Effects of liraglutide on neurodegeneration, blood flow and cognition in Alzheimer's disease - Protocol for a controlled, randomized double-blinded trial

INTRODUCTION: Type 2 diabetes (DM-2) increases the risk of developing Alzheimer's disease (AD), and patients with AD are more likely to develop DM-2. DM-2 and AD share some pathophysiological features. In AD, amyloid-β (Aβ) is accumulated as extracellular plaques in the gray matter of the brain, while in DM-2 islet amyloid polypeptide (IAPP) is accumulated in the pancreas. Premature cellular degeneration is seen in both diseases. Glucagon-like peptide-1 (GLP-1) reduces the amount of Aβ and improves cognition in animal studies. The present study tests the hypothesis that treatment with the long-acting GLP-1 receptor agonist liraglutide affects the accumulation of Aβ in patients with AD. MATERIAL AND METHODS: This is a randomized, controlled, double-blinded intervention study with AD patients treated for six months with liraglutide (n = 20) or placebo (n = 20). The primary outcome is change in deposition of Aβ in the central nervous system (CNS) by Pittsburgh compound B positron emission tomography (PET). The secondary outcome is evaluation of cognition using a neuro-psychological test battery, and examination of changes in glucose uptake in the CNS by ¹⁸F-fluoro-deoxy-glucose PET. Finally, a perfusion-weighted magnetic resonance imaging with contrast will be performed to evaluate blood flow. CONCLUSION: No registered drug affects the deposition of Aβ in the brain of AD patients. Our goal is to find a new therapeutic agent that alters the pathophysiology in AD patients by decreasing the formation of Aβ plaques and thereby presumably improves the cognitive function. FUNDING: The trial is investigator-initiated and investigatordriven and is supported by Novo Nordisk Scandinavia. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01469351.