Hypertension linked to higher dementia risk in middle-aged patients

By Dr. Priyom Bose, Ph.D.Apr 4 2024Reviewed by Benedette Cuffari, M.Sc.

A recent study in the journal Hypertension Research investigates whether patients with hypertension are at a higher risk of developing dementia.

Study: Predicting cognitive function and dementia risk in patients with hypertension. Image Credit: Bits and Splits / Shutterstock.com

What causes dementia?

Dementia is a neurodegenerative disease associated with an impaired ability to think, remember, or make decisions. Since dementia has a long pre-clinical stage, early diagnosis is crucial.

Several modifiable vascular and non-vascular risk factors have been associated with over 40% of dementia cases. Among these, hypertension could be the most potentially modifiable vascular risk factor that affects individuals over 40 years of age.

Hypertension can lead to brain damage, small vessel disease (SVD), increased white matter lesions (WML), as well as lower brain cortical and subcortical volumes. These conditions are significantly associated with the clinical manifestation of dementia, cognitive impairment, and Alzheimer's Disease.

Understanding the factors that impact the brain could assist in predicting the risk of developing dementia. To date, several tools have been designed to project risk scores for the possibility of disease onset. For example, the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) score is a well-accepted and validated tool used to predict future dementia risk based on specific middle-age parameters.

Since hypertension is one of the main risk factors of dementia, its presence could be used to predict risk scores for the disease. Therefore, it is important to validate whether hypertension can be used to accurately predict the risk scores for dementia.

About the study

The current study included 1,279 white Argentinian hypertensive patients between 21 and 95 years of age to stratify dementia risk using the CAIDE risk score. All relevant data were obtained from the multicentre Heart and Brain study conducted in Argentina that evaluated cognitive impairment in hypertensive patients. The blood pressure of all study participants was collected using a digital sphygmomanometer.

Study participants were categorized into three groups based on their education level. These included levels one, two, and three, which comprised individuals with less than seven, between eight and 12, and over 12 years of education, respectively.

The cognitive function of the participants was assessed using the Mini-mental Statement Examination (MMSE), Clock Drawing test (CDT), and MiniBoston Naming tests. MMSE was used to assess global cognition, whereas CDT was used to assess executive function.

Physical inactivity was defined as moderate physical activity of less than 150 minutes/week. The CAIDE dementia risk score version without apolipoprotein E (ApoE) was used to assess the risk of disease.

Study findings

According to the CAIDE score, around 40% of the cohort exhibited an increased risk of developing dementia. More specifically, 28% of the participants between 47 and 53 years were associated with a higher risk of developing dementia. When this “middle age” group was broadened to include individuals aged between 40 and 55, no significant increase in the risk of dementia was observed. 

Importantly, the dementia risk score was not altered in the middle age group, even when some of the variable cut-off points like cholesterol and physical inactivity were altered.

Older patients with a lower educational level were associated with a higher risk of dementia. These patients were also more likely to be obese, physically inactive, be diagnosed with hypercholesterolemia, and maintain poor blood pressure control.

An inverse association between the cognitive test result and CAIDE score was observed. This finding was in line with the Northern Manhattan study, which revealed a link between the CAIDE score and baseline cognitive evaluation. Likewise, a previous epidemiological study indicated a similar association between arterial hypertension, diabetes, obesity, and cognitive impairment.

Conclusions

Hypertension is a key modifiable vascular risk factor for the onset of dementia. The current study indicated the use of this factor as a predictor of dementia risk, particularly in middle-aged populations. Taken together, the study findings provide important insights into the development of future intervention approaches that can be used to prevent dementia onset by improving blood pressure levels.

A key limitation of the study is that arterial hypertension was not considered, which is a key risk factor for dementia. Nevertheless, the use of a sample of hypertensive participants and the CAIDE score to assess the cognitive status and the risk of dementia are novel features of the study.