Understanding Ketones

If you starve for more than a few hours, then the body will run out of glucose (sugar) stores and will switch to breaking down fats and produce 'ketones'. Ketones smell like pear drops and are found in your breath and urine, which is how the body tries to get rid of them.

Insulin is important as it acts as a 'key' to allow sugar to move from the blood into the cells, if you have diabetes and do not have enough insulin then the body behaves as if it has run out of glucose and switches to breaking down fats resulting in ketones.

If this is unrecognised, it can lead to 'diabetic ketoacidosis' (DKA) where you will feel very thirsty, start breathing fast and become very dry and vomit profusely.

Situations where large amounts of ketones are produced

Poor diabetic control with high HbA1c:

In this situation, you are always running with insufficient insulin and high blood sugars. As there is not enough insulin the sugar is in the wrong place by staying in the blood stream and not crossing into the cells to make them work efficiently. Your body's cells behave as if they are deficient in sugar all the time. If you then become unwell, miss insulin or exercise very hard, you can suddenly make the situation worse.

Intercurrent illness:

This can be any illness such as flu, tonsillitis or chickenpox. If the body becomes unwell in these situations, it works much harder (equivalent to running very fast) and demands more sugar. Although blood glucose levels rise, the glucose is in the wrong place and the body needs both more glucose and more insulin to deal with the stress of illness.

Starvation:

If you miss food, particularly carbohydrates, the body will naturally form ketones. This will be more rapid if you are unwell or your diabetes is not well controlled.

Exercise:

Exercise is good for you but when the blood sugars are high and ketones are present then the situation will become worse if you exercise suddenly. The body will demand more energy sources and if there are not enough carbohydrates, more fats will be broken down to form ketones.

How to prevent ketones and the subsequent development of DKA

General points:

Try to eat sensibly and regularly. Although there is no harm in missing occasional meals, in general you should not do this too often. A sensible mixed diet with a regular source of carbohydrates will help prevent ketones.
Try not to forget insulin. Those on pumps or multiple insulin injections should have their carbohydrate counting as accurate as possible and remember to bolus.
Monitor blood glucose levels and if they are high (in double figures) a lot of the time then discusses what action needs to be taken with your diabetes nurse.

Illness:

Often you do not feel like eating when you are unwell. If this is the case you must have liquids to match what you would normally eat. This might be Lucozade, milk or fresh orange juice. If you cannot drink suck Dextrosol tablets to match the carbohydrates you would normally eat. (3 Dextrosol tablets are about 10 grams of CHO).
Often you need more insulin when you are unwell. Monitor blood glucose levels and take your insulin regularly. For those on the pump or multiple insulin injections if your blood sugars are high (10mmol/l or above) give correction boluses or insulin. For those on twice daily insulin you may need to increase your normal or give some fast acting insulin at lunch.
If you start vomiting, particularly if you have high sugars, are passing a lot of urine, feel cold and breathe fast, you must seek very urgent advice and come into hospital.

Ketone monitoring:

Ketones can be checked in both urine (ketostixs) and blood (ketone test strips). Levels moderate to high require further management.

Your Diabetes Team is her to help. Contact them if you are uncertain what to do.

Disclaimer

This website is designed for use by the Leeds Paediatric Diabetes Team and children and parents referred to their service. Every effort has been made to make sure there are no errors on the website. If you think there are any inaccuracies could you please e-mail us so that we can check. kate.barker@leedsth.nhs.uk