High glucose levels, followed by a decline occurring years before diagnosis in African Americans with diabetes, may represent a powerful presymptomatic metabolic indicator of dementia, according to a recent study. Researchers conducted a secondary data analysis merging electronic medical records (EMRs) with data collected from the Indianapolis–Ibadan Dementia Project (IIDP). Of the enrolled 4,105 African Americans, 3,778 were identified in the EMR. Study endpoints were dementia, mild cognitive impairment (MCI), or normal cognition and repeated serum glucose measurements were used as the outcome variables. They found:

• Diabetic participants who developed incident dementia had a significant decrease in serum glucose levels in the years preceding the diagnosis compared to the participants with normal cognition.
• They also had significantly higher glucose levels up to 9 years before the dementia diagnosis.