New cases of Alzheimer's and dementia continue to rise, even in the 'oldest old'

Jul 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 research reported today at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease (ICAD 2009) in Vienna.

Previous epidemiological studies have suggested that the number of people with Alzheimer's and 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 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 there is 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 reported at ICAD 2009 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.

The Monzino 80-plus Study - Dementia Risk Continues to Rise in the "Oldest Old"

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, roughly 30 kilometers (20 miles) north of Milan (known as the Monzino 80-plus Study). 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% 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% and was higher in women (25.8%) than in men (17.1%). Prevalence increased with advancing age:

  • 13.5% at 80-84 years
  • 30.8% at 85-89
  • 39.5% at 90-94
  • 52.8% over 94
The estimated annual incidence of dementia standardized on the 2008 Italian population was 8.6% and was higher in women (9.2%) than in men (7.2%). Incidence also rose with increasing age:
  • 6.0% at 80-84 years
  • 12.4% at 85-89
  • 13.1% at 90-94
  • 20.7% 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."

According to the researchers, though the rate of women who developed dementia during the follow-up period was higher than in men in this study, no definite conclusion can be drawn about this difference because the number of men in the oldest ages became very small.

Systematic Review of Dementia in Europe - Higher Prevalence in Female "Oldest Old"

The goal of Dr. Emma Reynish, a consultant geriatrician and coordinator of the European Consortium from the Victoria Hospital, Kirkcaldy, Scotland, UK, and colleagues at the EuroCoDe (European Collaboration on Dementia) project, was to determine the prevalence of dementia in Europe based on up to date research findings and including data from Eastern Europe. They conducted an extensive literature search using Cochrane review methodologies and compiled a database of all European epidemiological studies in the field up to the present date. 194 articles were identified by the review and 26 studies met inclusion criteria to participate with raw data in the collaborative analysis.

According to the researchers, while dementia prevalence rates for all men and for women up to age 85 confirmed previous findings, age-specific prevalence rates were higher than previously documented in the female "oldest old" age groups, rising to over 50% in those over 95 years.

"Our key findings confirmed that age remains as the single most important risk factor for dementia," Reynish said. "Nevertheless, due to the lack of data in the oldest old in previous prevalence studies, the prevalence of dementia of women over the age of 85 had been underreported."

Source: Alzheimer's Association

Explore further: Malaysia quarantines 64 villagers over MERS virus

add to favorites email to friend print save as pdf

Related Stories

Women over 90 more likely to have dementia than men

Jul 02, 2008

Women over 90 are significantly more likely to have dementia than men of the same age, according UC Irvine researchers involved with the 90+ Study, one of the nation's largest studies of dementia and other health factors ...

Having a parent with dementia may affect memory in midlife

Feb 18, 2009

People who have parents diagnosed with Alzheimer's disease or dementia may be more likely to have memory loss themselves in middle age, according to a study released today that will be presented at the American Academy of ...

Researchers find parental dementia may lead

Feb 19, 2009

People who have parents diagnosed with Alzheimer's disease or dementia perform less well on formal memory testing when compared to people of the same age whose parents never developed Alzheimer's disease or other dementia. ...

Recommended for you

Malaysia quarantines 64 villagers over MERS virus

6 minutes ago

Malaysia has quarantined 64 people in a southern village after one of its residents become the country's first person to die of a respiratory illness that is spreading from the Middle East, local media reported Thursday.

Spate of Mideast virus infections raises concerns

36 minutes ago

A recent spate of infections from a frequently deadly Middle East virus is raising new worries about efforts to contain the illness, with infectious disease experts urging greater vigilance in combatting ...

New MRSA superbug emerges in Brazil

1 hour ago

An international research team led by Cesar A. Arias, M.D., Ph.D., at The University of Texas Health Science Center at Houston (UTHealth) has identified a new superbug that caused a bloodstream infection ...

User comments : 0

More news stories

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Proper stem cell function requires hydrogen sulfide

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study from the Center for Craniofacial Molecular Biology at the Herman Ostrow School of Dentistry ...

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...