Retraction notice to “A feasibility study of the combination of intranasal insulin with dulaglutide for cognition in older adults with metabolic syndrome at high dementia risk- Study rationale and design” [Mech. Ageing Dev. 213 (2023) 111825] (Mechanisms of Ageing and Development (2023) 213, (S0047637423000519), (10.1016/j.mad.2023.111825))

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). “This article has been retracted at the request of the authors and Editor-in-Chief. The authors brought to the Editor-in-Chief's attention that they encountered an issue during the ongoing preparations for their research study involving the formulation of the placebo for Dulaglutide. The manuscript described the design and methods of a double-blind placebo controlled clinical trial examining the combined effects of twice daily intranasal insulin and once weekly an injection of dulaglutide. At the time of publication, the authors were awaiting a placebo syringe for dulaglutide to be shipped to them. Regrettably, the syringe the authors received was not in line with their initial order and did not match their specifications. Despite enormous efforts to find an alternative supplier for syringes for the placebo of Dulaglutide, they were unable to identify a suitable provider. Consequently, they made the decision to transition to an alternative GLP1 receptor agonist medication drug named Semaglutide. Semaglutide is administered orally, marking the only change in their study design and rationale, with the core objectives remaining unchanged. All other components of the study rationale, design and methods, including the four study arms, the length of the study, the number of face-to-face assessments, and all outcome measures remained unchanged. Changes relate to the potential adverse events from Semaglutide. The authors confirmed that the funding organization supporting their research reviewed and approved of this change. Following this change, the authors have submitted an amended version of the article, which was subject to standard peer review, and has been accepted by Mechanisms of Ageing and Development. It has been published online and is available via https://www.sciencedirect.com/science/article/pii/S0047637423001240 and the DOI: https://doi.org/10.1016/j.mad.2023.111898. The authors apologize for any inconvenience”.