Meta meta-analysis of cardiovascular risk factors in Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Identifying some of the cardiovascular risk factors for AD could be crucial for primary prevention and help reduce the incidence of AD. Objective: We aimed to perform a meta-meta-analysis of 3 studies to assess the effect of cholesterol, blood pressure and stroke on diagnosis of AD.

The search was restricted to meta-analyses in the last three years assessing cholesterol, blood pressure, stroke and Alzheimer's disease. We applied the PRISMA guidelines.

The total effect of cholesterol on risk of AD was significant and heterogeneous. Subgroup analysis shows that LDL-C levels influence the development of AD. High SBP is associated with AD. The exploration of parameters (sex, age, study design, region, and BP measurements) shows that only region significantly moderates the relationship between BP and AD. Results report significant association between ischemic stroke (IS), hemorrhagic stroke (HS) and microinfarcts (MI) with the risk of AD.

These results strengthen the evidence that the risk factors related to cardiovascular diseases increase risk for AD. Moreover, moderator analysis supports the robustness of our results. Therefore, future studies should use other uncontrolled factors, such as diabetes, to explain the relationship between these variables.