Hyperinsulinemia is believed to increase the risk of Alzheimer's dementia through both cerebrovascular and A related mechanisms, and this hypothesis has prompted testing strategies related to hyperinsulinemia and diabetes in the prevention and treatment of Alzheimer's dementia.These strategies usually entail improving insulin sensitivity to lower insulin and glucose levels, such as lifestyle (diet and exercise) and metformin, which were effective strategies for preventing diabetes in the DPPOS. There are conflicting data relating metformin with increased AD risk, and this needs to be clarified in DPPOS. Several laboratory and human studies have suggested that metformin increases the risk of Alzheimer's dementia, but this is countered by other studies indicating that it is beneficial. Preliminary data in humans and animals support the beneficial effects of metformin on Alzheimer's dementia risk.