Ketone Monitoring

1. Ketones and Diabetes

For people with type 1 diabetes - and for some with type 2 diabetes - ketones can be a problem. Raised levels can lead to diabetic ketoacidosis and possibly a trip to the hospital emergency room.

So what exactly are ketones, why do they make you ill, and how can you check if they are rising in your blood?


2. What are ketones?

Everyone needs fuel to turn into energy. Your body's first choice of fuel is glucose, but if for any reason your body can't use glucose it has an alternative - fat. To use fat as a fuel your body first has to break it down into small pieces; these small pieces are called ketones.


3. When do ketone levels rise?

Everyone uses ketones as fuel sometimes. For example, someone who doesn't eat for a while will burn ketones, so you may have a small amount of ketones in your blood first thing in the morning. Energetic exercise can also make ketone levels rise when all the glucose has been used up. In both these cases ketone levels rise but blood glucose levels do not.

But when you have diabetes rising blood glucose and rising blood ketones can go together. Insulin is needed to move glucose from your blood into your muscles and brain so they can use it as fuel. When you don't have enough insulin in your blood your body will begin to turn fat into ketones to use as fuel instead.

This is not good news for people with diabetes . Without insulin your body goes on making ketones and your levels can get dangerously high.

There are three times when you may be particularly at risk from raised ketones:

  1. If your diabetes has recently been diagnosed or your medication has been changed.
    If you have type 1 diabetes you probably had raised ketone levels when you were first diagnosed, you may even have had ketoacidosis. Then once your diabetes has been diagnosed - or when you change your treatment - establishing the right insulin dose can take time, during which you may be at risk again from rising ketones.
  2. If you don't monitor your blood glucose regularly.
    It's very easy to let your blood glucose levels creep up without meaning to. A special meal, a drink with friends, simple things can tip the balance. If you aren't monitoring your blood glucose regularly and your levels stay high, ketoacidosis is a real risk, particularly if you become ill.
  3. If you are ill.
    Your risk of developing ketoacidosis is much greater if you are ill. More glucose is produced as a result of the body's defence mechanism for fighting illness . You can make glucose from your own body stores. Normally extra insulin would then be produced to move this glucose from your blood into your muscles. But if you don't have enough insulin to meet the demand, your body turns to its other source of fuel - fat - to make energy and the by-products of that are ketones.



4. What happens when ketone levels rise?

High levels of ketones are harmful, so as soon as they start to rise your body tries to get rid of them in your urine. Consequently an early sign of rising ketones is a need to pass water more often and feeling thirsty. (Remember your blood glucose levels will be also be high and this will also be making you pass water more and feel thirsty too.)

If your ketone levels continue to rise they act like a poison. You may feel sick and you may find it difficult to keep liquids down, making you even more dehydrated. Your skin may become dry, your eyesight blurred and you may find you are breathing faster. You can also smell ketones on your breath - the smell may resemble nail varnish.

To start with: Later on:
Thirst or very dry mouth Feeling or being sick
Going to the toilet more than usual Blurred eyesight
High blood glucose readings Dry or flushed skin



5. Measuring ketones

Sometimes it is difficult to know at first if a raised blood glucose reading is just a one-off or something more serious. But the earlier you detect rising blood ketones the easier it is likely to be for you and your diabetes care team to bring them back down

There are two ways of detecting rising ketones:

  1. Urine testing
  2. Blood testing



6. Urine testing for ketones

Until recently the only way to test for ketones was to use a urine test strip. This has some disadvantages:

  1. Urine Ketone Testing is not specific because it can be interfered by many things.
  2. There are three types of ketones - called acetone, acetoacetate and ß-hydroxybutyrate. The most common ketone when you are developing ketoacidosis is ß-hydroxybutyrate. Unfortunately urine tests don't detect ß-hydroxybutyrate.
  3. Ketones accumulate in your urine over several hours, so measuring them in urine cannot tell you what your levels are right now.
  4. When you have - or are developing - ketoacidosis you can become very dehydrated so a urine sample can be difficult to obtain.



7. Blood testing for ketones

It is recommended you test your blood ß-Ketone because Ketones are detectable in the blood far earlier than in urine, so blood ß-Ketone testing can give early warning of impending DKA.

Who benefits most from blood ketone testing?

  • Pediatric patients with diabetes
    • To help parents detect and react swiftly to developing ketoacidosis
    • To help distinguish the symptoms of ketoacidosis from other childhood illnesses
  • Insulin pump users
    • In case of pump failure or catheter obstruction
  • Insulin users during illness or stress
    • To manage the risk of ketoacidosis and take action

When is it recommended to test?

  • During acute illness
    • During acute illness, infection or fever
    • Test ketone every 2 to 4 hours until better
  • Whenever symptoms of DKA are present
    • Nausea
    • Vomiting or diarrhea
    • Abdominal Pain
    • Fruity breath odor
    • Rapid breathing
    • Thirst and frequent urination
    • Fatigue or lethargy
    • When blood glucose remains elevated

Learn about the Precision Xtra Blood Glucose and Ketone Monitoring System: a meter designed to help you monitor your blood sugar and blood ketones with one easy-to-use monitor.

Source: 2003 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada

Important Notice: Information provided is for general background purposes and is not intended as a substitute for medical diagnosis or treatment by a trained professional. You should always consult your physician about any health care questions you may have, especially before trying a new medication, diet, fitness program, or approach to health care issues.