Type 2 Diabetes Mellitus as a causal factor for dementia – is there sufficient evidence from interventional studies?

Type 2 Diabetes Mellitus is associated with a 2-3 fold greater risk of incident dementia, possibly secondary to neurodegeneration and/or cerebrovascular disease. There is great interest in determining underlying biological mechanisms with the promise of interventions to reduce dementia risk. Interventional studies, although the highest level of evidence for causal relationships, are few in this regard. This review summarises the current state of play in interventions designed to modify diabetes-related mechanisms that may promote cognitive decline. It is clear at this stage that further work needs to be done to establish a clear causal relationship between diabetes and dementia.