̽��ֱ�� of Cambridge - high blood pressure

Women who experience high blood pressure during pregnancy are more likely to develop heart disease

cjb250 — Wed, 01 Jul 2020 12:14:12 +0000

Between 1-6% of all pregnancies in Western countries are affected by high blood pressure, which usually returns to normal after giving birth. This condition is known as gestational hypertension, or pregnancy-induced hypertension. It differs from pre-eclampsia in that traces of protein are not found in the urine. Clinicians increasingly recognise that women who have had gestational hypertension are more likely to develop cardiovascular disease in later life.

However, studies of different kinds of cardiovascular disease, such as heart disease and heart failure, have found mixed results. To examine these links further, an international team of researchers conducted a systematic review and meta-analysis of 21 studies involving a total of 3.6 million women, 128,000 of who previously had gestational hypertension. This type of study is a way of combining data from all existing relevant studies, allowing researchers to compare and consolidate results from often-contradictory studies to reach more robust conclusions.

̽��ֱ��results are published in the Journal of the American Heart Association.

̽��ֱ��researchers found that women who experienced high blood pressure during their first pregnancy were at 45% higher risk of overall cardiovascular disease and 46% higher risk of coronary heart disease compared to women who did not have high blood pressure in pregnancy. Women with one or more pregnancies affected by high blood pressure were at 81% higher risk of cardiovascular disease, 83% higher risk of coronary heart disease and 77% higher risk of heart failure.

“When we looked at all the available research, the answer was clear: women who develop high blood pressure during pregnancy – even when it doesn’t develop into pre-eclampsia – are more likely to develop several different kinds of cardiovascular disease,” said senior author Dr Clare Oliver-Williams from the Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, ̽��ֱ�� of Cambridge.

̽��ֱ��study adds to growing evidence of the relationship between pregnancy and subsequent risk of cardiovascular events. Recurrent miscarriages, preterm birth, foetal growth restriction and pre-eclampsia have all previously been linked with a greater risk of heart disease.

̽��ֱ��researchers say it is not entirely clear why gestational hypertension is associated with heart disease in later life. However, they suggest it may be that high blood pressure in pregnancy causes lasting damage that contributes to cardiovascular disease. Alternatively, women who develop gestational hypertension may have a pre-existing susceptibility to cardiovascular disease that is revealed due to the large demands that pregnancy places upon women’s bodies.

Dr Oliver-Williams added: “It’s important that women know that it isn’t their fault that they developed high blood pressure in pregnancy, and developing heart disease isn’t a foregone conclusion. Women who have experienced gestational hypertension may have been dealt a tough hand, but it’s how they play those cards that matters the most. Small positive changes can really help. They can be as simple as eating more fruit and vegetables, small bouts of regular exercise and finding time to unwind, if that’s possible with kids around.”

Dr Oliver-Williams is a Junior Research Fellow at Homerton College, ̽��ֱ�� of Cambridge. ̽��ֱ��Cardiovascular Epidemiology Unit is supported by the British Heart Foundation and the Medical Research Council.

Reference
Lo, CCW & Lo, ACQ, et al. Future cardiovascular disease risk for women with gestational hypertension: a systematic review and meta-analysis. JAHA; 24 Jun 2020; DOI: 10.1161/JAHA.119.013991

Women who experience high blood pressure during pregnancy are more likely to develop heart disease and heart failure in later life, according to an international team of researchers.

When we looked at all the available research, the answer was clear: women who develop high blood pressure during pregnancy – even when it doesn’t develop into pre-eclampsia – are more likely to develop several different kinds of cardiovascular disease

Clare Oliver-Williams

Free-Photos

Pregnant woman

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Licence type:

Public Domain

Major global study reveals new hypertension and blood pressure genes

sc604 — Mon, 12 Sep 2016 15:00:00 +0000

̽��ֱ��discoveries include DNA changes in three genes that have much larger effects on blood pressure in the population than previously seen, providing new insights into the physiology of hypertension and suggesting new targets for treatment.

High blood pressure or hypertension is a major risk factor for cardiovascular disease and premature death. It is estimated to be responsible for a larger proportion of global disease burden and premature mortality than any other disease risk factor. However, there is limited knowledge on the genetics of blood pressure.

̽��ֱ��teams investigated the genotypes of around 347,000 people and their health records to find links between their genetic make-up and cardiovascular health. ̽��ֱ��participants included healthy individuals and those with diabetes, coronary artery disease and hypertension, from across Europe, (including the UK, Denmark, Sweden, Norway, Finland and Estonia), the USA, Pakistan and Bangladesh. ̽��ֱ��study brought together around 200 investigators from across 15 countries.

Study author Professor Patricia Munroe from QMUL said: “We already know from earlier studies that high blood pressure is a major risk factor for cardiovascular disease. Finding more genetic regions associated with the condition allows us to map and understand new biological pathways through which the disease develops, and also highlight potential new therapeutic targets. This could even reveal drugs that are already out there but may now potentially be used to treat hypertension.”

Most genetic blood pressure discoveries until now have been of common genetic variants that have small effects on blood pressure. ̽��ֱ��study, published in Nature Genetics, has found variants in three genes that appear to be rare in the population, but have up to twice the effect on blood pressure.

“ ̽��ֱ��sheer scale of our study has enabled us to identify genetic variants carried by less than one in a hundred people that affect blood pressure regulation,” said study author, Dr Joanna Howson from Cambridge’s Department of Public Health and Primary Care. “While we have known for a long time that blood pressure is a risk factor for coronary heart disease and stroke, our study has shown that there are common genetic risk factors underlying these conditions.”

RBM47 is a gene that encodes for a protein responsible for modifying RNA. RRAS is involved in cell cycle processes and has already been implicated in a syndrome related to ‘Noonan syndrome’ which is characterised by heart abnormalities. COL21A1 is involved in collagen formation in many tissues, including the heart and aorta. COL21A1 and RRAS warrant particular interest since both are involved in blood vessel remodelling, with relevance to hypertension.

̽��ֱ��team also found a mutation in a key molecule ENPEP that affects blood pressure. This gene codes for an enzyme that is a key molecule involved in regulating blood pressure through the dilation and constriction of blood vessels, and is currently a therapeutic target.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation which part-funded the research, said: “Large scale genetic studies continue to expand the number of genes that may contribute to the development of heart disease, or risk factors such as high blood pressure. But so far most of the genes discovered in these studies individually have only very small effects on risk – though they may still provide valuable clues for new drug targets.

“This study has increased the number of genes implicated in control of blood pressure to almost 100 and, in the process, has also identified three genes that have larger effects on blood pressure than previously found.”

̽��ֱ��study was also funded by the National Institute for Health Research (NIHR), National Institute of Health (NIH), Wellcome Trust and the Medical Research Council.

Reference:
Surendran et al. ‘Trans-ancestry meta-analyses identify rare and common variants associated with blood pressure and hypertension’. Nature Genetics 2016. DOI: 10.1038/ng.3654

Thirty-one new gene regions linked with blood pressure have been identified in one of the largest genetic studies of blood pressure to date, involving over 347,000 people, and jointly led by Queen Mary ̽��ֱ�� of London (QMUL) and the ̽��ֱ�� of Cambridge.

While we have known for a long time that blood pressure is a risk factor for coronary heart disease and stroke, our study has shown that there are common genetic risk factors underlying these conditions.

Joanna Howson

Yale Rosen

Pulmonary hypertension-associated vasculitis

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-ShareAlike

New research leaves tumours with nowhere to hide

Anonymous — Thu, 24 Sep 2015 09:25:29 +0000

̽��ֱ��small tumours concealed in the adrenal gland are “unmasked” in early pregnancy, when a sudden surge of hormones fires them into life, leading to raised blood pressure and causing risk to patients.

New research published today in the New England Journal of Medicine conducted by a team led by Professor Morris Brown, professor of clinical pharmacology at Cambridge ̽��ֱ�� and a Fellow of Gonville & Caius College, identifies this small group of lurking tumours for the first time, and explains why they behave as they do.

̽��ֱ��study means that, when patients are found to have high blood pressure early in pregnancy, doctors will now be encouraged to consider that the cause could be the tumours, which can be easily treated. Currently, adrenal tumours are not usually suspected as the cause of high blood pressure in pregnancy, and so go undiagnosed.

Brown and an international group of PhD students including first-author Ada Teo of Newnham College used a combination of state-of-the-art gene “fingerprinting” technology and old-fashioned deduction from patient case histories to work out that the otherwise benign tumours harbour genetic mutations that affect cells in the adrenal gland.

̽��ֱ��mutation means the adrenal cells are given false information and their clock is effectively turned back to “childhood”, returning them to their original state as ovary cells. They then respond to hormones released in pregnancy, producing increased levels of the salt-regulating hormone aldosterone.

Aldosterone in turn regulates the kidneys to retain more salt and hence water, pushing up blood pressure. High blood pressure – also known as hypertension – can be fatal, since it greatly increases the risk of stroke and heart attack.

̽��ֱ��new findings build on a growing body of research focusing on the adrenal gland and blood pressure. Sixty years ago, the American endocrinologist Dr Jerome Conn first observed that large benign tumours in the adrenal gland can release aldosterone and increase blood pressure (now known as Conn’s Syndrome).

Brown and his team have previously found a group of much smaller tumours, arising from the outer part of the gland, that have the same effect. ̽��ֱ��latest discovery drills down still further, revealing that roughly one in ten of this group has a mutation that makes the cells receptive to pregnancy hormones.

Brown said: “This is an example of what modern scientific techniques, and collaborations among doctors and scientists, allow you to do [through a form of genetic fingerprinting]. Conditions are often around for 60 years which we have had no explanation for, and now we can get to the heart of what has gone wrong.”

But the discovery also relied on what doctors call “clinical pattern recognition” – using experience to spot similarities. Brown was able to link together the cases of two pregnant women almost ten years apart and a woman in early menopause. All suffered high blood pressure, leading him to screen their adrenal tumours and identify a matching genetic mutation.

Pregnant women found to have the newly identified subset of tumours can now be identified more readily, and the tumours either treated with drugs or potentially even removed.

̽��ֱ��research was funded by the Wellcome Trust, National Institute for Health Research, British Heart Foundation and A* Singapore.

Hidden tumours that cause potentially fatal high blood pressure but lurk undetected in the body until pregnancy have been discovered by a Cambridge medical team.

Conditions are often around for 60 years which we have had no explanation for, now we can get to the heart of what has gone wrong

Morris Brown

11C metomidate PET CT of small Conn's tumour

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution

New research shows clear association between ACE inhibitors - drugs used to treat high blood pressure and heart disease - and acute kidney injury

sj387 — Wed, 06 Nov 2013 22:01:00 +0000

Cambridge scientists have found an association between ACE inhibitors (and similar drugs) and acute kidney injury - a sudden deterioration in kidney function. ̽��ֱ��research is published today, 06 November, in the journal PLOS ONE.

ACE inhibitors and related drugs known as angiotensin receptor antagonists (ARAs or ‘sartans’) are the second most frequently prescribed medicines in UK clinical practice, and are used to treat common conditions such as high blood pressure, heart disease and kidney problems, especially in people with diabetes. Although concerns about a link between these drugs and kidney function have been raised in the past, the size of the problem had previously been unknown.

̽��ֱ��researchers therefore examined the issue using data from the whole of England. They compared the admission rates for acute kidney injury to English hospitals with the prescribing rates of ACE inhibitors and ARAs. From 2007/8 to 2010/11, there was a 52 per cent increase in acute kidney injury admissions. During this same period of time, there was an increase in the number of prescriptions for ACE inhibitors and ARAs issued by GP surgeries by 16 per cent.

̽��ֱ��results show a clear association between the increase in prescriptions and the increase in hospital admissions. ̽��ֱ��researchers estimate that 1636 hospital admissions with acute kidney injury – which has a mortality rate in the UK of around 25-30 per cent of patients - could potentially have been avoided if the prescribing rate had remained at the 2007/8 levels. They estimate that one in seven cases of acute kidney injury could be due to increased prescriptions for these drugs.

This is the first time that a study has been able to assess the extent to which these medications are linked to acute kidney injury. However, the researchers emphasise that we cannot assume that the medication was a direct cause of the acute kidney injury in this study, and no one should stop taking these medications unless advised by their doctor to do so.

Dr Rupert Payne, senior author of the study from the ̽��ֱ�� of Cambridge’s Institute of Public Health, said: “There has been lots of anecdotal evidence suggesting these drugs may be a contributory factor in patients developing acute kidney injury, and this work gives us an opportunity to estimate the size of the problem, as well as making clinicians and patients more aware of the importance of using these drugs in accordance with current clinical guidelines.

“As both a GP and clinical pharmacologist, it also highlights to me the importance of improving our understanding of the risks and benefits of drugs more generally in the real world of clinical practice, away from the artificial setting of clinical trials.”

Dr Laurie Tomlinson, co-author of the study, added: “As a kidney doctor I have looked after many patients with acute kidney injury who were taking these medications prior to becoming unwell and have often worried that the drugs were doing more harm than good. These results are the first to estimate to what extent these drugs may be contributing to the growing incidence of acute kidney injury. Therefore, they represent the first step of research needed to better define when they can be prescribed safely, which should reduce the growing burden of acute kidney injury and save NHS costs and ultimately lives.”

̽��ֱ��researchers will next use large primary care databases to examine the association between the drugs and acute kidney injury for individual patients and, in particular, the role of other medication, patient factors (such as the existence of chronic kidney disease) and infections in causing acute kidney injury.

̽��ֱ��full article is available at http://dx.plos.org/10.1371/journal.pone.0078465

These and similar drugs are the second most prescribed on the NHS

These results are the first to estimate to what extent these drugs may be contributing to the growing incidence of acute kidney injury

Dr Laurie Tomlinson

Jynto

Ball-and-stick model of the '''captopril''' molecule, an ACE inhibitor used for the treatment of hypertension

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

New test could help thousands of patients with high blood pressure

gm349 — Wed, 30 Nov 2011 16:01:56 +0000

A new test developed by researchers at the ̽��ֱ�� of Cambridge could help doctors diagnose thousands of people with the most common curable cause of high blood pressure (hypertension). Research funded by the British Heart Foundation (BHF) and National Institute for Health Research (NIHR), showed a high-tech PET-CT scan could detect Conn’s syndrome, which causes up to five per cent of hypertension cases.

Around 12 million people in the UK are diagnosed with hypertension, a condition which greatly increases the risk of having a heart attack or stroke. For most people with hypertension there is no single underlying cause, but in a small minority there is a specific condition that causes blood pressure to rise. One of these conditions is called Conn’s syndrome – the most common curable cause of high blood pressure.

Conn’s syndrome is difficult to diagnose but an accurate diagnosis often leads to successful treatment. It’s caused by a benign tumour called an adenoma – about the size of a 5-pence coin – in one of the adrenal glands, which lie close to the kidneys. ̽��ֱ��tumour causes the over-production of a key blood pressure-regulating hormone called aldosterone. It can be treated either by surgically removing an affected gland, or by using a drug to block the effects of aldosterone.

̽��ֱ��new test, studied in 44 patients at Addenbrooke’s Hospital in Cambridge, scans the abdomen using ‘positron emission tomography with x-ray computer tomography’ technology, better known as a PET-CT and more commonly used in cancer diagnosis. ̽��ֱ��researchers developed a special radioactive tracer called 11C-metomidate, which lights up culprit adenomas in the scan. ̽��ֱ��test takes around 45 minutes.

̽��ֱ��current standard test for Conn’s syndrome relies on taking blood samples from a vein supplying the adrenal gland to measure the aldosterone level, a complex and difficult procedure which often fails to confirm the diagnosis. However, the researchers showed that their scan picked up adenomas causing hypertension in the majority of study patients, making it a potentially useful alternative to the standard test.

Morris Brown, Professor of Clinical Pharmacology at the ̽��ֱ�� of Cambridge, who led the study, said: “We were excited to see our technique work so well, and shortcut the delays and discomforts associated with the alternative test. We’re using PET-CT on our patients already, but we also plan a larger study to work out who will benefit the most. ̽��ֱ��test could be especially important for older patients – we often see growths in the adrenal glands during a routine CT scan. Often these growths are not Conn’s adenomas, but it’s difficult to be sure and they create a lot of anxiety in patients and doctors. In the future PET-CT could be a quick way to reassure a lot of patients without the need for detailed investigations.”

Dr Shannon Amoils, Research Advisor at the BHF, said: “Conn’s syndrome is the most common curable cause of high blood pressure. And although it affects only a small fraction of people with hypertension, it’s almost certainly more widespread than we previously thought. There are drugs that can control the high blood pressure caused by Conn’s syndrome, but the only cure is surgery, so making the diagnosis is very important. This new approach, using a PET-CT scan, offers real hope that more people with Conn’s syndrome will be accurately diagnosed in the future.”

Chris Wood, 56, who was diagnosed as having Conn’s syndrome by the new test, said: “When I had blood tests before, the results were never clear. I enrolled in Professor Brown’s study I had the scan, which took less than an hour, and immediately after the scan they showed me the pictures of the lump in my adrenal gland that was causing the problem. Getting the definitive diagnosis is fantastic because it removes all the worry, and because I’m on much much less medication than I had been for 15 years. I feel absolutely great.”

̽��ֱ��study was published online in the Journal of Clinical Endocrinology and Metabolism. ̽��ֱ��work was funded mainly by the BHF and the National Institute for Health Research (NIHR), the research funding arm of the NHS.

Scan can detect 5p-sized growth that causes hypertension.

̽��ֱ��test could be especially important for older patients – we often see growths in the adrenal glands during a routine CT scan.

Morris Brown, Professor of Clinical Pharmacology at the ̽��ֱ�� of Cambridge

Morris Brown

Conn's adenoma

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes