Congenital hyperinsulinism (CHI)

Insulin is a hormone (chemical messenger), which, along with other hormones, controls the level of glucose (sugar) in the blood. Insulin is released by specialised beta-cells spread throughout the pancreas.

Normally, the beta-cells release insulin in response to the level of glucose in the blood. Insulin converts the glucose into a form that can be used by the body. If too much glucose is converted, it is stored in the liver and muscles as glycogen. Glycogen can be converted back to glucose to be used when glucose is not available.

When there is a high level of blood glucose, the beta-cells release more insulin to allow the glucose to be absorbed from the blood. If there is a low level of glucose, the beta-cells release much smaller amount of insulin or even switch off insulin production. This keeps the blood glucose level balanced and at the right level for the rest of the body to function normally.

As well as controlling insulin release, the pancreas also secretes digestive juices containing pancreatic enzymes into the first part of the small intestine (duodenum). These are necessary to digest your food.

CHI occurs when the beta-cells in the pancreas release too much insulin all the time regardless of the level of glucose in the blood. This causes hyperinsulinaemic hypoglycaemia (low blood sugar levels caused by too high a level of insulin). The high insulin level also stops ketone bodies being made – which are used by the brain as an alternative fuel source when there is not enough glucose in the body. Hypoglycaemia in CHI means that the brain does not have either source of fuel (glucose and ketone bodies) so cannot function properly.

You will have a ‘hypo plan’ from GOSH – this is worked out just for you. Keep a copy with you all the time – either on paper or perhaps a photo of it on your phone. You could also wear some medical alert jewellery.

If you have a hypo

The signs of a hypo vary from person to person but you might feel shaky, wobbly and have a headache. As you grow older, you will become aware of how a hypo starts for you so you can treat it as soon as you spot the signs.

• If your blood glucose level is 3.5mmol/litre or lower when you check it, have a fast-acting carbohydrate snack – this could include glucose tablets, non-diet fizzy drink or jelly sweets.
• Wait five to 10 minutes and test your blood glucose level again using another finger and fresh test strip.
• If your blood glucose level is still 3.5mmol/litre or lower, repeat the fast-acting carbohydrate snack and recheck in another five to 10 minutes.
• If you feel no better and your blood glucose level does not go up, call 999 for an ambulance to take you to hospital.

The most important part of treating CHI is to keep your blood glucose level above 3.5mmol/litre. You will usually do this by taking medication to reduce the amount of insulin released by the pancreas.

It is important to keep taking the medications as advised otherwise you are at risk of having a ‘hypo’.

You will need to check your blood glucose levels regularly throughout the day and more often when you are feeling ill. You should carry your glucose monitor, testing strips and lancets with you all the time.

The CHI nurses will have given you a programme for your daily testing – although the glucose monitor records each test result, you might also like to store them in a fitness tracker on your phone.

The advantage of this is that you can add notes about how you were feeling, what you had eaten and what you were doing before each test. Over time, you will start to see a picture emerging that you can use to plan day to day life reducing the risk of a hypo.

If you need to be admitted to hospital, you will usually have a drip to raise your glucose levels. Show hospital staff your GOSH hypo plan and tell them they can ring the team at GOSH if needed.

Everyone should follow a healthy lifestyle, eating a balanced diet and doing some exercise, and this is just as important if you have CHI.

You will have medications to treat your CHI and stop your pancreas releasing too much insulin. The most common types are:

• Diazoxide and chlorothiazide – taken two to three times a day
• Lanreotide – given as an injection under the skin every 28 days
• Digestive enzymes – taken as capsules before each meal or feed

There are lots of ways to remember to take medicines – you could set a reminder on your phone, keep your medicines somewhere to remind you or even use a dosette box so you know when you have taken a day’s tablets.

Some medicines interact with other medication which can change their effect. Before you take any medicines other than those prescribed for you, check with your CHI team – this applies to herbal and complementary medicines as well as those bought ‘over the counter’.

You will also need to keep on top of your prescriptions – many CHI medicines are not readily available from your community pharmacy so you may need to collect them from GOSH or have them ordered in to your local chemist.

As they are imported abroad, it can take several days for them to arrive so always order them in plenty of time. It is important that you take responsibility for your medication, especially when transferring to adult services.

Even when you are feeling fine, you should still go to your check-ups and other appointments. The reason we ask you to see the CHI team regularly is to monitor how you are doing. If we only see you when you are unwell, we do not know how you are when you are well, so we are really only seeing you at your worst!

In time, the hospital (whether GOSH or the adult service at St Mary’s Hospital) will only notify you about your appointments, not your family as well, so make sure you make a note on your mobile phone calendar and set reminders too. You might have to give some notice before taking time off school, college or work so do this as soon as you get the notification.

You may get a text reminder about your appointments, but very few services will ring you the day before to remind you. There may be serious consequences to your health if you miss an appointment without telling anyone as many services will discharge you if you miss only one or two appointments and send your referral back to your family doctor (GP).

An important part of growing up is taking responsibility for having a diary so you know what you are doing on which day. Start practising this before you move onto adult services so that it becomes second nature.

Learning independence

You might already feel pretty independent, taking your medicines without being reminded and dealing with everyday life but there is always a lot more to learn. As part of getting ready to move on to adult health services, the team at GOSH will work with you to identify things you do well and areas where you could do with a bit of practice. They might set you some goals to work on in between appointments and suggest keeping a diary to record how you are feeling during the process.

Transition to adult services

Transition is the purposeful, planned process of preparing young people and their families or carers for, and moving them from, child-centred healthcare to adolescent or adult oriented healthcare.

The transition process aims to:

• Support teenagers in the development of skills to become more independent in their healthcare
• Support parents in helping their teenager to achieve this to the best of their ability
• Prepare for transfer from child-centred healthcare to adult healthcare

Young people attending the CHI service at GOSH almost always transfer to the non-classical diabetes service at St Mary’s Hospital in Paddington, West London.Although CHI is caused by too much insulin and diabetes is caused by not enough insulin or the body not reacting to insulin, the ways of managing both types of imbalance are similar so this service is the best fit for you.

As well as the Consultants, Professor Nick Oliver and Dr Shivani Misra, the diabetes team includes specialist nurses, psychologists, dietitians and podiatrists.

Preparing for transfer

In the CHI team at GOSH, we start this when you are 14 years old and consider transfer of your care around 18 years old.

One of the GOSH CHI nursing team will be your named worker who will help coordinate your care and offer support before, during and after transition.

Transition goals

1. Remember to take your own medication as prescribed
2. Be aware of which medications you take and their possible side effects
3. Keep a CHI diary – this could include your symptoms and feelings on a day to day basis
4. Write down any questions for the team before your clinic visits
5. Make (and change) your own appointments, both for clinic and your GP
6. Contact your CHI CNS if you have any questions or concerns in between clinic visits
7. Know your options about medication
8. Become involved in making decisions about your health
9. Start to take the lead in your clinic appointments – at first this might be alongside your parents but eventually you will feel confident to go to appointments on your own
10. Be aware of how your lifestyle can have an effect on your CHI – a healthy diet and exercise are important

Clinic appointments

The CHI team at GOSH hold a joint clinic with St Mary’s once a month – the first appointment is held at GOSH, with the St Mary’s team coming along to meet you. The second appointment is held at St Mary’s with the GOSH team attending to support you.

The idea behind both these clinic appointments is that you can get to know the adult team and they can get to know you – it also helps both teams to share useful information so that when you transfer to the adult service, everything is in place and your care continues smoothly. We will ensure that all your scans, results and reports are sent across to St Mary’s.

While having CHI should not stop you doing day to day activities, there are some things you should remember to stop you having a hypo and keep your blood glucose levels under control.

Food and drink

Eating a balanced diet will help keep you at the right weight for your age and size. Some of the medicines you take can affect your appetite making you go off food but it is important to keep eating. You will learn if particular foods make you feel worse or better if you keep a diary of what you eat and how you feel. If you are worried about eating, please talk to us or your GP who may be able to arrange a meeting with a dietitian to advise you.

School and college

We know that you might not want to tell everyone in your life that you have CHI, but it can be useful to let your school or college (teachers, tutors, lecturers) or employers know so that they can support you and allow you time off for appointments. This could also be important in an emergency. We suggest you wear a medical identity bracelet or necklace as well – there are lots of different kinds so talk to your CHI nurse for further information.

Games and sports

Having CHI should not stop you from taking part in games and sports although you may struggle at times with fatigue. Remember – people with CHI take part in all sorts of sport and exercise – the trick is to find the those that you enjoy.

One important thing is to test your blood glucose level before you start exercising and eat a carbohydrate snack if it is a bit on the low side. This should keep your levels normal even if you are burning up more energy through exercise.

Always carry extra snacks and make sure you stop to eat one if you feel wobbly or shaky.

Holidays

There is no reason why you should not have holidays but make sure you have travel insurance. If something goes wrong on holiday or you have to cancel at the last minute, you may be liable for a lot of expense, so it is always important to have insurance. There are several companies that offer insurance to people with existing health conditions so please ask your team for advice.

You could also read the Contact publication called Holidays, play and leisure available.

You may need to provide a letter stating that you are fit to travel. Please contact the team with as much notice as possible (at least three weeks) to request this. We may need to see you in clinic to check your fitness before providing the letter.

If you need vaccinations before you travel, check with the CHI team in case any of them could react with your regular medications.

Always make sure you have enough of your medications for the entire holiday plus a few days’ or weeks’ worth extra. When packing, remember to carry your medications in your hand luggage – that way if your hold baggage goes missing, you will always have the medications with you. It may be an idea to ask the CHI team for a letter explaining your medications, especially if they are in liquid or injectable form and you need to carry more than the allowed volume.

It is also helpful to work out the nearest hospital to your holiday destination just in case you have a hypo and need to get there quickly. The CHI team may be able to contact them to provide a copy of your hypo plan if needed.

Further education and jobs

There is no reason at all why you shouldn’t go onto college or university if you want and get a fulfilling job. It is up to you when (and if) you disclose your CHI to your university or employer. Remember that you are entitled to reasonable adjustments under the Equality Act – this could include being allowed to take snacks into exams or whatever you need to let you have the same equality of opportunity as everyone else.

Driving

Having CHI should not stop you driving, but there are some circumstances where you have to inform the Driver and Vehicle Licensing Agency (DVLA) that you are at risk of having a hypo.

Diabetes UK has useful information about driving safely and avoiding hypos.

Body image

As we grow up, we all become more aware of our appearance and anything that makes us different from our friends. The medicines you take have certain side effects that might alter your appearance, for instance, hair thinning or extra hairiness. Please talk to us as there are ways of managing side effects so that they are less troublesome.

Mental health and wellbeing

It is well known that having any life-long health condition can affect your mood, how you feel and deal with everyday life. The CHI team can refer you to our psychologist, who will work with you to explore how you are feeling and help develop strategies for coping with everyday challenges as well as during hypos.

Cigarettes and alcohol

We do not advise anyone to smoke – cigarettes contain many toxins, which are harmful to you and people around you. E-cigarettes, which heat a liquid to a vapour to be breathed in, are a fairly recent invention and can be used as an aid to stop smoking cigarettes. However, there is still no industry standard for e-cigarettes so no guarantee of the quality of the liquid used.

In line with NHS guidance for everyone, we recommend that you should not drink any more than two units of alcohol per day. As a rough guide, a standard 175ml glass of wine contains 2.1 units and a pint of lager, beer or cider is 2.5 units.

Read more information on units of alcohol.

Drinking more alcohol than you should can affect your blood glucose levels so always load up on carbohydrate snacks before you drink – not only will this help your glucose levels it will reduce the effects of alcohol too. Try to avoid drinking so much that you are sick – dehydration can also affect your blood glucose levels. Alcohol can also react with diazoxide causing your blood pressure to drop very low, making you feel wobbly and faint.

Street drugs and other illegal substances

We do not advise anyone to take street drugs or other similar substances – there is no way of knowing what they contain, how strong they are and how they could react with your medicines.

Body piercing and tattoos

Body piercing and tattoos are generally not advised due to the risk of infection through dirty needles. If you have had abdominal surgery (for instance, to remove some of your pancreas), it is best to avoid piercing or tattooing over scare tissue. If you feel you want to have a piercing or tattoo, you should always discuss this with us and use licensed premises that are registered with the local health authority.

Sex, contraception and pregnancy

Having CHI should not have any effect on your fertility as a man or woman.

If you are not ready to start a family, make sure you use contraception. Some medicines may affect how well the contraceptive pill work so talk to your GP or CHI team to find the best one for you. Although you should be able to go on contraception of your choice, some medications have nausea and vomiting as a side effect, which would stop some contraceptives working.

Remember that although taking using the pill or having an intrauterine device can reduce your risk of pregnancy, it will not protect you again sexually transmitted infections (STIs). Only barrier methods, such as condoms (male and female), can reliably protect you. Further information about sex and contraception is available on the Brook website.

CHI will not affect your pregnancy although it may affect your blood glucose levels and how you manage them so we would advise discussing this with the CHI team before you get pregnant if possible. With some of the newer medicines used to treat CHI, for instance lanreotide, we do not know if the active ingredients have any effect on the baby in the womb.

If you have a genetic form of CHI, we would advise having genetic counselling before starting a family. If the genetic fault has been identified, prenatal (before birth) diagnosis might be possible.

Call the Congenital Hyperinsulinism Clinical Nurse Specialists:

Email: CNS.hypoglycaemia@gosh.nhs.uk

Telephone: 020 7405 9200 ext 0360 or bleep 1016

You can also contact the team through MyGOSH once you have registered.