Scientists at a Japanese university say people suffering from diabetes have a greater chance of developing dementia.

Dementia refers to a considerable loss of cognitive abilities, including memory capacity, which severely undermines social or occupational functioning. Dementia is not merely a problem of memory. It reduces the ability to learn, reason, and retain or recall past experience and there is also loss of patterns of thoughts, feelings and activities.

Researchers at the Kyushu University in Fukuoka, Japan, studied 1,017 individuals aged at least 60 years. These individuals underwent a glucose tolerance test after overnight fasting to determine whether they had diabetes.

They were followed up closely for 11 years on average and then assessed for signs of dementia. Researchers found 27 percent of the diabetics have developed dementia, compared to 21 percent of people without diabetes.

According to the research findings, diabetics had doubled the risk of developing different forms of dementia such as Alzheimer's and vascular dementia, compared to individuals with normal blood glucose levels. Vascular dementia occurs when blood vessels that provide the brain with oxygen are damaged.

Additional mental and behavioral problems often affect people who have dementia, and may influence quality of life. As dementia worsens, individuals may neglect themselves.

Proper differential diagnosis between the types of dementia (cortical and subcortical) will require, at the least, referral to a specialist. Duration of symptoms must be evident for at least six months for a diagnosis of dementia or organic brain syndrome to be made.

Dementia is much less common under 65 years of age. Alzheimer's disease is still the most frequent cause, but inherited forms of dementia are rising. Frontotemporal lobar degeneration and Huntington's disease account for most of the remaining cases.

Many studies, however, have been taken place to indicate relation between diabetes and dementia. Although no research confirms specific connection between diabetes and dementia, scientists say their current emphasis is on the prevention of dementia. A recent study showed that inhaling insulin twice a day can control mild Alzheimer's.

The present study was published in the latest issue of the journal Neurology.