Participants

SABRE is an important study first started in 1988 and involving nearly 5000 people of European , Indian Asian and African Caribbean  origins.   SABRE is investigating the causes of diabetes and disorders of the heart and circulation, as well as the reasons why some  people  stay well  in older age and why some people experience illness and disability.

If you took part in SABRE, you may remember that we first invited you take part between 1988 and 1991 when you were living in Southall and Brent in west and north-west London.  You may have been chosen from your GP practice or from your workplace (for example: British Airways, Crown Cork, Lucas CAV, Lyons Tetley, Quaker Oats).

Recently we invited participants to take part in a follow-up study (between 2008 and 2011) at our clinic at St Mary’s Hospital in Paddington.  Participants also had the option of completing a health and lifestyle  questionnaire or allowing  us to look at their GP medical records.

We have received funding from the British Heart Foundation to carry out a second follow-up study- started in 2014 at University College London. This time we are also inviting the partners of the original study participants to join the study, together with new African and African Caribbean participants. This phase of follow-up will end in January 2018.

Why SABRE?

SABRE was first started in order to understand why some people are more likely than others to suffer from diabetes, coronary heart disease and strokes.  At the time very little was known about whether people of different ethnicities might be more or less likely to suffer these disorders.

We now know, partly as a result of the first SABRE study, that there are large differences in risk of coronary heart disease and strokes between different ethnic groups in the UK, as well differences in risk factors such as diabetes, blood pressure and levels of ‘good’ and ‘bad’ blood fats.  But we still don’t know why these ethnic differences happen.

Visit 3, the 25 year follow-up (2014-2018)

SABRE Visit 3 (25 year follow-up visit) started in July 2014 and will end in January 2018. We are grateful to the British Heart Foundation for funding this research programme.

We are inviting SABRE participants, their partners and new African Caribbean participants to come to our clinic at University College London.  We will also ask them to complete 3 questionnaires about their health and lifestyle and to give permission for us to link to some of their health-related records, for example, regarding hospital admissions and GP visits.

The aims of the study are to build on what we have learned already  from the first study and from visit 2(2008-2011).  We will measure changes in the health of the heart and circulation, with a special focus on the health of the blood vessels of the brain, as well as  early signs of diabetes.    We also want to look at physical function and how well (or otherwise) people  are keeping as they get older.

The more we understand about what causes these problems, the more likely we are to be able to work out how to prevent  or to treat them in people of all ethnicities.

In our clinic we carry out detailed measurements of blood pressure and assess the health of the heart and large and small blood vessel using non-invasive measurements, such as echocardiography.  We will carry out  MRI scans of the brain, together with a test of memory and problem solving as at visit 2. We will measure levels of glucose and fats in the blood as well as some markers of inflammation and how well the liver, kidneys and lungs  are working.  There will be some simple tests of balance and eyesight.  A short exercise test (walking) will measure how well the heart and circulation are working during exercise.

Participants and their partners  who are unable to visit our clinic can still take part in the study by completing the health and lifestyle questionnaires and /or by giving permission for us to link to  their health-related records so that we can follow-up their health.

Click here to access Participant information sheets for the study.

Diabetes during follow-up

An astonishing number of people have developed diabetes over the last 20 years. By the age of 70, almost 1 in 3 Indian Asians and African Caribbeans and 1 in 6 Europeans will have diabetes.  There is a steady rise in the numbers of people with diabetes even into older age. This is hugely important. We know that diabetes affects every system in the body and that it can shorten people’s lives, particularly because it can cause heart disease and stroke. Not only does diabetes shorten peoples’ lives, it can harm the quality of their lives too.

Our findings  leads us to ask why  Indian Asians and African Caribbeans have more diabetes than Europeans?

Type 2 diabetes is usually thought to be a disorder caused by overweight, particularly when fat accumulates around the waist. When we set out on the 20 year follow-up study we had proposed that it would be the patterns of where fat is deposited that would explain the ethnic differences in the amount of diabetes.  Was this true? Yes and no!

As we expected, extra fat around the waist measured 20 years ago (both inside the abdomen and under the skin) is an important predictor of later development of diabetes in everyone and it mostly explains why Indian Asian and African Caribbean women are more at risk than European women. However, extra fat and extra resistance to the effects of insulin in middle age are only part of the reason why Indian Asian and African Caribbean men are more at risk and none of the risk factors that we measured 20 years ago was able to explain all of the extra risk of diabetes in these ethnic groups.

We hope that the next SABRE follow-up(2014-17) will give us some more answers to this question

For more information about diabetes, visit Diabetes UK

Heart Failure

The heart is a pump which makes sure that all the tissues of the body receive a blood supply containing oxygen and nutrients. Like all pumps, the heart may become less efficient as it gets older and eventually it may not be able to keep up with the demands of the body- this is called heart failure, and although there are treatments available for heart failure, it is a serious and unpleasant disorder . Heart failure is more likely to happen when people have already had a heart attack and it may also be related to high blood pressure and diabetes.

The 3 dimensional echo scans that participants underwent at the SABRE follow-up are new and tell us about early signs of heart failure. We found that African Caribbeans and Europeans were very similar with regard to the size of the left ventricle (this is the part of the heart which pumps blood around the whole body and if it becomes enlarged it may be an early sign that the heart is under strain (picture of heart here)). On the other hand, in Indian Asians the left ventricle was on average a little smaller in relation to body size than in Europeans, but at the same time their heart muscles needed more oxygen to work efficiently.

Very few SABRE participants had actual heart failure at the 2008-2011 follow-up. However, as participants are moving towards older age, they are more at risk of this disorder.  the next  follow-up study (2014-17) will focus on heart failure, using these measurements and some measurement made 20 years ago to understand why some people are at particular risk of heart failure in later life.

For more information about heart failure, visit the British Heart Foundation.

Strokes during follow-up

As expected, numbers of strokes increase as people get older in all ethnic groups. Interestingly, in study participants who were free of diabetes in 1988-91, there were no ethnic differences in the proportions of people who developed strokes during follow-up. However, when we looked at people who had diabetes at the time of the baseline studies in 1988-91, we found that both Indian Asians and African Caribbeans with diabetes were twice as likely to develop strokes as Europeans with diabetes. 

We also found that the MRI brain scans showed that African Caribbeans had more early signs of blood vessel problems in the brain than Europeans and that this was particularly related to having diabetes. These findings suggests that diabetes is especially harmful to people in our ethnic minorities, and although we don’t yet know why this is, it may be because the blood vessels in the brain are more affected by diabetes and pre-diabetes making them less able to cope with day to day changes in blood pressure – more research is needed to confirm this.

(MRI scans from the Indian Asians haven’t yet been fully analysed… coming soon)

For more information about stroke, visit The Stroke Association.

 

The first follow-up (2008-2011)

4857 people took part in the first studies between 1988 and 1991.  Of these

  • 3433 were still alive and living in the  UK in 2008
  • The average age of participants in 2008 was  70 years(range: 57-90)
  • Between 2008 and 2011, 1438 people visited our clinic at St Mary’s for follow-up, another 29 people had some measurements done at home.
  • 2011 people completed a follow-up questionnaire about their health and lifestyle
  • 1872 people gave permission for us to study their GP medical records so that we could record heart and circulatory diseases and diabetes that have developed during the 20 years since the study started.

This was a fantastic response after 20 years, involving over 60% of participants.  We are truly grateful for their help.  Their efforts have been put to good use and we’re busy analysing all the information that we collected- this involves statistical analysis and scientific interpretation.   We have already published several papers  and there is much more work to be done.

We would also like to remember the 1124 people who have died since the first studies.  They too gave their time to this research in its early days and we did not wish for their contribution to be lost.  With special permissions, we have been able to obtain information regarding their health before they died.

We are currently carrying out  another follow-up (2014-18) at University College London.This is funded by  the British Heart Foundation.

Why did we follow-up participants between 2008 and 2011?

From the first study we had collected lots of very valuable information about health in mid-life (participants were aged between 40 and 69 at the time).  From that time, we have blood measurements (such as glucose, insulin and fats), blood pressure, information that participants gave us by filling in a questionnaire about their health and lifestyle as well as many measurements of where body fat was stored. 

This recent follow-up of health means that we can use the information from 20 years ago to see

  • which measurements predict good health in older age
  • which measurements predict  diabetes, heart disease or strokes or any serious disabilities or other health problems
  • who has pre-diabetes or early signs of disorders of the heart and circulation  that they are not aware of
  • whether we can explain why some people developed these disorders and others didn’t