Alzheimer's increasing among 'oldest old'

VIENNA, July 14 (UPI) -- Cases of Alzheimer's and dementia, in contradiction of conventional wisdom, continue to rise among the very old, researchers in Italy said.

Previous epidemiological studies have suggested 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."

Ugo Lucca -- head of the Laboratory of Geriatric Neuropsychiatry at the Mario Negri Institute for Pharmacological Research in Milan, Italy -- and colleagues conducted a door-to-door, population-based study of all people age 80 or older in eight municipalities of Varese province, Italy, roughly 20 miles north of Milan.

The researchers gathered information and an initial dementia evaluation for 2,138 people. The mean age at the first evaluation was 87.5 years and 74.1 percent of subjects were women.

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 at 25.8 percent than in men at 17.1 percent. Prevalence increased with advancing age:

-- 13.5 percent at 80-84 years.

-- 30.8 percent at 85-89 years.

-- 39.5 percent at 90-94 years.

-- 52.8 percent over age 94.

The findings were presented at the Alzheimer's Association International Conference on Alzheimer's Disease in Vienna.