Exploring the intersection: Cardiovascular mortality trends among Alzheimer’s patients in the U.S.

In a recent study published in The American Journal of Cardiology, researchers compare the trends in cardiovascular disease-related mortality among patients with Alzheimer’s disease (AD) with the general United States population aged 65 years and older.  

Study: Trends in Cardiovascular Mortality Among Individuals with Alzheimer’s Disease in the United States, 1999-2020. Image Credit: Nymphalyda / Shutterstock.com

Cardiovascular disease and AD

As the global population continues to age, a gradual increase in the prevalence of AD has been observed over the past several decades. Several genetic and non-genetic risk factors are associated with the development of AD, which is the main cause of dementia.

Various cardiovascular disease (CVD)-related risk factors are also known to increase the risk of AD. For example, apolipoprotein E (APOE) is a common genetic risk factor for AD and CVD due to its involvement in cholesterol transportation as well as brain development. Among non-genetic risk factors, hypertension, and cholesterol serve as potential risk factors for both AD and CVD.

The accumulation of amyloid-beta plaques in the brain is a major hallmark of AD. Impaired clearance of amyloid-beta plaques because of poor vascular integrity due to CVD is believed to be a potential mechanism linking CVD with AD. The poor vascular integrity in CVD has also been associated with poor integrity of the blood-brain barrier (BBB) in AD.

About the study

In the current study, scientists compare CVD-related mortality rates between AD patients and the general U.S. population aged 65 years and above. Moreover, they investigate whether certain demographic characteristics including sex, ethnicity/race, geographic region, and urbanization can influence the risk of CVD-related mortality among AD patients.     

The U.S. Centers for Disease Control and Prevention (CDC) dataset was used to determine national trends in age-adjusted CVD-mortality rates and average annual percent change values in the study populations between 1999 and 2020.

Important observations

A total of 332,870 deaths due to CVD as a primary cause and AD as a contributory cause were identified between 1999 and 2020. This accounted for an age-adjusted mortality rate of 35.8 for every 100,000 individuals.

Among AD patients, a reduction in age-adjusted CVD-related mortality rate was observed between 1999 and 2020 from 51.7 to 25.9, respectively, for every 100,000 individuals. Regarding the annual percent change in CVD-related mortality, a 3.5% reduction among AD patients and 2.6% reduction in the general U.S. population was observed. The reduction in CVD-related mortality in AD was significantly higher than that in the general population.

Among various causes of CVD-related deaths, including ischemic heart disease, hypertensive disease, cerebrovascular disease, and heart failure, no significant difference in hypertensive disease-related mortality rate was observed between AD patients and the general U.S. population. For other causes, the reduction in mortality rates between 1999 and 2020 was significantly higher among AD patients. The reduction was most prominent for ischemic heart disease-related mortality.       

A similar reduction in CVD-related mortality rates between 1999 and 2020 was observed among male and female AD patients. No significant difference in mortality rate reduction was observed between individuals living in urban or rural regions.

Considering racial groups, the highest reduction in CVD mortality rates was observed among American Indians and Alaskan Natives. Comparatively, the lowest reduction was observed among Asian or Pacific Islander patients with AD. 

When age was considered, a greater reduction in CVD mortality rates was observed among patients aged 65-74 and 75-84 years as compared those 85 years of age and older. In terms of ethnicity, a lower reduction in CVD mortality rates over time was observed among Hispanic AD patients as compared to non-Hispanic AD patients.

Study significance

The current study reports a gradual reduction in CVD-related mortality rates among AD patients in the U.S. over the past two decades. This reduction is higher among AD patients as compared to the general U.S. population 65 years of age and older.

The study findings are valuable for public health efforts aimed at improving cardiovascular health among AD patients. Clinicians should motivate AD patients who are at higher risk for CVD mortality to adopt healthy lifestyle habits, such as a balanced diet, regular physical activity, adequate sleep, and smoking and alcohol cessation.    

Written by

Dr. Sanchari Sinha Dutta

Dr. Sanchari Sinha Dutta is a science communicator who believes in spreading the power of science in every corner of the world. She has a Bachelor of Science (B.Sc.) degree and a Master's of Science (M.Sc.) in biology and human physiology. Following her Master's degree, Sanchari went on to study a Ph.D. in human physiology. She has authored more than 10 original research articles, all of which have been published in world renowned international journals.