Individuals with diabetes have a much greater chance of developing dementia than other people, researchers from Kyushu University in Fukuoka, Japan, reported in the journal Neurology. Dementia refers to a considerable loss of cognitive abilities, including memory capacity, which is severe enough to undermine social or occupational functioning.
Yutaka Kiyohara, MD, PhD, said:
“Our findings emphasize the need to consider diabetes as a potential risk factor for dementia. Diabetes is a common disorder, and the number of people with it has been growing in recent years all over the world. Controlling diabetes is now more important than ever.”
The authors explained that diabetes patients have a greater risk of developing Alzheimer’s disease and other dementias, such as vascular dementia. Vascular dementia occurs when blood vessels which provide the brain with oxygen are damaged – the brain becomes deprived of oxygen.
Their study included 1,017 individuals aged at least 60 years. They underwent a glucose tolerance test after fasting overnight to determine whether they had diabetes. They were followed-up closely for 11 years (average) and then assessed for signs of dementia. 232 of them developed dementia during this period.
They found that those with diabetes had double the risk of developing dementia, compared to individuals with normal blood glucose levels. 41 of the 150 people with diabetes developed dementia, compared to 115 out of 559 who did not have diabetes and developed dementia. Some of the 559 had raised levels of glucose, but not enough for a diabetes diagnosis.
The results still stood, even after the investigators took into account such factors as hypertension, smoking and high cholesterol.
The authors also found that people with pre-diabetes – those with impaired glucose tolerance – also had a higher risk of developing dementia. Even those whose blood sugar remained high two hours after a meal had a higher dementia risk.
Written by Christian Nordqvist