July 13, 2009
The number of people with Alzheimer's and dementia--both new cases and total numbers with the disease--continues to rise among the very oldest segments of the population in contradiction of the conventional wisdom, according to new research.
Previous epidemiological studies have suggested that the number of people with Alzheimer's and dementia begins to level off and perhaps even go down a bit in people age 90 and above, known as the "oldest old." This is the fastest growing segment of the population in western countries.
"The number of people affected by Alzheimer's and dementia is growing at an epidemic pace, and the skyrocketing financial and personal costs will devastate the world's economies and healthcare systems, and far too many families," said William Thies, Ph.D., Chief Medical & Scientific Officer at the Alzheimer's Association. "We must make the fight against Alzheimer's a priority before it's too late."
However, experts see plenty of hope. There are many drugs in late stage clinical trials for Alzheimer's that show promise to slow or stop the progression of the disease.
"This, combined with advancements in early detection, has the potential to change the landscape of Alzheimer's in our lifetimes. But we need more funding for research to see these possibilities through to completion," Thies said.
The research includes a study of more than 2,100 individuals age 80 years or older in eight municipalities of Varese province, Italy, and a systematic review and collaborative analysis of studies reporting the prevalence of dementia in Europe.
Ugo Lucca, head of the Laboratory of Geriatric Neuropsychiatry at the Mario Negri Institute for Pharmacological Research in Milano, Italy, and colleagues conducted a prospective, door-to-door, population-based study of all people age 80 years or older in eight municipalities of Varese province, Italy. Their goal was to estimate the prevalence (total number with the disease) and incidence (new cases of the disease) of dementia in this population.
The researchers were able to gather information and an initial dementia evaluation for 2,138 individuals. The mean age of the population at that first evaluation was 87.5 years; 74.1 percent were women. Mean education was 5.1 years, and mean MMSE score was 21.4. After an average follow-up period of three years, of the 1,085 survivors non-demented at baseline, 995 were re-evaluated for dementia.
Prevalence of dementia standardized on the 2008 Italian population was 22.9 percent and was higher in women than in men. Prevalence increased with advancing age:
13.5 percent at 80-84 years
30.8 perecent at 85-89
39.5 percent at 90-94
52.8 percent over 94
"Gathering reliable information on such a large number of the 'oldest old' makes this one of the largest studies investigating dementia in this age segment of the population," Lucca said. "This study's results confirm that Alzheimer's and dementia are very common among the oldest people in society. We believe this strengthens the need to shift more of the focus of clinical research to this segment of the elderly population."
