New Study Reveals Genetic Predisposition to High Blood Pressure and Cholesterol Linked to Increased Risk of Alzheimer’s Disease

A recent study suggests that individuals with a genetic predisposition for higher systolic blood pressure and HDL cholesterol may have an increased risk of developing Alzheimer’s disease. It is important to note that the study does not establish a direct causal relationship between these factors and the disease; rather, it identifies an association between them. However, previous research has indicated that high blood pressure is a common modifiable risk factor for Alzheimer’s disease.

The findings of this study have the potential to provide valuable insights into new drug targets and improved early prevention strategies for Alzheimer’s disease. The authors of the study, writing in JAMA Network Open on May 17, believe that these results may contribute to advancements in the field of dementia prevention.

Alzheimer’s disease affects a significant number of older adults in the United States, with an estimated 5.8 million cases in 2020. This number is projected to triple by 2060, according to the Centers for Disease Control and Prevention. The exact causes of the disease remain unclear, but researchers believe it is likely a result of a combination of age-related brain changes, genetic factors, environmental influences, and lifestyle choices. While certain medications can slow the progression of Alzheimer’s disease, there is currently no known cure.

In recent decades, scientists have been diligently working to unravel the underlying mechanisms of the disease in order to develop effective preventive and treatment approaches. In this particular study, researchers aimed to identify modifiable risk factors that could potentially increase an individual’s susceptibility to Alzheimer’s disease. To accomplish this, they analyzed data from the European Alzheimer & Dementia Biobank, which contains genetic information from individuals both with and without the disease. Genetic factors are estimated to contribute to 60% to 80% of the risk for developing Alzheimer’s disease.

The study encompassed a sample size of over 39,000 individuals diagnosed with Alzheimer’s disease and over 401,000 individuals without the disease. The results revealed that individuals with certain genes associated with higher levels of high-density lipoprotein (HDL) cholesterol had a slightly elevated risk of developing Alzheimer’s disease. Similarly, those with genes linked to higher systolic blood pressure demonstrated an increased risk as well. The study found that for every standard deviation increase in HDL cholesterol, the risk of Alzheimer’s disease rose by approximately 10%. Additionally, each 10-millimeter increase in systolic blood pressure was associated with a 22% higher risk of developing the disease.

Dr. James E. Galvin, a professor at the University of Miami and director of the Comprehensive Center for Brain Health at UHealth, noted that the study primarily focused on genetic predispositions rather than diagnosing specific conditions in individuals. However, he emphasized that identifying novel genetic associations could potentially lead to the discovery and validation of new drug targets for the treatment and prevention of Alzheimer’s disease.

Interestingly, the study did not find an increased risk of Alzheimer’s disease associated with genes related to other potentially modifiable risk factors such as blood lipids, alcohol consumption, and diabetes. The results for genes linked to smoking and body mass index (BMI) were inconclusive. Galvin expressed surprise that risk factors like diabetes, smoking, and obesity, which often coexist with high blood pressure and high cholesterol, did not appear to elevate the risk of Alzheimer’s disease.

It is worth mentioning that the majority of participants in the study were of European descent, so the findings may not necessarily apply to individuals from other regions who may have different gene variants associated with the risk of Alzheimer’s disease.

Although the study was not specifically designed to explore why high blood pressure and high HDL cholesterol might increase the risk of Alzheimer’s disease, the authors put forward a few hypotheses. Previous research has indicated that high blood pressure in midlife and late life can raise the chances of developing Alzheimer’s disease . Moreover, the authors suggest that high systolic blood pressure could impair the functioning of blood vessels, leading to disruptions in blood flow to the brain. This finding implies that managing and treating high blood pressure could potentially lower the risk of Alzheimer’s disease. Some studies have supported this notion, although the effects observed in these trials were limited to the duration of the clinical trials.

Dr. Galvin expressed surprise at the association between increased risk of Alzheimer’s disease and higher levels of HDL cholesterol, often referred to as “good” cholesterol. Traditionally, LDL cholesterol and triglycerides have been linked to poorer health outcomes, while higher levels of HDL cholesterol have been associated with a decreased risk of heart disease and stroke. HDL cholesterol plays a role in absorbing cholesterol in the blood and transporting it to the liver. The authors of the study propose that elevated levels of HDL cholesterol may disrupt the balance between blood particles and the fluid surrounding the brain, potentially contributing to dementia. However, it should be noted that reducing HDL cholesterol levels does not necessarily translate to a reduced risk of dementia. Further research is needed to fully understand the specific connection between HDL cholesterol and Alzheimer’s disease.

Regardless of the genetic associations found in the study, Dr. Galvin emphasizes that the modifiable risk factors investigated in the research play significant roles in the development of Alzheimer’s disease. He suggests that when genetic associations are absent, environmental and lifestyle factors are more likely to contribute to increased risk. A comprehensive report by the Lancet commission on dementia in 2020 estimated that addressing 12 modifiable risk factors could potentially prevent or delay up to 40% of dementia cases. This study, along with other research, supports the notion that Alzheimer’s disease is a complex and chronic condition that requires multifaceted treatment approaches.

Dr. Galvin suggests that an effective approach to Alzheimer’s disease management would involve a combination of medications, psychotherapy, lifestyle modifications, behavioral changes, risk reduction strategies, and the management of comorbid conditions. This holistic approach acknowledges the involvement of various factors and emphasizes the importance of maintaining brain health through resilience activities and reducing vulnerabilities. Individuals who invest in proactive brain health strategies may experience greater resilience against the development of Alzheimer’s disease later in life.

In conclusion, a recent study has identified a genetic predisposition to higher systolic blood pressure and HDL cholesterol as potential risk factors for Alzheimer’s disease. While the study does not establish a causal relationship, it provides valuable insights into the associations between these factors and the disease. The findings may contribute to the development of new drug targets and improved preventive measures for Alzheimer’s disease. It is crucial to continue researching the underlying mechanisms and exploring comprehensive approaches that address modifiable risk factors. By focusing on genetic predispositions, environmental factors, and lifestyle modifications, it may be possible to reduce the risk and impact of Alzheimer’s disease on individuals and society as a whole.