would nearly quadruple by the middle of this century, by which time approximately one in 45 Americans will be affected. His 2007 study also projected that one in 85 persons worldwide will be living with the disease by 2050, with nearly half of them requiring a level of care equivalent to that of a nursing home.
As part of his recent research, Brookmeyer considered both demographic trends and the severity of the disease. “This is a long illness,” he said. “Once you’re diagnosed, you might live with it for 10 or more years, and the intensity of the care required will vary during that time. From a public health point of view, it’s very important to look at where people will be in different stages of the disease and the needs we will be facing as a society.”
Through a systematic review of Alzheimer’s studies, Brookmeyer and his team found that the rate of being diagnosed with the disease doubles every five years in older populations. For example, the likelihood of a diagnosis at age 77 is approximately 1%; by age 82, it is 2%; and at age 87, it is 4%.This rate of increase with aging is consistent across the world, Brookmeyer noted. Combining those factors with trends in other causes of aging-related mortality, such as cardiovascular disease and cancer, he and his team were able to forecast the future prevalence of Alzheimer’s disease.
According to Brookmeyer’s data, the worldwide prevalence of the disease is expected to balloon from 35 million cases in 2015 to 106 million cases in 2050.
The modeling also allowed Brookmeyer and his colleagues to factor in the future effect of advances in Alzheimer’s disease prevention and treatment.
“What if we could delay the onset of the disease for a few years?” he asked. “In an aging population, even modest advances could be home runs in terms of their public health impact.” For example, Brookmeyer has found that if an intervention could delay the average disease onset by even a single year, it would reduce by 9 million the number of projected worldwide cases by mid-century.
While Brookmeyer’s projections of the increase in Alzheimer’s disease paint a bleak picture, given the current state of prevention and treatment, he points out that recent developments in the field offer room for optimism.
There have been new insights into how the disease develops, as well as the identification of new biomarkers that can assist in diagnosing Alzheimer’s and tracking the impact of potential therapies. “Among the most promising interventions currently under investigation are those that target the buildup of amyloid beta proteins in an effort to slow the onset and progression of Alzheimer’s,” Brookmeyer said.
He is now developing new models to better understand the potential affect of these so-called anti-amyloid beta interventions.
Source: UCLA; January 5, 2016.