Treatment status may alter the relationship between type 2 diabetes (T2D) and both Alzheimer disease (AD) biomarker profile and risk for dementia, according to a recent study. Furthermore, untreated diabetes (UD) is associated with elevated tau pathology and risk for dementia, whereas treated diabetes (TD) is not. These findings support the potential importance of treatment status in AD risk associated with T2D. Participants included individuals form the Alzheimer Disease Neuroimaging Initiative (n=1,289) who were dementia-free at baseline and underwent health assessment, cognitive testing, and MRI. A subset (n=900) obtained a lumbar puncture to determine cerebrospinal fluid (CSF) phosphorylated tau (p-tau), total tau (t-tau), and β-amyloid 1-42 (Aβ1-42). Participants were grouped by fasting blood glucose and medication history: euglycemia (EU), prediabetes (PD), UD, and TD. Researchers found:
- The UD group displayed greater p-tau, t-tau, and p-tau/Aβ1-42 levels than the EU, PD, and TD groups and higher t-tau/Aβ1-42 than the EU and PD groups.
- The UD group progressed to dementia at higher rates than the EU group (hazard ratio 1.602).
McIntosh EC, Nation DA, for the Alzheimer’s Disease Neuroimaging Initiative. Importance of treatment status in links between type 2 diabetes and Alzheimer disease. [Published online ahead of print March 4, 2019]. Diabetes Care. doi:10.2337/dc18-1399.