This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
High blood pressure increases the risk of diseases of the heart and blood vessels. Medicines that reduce blood pressure (antihypertensives) protect against these diseases. But the negative effects of blood pressure medicines are less well-studied.
New research found that, among people aged 80 or more and those with frailty (who are less able to recover from injury or illness), these medicines increased the chance of being admitted to hospital or dying because of a fall.
Researchers reviewed the medical records of almost 4 million people with high blood pressure (a top reading of between 130 – 179 mmHg) to identify negative effects of treatment. They then assessed the risk of hospital admission or death from falls among some of the group (almost 500,000) who were newly treated with blood pressure medications. These events were rare in the overall population, but much more common in people over 80 and those with frailty.
Among people aged 80 or more, blood pressure medication was as likely to lead to a serious fall as to prevent a stroke or heart attack. The analysis found that 1 serious fall would occur each year in every 33 people treated; this is similar to the likely benefit. Other research suggests that 1 stroke or heart attack would be prevented for every 38 people treated in people aged 85+.
The findings could inform medication reviews and conversations between clinicians and patients about the risks and benefits of blood pressure treatment. People could be offered the choice to stop treatment if the risks outweigh the benefits.
The issue: what are the risks of blood pressure treatment in older people with frailty?
Blood pressure medicines help protect against heart attacks and stoke. Research, including a study highlighted in a previous Alert, suggests that the benefits increase with age. However, the risks may also increase with age and frailty. Guidelines from the National Institute for Health and Care Excellence (NICE) recommend that clinicians weigh up the benefits and risks of blood pressure medications. But before this study, there was a lack of evidence on the risks.
A previous review found that treatment was associated with kidney damage, low blood pressure, and fainting, but not falls or fracture. However, the review did not separate out the effects of treatment on older people or those with frailty. Serious negative effects pose more danger to these groups compared with the general population.
This large study included adults with high blood pressure. It explored the link between the serious negative effects of treatment and age or frailty.
The study was based on data from patient records from 1,256 GP practices in England between 1998 and 2018. Almost 4 million people with high blood pressure (a top reading of between 130 – 179 mmHg) were included in the analysis. They were aged 40 years and older, and followed up for 7 years on average.
Overall, the study found that people treated with blood pressure medicines had a higher risk of hospital admission or death due to falls, than people not taking treatment. People taking the medicines were more likely to have low blood pressure, fainting, kidney damage, electrolyte imbalances, and GP appointments for gout (but not fracture).
The study found that, for every 10,000 people treated, the risk of hospital admission or death from falls within 10 years of this first prescription:
- was low overall (6 falls per year)
- increased with age (1 fall per year among people in their 40s; 61 falls per year for people in their 80s)
- increased with frailty (5 falls per year for fit people with no frailty; 84 falls per year among people with severe frailty).
Comparing these results with previous studies conducted among people over 80, blood pressure medication was as likely to lead to a serious fall as to prevent a stroke or heart attack. In this age group, 1 serious fall would occur each year in every 33 people treated, 1 stroke or heart attack would be prevented for every 38 people treated.
Why is this important?
The risk of negative effects of blood pressure medications was low overall but much higher among people over 80 and those with frailty. These groups were as likely to have a serious fall as to benefit from treatment. These findings could guide conversations between clinicians and patients about the benefits and risks of treatment.
The research is in line with international guidelines, which recommend that treatment takes age into account (for example, people over 80 are treated only if their top blood pressure reading is 160 mmHg or more). Some specialists disagree with an age-related approach. The finding from this study that the risks of treatment increase with age supports these guidelines.
Other factors (beyond age and frailty) affect the balance of likely benefits or harm of treatment. Future research could explore these factors and help clinicians make personalised recommendations about whether to take blood pressure medications.
The data in this study represent the general population across all ages. But this was not a randomised controlled trial, and could not rule out the possibility of bias. For example, people who are more sick are often prescribed treatment because of their condition and would be more likely to experience adverse outcomes such as falls. These results should therefore be interpreted with caution; where appropriate, patients still need potentially lifesaving treatment.
This study was part of a project exploring the risks of blood pressure treatment in different groups of people. A related study is examining what happens when people stop taking blood pressure medications.
The researchers developed a tool to predict the risk of a serious fall or kidney damage while on blood pressure medication. They are developing another tool to predict the risk of low blood pressure, fainting and fracture. These tools, and the information from this study, will help GPs to make personalised recommendations about who should start, continue, or stop treatment.
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This Alert is based on: Sheppard JP, and others. The association between antihypertensive treatment and serious adverse events by age and frailty: A cohort study. PLOS Medicine 2023; 20: 1 – 18.
Patient resources and support from Blood Pressure UK.
Information on high blood pressure from the British Heart Foundation.
Information on taking part in NIHR studies regarding with high blood pressure.
Funding: this study was supported by the NIHR School for Primary Care Research.
Conflicts of Interest: none declared.
Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.