Can antihypertensives reduce dementia risk?
Can antihypertensives reduce dementia risk?
The Link Between Hypertension and Dementia: What Recent Studies Reveal
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Hypertension, or high blood pressure, affects over one billion people globally and has long been associated with an increased risk of dementia. However, the specific nature of this relationship has remained unclear. Recent research sheds new light on the subject, suggesting that older individuals who continue taking antihypertensive medications have a 26% lower risk of developing all-cause dementia compared to those with untreated hypertension[^1^].
A Groundbreaking Meta-Study
This groundbreaking meta-study involved 17 different investigations and included 34,519 community-dwelling older adults from 15 countries across Asia, Africa, Europe, Australia, and North and South America[^1^]. The researchers discovered that individuals with untreated hypertension were more likely to develop dementia, confirming the connection between hypertension and dementia[^1^].
Participants in the study were, on average, 72.5 years old, with 58.4% of them being female. Among the participants, approximately half (14,759 individuals) had treated hypertension, while the other half consisted of healthy controls and those with untreated hypertension. All participants were dementia-free at the beginning of the study and were followed for an average of 4.3 years[^1^].
The Nuances of Hypertension and Dementia
Dr. Matthew Lennon, the lead author of the study and a neuroscientist from New South Wales, Australia, emphasized the significance of examining older individuals and populations in developing countries. He explained that past studies produced conflicting results, with some suggesting that antihypertensive use in later life may increase dementia risk, decrease it, or have no effect at all[^1^]. By including a diverse range of participants, the meta-study aimed to capture the nuances that may influence treatment effectiveness.
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Dr. Jayne Morgan, a cardiologist and clinical director of the Covid Task Force at the Piedmont Healthcare Corporation, praised the study for including data from a broader global population. She noted that relying solely on data from randomized clinical trials in developed nations may disregard potential variations in treatment effectiveness within different contexts[^1^].
Unraveling the Mechanisms
While various forms of dementia exist, hypertension logically leads to vascular dementia. This type of dementia is associated with problems or blockages in the brain’s small blood vessels[^1^]. Hypertension is a known risk factor for atherosclerosis, or artery disease.
According to Dr. Cheng-Han Chen, a cardiologist, untreated hypertension can lead to more atherosclerotic disease in the brain, ultimately contributing to vascular dementia[^1^]. Over time, the blood oxygen supply to the brain decreases, and the small vessels in the brain thicken, impeding the efficient clearance of pathological proteins such as amyloid[^1^]. The accumulation of these proteins, along with changes in the blood-brain barrier permeability and receptor profiles, accelerates the development of dementia[^1^].
The Implications for the United States
In the United States, nearly half of all adults, or 48.1%, have high blood pressure[^1^]. Shockingly, approximately one in five Americans with hypertension remains unaware of their condition due to its silent nature, devoid of obvious symptoms[^1^]. This lack of awareness may be attributed to various factors, including the growing obesity epidemic, limited access to healthcare, and the reliance on self-diagnosis through the internet and social media[^1^].
Dr. Morgan highlights the importance of public blood pressure machines as a tool for monitoring hypertension. While financial barriers can make access to healthcare challenging, free blood pressure machines are available in many pharmacies[^1^]. Individuals can measure their blood pressure and interpret the results using guidelines provided by the Centers for Disease Control and Prevention (CDC)[^1^].
Conclusion
The connection between hypertension and dementia has long captivated researchers. Recent findings from a comprehensive meta-study provide valuable insights into the subject. The study confirms that individuals with untreated hypertension are at a higher risk of developing dementia[^1^]. In contrast, older individuals who continue taking antihypertensive medications have a significantly lower risk of all-cause dementia[^1^]. Understanding this link is crucial in the ongoing efforts to prevent and mitigate the impact of dementia worldwide.
References: [^1^]: Uncontrolled blood pressure could be a risk factor for dementia. Retrieved from Medical News Today
