Grant: Catalyst Grant: Secondary Analysis of Neuroimaging Databases

Alzheimer's disease (AD) affects more than 35 million people worldwide. Approximately 750,000 Canadians have cognitive impairment or AD, a number expected to double within a generation. High blood pressure is an important risk factor for the development of AD and 62% of Canadians at the age of AD onset have high blood pressure. High blood pressure is believed to cause damage in the brain's white matter, appearing as hyperintense lesions (bright spots), increased ventricle size, and brain tissue loss on brain imaging (e.g., MRI). A potential factor in the development of AD is that this damage leads to the build-up of a protein called Beta-amyloid (Abeta), which is found in the brain of patients with AD. Medications called angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptive blockers (ARBs) are the most commonly prescribed treatments for high blood pressure and cardiovascular disease prevention. However, these medications have very different effects on how the brain processes and eliminates the Abeta protein from the blood vessels, which might have an important impact on brain structure and cognitive ability. The proposed study will determine whether 1) the risk of increased damage and build up of amyloid in the brain seen on different types of brain imaging differs in elderly adults taking ACEI medication for high blood pressure compared to those taking ARB medication and 2) the risk of decline in cognitive ability differs in people taking these different medications. Our research team will use information from the ADNI database to identify adults treated with these different medications and test for differences in brain damage and cognitive abilities between individuals in each medication group. This study could have an important impact on which medications are prescribed for high blood pressure in elderly adults at risk for AD and may also provide new information about what processes in the brain are involved in the development of AD.