In recent years, it has been observed that the type 2 diabetic patients (DM-2) have an increased risk of developing dementia, both vascular and Alzheimer's disease (AD). The term mild cognitive impairment (MCI) describes a transition state between normal cognitive function and dementia. The annual rate of conversion to dementia in MCI patients is around 15% in the general population, regardless of the presence or absence of diabetes. At present it is not possible to identify which patients with MCI are most likely to progress to AD. On this basis, the main objective of this study is to evaluate whether the presence of diabetes and or the presence of its related genes favors the conversion of MCI to AD.