Age Matters Clinic


Toronto Geriatric Assessment and Memory Clinic

Can Hypertension Be Linked to Alzheimer's Disease?

Did you know that Alzheimer's disease currently affects over 36 million people worldwide? This startling statistic has lead to countless studies related the disease and why it exists. A recent study published in the Journal of the American Medical Association Neurology found there might be a link between hypertension and Alzheimer's disease.

Dr. Karen Rodrigue, assistant professor at the UT Dallas Center for Vital Longevity (CVL), conducted this study. It explored the possibility that people with hypertension, along with a genetic predisposition to Alzheimer's disease, may have an increased risk of developing the disease. The study looked at the idea that a protein build-up or "brain plaque" known as an amyloid protein occurred more frequently in those with hypertension.

The amyloid protein or brain plaque is also known as APOE 4 and is carried by 20% of the older adult population. This statistic is typically measured by autopsies as well as newer brain scanning methods that allow scientists to study the amount of brain plaque that has built up in healthy living brains. Amyloid proteins have been directly linked to Alzheimer's disease - many scientists believe the discovery of amyloid proteins is the first symptom of the disease. They are typically found in people over a decade prior to the occurrence of any other symptoms. This means that many years before any signs of memory loss or dementia actually begin, a build up of this "brain plaque" may already be present in the brain.

Upon discovering this, Dr. Rodrigue said she became interested in finding out whether or not hypertension "was related to increased risk of amyloid plaques in the brains of otherwise healthy people." She felt it was important to know what the risk factor for developing these proteins were as a way to prevent long-term repercussions of Alzheimer's disease in the future.

Dr. Rodrigue thought that the combination of hypertension as well as a predisposition to the Alzheimer's (the APOE-e4 gene) might result in higher levels of amyloid protein in adults. The result was a study of 147 people between the ages of 30 and 89 years old, which looked at the aging brain. This study was a part of the Dallas Lifespan Brain Study, funded by the National Institute of Aging.

The participants in the study were divided into groups based on whether or not they were taking medication for hypertension. They were also divided into "genetic risk groups" based on whether or not they carried the APOE-e4 gene. The study found that participants who were not taking medication for hypertension had much higher amyloid protein levels than the other test groups.

So, what do the results of the study really mean? Essentially, by properly controlling hypertension, the risk of developing these amyloid proteins may be decreased, even with an increased genetic risk of Alzheimer's disease in the patient. While there are still long-term studies to be done on this topic, it is clear that proper diagnosis and medication for hypertension is crucial.

The combination of untreated high blood pressure combined with a genetic predisposition may increase the risk of developing Alzheimer's disease. Dr. Rodrigue's study sheds light on what may be a cause of this degenerative brain disease. It also provides hope that preventative measures may decrease the risks of developing Alzheimer's disease in the future.