Aug. 12, 2008 — Adults who have severe or long-term diabetes or who develop the disease before age 65 have anincreased risk of mild but noticeable memory problems.
Researchers reporting in the August issue of Archives of Neurology havelinked mild cognitive impairment to earlier onset, longer duration, and greaterseverity of diabetes.
Mild cognitive impairment is a condition marked by mild forgetfulness, languagedifficulties, and other cognitive problems that are noticeable but do notinterfere with everyday tasks. It is considered a transition stage betweennormal aging and dementia (including Alzheimer’s disease), according to the journalarticle.
The new findings confirm results from previous studies, which have suggested anassociation between diabetes and declining cognitive function. Diabetes alsoraises one’s risk of cardiovascular disease, including stroke, which can make cognitive problems morelikely.
For the current study, Rosebud O. Roberts, MBChB, and colleagues at the MayoClinic in Rochester, Minn., compared 329 adults aged 70 to 89 with mildcognitive impairment to 1,640 people of the same age who did not have any typeof cognitive impairment. Each participant had a neurological exam,neuropsychological evaluation, and lab work to measure fasting blood glucose(blood sugar) levels. Researchers asked the participants questions about theirdiabetes history, treatment, and complications. Medical records were used toconfirm their diabetes history.
Similar rates of diabetes were noted between the two groups (20.1% for theimpaired group vs. 17.7% for the unimpaired participants).
However, those with mild cognitive impairment were more likely to:
- Have developed diabetes before age 65
- Have had the disease for 10 or more years
- Require insulin treatment
- Have complications of the disease
Roberts’ team says severe diabetes is more likely to be associated withpoorly controlled blood sugars, which can damage nerve cells in the brain andlead to cognitive impairment.
Diabetes-related damage to blood vessels may also lead to cognitive problems.People with diabeticretinopathy, a complication of diabetes that affects small blood vessels inthe eyes, are twice as likely to have mild cognitive impairment, a finding thatsupports this theory, study authors add.