A German study has found that mild cognitive impairment (MCI) occurs twice as often in individuals diagnosed with diabetes mellitus type 2.
However, the study also found that this strong association was only observed in middle-aged people — those between 50 and 65 years of age — while it vanished in people older than 65.
MCI is an intermediate state between normal cognitive aging and dementia. Although people with MCI have a higher dementia risk, very few actually develop dementia, researcher said. In fact, many people with MCI convert back to a cognitively normal state. This transitional — and possibly modifiable — characteristic makes MCI a promising approach in the development of prevention strategies, researchers noted.
Four criteria must be met for a diagnosis of MCI: Patients have a subjective impression of a declined cognitive performance over the last two years; this subjective impression is validated using objective measures, such as a cognitive test battery; patients are capable of handling the activities of daily living; and a diagnosis of dementia is ruled out.
There are two subtypes of MCI — patients with impairment in the memory domain are categorized as amnestic MCI, while those with deficits in non-memory domains are categorized as non-amnestic MCI.
For their study, scientists used data collected from the Heinz Nixdorf Recall (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) study, which examined 4,814 people between 2000 and 2003 in the metropolitan Ruhr area in Germany. After five years a second examination was conducted with 90% of the participants taking part.
According to researchers, 560 participants diagnosed with MCI were compared with 1,376 cognitively normal participants. Of participants with MCI, 289 had amnestic MCI and 271 had non-amnestic MCI.
The researchers found that diabetes mellitus type 2 was strongly associated with MCI, as well as MCI subtypes, but only in the middle-aged group. Examination of differences by gender revealed a stronger association of diabetes with amnestic MCI in middle-aged women and a stronger association with non-amnestic MCI in middle-aged men.
The findings suggest that middle-aged individuals with diabetes mellitus type 2 are particularly vulnerable to MCI, researchers noted in the study, which was published in the Journal of Alzheimer’s Disease.
“This underlines the importance of high quality treatment of diabetes especially in middle age, not only because of cardiovascular damage, but also because it might help to prevent or delay cognitive decline,” the researchers concluded.
Source: IOS Press