Global view on Alzheimer's Disease and Diabetes Mellitus: Threats, Risks and Treatment Alzheimer's Disease and Diabetes Mellitus

The incidence of both diabetes and Alzheimer's disease (AD) is increasing and is becoming a social and economic threat worldwide. Recent research studies indicate that both diseases share some pathophysiological features and that specifically, Type 2 Diabetes Mellitus (T2DM) is a risk factor of Alzheimer's disease. The aim of this study is to explore the relationship between diabetes mellitus and AD, explore the efficacy of selected drugs on patients with diabetes and AD, and compare the relative risk of diabetes for Alzheimer's disease within different clinical studies. The method of literature search in several acknowledged databases such as Web of Science, Elsevier Science Direct, PubMed and Scopus in the period from 2000 to 2015 for the following keywords: "Alzheimer's AND disease AND diabetes AND mellitus" was used. The identified studies were divided into two basic groups, based on their focus: efficacy of the selected drugs on patients suffering from AD and diabetes, and a link between diabetes and AD; as diabetes is seen as a risk factor of AD. The findings of this study confirm that there is a close and direct link between diabetes and AD, which indicates that there is a need for early diagnosis of metabolic syndrome, insulin resistance, and T2DM. In fact, the reviewed clinical trials have proved an increase in the risk of AD. However, the values of this risk are relatively low. The results also illustrate that both pharmacological (e.g., the antidiabetic drugs together with insulin dosing) and non-pharmacological (e.g., being intensively engaged in physical activities) treatments can have a positive effect. The results of this study confirm that diabetes and AD are not independent disorders since they share some common pathophysiological mechanisms. In addition, more clinical randomized control trials are needed to explore the efficacy of both pharmacological and non-pharmacological approaches to the treatment of T2DM and AD.