Posted Apr 19 , 2019 09:16 AM

Importance of Treatment Status in Links Between Type 2 Diabetes and Alzheimer Disease

McIntosh EC, et al. Diabetes Care 2019 Online March 4th

Institute Summary (excerpted from the Abstract):

The purpose of this study is to investigate relationships among type 2 diabetes treatment, Alzheimer disease biomarkers, and the risk for dementia. Participants from 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 b-amyloid 1-42 (Ab1-42). Participants were grouped by fasting blood glucose and medication history: euglycemia (EU), prediabetes (PD), untreated diabetes (UD), and treated diabetes (TD). Relationships were investigated between treatment status and CSF biomarkers and risk for dementia. The UD group displayed greater p-tau, t-tau, and p-tau/Ab1-42 levels than the EU, PD, and TD groups (P values <0.05) and higher t-tau/Ab1-42 than the EU and PD groups (P values <0.05). The UD group progressed to dementia at higher rates than the EU group (hazard ratio 1.602 [P = 0.026]).

Why is this important?

Alzheimer’s disease has been associated with diabetes and insulin resistance (Ferreira LSS, et al. Insulin Resistance in Alzheimer's Disease. Frontiers in Neuroscience 2018; 12:830). Treatment status may alter the relationship between type 2 diabetes and both Alzheimer disease biomarker profile and risk for dementia. UD is associated with elevated tau pathology and risk for dementia, whereas TD is not. Although this study is observational and therefore causality cannot be inferred, findings support the potential importance of treatment status in Alzheimer disease risk associated with type 2 diabetes. Were you aware of the link between insulin resistance and Alzheimer Disease? Have you mentioned that to any of your patients?

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